Bone Mineral Density Research Articles

6983 Pembrolizimab Induced Hypophysitis: Uncommon Side Effect Leading To Late Diagnosis

Abstract Disclosure: T. Chaudhary: None. O. Syed: None. A. Shridar: None. R. Kaur: None. O. Chaudhary: None. M.S. Zubair: None. Background: Pembrolizumab, an immune checkpoint inhibitor, has shown efficacy inducing remission in various malignancies. Associated immune-related adverse effects (irAEs) have been recorded but cases of concomitant hypophysitis and thyroiditis are rare. Clinical case: The patient is a 41-year-old male with a past medical history significant for metastatic melanoma of the left calf, status post sentinel lymph node biopsy and left inguinal lymph node dissection, treated with pembrolizumab for one year. He initially presented with a severe headache that was preceded by two months of fatigue and impaired concentration. CT and MRI head were both unremarkable while lab work was significant for cortisol 0.2 ug/dL and adrenocorticotropic hormone (ACTH) 1.1 pmol/L. A full hormone panel was ordered which showed normal insulin-like growth factor-1 (IGF-1), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Free testosterone was at the lower end of normal. Prolactin was elevated at 27.3 ng/mL. The thyroid function tests showed primary hypothyroidism with elevated thyroid stimulating hormone (TSH) at 109 uIU/mL, low T4 at 1.5 ug/dL, and low free T4 at 0.4 ng/dL. There were no signs or symptoms of posterior pituitary dysfunction. The patient was diagnosed with hypophysitis and started on hydrocortisone 20 mg once daily along with levothyroxine 175 mcg once daily. DEXA scan showed normal bone mineral density. Subsequently, the patient presented to our care and reported symptom improvement after taking the prescribed medication however he continued to develop fatigue by the end of the day. Therefore, hydrocortisone prescription was switched to 15 mg in the morning and 10 mg at noon. A repeat thyroid function panel, sex hormone binding globulin, and LH were ordered, to be followed up at the patient's next visit. The patient was also advised to wear a medical alert bracelet at all times moving forward. Conclusion: Due to non-specific symptoms at onset, hypophysitis can be undiagnosed or misdiagnosed therefore it is important to have a high clinical suspicion with patients on PD-1 inhibitors presenting with such symptoms. It is also imperative to order a full set of hormones as this patient had concomitant primary hypothyroidism. Presentation: 6/1/2024

7465 Impact Of Geography And Insurance On Healthcare Utilization Preferences Of Individuals With Congenital Adrenal Hyperplasia In The United States

Abstract Disclosure: P.N. Surampudi: Research Investigator; Self; Spruce Biosciences. A.H. Hamrahian: Consulting Fee; Self; Spruce Biosciences. Research Investigator; Self; Spruce Biosciences. R. Charlton: Employee; Self; Spruce Biosciences. P. Ramtin: Employee; Self; Spruce Biosciences. M.E. Geffner: Consulting Fee; Self; Spruce Biosciences, Ferring Pharmaceuticals, Adrenas, Neurocrine Biosciences, Novo Nordisk, Eton, Pfizer, Inc., Nutritional Growth Solutions, Nutritional Growth Solutions. Research Investigator; Self; Novo Nordisk. Background: Relative to the general population, patients with classic congenital adrenal hyperplasia (CAH) have increased risks for morbidity and mortality which require specialized management across life stages[1]. Endocrine care, particularly as part of multi-disciplinary teams, can help mitigate risks of developing adrenal crises as well as the impact of glucocorticoid under- or overexposure, including adrenal insufficiency; cardiometabolic risk associated with insulin resistance and excess weight gain; fertility issues associated with irregular menses and gonadal adrenal rest tumors; diminished quality of life; increased mental health issues, including anxiety, depression, and sleep disturbance; and increased fracture risk associated with decreased bone mineral density. Study Objectives and Design: We hypothesized that the utilization of endocrine and multi-disciplinary care by patients with CAH in the United States (U.S.) could be adversely affected by non-therapeutic factors related to geographic location and access to health care. In this cross-sectional study, we utilized the Definitive Healthcare database (Nov. 2020-Nov. 2022) to gain insight into these factors in adults with CAH. Study Findings: Analysis of healthcare provider utilization revealed that only ∼30% of U.S. adults with CAH received care from endocrinologists. The rest utilized primary-care providers (PCPs: IM, FP, NP, PA, and Ob-Gyn) to obtain care. A review of insurance coverage of U.S. adults with CAH suggests that ∼70% had access to commercial insurance and over 50% resided in states with the largest populations (California, Texas, New York, Florida, Ohio, Michigan, and Illinois), both factors which should ordinarily increase accessibility of subspecialty endocrine and multi-disciplinary care. Conclusions: In our study, only 30% of U.S. CAH adults received care from an endocrinologist. Limited utilization of specialty care does not appear to be due to either diverse geographical distribution or access to healthcare. The gap in expert care may adversely affect the management of CAH and contribute to associated comorbidities. Increased partnership between PCPs and endocrinologists, and increased awareness and education regarding specialty care among patients with CAH are needed to improve health outcomes and thereby reduce the risk of morbidity and mortality in adults with CAH.

