Serum Calcium Concentrations Research Articles

The effects of soy protein and soy isoflavones intake on chronic kidney disease: a systematic review and meta-analysis.

Existing literatures on the potential impact of soy protein consumption on kidney function present conflicting findings. In this study, a meta-analysis has been conducted to assess the impact of soy protein consumption in comparison to animal protein consumption among individuals with chronic kidney disease (CKD). A structured electronic search was conducted on Medline, EMBASE, and Cochrane Library for randomized controlled trials published up to March 2024. The outcome measures were serum creatinine (SCR), triglyceride (TG), total cholesterol (TC), calcium (Ca), C-reactive protein, proteinuria, high-density lipoprotein (HDL), low-density lipoprotein (LDL), uric acid (UA) and phosphorus concentrations. Mean differences were calculated for net changes using random-effects models. Eighteen trials with a total of 522 participants were included in this systematic review. The results showed that consumption of soy protein led to a significant decrease in total cholesterol, LDL, and proteinuria levels. The average reduction was - 20.55mg/dL (95% CI - 38.25, - 2.85mg/dL) for total cholesterol (P = 0.02), - 8.26mg/dL (95% CI - 13.35, - 3.17mg/dL; P = 0.001) for LDL and - 140.53 (95% CI - 205.83, - 75.23mg/day) for proteinuria. No statistically significant impact was observed on serum creatinine, triglycerides, calcium, C-reactive protein, HDL, uric acid, or phosphorus levels. The findings of the meta-analysis showed a potential protective impact of soy protein intake on hyperlipidemia and proteinuria inCKD patients. It is important to note that the evidence presented may be of limited accuracy due to relatively small number of trials and participants.

Dietary 25-Hydroxycholecalciferol Supplementation from Day 85 of Gestation to Farrowing Enhances Performance, Antioxidant Capacity, and Immunoglobulins of Sows and Newborn Piglets

In this study, the aim was to evaluate the effects of dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation on performance, antioxidant capacity, and immunoglobulin level of sows and newborn piglets. On day 85 of gestation, forty Landrace × Yorkshire gestating sows (average body weight of 241 ± 6.8 kg; average parity of 3.47 ± 0.6) were allotted into two treatments (20 replicates per treatment) based on parity, body weight, and back fat thickness. From day 85 of gestation to farrowing, sows were fed a normal vitamin D3 diet as control (containing 50 μg/kg vitamin D3; CON), or a 25-hydroxycholecalciferol-supplemented diet (containing 50 μg/kg 25-hydroxycholecalciferol). Compared with CON, dietary 25-hydroxycholecalciferol supplementation increased (p < 0.05) protein and fat content in colostrum and the average birth body weight of newborn piglets. Sows fed 25-hydroxycholecalciferol showed increased (p < 0.05) apparent total tract digestibility of crude protein compared with CON. Diets supplemented with 25-hydroxycholecalciferol also increased (p < 0.05) the content of superoxide dismutase (SOD), and tended to increase (p = 0.06) the total antioxidant capacity content and reduce (p = 0.09) the malondialdehyde (MDA) level in colostrum. An increase (p < 0.05) in the content of SOD and a reduction (p < 0.05) in the content of MDA in the serum of newborn piglets was also observed in the 25-hydroxycholecalciferol treatment compared with CON. Dietary 25-hydroxycholecalciferol supplementation also enhanced (p < 0.05) the immunoglobulin G content and reduced (p < 0.05) the concentration of tumor nuclear factor-α in the serum of sows, as well as reducing (p < 0.05) the content of immunoglobulin G and immunoglobulin A in the serum of newborn piglets compared with CON. Supplementation of 25-hydroxycholecalciferol in sow diets increased (p < 0.05) the content of alkaline phosphatase in the serum and colostrum of sows, the concentration of insulin and crosslap in serum of sows, and the serum calcium content of newborn piglets compared with CON. In conclusion, dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation could enhance performance, antioxidant capacity, and immunoglobulin in sows and newborn piglets.

Relationship of serum calcium concentration with chronic kidney disease and mortality in type 2 diabetes mellitus patients: evidence from the NHANES 1999-2018.