7293 An Unusual Case Of Adult-Onset Heterozygous HHRH In A Male With Normal Phosphorus And Severe Osteoporosis

Abstract Disclosure: M. El Najjar: None. A. Sabet: None. D. Willard: None. Introduction: Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare genetic disorder characterized by renal phosphate wasting, which can affect bone metabolism. Although onset is typically in childhood, adult-onset forms have been described, and the manifestation depends on the zygosity of each patient. Most commonly, adults with HHRH demonstrate markedly reduced bone density and multiple fractures. Heterozygotes have milder presentations with mild hypophosphatemia, hypercalciuria, and nephrolithiasis, usually without bone disease; however, it is less well characterized. Case report: A 73-year-old man suffered an L1 vertebral compression fracture while playing golf. Bone mineral density testing revealed T-scores of -0.9 at the lumbar spine and -3.4 at the femoral neck (Z-score -2.6). He started alendronate 70 mg weekly for osteoporosis treatment. A year later, the patient sustained an L3 vertebral compression fracture while on treatment with no improvement in his bone density. His family history was remarkable for osteoporosis in his mother but no nephrolithiasis or hypercalcemia. Physical examination was unremarkable. Laboratory evaluation was notable for a 1,25-dihydroxyvitamin D of 87 pg/mL (18-72 pg/mL) , a 24-hour urine calcium of 240 mg/g Cr (30-210 mg/g),a serum PTH of 9 pg/mL (16-77 pg/ml) , but otherwise a normal serum calcium level of 9.4 mg/dL (8.6-10.3 mg/dL) and serum phosphate level of 2.2 mg/dl (2.1-4.3 mg/dl). Genetic testing revealed heterozygosity for SLC34A3 mutation, which is associated with HHRH. The patient discontinued alendronate and started 250 mg phosphorus supplementation 4 times daily. At 6 months follow up, he reported improvement in his body aches, and biochemical testing showed normalization of his 24-hour urine calcium to 171 mg/g Cr and serum PTH to 21 pg/mL. Repeat bone density scan after 1 year of phosphorus supplementation showed T-scores of -0.3 at the lumbar spine (5.8% increase) and -2.6 at the femoral neck (15.5% increase). Clinical Lesson: HHRH is an autosomal recessive hypophosphatemic rickets associated with mutations of the SLC34A3 sodium-phosphate cotransporter, where it is believed that selective phosphate wasting leads to increased calcitriol, in contrast to other forms of hypophosphatemic rickets, causing increased intestinal calcium absorption and resulting hypercalciuria. Adult-onset forms of HHRH have been described in heterozygous carriers of the SLC34A3 mutation and usually present with low to low-normal phosphate levels, hypercalciuria, and nephrolithiasis but without bone disease. However, clinical variations of heterozygous carriers have also been recognized, and therefore are likely underdiagnosed. Our patient’s serum phosphorus level was within the normal range, and hypophosphatemic rickets could have been missed if a more extensive laboratory evaluation had not been performed. Presentation: 6/1/2024

9342 Managing Osteoporosis In Patients With Phocomelia: Challenges And Strategies

Abstract Disclosure: M. Renzu: None. C. Hubers: None. V. Mehta: None. A.M. Qazi: None. A.M. Satei: None. D.K. Yerasuri: None. Introduction: Phocomelia, a rare congenital limb malformation, often results from disruptions in limb bud formation during embryonic stage, due to genetic mutations, teratogens, or environmental factors like thalidomide embryopathy. These disruptions pose unique challenges in bone health management, including an increased risk of osteoporosis.We present a case report of a 52-year-old patient with phocomelia who developed an early onset severe osteoporosis. This case stresses the need for specific measures and care to tackle bone health in individuals with congenital limb anomalies. Case Presentation: A 52-year-old white female with phocomelia, had absence of the left forearm and hand, as well as a transverse tibial deficiency with a prosthetic left lower leg since the age of 1. Osteoporosis was diagnosed after follow-up, with initial osteopenia noted at age 49. DEXA scan showed lumbar osteopenia, radial osteoporosis, and bilateral femoral neck osteopenia. FRAX score showed an 11.9% risk of osteoporotic fracture and 3.1% risk of a hip fracture.Risk factors to her osteoporosis included late menarche, early menopause due to hysterectomy, and a history of hormone replacement therapy without pregnancies. Also, chronic colitis and diarrhea caused malabsorption issues. Her left hip bone mineral density was disproportionately low due to chronic prosthesis use, necessitating close monitoring and treatment initiation with Denosumab, along with vitamin D3 and calcium supplementation.As of the latest follow-up, the patient is closely monitored, and improvement is noted in her condition. She has incorporated daily gym sessions into her routine, indicating proactive engagement in her well-being. Discussion: Managing osteoporosis in patients with phocomelia needs a personalized approach, considering the patient's unique anatomical challenges and the limitations of traditional osteoporosis management strategies. Bone tissue adapts its structure based on mechanical loading, with reduced loading in deformed limbs leading to increased resorption and elevated osteoporosis risk. Tailored treatment plans, including Denosumab, which is known as an effective pharmacological option for managing osteoporosis, complemented by dietary adjustments to enhance vitamin D and calcium intake. Physical therapy programs play a vital role in muscle strengthening and balance improvement, reducing fracture risk.Another challenge that patients with phocomelia face is barriers to accessing healthcare services, like limited specialized care providers, financial constraints, and transportation difficulties, leading to increased morbidity. Hence early screening and intervention are essential to prevent osteoporotic complications. Overall, a comprehensive approach to osteoporosis management in phocomelia patients is crucial for optimizing outcomes and enhancing quality of life. Presentation: 6/3/2024

8129 A Case of Pituitary Stalk Interruption Syndrome Presenting With Panhypopituitarism

Abstract Disclosure: A. Salvat: None. M. Sevilla: None. Background: Pituitary stalk interruption syndrome (PSIS) is a rare congenital abnormality characterized by the classic triad of a thinned or interrupted pituitary stalk, an ectopic or absent neurohypophysis, and a hypoplastic or absent anterior pituitary gland. Clinical manifestations vary and can include neonatal hypoglycemia, short stature, cryptorchidism, and delayed puberty. Symptoms can present at birth or later in life with variable degrees of hormone deficiency. Clinical case: A 25-year-old male with hypothyroidism (on levothyroxine since age 13) presented for evaluation of hypogonadotropic hypogonadism. At birth, he was diagnosed with bilateral cryptorchidism and had frequent hypoglycemic episodes. During his childhood and early teenage years, his growth paralleled of his peers. However, at age 18, he experienced a growth spurt with unusually long arms and legs. He never developed secondary sexual characteristics. Physical examination showed blood pressure of 109/62 mmHg, height 193 cm, weight 76 kg, Tanner stage 1 pubic hair, microphallus, and nonpalpable testicles. The initial labs were consistent with panhypopituitarism: FSH 0.14 mIU/mL (0.95–11.95 mIU/mL), luteinizing hormone <0.09 mIU/mL (0.57–12.07 mIU/mL), total testosterone <4 ng/dL (240–871 ng/dL), prolactin 30.31 ng/dL (3.46–19.40 ng/dL), AM cortisol <1 ug/dL (3.7–19.4 ug/dL), ACTH 14 pg/mL (6–50 pg/mL ), cortisol levels 60 minutes after consyntropin stimulation test of 3.6 ug/dL (3.7–19.4 ug/dL), IFG-1 <16 ng/mL (63–373 ng/mL), TSH 7.24 uIU/mL (0.35–4.94 uIU/mL), free T4 0.53 ng/dL (0.70–1.48 ng/dL). Karyotype 46, XY, inv (9) (p12q13). The whole exome sequencing testing was negative. Pituitary magnetic resonance imaging showed hypoplasia of the anterior pituitary gland, ectopic location of the posterior pituitary gland at the expected base of the pituitary infundibulum anterior to the mammary bodies, and hypoplastic or absent pituitary infundibulum, findings suggestive of pituitary stalk interruption syndrome. Scrotal ultrasound showed no testicular or epididymal tissue within the scrotum. DEXA scan showed osteoporosis associated with a long history of non-treated testosterone deficiency. The levothyroxine was adjusted, and the patient was started on intramuscular testosterone, calcium, and vitamin D to manage the hypogonadism and improve the bone mineral density. Conclusion: Diagnosis of PSIS is often delayed due to its variable presentation and age of onset. Although this condition is considered rare, it should be in the differential diagnosis of patients presenting with panhypopituitarism. Early identification of deficient hormones, as well as prompt initialization of hormone replacement therapy, is essential to prevent serious complications associated with these deficiencies, such as adrenal crisis, osteoporosis, diminished quality of life, delayed puberty, and infertility. Presentation: 6/3/2024

7867 Treatment-Related Changes in Total Hip Bone Mineral Density and Fracture Risk Reduction for Drugs With Different Mechanisms of Action: The FNIH-ASBMR-SABRE Project

Abstract Disclosure: T. Vilaca: None. M.T. Schini: None. A.R. Thompson: None. E. Vittinghoff: None. L. Lui: None. S.K. Ewing: None. D.C. Bauer: None. D.M. Black: None. M. Bouxsein: None. R. Eastell: Consulting Fee; Self; Immunodiagnostic Systems, CL Bio, CureTeQ, Biocon, Takeda, UCB. Grant Recipient; Self; Alexion Pharmaceuticals, Inc., Osteolabs. Speaker; Self; Pharmacosmos, Alexion Pharmaceuticals, Inc., Amgen Inc, UCB. Introduction: To date, trials of new anti-osteoporosis therapies have used fractures as primary endpoints. In the FNIH-ASBMR-SABRE project, we posited that the treatment-related change in total hip BMD (THBMD) could be used as a surrogate endpoint for fractures in future clinical trials of new osteoporosis therapies. To demonstrate this, we compiled a large dataset of individual patient data (IPD) from randomized trials and showed a strong association between the change in THBMD at 24 months and reduction in fracture risk. To further explore the use of THBMD as a surrogate endpoint, here we examine whether the association is robust across drugs with different mechanisms of action. Methods: We used IDP (n>120,000 participants) from 22 randomized, placebo-controlled, double-blind trials of osteoporosis medications (17 anti-resorptive, 3 PTH analogs, 1 odanacatib, and 1 romosozumab). We calculated the treatment-related difference (active-placebo) in mean % change in THBMD at 12, 18, and 24 months for each trial. We determined the treatment-related fracture risk reductions for the entire follow-up period, using logistic regression for radiologic vertebral fractures and Cox regression for all clinical fractures (a combination of non-vertebral and clinical vertebral fractures). We used meta-regression to estimate the study-level association (r2) between treatment-related differences in THBMD changes and fracture risk reduction, including only the 17 trials of anti-resorptive drugs and then using the entire set of 22 trials. Since there were only 3 trials of anabolic drugs, we did not perform separate analyses for the anabolic trials. Results: The r2 values were similar between all trials and antiresorptive trials only for both fracture outcomes at all time points. Specifically, for vertebral fractures, the r2 was 0.59 vs 0.70 at 12 mo, 0.69 vs 0.74 at 18 mo, and 0.73 vs 0.78 at 24 mo for all trials vs anti-resorptive trials only. For all clinical fractures, the r2 was 0.46 vs 0.51 at 12 mo, 0.64 vs 0.60 at 18 mo, and 0.71 vs 0.65 at 24 mo for all trials vs anti-resorptive trials only. Conclusion: These results demonstrate that the associations between treatment-related changes in THBMD and fracture risk reductions are robust across anti-osteoporosis therapies with varying mechanisms of action. We conclude that the treatment-related difference in THBMD change would predict fracture reduction equally well for drugs with different mechanisms of action. Presentation: 6/2/2024

6821 Characterization Of A Novel Oral Small Molecule PTH1R Agonist: Proof Of Concept For An Alternative To Injectable Peptide-Based Therapy For Hypoparathyroidism