This study aims to explore the relationship of serum calcium (Ca) concentration with diabetic kidney disease (DKD) and all-cause mortality among type 2 diabetes mellitus (T2DM) patients using National Health and Nutrition Examination Surveys (NHANES). Data of T2DM patients aged ≥ 40 years were screened from the NHANES database from 1999 to 2018. The outcomes were the risk of DKD diagnosed by urine albumin-to-creatinine ratio (UACR) ≥ 30 mg/g or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 and the risk of all-cause mortality ascertained by linkage to National Death Index (NDI) records through 31 December 2019. The weighted univariate and multivariate logistic regression model and cox proportional hazard model were utilized to explore the relationships of serum Ca concentration with DKD and all-cause mortality, respectively, with odds ratios (ORs), hazard ratios (HRs) and 95% confidence interval. The relationships were further explored stratified by age, gender, body mass index (BMI), the duration of T2DM, and the history of cardiovascular disease (CVD), cancer and DKD. Totally, 6595 T2DM patients were included. Of these patients, 2441 (37.01%) had DKD and 1868 (28.32%) deaths occurred over a mean follow-up of 104.50 (± 1.61) months. In fully adjusted model, we observed high serum Ca concentration was associated with high risk of DKD (OR = 1.45, 95% CI 1.18-1.77) and high all-cause mortality risk (HR = 1.33, 95% CI 1.16-1.52). These relationships remained significant after performing subgroup analyses. The Restricted cubic spline curves shown that linear correlations were observed between serum Ca concentration and DKD as well as all-cause mortality (P < 0.05). Elevated serum Ca concentration may predict the high risk of DKD and poor prognosis in T2DM patients, and future large-scale and well-designed prospective cohort study is needed to explore the association of serum Ca concentration and DKD and prognosis in T2DM patients.

Association between proteinuria and mineral metabolism disorders in chronic kidney disease: the Japan chronic kidney disease database extension (J-CKD-DB-Ex)

Chronic kidney disease-mineral and bone disorder (CKD-MBD) are recognized as a systemic disease affecting the prognosis of patients with CKD. Proper management of CKD-MBD is important to improve the prognosis of patients with CKD. Although proteinuria is recognized as a poor prognostic factor in these patients, few reports have examined its association with CKD-MBD. We examined the association between proteinuria and CKD-MBD using data from the Japan Chronic Kidney Disease Database Extension (J-CKD-DB-Ex). Among the patients registered in the J-CKD-DB-Ex, 30,977 with CKD stages G2–G5 who had serum creatinine, albumin, calcium, and phosphate concentrations measured at least once and urinalysis performed were included. The patients were divided into four groups (negative, 1+, 2+, and 3+) according to the degree of proteinuria. The association between proteinuria and CKD-MBD was examined by a logistic regression analysis. In a model adjusted for age, sex, diabetes, and the estimated glomerular filtration rate (eGFR), the odds ratio of the 3 + group compared with the negative group significantly increased to 2.67 (95% confidence interval, 2.29–3.13) for hyperphosphatemia, 2.68 (1.94–3.71) for hypocalcemia, and 1.56 (1.24–1.98) for hypomagnesemia. Proteinuria is associated with hyperphosphatemia, hypocalcemia, and hypomagnesemia in patients with CKD independently of eGFR.

Acute phase responses in clinically healthy multiparous Holsteins with and without calcium dysregulation during the early postpartum period