Abstract Disclosure: J. Zhang: None. I. Gomez: None. C. He: None. J. Wang: None. X. Du: None. K. Nguyen: None. K. Alvarez: None. A.M. Mirza: None. Hypoparathyroidism (HP), a rare endocrine disorder characterized by insufficient levels of parathyroid hormone (PTH), leads to hypocalcemia and hyperphosphatemia. Most HP cases arise due to damage of the parathyroid glands during thyroid or neck surgery. HP symptoms include severe muscle cramps, tingling, burning and numbness, memory loss, and headaches, all leading to a decreased quality of life. Calcium and vitamin D supplementation do not fully ameliorate the disease and may contribute to renal disease. Chronic HP increases the risk of major complications, such as calcium depositions in the brain, eye, and kidneys. Similarly, it can lead to low bone turnover and increased bone mineral density with associated increased bone mineralization. In comparison to standard of care and traditional injectable peptide-based therapies, oral small molecules may have multiple advantages clinically. However, there are no oral small molecules currently in development. PTH functions through activation of the parathyroid hormone 1 receptor (PTH1R), a class B G protein-coupled receptor. The main target tissues for PTH1R activation include bone and kidney. In the kidney, PTH increases tubular reabsorption of calcium and promotes renal excretion of phosphate. In bone, PTH stimulates bone turnover and mobilizes calcium into the circulation to maintain serum calcium. Here we describe the characterization of SP-1462, a novel, potent, and selective oral small molecule, and show that, like the PTH peptides, it acts on PTH1R as an agonist and elicits similar downstream functions in vitro and in vivo. To assess PTH1R engagement in the major targeted organs, kidney and bone, primary human renal proximal epithelial cells (RPTEC) and a human osteoblast cell line (Saos-2) were used, respectively. RPTECs treated with PTH and SP-1462 showed significant changes in transporter genes (SLC22A2 and SLC13A1), immune related genes (CCL2 & DPP4), and matrix reorganization genes (ITGA5 and COL1A1). Saos-2 cells treated with PTH and SP-1462 both significantly affected the expression of Wnt signaling genes (DKK1 and TCF7) and the expression of coupling genes that bridge anabolic/catabolic activities (M-CSF, RANKL, HDAC4, and OPG). Importantly, oral administration of a single dose of SP-1805 in a rat surgical thyroparathyroidectomy (TPTx) model resulted in significant upregulation of serum calcium levels for a period of 24 hours in a dose dependent manner at 3, 10 and 30 mg/kg. The window of calcium upregulation is comparable to injectable PTH peptides currently in development to treat hypoparathyroidism. These data suggest that oral small molecule PTH1R agonists engage PTH pathways similar to native PTH and have the potential to replace injectable PTH peptides to treat PTH-related disorders, including hypoparathyroidism. Presentation: 6/3/2024

Effects of dopaminergic neuron degeneration on osteocyte apoptosis and osteogenic markers in 6-OHDA male rat model of Parkinson's disease

Parkinson's disease (PD) and osteoporosis are prevalent chronic conditions that impact a significant proportion of the aging population. Observational and longitudinal studies consistently demonstrate that individuals with PD face an elevated risk of osteoporosis and reduced bone mineral density compared to control groups. However, there is currently no experimental evidence demonstrating the impact of dopaminergic neuron degeneration on bone metabolism. In the present study, we used a male rat model of PD induced by unilateral injection of 6-hydroxydopamine (6-OHDA) in the left medial forebrain bundle (MFB) to evaluate the effect of dopaminergic neuron lesion on certain parameters of bone metabolism. To confirm the dopaminergic neuron lesion, cylinder and Rotarod tests were applied to rats injected with 6-OHDA or vehicle. Osteocyte density and viability were determined through histology and TUNEL assay. Western Blot and immunohistochemistry analysis were performed to investigate whether dopaminergic degeneration influences the expression of some apoptotic markers (Caspase 3 and Cytochrome C) and some osteogenic markers (ALP, OCN, and RUNX2). Our findings show that the dopaminergic lesion resulting from the injection of 6-OHDA was successfully confirmed through behavioral tests. Furthermore, the degeneration of dopaminergic neurons induced by 6-OHDA leads to apoptosis of osteocytes associated with a significant reduction in the tissue expression of the studied osteogenic markers. Thus, our study provides evidence that 6-OHDA-induced degeneration of dopaminergic neurons leads to osteocyte apoptosis, which may contribute to the development of some signs of osteoporosis.

5071 Impact of Estrogen Replacement Therapy on Bone Health in a Novel Non-human Primate Model of Postmenopausal Women Living with HIV

Abstract Disclosure: K. Sauter: None. D.L. Takahashi: None. G. Webb: None. H. Hofmeister: None. O. Varlamov: None. J. Sacha: None. P. Kievit: None. Current antiretroviral therapy (ART) regimens have rendered HIV a manageable chronic condition rather than a fatal disease, with people who initiate ART soon after infection achieving nearly normal life expectancy. As a consequence of increased survival, more women living with HIV (WLWH) will now undergo menopause and be subject to a disease burden that reflects age along with adverse skeletal consequences of postmenopausal estrogen deficiency. In addition to known bone loss and increased fracture risk in postmenopausal women, ART also causes decreased bone mineral density. Therefore ART-suppressed WLWH may have a compounded detrimental effect on bone due to long-term ART treatment combined with menopause that may be attenuated with estrogen replacement. Eleven rhesus macaques were infected intravenously with SIVmac239M and received ART two weeks post-infection (PI). All animals were ovariectomized (OVX) at 35 weeks PI and received estrogen implants (n=6) or cholesterol implants (n=5). Weekly blood samples were collected and animals were monitored longitudinally for body composition including bone mineral content (BMC) via dual x-ray absorptiometry (DEXA). Infection with SIV caused a significant decrease, -8.2%, in pelvis BMC after 14 days of peak viremia with SIV. These changes were not observed in the BMC of spine or extremities. BMC remained suppressed by ∼7% for an additional 25 weeks PI during ART treatment. Measurement of circulating bone turnover markers (BTMs), osteocalcin and C-terminal telopeptide of type 1 collagen (CTX), decreased post infection without significant improvement after ART suppression. Induction of menopause via OVX and loss of estrogen induced a drastic increase in BTMs with a much larger increase in CTX, indicating potential global bone loss due to OVX. Post-implant, the control animals’ pelvis BMC continued to decrease to -20.9% and pelvis BMD to -9.3% indicating that OVX further exacerbated the effect of SIV and ART. However, animals that received estrogen implants demonstrated marked improvement in both measures to greater than baseline. SIV and subsequent long-term ART negatively impact pelvic BMC and BMD and this effect is compounded by menopause in our model of post-menopausal WLWH. However, estrogen replacement post-menopause may attenuate these detrimental bone effects despite long-term ART treatment. Presentation: 6/1/2024