Patterns of calcium dysregulation resulting in low total serum calcium concentrations (tCa) at 4 DIM, known as dyscalcemia, commonly occur in multiparous Holsteins. Dyscalcemia is associated with risk of disease, decreased production, and poor reproductive performance. Inflammation is well-documented early in lactation and is associated with similarly suboptimal outcomes. The acute phase response produces markers and mediators of inflammation; therefore, the objective of our case-control study was to evaluate postpartum patterns of 3 positive acute phase proteins in cows with and without dyscalcemia. We hypothesized that dyscalcemic cows would experience more activated inflammation than eucalcemic cows and that inflammation would precede dyscalcemia diagnosis. Multiparous Holstein cows at 2 commercial dairy farms in central New York were enrolled from a parent study based on tCa at 4 DIM, at a 2:1 ratio of eucalcemic (tCa >2.3 mmol/L; n = 32) to dyscalcemic cows (tCa <2.2 mmol/L; n = 16). Blood was collected 1 to 3 d before parturition and once every 24 h postpartum through 4 DIM. Samples were analyzed for 3 acute phase proteins, serum amyloid A (SAA), haptoglobin and lipopolysaccharide binding protein (LBP). Patterns of protein concentrations in blood over time were compared using linear mixed effects models including fixed effects of calcium status group, time, parity group, farm, relevant 2-way interactions, and the random effect of cow. Overall, dynamics of acute phase proteins showed that dyscalcemic cows experienced increased acute phase responses compared with eucalcemic cows, and that these responses preceded dyscalcemia diagnosis at 4 DIM. Dyscalcemic cows had elevated concentrations of SAA beginning at 2 DIM (eucalcemic: mean = 13.88 µg/mL, 95% CI = 11.34 to 16.99 µg/mL; dyscalcemic: mean = 32.95 µg/mL, 95% CI = 24.55 to 44.21 µg/mL). and continuing through 4 DIM (eucalcemic: mean = 8.14 µg/mL, 95% CI = 6.66 to 9.95 µg/mL; dyscalcemic: mean = 30.01 µg/mL, 95% CI = 22.60 to 39.83 µg/mL). Haptoglobin concentrations were also elevated in the blood of dyscalcemic cows from 2 DIM (eucalcemic: mean = 0.39 g/L, 95% CI = 0.31 to 0.49 g/L; dyscalcemic: mean = 1.11 g/L, 95% CI = 0.79 to 1.56 g/L) through 4 DIM (eucalcemic: mean = 0.27 g/L, 95% CI = 0.21 to 0.34 g/L; dyscalcemic: mean = 1.65 g/L, 95% CI = 1.19 to 2.28 g/L). Concentrations of LBP exhibited a different pattern with a small difference between groups at 3 DIM (eucalcemic: mean = 4.67 µg/mL, 95% CI = 4.02 to 5.42 µg/mL; dyscalcemic: mean = 7.91 µg/mL, 95% CI = 6.49 to 9.63 µg/mL) that became larger at 4 DIM (eucalcemic: mean = 4.88 µg/mL, 95% CI = 4.22 to 5.64 µg/mL; dyscalcemic: mean = 10.79 µg/mL, 95% CI = 8.84 to 13.17 µg/mL). Our work supports the hypothesis that dyscalcemia and inflammatory activity are associated in dairy cows under naturally occurring postpartum conditions. While the causal structure of this relationship remains unknown, improved understanding of inflammation and dyscalcemia may provide insight into mechanisms by which some cows experience maladaptation during the early postpartum period.

Reference Interval for Calcium among Libyan Healthy Individuals

The goal of this study was to determine the reference intervals (RIs) of calcium levels (Ca) in the blood of Libyan individuals. Blood samples were obtained from 120 healthy males and females through aseptic venipuncture. Informed consent was obtained prior to sample collection. Serum was extracted from the centrifuged samples and analyzed spectrophotometrically to determine calcium concentrations. The non-parametric percentile method was applied to establish the RIs of calcium, results showed the reference period is 7.8- 10.1 mg/dl. The study establishes RIs for serum calcium concentration between 7.8 mg/dl and 10.1 mg/dl in the Libyan population. These findings underscore the importance of developing geographically specific RIs, as RIs derived from manufacturer's kits or other populations may not accurately reflect the unique characteristics of the Libyan population. The RIs identified in this study are more relevant and appropriate for the Libyan context.

Effect of coated calcium feeding on growth performance, carcass traits, immunity, blood biochemistry and tibial bone morphometry in commercial broiler chicken.

The bone abnormalities pose great concern in heavy, rapidly growing broilers, resulting in significant economic loss, and health issues in birds. To address these problems and prevent unnecessary mineral excretion into environment, it is crucial to optimise the inclusion level of dietary calcium in broiler's diet. The calcium utilisation by the bird is also affected by its source, particle size, bioavailability etc. Hence this study aimed to study the effect of partially replacing conventional dietary calcium source with coated calcium on growth performance, immune response, carcass traits, blood calcium and phosphorus, and mineral retention in broilers. About 416 broiler chicks were randomly distributed into four treatments, each with eight replicates of 13 birds and fed with iso-calcium, isocaloric, and isonitrogenous diet for 42 days. The T0 (control) was a basal diet while the T1, T2, and T3, were treatment diets in which conventional calcium source (limestone) was partially replaced with coated calcium by 10, 20, and 30% respectively. The birds of T3 group showed higher (P < 0.05) body weight gain, better feed conversion ratio and higher carcass yields compared to T0, T1, and T2 diet fed birds. Further the treatment groups exhibited higher (P < 0.05) cell-mediated and humoral immune responses and immune organ weights compared to control. The tibial bone weight, length and average diameter was highest (P < 0.05) in T3. Moreover, the T3 diet fed group also showed higher (P < 0.05) calcium and phosphorus content in serum and bone and lowest content of these minerals in the excreta followed by T2, T1 and control. These findings suggest that a 30% conventional calcium source with coated calcium may be used as a high-grade mineral source for broiler chicken feed.

Metabolic Alkalemia in Hypercalciuria Stone Formers: Does It Matter?

Introduction: The literature lacks whether metabolic alkalemia occurs in outpatients with hypercalciuric nephrolithiasis. Thus, we aim to investigate it because these patients are often treated with thiazides to reduce urinary calcium excretion. However, thiazides induce chloride losses due to the inhibition of Na-Cl cotransporter expressed in the renal distal tubule cells. Besides thiazide prescription, many of these patients are also supplemented with potassium citrate, which is an addition of alkali source in their bodies. Methods: We collected clinical, demographic characteristics, and laboratory data from electronic medical charts of outpatients with calcium kidney stones followed in our institution from January 2013 to July 2021. We diagnosed those cases as metabolic alkalemia, in which the venous blood gas tests showed pH ≥7.46 and bicarbonate concentration >26 mEq/L. Then, we applied statistical analysis to compare distinct categories between patients with and without metabolic alkalemia. Results: We diagnosed metabolic alkalemia in 4.3% of hypercalciuric nephrolithiasis outpatients, and we verified that thiazides had been used in all of them except in one case. Furthermore, we observed that the amount of thiazide taken daily was higher in patients with metabolic alkalemia than in those without this imbalance. Additionally, hypokalemia was present in 37% of patients who developed metabolic alkalemia. We also found lower chloride, magnesium and ionic calcium serum concentrations in patients with metabolic alkalemia than in those without an acid-base disequilibrium. Conclusion: Despite the low prevalence of metabolic alkalemia in hypercalciuric kidney stone formers, it is important to monitor these patients due to the high incidence of hypokalemia and the potential presence of other electrolyte disorders.

Ramadan fasting and exercise combination therapy: A novel approach for osteoporosis prevention in ovariectomized rats.

Osteoporosis is a chronic bone metabolic disease that affects millions of people worldwide, particularly the elderly and postmenopausal women. It is characterized by weakened bones, increasing the risk of fractures and leading to significant morbidity and mortality. The goal of the current study is to examine the reported osteo-preservative effects of exercise and/or fasting in the Ramadan fasting model (RFM) in ovariectomized (OVX) rats. The experimental intervention started 1month following the ovariectomy procedure and consisted of five 15-min exercise sessions per week at 18-25m/min and/or an approximately 13-h fast from sunrise to sunset (6:00 AM-19:00 PM). Serum bone metabolism biomarker levels were measured, and mineral concentrations in femoral ashed bones and digested serum were determined. Additionally, serum bone alkaline phosphatase (b-ALP), parathyroid hormone, osteocalcin, calcitonin, and vitamin D3 concentrations were measured using the competitive enzyme immunoassay technique. Calcium, magnesium, and phosphorus showed a notable decrease in mineral concentration among OVX rat femurs compared with the combination group (OVX + RFM + E) and control groups. In addition, homeostasis of serum concentrations of calcium, magnesium, and phosphorus was observed to increase in the OVX + RFM + E group rather than in the OVX group without intervention when compared with a control group. Furthermore, fasting and exercise, either alone or concurrently with ovariectomy, induced a non-significant elevation in osteocalcin, parathyroid hormone, and vitamin D3, whereas b-ALP and calcitonin increased significantly compared with those in control rats. The combination of the Ramadan fasting model and moderate intensity exercises among OVX rats manifested advantageous effects in bone biomarkers compared with OVX rats without intervention. This could be recommended as a lifestyle modification that is protective against osteoporosis, especially in the context of depleted estrogen hormone after menopause.

Seasonal dynamics of indicators of mineral metabolism in horses in the conditions of the Leningrad region