8305 Assessing The Relationship Between Oral Health And Bone Disease Among Post-menopausal Women

Abstract Disclosure: N. Tahir: None. S. Ahmad: None. K. Batra: None. A. Gupta: None. K.E. Izuora: Research Investigator; Self; Novo Nordisk. Background: Menopause is associated with significant bone loss and worsening oral health, especially periodontal disease (PD). The purpose of this study was to understand the relationship between oral health and bone loss and the factors that influence this relationship. This will help better understand their pathophysiology and provide guidance for more appropriate care. Methods: ​​This cross-sectional study included post-menopausal women undergoing routine bone density evaluation at a diagnostic radiology center. After participants signed informed consent, histories were collected via an investigator-administered questionnaire, the oral cavity was inspected for teeth loss and PD, and a bone density assessment, interpreted by a radiologist, was obtained. The significance level was set at 5% and data were analyzed using chi-square and logistic regression tests. Results: In a sample of 100 eligible participants, the mean age and body mass index (BMI) were 68.17 ± 8.33 years and 29.59 ± 6.13 kg/m2 respectively. Twenty-three participants (23.0%) had T2DM, 29 (29.0%) had < 20 natural teeth and 17 (17.0%) had normal bone mineral density. In an unadjusted simple logistic regression, age, BMI, race/ethnicity, number of natural teeth, history of PD, and history of osteoporotic fracture were associated with bone loss. However, in the binary logistic regression, the only significant predictors of bone loss included age (aOR 1.171, p<0.001), BMI (aOR 0.763, p<0.001), and the history of osteoporotic fractures (aOR 21.273, p=0.021). Conclusion: Clinical variables associated with bone loss in our study included older age, lower BMI, and history of osteoporotic fracture. These are established risk factors for bone loss. Although unadjusted results suggest a relationship between oral health measures and bone loss, these relationships were not present when other factors were included in a multivariate model. These findings suggest PD by itself may not be a risk factor for bone loss but may reflect the similarity in the risk factors for both conditions. Presentation: 6/3/2024

7281 Increased Incidence Of Fracture And Predicted Fracture Risk In Patients With Mild Autonomous Cortisol Secretion

Abstract Disclosure: R. Sagar: None. A. Saadulla: None. A. Abbas: None. Background: Mild autonomous cortisol secretion (MACS) is common in patients presenting with adrenal incidentalomas (AI) and has been associated with cardiovascular and metabolic co-morbidities. Whilst there is growing evidence to support the increased risk of cardiometabolic co-morbidity in this cohort, the bone health effects are less well characterised. Our study evaluated the prevalence of fragility fracture and fracture risk in patients with AI and MACS compared with a cohort of patients with benign, non-functional AI. Methods: Retrospective observational data were collected on 391 patients with MACS and an AI along with 626 patients with a benign, non-functional AI. Demographic, biochemical, radiological and bone health data were recorded. FRAX, a validated fracture risk stratifying tool, was used to calculated risk scores for all patients aged between 40 and 90 and risk category according to national guidance were also recorded. Results: MACS cohort (mean age 69±10 and 53% female) had a mean cortisol on overnight dexamethasone suppression test of 76.6±21nmol/l. Benign, non-functional patients had a mean age 61.4±12 and 57% female. Both cohorts had predominantly unilateral lesions (76% in MACS versus 84%). Patients with MACS had a significantly higher prevalence of all fragility fractures, 15.9% compared with 6.7% in the benign, non-functional group, p<0.0001. Patients with MACS had a significantly higher 10-year risk of major osteoporotic fracture (10.6±3.8% versus 7.1±5.4%, p<0.0001) and also hip fracture (7.2±4.1% versus 1.9±2.7%, p<0.0001). 17% of MACS cohort were classed as either high or very high fracture risk, with a further 28% classed as intermediate risk requiring further assessment of bone health compared with 3% high/very high risk in the non-functional group. Despite this only 31% of the MACS group had undergone DEXA scan to assess bone mineral density compared to 13% of the non-MACS group. Only 5% of MACS patients were on osteoporosis treatment (3% in non-MACS cohort). Conclusions: Patients with MACS make up a large proportion of those presenting with adrenal incidentaloma. Our study suggests an increased prevalence of fragility fractures along with increased fracture risk in patients with MACS compared to those with non-functional AI. However, we also demonstrate an unmet need, with less than 1/3 of patients with MACS undergoing formal bone health assessment and just 5% of the total cohort on treatment for osteoporosis despite a significant proportion meeting intervention thresholds. Presentation: 6/1/2024