The article analyzes the seasonal dynamics of mineral metabolism indicators in adult horses kept in private stables in the Leningrad region. As a result of the research, knowledge of the concentration and dependence of indicators on the seasonality of the year was obtained. It is important to remember that macro- and microelements are not synthesized in the body, they come from food, water, and air. The degree of their assimilation depends on the state of the respiratory and digestive organs. The most difficult period for animals is winter, when there is a decrease in the resistance of the body as a whole due to poor climatic conditions and minimizing physical activity in the fresh air. All these are predisposing factors for the imbalance of indicators at the level of the whole organism.It is established that in the autumn-winter period there is a decrease in indicators relative to the average annual digital values. Thus, there is a linear relationship between the concentration of calcium and phosphorus in blood serum – the minimum values are observed in winter and are 2.53±0.27 mmol/l and 1.76± 0.11 mmol/l, respectively. And the maximum values are typical for the autumn period and are 3.63±0.29 mmol/l for calcium and 2.33±0.12 mmol/l for phosphorus. Similar dynamics is observed in other indicators of the body's mineral metabolism. Thus, for trace elements such as copper, iron, protein-bound iodine, the minimum values were noted in the spring period. This can be explained by a decrease in the mineral components of the feed itself, as a result of long-term storage, resulting in changes in the chemical composition of vegetable feed with fat oxidation. Microelementoses and osteodystrophic processes are observed in animals. The autumn period is characterized by the highest concentrations of minerals in the blood serum of horses, on average by 8-12% compared with the average annual figures, This is explained by the fact that it was in the summer period that the greatest benefit was obtained from juicy plant substances of feed and proper exercise.This knowledge is necessary to understand the processes occurring in the body of horses at different times of the year and the possibility of correcting mineral supplements based on the data obtained

Parathyroid carcinoma: molecular pathology and correlation with clinicopathologic features, a single center experience

Abstract Introduction/Objective Parathyroid Carcinomas are rare malignant neoplasms, accounting for less than 1% of primary hyperparathyroidism cases. Parathyroid carcinomas are characterized by markedly elevated levels of PTH, severe hypercalcemia and established target organ damage. The authors report the experience of a single center regarding the clinic-pathologic and genetic analysis of parathyroid carcinoma cases. Methods/Case Report The study is a retrospective review of all patients with parathyroid carcinoma that were evaluated at a tertiary oncologic center from 2001 until 2023. Results (if a Case Study enter NA) A total of nine cases (6 male and 3 female) were identified, with a mean age at diagnosis of 52 ± 16 years and a median follow-up of 16.5 years. Most patients presented with hypercalcemia (n = 7), with a mean serum calcium concentration of 13.5 mg/dl (9.6-16.5) and a mean PTH of 1123 pg/ml (&amp;lt;a href=“tel:276- 2500”&amp;gt;276-2500&amp;lt;/a&amp;gt;). En bloc surgical resection was performed in 6 patients and 3 patients underwent adjuvant radiotherapy. Recurrence was observed in 4 cases (44.4%) after a median of 24 months following surgery. Negative immunohistochemical staining of parafibromin was noted in 3/4 cases of recurrence. Parathyroid carcinoma was diagnosed on the basis of finding lesions with vascular or perineural invasion, capsular penetration, and/or documented metastases. Immunohistochemical staining for parafibromin, Ki-67, and E-cadherin was performed on formalin-fixed, paraffin-embedded tissue samples. Next generation sequencing (NGS) was performed in 6/9 cases and CDC73 mutations were present in 38.5% of analyzed patients. Loss of TP53 and RB1 alleles and CCND1 amplification were other reported genetic alterations in the study cohort. Conclusion Parathyroid carcinoma is associated with a significant rate of recurrence and limited effective treatment beyond initial complete surgical resection. Inactivating CDC73 alterations which include truncating or frameshift mutations, as well as missense mutations lead to the loss of parafibromin immunoreactivity. Other molecular alterations like PTEN and PIK3CA mutations may represent potential targets for molecular therapy. An IHC panel of parafibromin, Ki-67 and E-cadherin may help to distinguish parathyroid carcinoma from other parathyroid neoplasms.

Measuring Calcium-Sensing Receptor Agonist-Driven Insertional Signaling (ADIS) and Trafficking by TIRF Microscopy.

The calcium-sensing receptor (CaSR), which regulates parathyroid hormone secretion by sensing serum calcium concentrations, has developed unique trafficking mechanisms to respond to constant exposure to its orthosteric ligand calcium. CaSR rapidly responds to fluctuations in serum calcium by driving forward trafficking of the receptor to cell surfaces in a mechanism known as agonist-driven insertional signaling (ADIS). This increase in CaSR at cell surfaces is counterbalanced by both constitutive and agonist-driven internalization of the receptor. Deciphering these mechanisms is important to understand how mutations in the CaSR and components of its signaling and trafficking pathways cause human disorders of calcium homeostasis.This chapter describes a protocol to measure CaSR ADIS and endocytosis in parallel using total internal reflection fluorescence (TIRF) microscopy. This utilizes a mammalian expression construct comprising the full-length human CaSR with an N-terminal bungarotoxin minimal-binding site that can be labeled with commercially available fluorescent ligands to measure endocytosis, and a super-ecliptic pHluorin (SEP) to measure total cell surface expression and exocytic events. This protocol could easily be adapted to simultaneously assess forward trafficking and endocytosis of other membrane proteins by TIRF microscopy.

Monitoring Calcium-Sensing Receptor (CaSR)-Induced Intracellular Calcium Flux Using an Indo-1 Flow Cytometry Assay.

The calcium-sensing receptor (CaSR) has a critical role in maintaining serum calcium concentrations within the normal physiological range, and mutations in the receptor, or components of its signaling and trafficking pathway, cause disorders of calcium homeostasis. Inactivating mutations cause neonatal severe hyperparathyroidism or familial hypocalciuric hypercalcemia (FHH), while gain-of-function mutations cause autosomal dominant hypocalcemia (ADH). Characterizing the functional impact of mutations of the CaSR, and components of the CaSR-signaling pathway, is clinically important to enable correct diagnoses of FHH and ADH, optimize management, and prevent inappropriate parathyroidectomy or vitamin D supplementation. CaSR signals predominantly by activating the G-alpha subunit-11 to mobilize calcium release from intracellular stores. Thus, measurement of CaSR-induced intracellular calcium (Ca2+i) signaling is the gold standard method to investigate the pathogenicity of CaSR genetic variants. This protocol describes a method to assess CaSR-induced Ca2+I signaling using the Indo-1 calcium indicator dye and flow cytometry. This method has been used to assess multiple genetic variants in CaSR and components of its signaling and trafficking pathway in HEK293 cells.

8317 Biochemical Adequacy And Renal Complications In Long-Term Management Of Patients With Postsurgical Hypoparathyroidism

Abstract Disclosure: A. Hong: None. J. Park: None. W. Choi: None. J. Yoon: None. H. Kim: None. H. Kang: None. Background: Hypoparathyroidism (HypoPT) most commonly develops after neck surgery, particularly thyroid surgery. Permanent postsurgical HypoPT necessitates calcium and active vitamin D supplementation for 12 months or more due to irreversible parathyroid damage following surgery. This study investigated the biochemical adequacy of conventional therapy (i.e., active vitamin D and/or calcium) in patients with permanent postsurgical HypoPT based on recent guidelines and assessed the incidence of renal complications. Materials and Methods: The study included 62 adult patients with permanent postsurgical HypoPT who underwent total thyroidectomy for papillary thyroid cancer at Chonnam National University Hwasun Hospital. Biochemical parameters, including albumin-adjusted serum total calcium, ionized calcium, phosphate, creatinine, parathyroid hormone, magnesium, 25-hydroxyvitamin D (25[OH]D), and 24-h urine calcium, were measured. Renal ultrasound and KUB X-ray were performed for all patients. Results: The mean age of the patients was 55.5 ± 12.4 years, with 48 (77.4%) being female. The median follow-up duration after surgery was 10.6 years (interquartile range 9.0-15.5 years). At the time of evaluation, all patients were treated with calcitriol. Additional treatment, including calcium carbonate or cholecalciferol, was received by 43 (69.4%), and 28 (45.2%) were given thiazide diuretics. Thirty-seven (59.7%) patients had values below the recommended serum calcium (albumin-adjusted or ionized) concentration, while three (4.8%) had values above the upper normal limit of serum phosphate level. Serum 25(OH)D levels were maintained within the normal range (30-50 ng/mL) in 27 (43.5%) patients, and 47 (75.8%) patients met normal serum magnesium levels. Hypercalciuria, defined as &amp;gt;7.5 mmol/day in men and &amp;gt;6.25 mmol/day in women, was observed in 12 (19.4%) patients. Nephrolithiasis and nephrocalcinosis were present in 2 (3.2%) patients each. No patient had chronic kidney disease (CKD), defined as an estimated glomerular filtration rate &amp;lt;60 mL/min/1.73 m2. Conclusion: Conventional management for permanent postsurgical HypoPT appears suboptimal for certain patients. However, the incidence of renal complications, such as hypercalciuria, nephrolithiasis/nephrocalcinosis, and CKD, was not commonly observed in a real-world setting during the 10 years of follow-up. This observation may be associated with a higher prescription rate of thiazide diuretics. Presentation: 6/2/2024

Serum calcium improves the relationship between fluoride exposure and hypothalamic-pituitary-testicular axis hormones levels in males—a cross-sectional study on farmers in the lower reaches of the Yellow River