7500 Effect Of Orchiectomy On Bone Microarchitecture In Male Mice With Kidney Disease

Abstract Disclosure: D. Wu: None. A. Patwardhan: None. O. Marks: None. Y. Komaru: None. E. Kefalogianni: None. R. Aurora: None. S. Dhindsa: None. A. Herrlich: None. Background: Chronic kidney disease (CKD) leads to decreased bone density and increased fracture risk. In males, an additional factor contributes to the low bone density. Around half of the men with CKD have low serum testosterone concentrations. We hypothesized that CKD and low testosterone would have an additive and detrimental effect on bone. Methods: Forty male C57BL/6 mice were divided into 4 groups: 1) renal injury, induced by ischemia-induced reperfusion (IRI) and sham orchidectomy (IRI-sham, N=8) at 2 months of age; 2) orchidectomy (ORX), performed 4 weeks after IRI (IRI + ORX, N=11); 3) sham-ORX, N=9; and 4) sham-sham surgery, N=12. 12 weeks after IRI, the mice developed renal fibrosis and decreased glomerular filtration rate, indicative of CKD. The mice were sacrificed when they were 7 months old. Femur and tibia were harvested for both histology and μCT analysis. Results: Bone volume to total volume fraction (BV/TV) was lower in the IRI-ORX (0.06±0.02) and sham-ORX (0.08±0.02), as compared to IRI-sham (0.10±0.03, p<0.05) and sham-sham group (0.14±0.03, p<0.05) respectively. Similarly, the volumetric bone mineral density (vBMD) in IRI-ORX (93±27 mgHA/cm3) and sham-ORX (112±39 mgHA/cm3) groups were lower than IRI-sham (150±43 mgHA/cm3, p<0.05) and sham-sham (187±30 mgHA/cm3, p<0.05) mice. Trabecular number (Tb.N) was decreased in the IRI-ORX group (2.7±0.7 #/mm) compared to IRI-sham group (4.1±1.1 #/mm, p<0.05). Tb.N was also lower in sham-ORX (3.2±1.1 #/mm) mice than sham-sham (4.5±0.2 #/mm), but not IRI-sham mice. In contrast, trabecular thickness (Tb.Th) was lower in IRI-ORX (0.035±0.002 mm) and IRI-sham (0.038±0.002 mm) compared to sham-ORX (0.045±0.005 mm) and sham-sham (0.047±0.005 mm, p<0.05). Trabecular spacing (Tb.Sp) was increased by 47% in IRI-ORX group compared to IRI-sham group (0.26±0.09 mm). Decreased trabecular numbers and increased spacing results in reduced connectivity density (Conn.Den), which was decreased by 60% in the IRI-ORX sham-ORX groups as compared to sham-sham group (423±58 #/mm3, p<0.05). 2 way ANOVA analysis showed that ORX significantly contributed to the variance in BV/TV (p<0.001), vBMD (p<0.001), Tb.N (p<0.01), Tb.Sp (p<0.01) and Conn.Den (p<0.001), while IRI contributed to Tb.Th (p<0.0001). There was no significant interaction between IRI and ORX in all endpoints. Conclusions: Taken together, these data indicate that even in the presence of established CKD, ORX has a greater effect on bone mass. ORX decreased trabecular number (Tb.N) and increased trabecular spacing (Tb.Sp) to a greater extent than IRI. IRI decreased trabecular thickness (Tb.Th) while ORX had no effect on that parameter. Trabecular bone loss starts by trabecular thinning. Eventually, the trabeculae will be completely resorbed, resulting in decreased trabecular numbers and increased spacing. Our data indicate that IRI and ORX affect bone at different time points. Presentation: 6/1/2024

The influence of proliferative tissue on Hounsfield unit and its correlation with BMD in middle-aged and elderly patients with lumbar degenerative diseases

PurposeThe difference of Hounsfield Unit (HU) value in different regions of L3 vertebra in middle-aged and elderly patients with lumbar degeneration diseases (LDD) was analyzed. To investigate the influence of proliferative tissue on HU value of cancellous bone and its correlation with bone mineral density (BMD).MethodsThe medical records of middle-aged and elderly patients with LDD in our hospital from December 2020 to December 2023 were retrospectively analyzed. The patients were divided into osteophyte group and no-osteophyte group according to the presence or absence of osteophyte formation on lumbar spine X-ray. In osteophyte group, cancellous bone HU value, containing cortical bone overall HU value and containing osteophyte overall HU value in L3 vertebra were measured on the lumbar CT cross-section. In no-osteophyte group, only the cancellous bone HU value and the containing cortical bone overall HU value were measured. Differences in HU value in different regions of the L3 vertebral body were compared within and between groups of middle-aged and elderly patients with LDD, respectively. To investigate its effect on cancellous bone HU measurements and to do a correlation analysis with patients’ BMD.ResultsA total of 115 patients with LDD were included in this study, including 65 males and 50 females, with an average age of 67.83 ± 6.59 years. The results of the study showed no statistical differences in age (P = 0.15), gender (P = 0.57), smoking (P = 0.88), drinking history (P = 0.76), medical history (P > 0.05) and BMI(P = 0.29) between the two groups. In osteophyte group, the mean cancellous bone HU value was 98.00 ± 25.50 HU, the containing cortical bone overall HU value was 189.02 ± 46.18 HU, and the containing osteophyte overall HU value was 232.69 ± 56.01 HU. The overall HU values containing cortical bone and containing osteophyte were significantly higher than cancellous bone HU value (P < 0.001). In no-osteophyte group, the mean cancellous bone HU value was 102.04 ± 19.64 HU, and the containing cortical bone overall HU value was 175.00 ± 28.97 HU, which was statistically significantly different (P < 0.001). There was no significant difference in cancellous bone HU value and the containing cortical bone overall HU value between the two groups (P > 0.05). The results of the Pearson correlation analysis showed a significant correlation between the cancellous bone HU value of the L3 vertebrae and the QCT BMD value of the patients (r = 0.95, P < 0.001). However, there was no significant correlation between containing cortical bone overall HU value and containing osteophyte overall HU value and the patient’s QCT BMD value (P > 0.05).ConclusionsVertebral HU value is an alternative measurement that effectively reflects the patient’s BMD. In middle-aged and elderly LDD patients, HU values in different areas of L3 vertebra are significantly different, and hyperplastic tissues such as cortical bone and osteophytes may exponentially lead to higher HU value in patients. Compared with other measurement areas, vertebral cancellous bone HU value have the advantage of accurately assessing patients’ BMD.