Numerous studies have reported the toxicity of fluoride to the male reproductive system, but epidemiological evidence is limited. We conducted a cross-sectional study in Kaifeng City, Henan Province in 2011 to explore the association between fluoride exposure and hypothalamic-pituitary-testicular (HPT) axis hormones in men. Morning urinary fluoride (UF), serum HPT axis hormones and serum calcium (SC) concentrations were detected. Percent changes and 95% confidence intervals in HPT axis hormones associated with UF were estimated using adjusted linear regression models, and performed subgroup analysis based on SC levels. The restricted cubic spline model was used to fit nonlinear relationships. For every 10% increase in UF, the concentrations of serum GnRH, T, SHBG and TSI decreased by 2.13%, 2.39%, 2.19% and 1.96%, while E2 and FEI increased by 1.11% and 3.33%. Subgroup analysis showed that for every 10% increase in UF, the levels of GnRH, T, TSI and FTI decreased by approximately 3.15%, 5.49%, 4.47% and 5.14%, while the E2 level increased by 2.92% in low-serum-calcium group (LCG). The levels of GnRH and T decreased by approximately 2.97% and 1.82% in medium-serum-calcium group (MCG). In high-serum-calcium group (HCG), serum SHBG levels decreased by 4.70%, while FTI and FEI levels increased by 4.93% and 4.20% as UF concentration increased (P < 0.05, respectively). The non-linear relationship between serum GnRH and UF concentrations presented an approximately inverted U-shaped curve, with a turning point UF concentration of 1.164 mg/L (P < 0.001), and their nonlinear relationship in LCG and MCG were similar to that in the overall subjects. In conclusion, excessive exposure to fluoride can interfere with male serum HPT axis hormones, and a moderate increase in SC alleviates the effect of fluoride. Prospective cohort studies are essential to confirm the causality.

8737 Primary Hyperparathyroidism (PHPT) “Phenotypes” and the Results of Parathyroid [99mTc]Tc-Sestamibi SPECT/CT Scintigraphy: Minimizing the Risk of Negative Imaging Results

Abstract Disclosure: K. Kucharczyk: None. A. Drynda: None. J. Podlewski: None. M. Trofimiuk-Muldner: None. A. Hubalewska-Dydejczyk: None. Introduction. Primary hyperparathyroidism (PHPT) is a prevalent endocrinopathy typically identified through biochemical testing. PHPT is characterized by hypercalcemia accompanied by increased or inappropriately normal plasma parathyroid hormone (PTH) concentrations. Preoperative imaging is conducted when surgery is indicated to pinpoint parathyroid adenomas. [99mTc]Tc-Sestamibi scintigraphy is highly specific and sensitive in diagnosing PHPT, with a higher adenoma detection rate demonstrated for patients with larger lesions or higher blood calcium concentrations. The study aimed to investigate the relationship between the results of biochemical tests and clinical manifestations (PHPT “phenotype”) and the rate of positive results of parathyroid [99mTc]Tc-Sestamibi scintigraphy. Materials and methods. This was a retrospective study of patients suspected of PHPT who underwent parathyroid [99mTc]Tc-Sestamibi SPECT/CT scintigraphy between 2010 and 2022. Patients’ cluster analysis was conducted based on PTH, serum calcium (Ca), and phosphate (Pi) concentrations to find distinct patterns in these parameters. Furthermore, we compared the distributions of additional patients’ attributes, including gender, lesion size, serum vitamin D, ALP concentrations, urinary calcium, urolithiasis prevalence, as well as parathyroid scintigraphy results. Results. 513 patients were divided into 5 clusters using different algorithms. Finally, clusters from K-means methods were selected based on statistical metrics and expert interpretation. Those were organized in ascending order of positive scintigraphy results, with Cluster 5 reaching a 79.5% positivity rate and median values of PTH - 315.5 pmol/L, Ca - 2.96 mmol/L, and Pi - 0.7 mmol/L. As the proportion of positive imaging outcomes declined, median PTH and calcium concentrations decreased while phosphate concentrations increased. In Cluster 1, with 30% of positive imaging results, medians were as follows: PTH - 79.06 pmol/L, Ca - 2.55 mmol/L and Pi - 1.1 mmol/L. A comparative analysis of various clinical and biochemical parameters revealed statistically significant differences between clusters. Patients from Clusters with a higher frequency of positive scintigraphy were significantly more likely to be males, vitamin D deficient, with higher ALP concentrations, diagnosed with urolithiasis, and harbouring larger lesions. Conclusions. PHPT “phenotypes” correlated with disease severity are evidently linked to parathyroid scintigraphy detection rate. Therefore, it is crucial to know that false-negative imaging is more likely in PHPT patients with minor deviations in laboratory tests. Judicious assessment of biochemical and clinical features may limit the number of redundant parathyroid scintigraphies and, in consequence, reduce healthcare costs and unnecessary radiation exposure. Presentation: 6/2/2024