Effects of over 10 weeks of resistance training on muscle and bone mineral density in older people with sarcopenia over 70 years old: A systematic review and meta-analysis of randomized controlled trials

ObjectiveWe aimed to examine the effects of more than 10 weeks of resistance training (RT) on muscle structure, muscle function, and bone mineral density (BMD) in older people with sarcopenia over 70 years old MethodsPubMed, Web of Science, Embase, MEDLINE, Cochrane Library, and CINAHL databases were searched for randomized controlled trials. Standardized mean difference (MD) or standard mean difference (SMD) was used to pool the effect of the RT intervention ResultsThirteen studies with 2080 older adults with sarcopenia were included. Resistance exercise significantly affected handgrip strength (MD = 1.67 kg; P = 0.02) and isometric muscle strength (standard mean difference [SMD] = 0.53; P = 0.02). Significant differences in chair stand test (SMD = 0.40; P = 0.02) and skeletal muscle mass index (mean difference [MD] = 1.67 kg/m2; P = 0.0002) were found between the RT and control groups ConclusionMore than 10 weeks of RT has beneficial effects on muscle but no favorable effect on BMD in older people with sarcopenia over 70 years old.

Tooth loss in young mice is associated with cognitive decline and femur-bone mineral density.

Osteoporosis is a prevalent disease that is associated with increased hip fractures which cause significant decline in quality of life. Tooth loss affects systemic condition such as cognitive function through various mechanism, but the link between tooth loss and femoral bone mineral density is still uncertain. This study aims to investigate whether tooth loss in young mice affects memory function and femoral bone mineral density. Eight-week-old male C57BL/6J mice were allocated randomly into the control group with sham operation and the tooth-loss group extracted all maxillary molar. Step-through passive avoidance test as cognitive function test, micro-CT analysis and western blotting analysis were performed after 1- and 2-month observation period. Step-through passive avoidance test revealed that the tooth-loss group in 2-month observation period impaired cognitive function. Additionally, micro-CT analysis revealed a significant decrease in both the length of the mandible and bone mineral density in the femur of the tooth-loss group compared to the control group. Claudin-5 level in the hippocampus, which is one of the tight junction markers in blood-brain-barrier, was significantly decreased in the tooth-loss group. The findings of our present study suggested that tooth loss impair cognitive function accompanied by reduced tight-junction marker, mandibular growth and bone mineral density of femur.

Fracture Risk Prediction Using the Fracture Risk Assessment Tool in Individuals With Cancer

The Fracture Risk Assessment Tool (FRAX) is a fracture risk prediction tool for 10-year probability of major osteoporotic fracture (MOF) and hip fracture in the general population. Whether FRAX is useful in individuals with cancer is uncertain. To determine the performance of FRAX for predicting incident fractures in individuals with cancer. This retrospective population-based cohort study included residents of Manitoba, Canada, with and without cancer diagnoses from 1987 to 2014. Diagnoses were identified through the Manitoba Cancer Registry. Incident fractures to March 31, 2021, were identified in population-based health care data. Data analysis occurred between January and March 2023. FRAX scores were computed for those with bone mineral density (BMD) results that were recorded in the Manitoba BMD Registry. This study included 9877 individuals with cancer (mean [SD] age, 67.1 [11.2] years; 8693 [88.0%] female) and 45 877 individuals in the noncancer cohort (mean [SD] age, 66.2 [10.2] years; 41 656 [90.8%] female). Compared to individuals without cancer, those with cancer had higher rates of incident MOF (14.5 vs 12.9 per 1000 person-years; P < .001) and hip fracture (4.2 vs 3.5 per 1000 person-years; P = .002). In the cancer cohort, FRAX with BMD results were associated with incident MOF (HR per SD increase, 1.84 [95% CI, 1.74-1.95]) and hip fracture (HR per SD increase, 3.61 [95% CI, 3.13-4.15]). In the cancer cohort, calibration slopes for FRAX with BMD were 1.03 for MOFs and 0.97 for hip fractures. In this retrospective cohort study, FRAX with BMD showed good stratification and calibration for predicting incident fractures in patients with cancer. These results suggest that FRAX with BMD can be a reliable tool for predicting incident fractures in individuals with cancer.

Decreased trabecular bone score in patients affected by Fabry disease.

Fabry disease (FD) is an inherited X-linked lysosomal storage disease characterized by increased risk of osteoporosis and fractures. The impact of FD on clinical measures of bone quality is unknown. This considered, aim of our study was to evaluate whether trabecular bone microarchitecture, measured by trabecular bone score (TBS), is altered in patients with FD compared to control subjects. This retrospective monocentric study enrolled 14 patients (M/F 1/1, median age 46 [37-63] years, range 31-72 years) newly diagnosed with FD between January 2016 and July 2023 who underwent dual-energy X-ray absorptiometry (DXA) image at the time of diagnosis and 42 matched controls. In all subjects, data about bone mineral density (BMD) and lumbar spine TBS were collected and total calcium, parathyroid hormone (PTH), 25(OH) vitamin D, alkaline phosphatase (ALP), creatinine and estimated glomerular filtration rate (eGFR) were evaluated. In subjects with FD, globotriaosylsphingosine (lyso-Gb3), 24-hour proteinuria and albumin-creatinine ratio were also assessed. Patients with FD presented significantly lower lumbar spine TBS (1.29 [1.22-1.38] vs. 1.42 [1.39-1.47], p < 0.001) and lower lumbar spine BMD (0.916 ± 0.166 vs. 1.031 ± 0.125g/cm2, p = 0.008) compared to controls; moreover, FD was shown to be an independent risk factor for both low lumbar spine TBS (β = -0.118, p < 0.001) and BMD (β = -0.115, p = 0.009). No differences were found in serum calcium, ALP, 25(OH) vitamin D and eGFR in both groups, but FD patients had significantly higher PTH levels compared to controls (p = 0.016). Finally, 8 patients with FD presented either moderately or severely increased albuminuria and only 2 patients presented normal lyso-Gb3 levels. Patients affected by FD present significantly lower lumbar spine TBS and BMD compared to controls. Our findings strongly support the importance of carrying out a thorough evaluation of bone status in all patients affected by FD at baseline.

Bone loss after bariatric surgery is observed mainly in the hip trabecular compartment and after hypoabsorptive techniques

We evaluated the impact of bariatric surgery on bone mineral density (BMD) and microarchitecture over one year using dual-energy X-ray absorptiometry (DXA), the trabecular bone score (TBS), and 3D-DXA to assess changes after different surgical techniques. This prospective, single-center study of 153 patients with severe obesity contrasts the effects on bone health of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and duodenal switch/single anastomosis duodeno-ileostomy with sleeve gastrectomy (DS/SADIS). To our knowledge, this is the first study to evaluate patients undergoing DS/SADIS and to incorporate 3D-DXA analysis in the assessment of bone loss.Patients were 81 % female with a mean age of 50 ± 9 years. Fifty-four per cent underwent SG; 16 %, RYGB; and 30 %, DS/SADIS. Our findings revealed a significant decrease in areal BMD at the LS (−3.49 ± 5.44 %), FN (−5.24 ± 5.86 %), and TH (−8.06 ± 5.14 %) one year after bariatric surgery. Bone microarchitecture at the LS assessed by TBS was degraded in 30 % of patients. Proximal femur 3D-DXA analysis showed that surgery-induced bone loss predominantly affects the trabecular compartment (Trabecular volumetric (v) BMD: −8.00 ± 6.57 %) rather than the cortical compartment (Cortical vBMD: −1.37 ± 2.79 %).These results suggest hypoabsorptive and mixed techniques (DS/SADIS and RYGB) were associated with greater BMD loss and deterioration of microarchitecture than restrictive techniques (SG).The primary determinants of bone density and impairment of microarchitecture were the extent of weight loss and the type of surgical procedure. Despite overall bone loss, Z-score assessments indicated that post-surgical bone status remained within or above the average ranges compared to a healthy population, except for TH following DS/SADIS.In conclusion, our research shows differences in the impact of bariatric surgery techniques on bone density and microarchitecture, emphasizing the need for careful postoperative monitoring of bone health, particularly in patients undergoing hypoabsorptive and mixed procedures.

Screening for endogenous hypercortisolism in patients with osteoporosis and fractures: why, when and how.

Skeletal comorbidities are frequent and clinically relevant findings in Cushing's syndrome (CS) since an uncoupled suppressed bone formation and enhanced bone resorption leads to a marked skeletal damage with a rapid increase of fracture risk. Reduced Bone Mineral Density (BMD) has been consistently reported and osteopenia or osteoporosis are typical findings in patients with CS. Vertebral Fractures (VFs) are frequently reported and may occur even in patients with an only mild reduction of BMD. Since CS is diagnosed late due to often difficult biochemical and radiological confirmation as well as to signs and symptoms common in other much more frequent diseases an approach suggested for overcoming underdiagnosis is to screen patients with manifestations which may overlap with those of CS such as arterial hypertension, diabetes mellitus and osteoporosis. Our review will focus on the rationale and best practice for screening osteoporotic patients for CS.

Osteogenic effect of alogliptin in chemical-induced bone loss: a tri-modal in silico, in vitro, and in vivo analysis.

To investigate the effects of Alogliptin in chemical-induced post-menopausal osteoporosis. The binding affinity of alogliptin with osteogenic proteins was analysed in silico. The effect of alogliptin on osteogenic proteins and mineralization of osteoblastic cells was evaluated in UMR-106 cells. Further, in vivo anti-osteoporotic activity of alogliptin was evaluated in postmenopausal osteoporosis. Various bone turnover markers were assayed in serum. This followed the analysis of microarchitecture of bone, histology, and immunohistochemistry (IHC) of bone tissue. Docking scores showed that alogliptin has binding affinity for bone alkaline phosphatase (BALP), osteocalcin, and bone morphogenic protein (BMP-2). Alogliptin also enhanced mineralization of osteoblast cells, evidenced with increased ALP, osteocalcin, and BMP-2. Animal studies revealed significant elevation of bone formation markers, bone ALP, osteocalcin and BMP-2, and decreased bone resorption markers, receptor activator of NF-κβ (RANKL), cathepsin K (CTSK), tartrate resistant acid phosphatase (TRAcP5b) in VCD-induced post-menopausal osteoporosis. Micro computed tomography (μCT) analysis and histology of femur bone and lumbar vertebrae demonstrated decrease in trabecular separation and improved bone density. IHC of femur showed reduced DPP4 enzyme. Alogliptin increased mineralization in osteoblast cells. It had beneficial effects also altered bone turnover markers, repaired the trabecular microstructure, improved bone mineral density, and exhibited bone forming capacity targeting DPP-4 enzyme in postmenopausal osteoporosis.