A-039 Parathyroid Hormone and Vitamin D Follow an Inversely Correlated Serum Level

Abstract Background Parathyroid hormone (PTH) is a polypeptide responsible for regulating the physiological level of serum calcium through a complex homeostatic process closely associated with bone metabolism. In response to a decreased serum concentration of calcium, PTH level is increased leading to the elevation of calcium via bone resorption. Furthermore, Vitamin D (Vit-D) is a critical component of the endocrine system that also contributes to calcium homeostasis. Vit-D increases the level of serum calcium by stimulating intestinal absorption and renal reabsorption. Vit-D impacts the serum level of PTH by two distinct mechanisms. First indirectly, an increase in serum concentration of calcium, caused by Vit-D-mediated intestinal absorption and renal reabsorption disengages the process of PTH release through interaction with calcium-sensing receptors on parathyroid cells. Secondly, Vit-D directly interacts with parathyroid cells resulting in a reduced expression of PTH. Taken together, Vit-D is assumed to negatively impact the serum level of PTH. This study examined the homeostatic correlation between the circulating concentrations of Vit-D and PTH. Methods Retrospective serum concentrations of PTH and Vit-D were retrieved from the biochemical profiles of hospitalized and ambulatory patients who presented to or admitted at the tertiary care level hospital of University of Texas Southwestern Medical Center during the period between July-to-September of 2021. Correlation analysis between Vit-D and PTH was performed using GraphPad-PRISM-version-8. Results A total of 163 corresponding serum Vit-D and PTH values were obtained. Vit-D and PTH values displayed an inverse correlation (Figure 1). Pearson r values for linear and logarithmic trendlines (-0.6745 and -0.785, respectively) demonstrated a negative correlation between Vit-D and PTH. Conclusions Measuring Vit-D and PTH levels are critically important for assessing the homeostatic status of calcium. PTH level maintains an inverse relationship with Vit-D. Therefore, therapeutic targeting of Vit-D or PTH would mutually affect their concentration eventually reflected in calcium homeostasis.

Features of the state of bone tissue in children with cerebral palsy. Part 1. Etiological aspects. A literature review

BACKGROUND: The growth of the human body is the most significant period of development of the bone tissue, because it is during this period that the size, shape, and architectonics of bone are formed against the background of increasing body weight and increasing physical exertion. Considering a number of pathological factors of the underlying disease (alimentary, neurological, hormonal, stress, and physical), bone tissue in children with cerebral palsy grows and develops with deviations from the norm. АIM: To present up-to-date generalized information about the features of bone tissue in children with cerebral palsy to orthopedic traumatologists, neurologists, and physical therapy specialists. MATERIALS AND METHODS: Studies on the problem of bone tissue condition in patients with cerebral palsy were analyzed. Data published over the past 20 years were searched in the scientific databases PubMed, Google Scholar, Cochrane Library, Crossref, and eLibrary without language restrictions. RESULTS: In the last 20 years, the number of studies about pediatric osteoporosis has increased. The gold standard for determining the level of bone mineral density is dual-energy X-ray absorptiometry. However, its use in children has presented some difficulties and limitations. In children, the relationship between bone mineral density values and the risk of fractures has not been well studied, which does not allow us to discuss about osteoporosis based on densitometric bone mineral density data alone. In patients with cerebral palsy, a decrease in bone mineral density and bone mass during growth was found. Previous studies showed that the main factors associated with a decrease in bone mineral density in this group of patients include neuroendocrine causes due to growth retardation against the background of CNS damage, alimentary factors, decreased calcium and vitamin D concentrations, systemic use of glucocorticoids, intake of antiepileptic drugs, decreased motor activity, and low muscle mass. Increasing serum vitamin D concentrations does not have a positive effect on bone mass, although increasing serum calcium concentrations is associated with an increase in bone mineral density. CONCLUSIONS: Identifying and correcting factors leading to decreased bone mineral density in children with cerebral palsy can improve bone health in this group of patients. The absence of a relationship between bone mineral density values and the risk of fractures in children with cerebral palsy does not allow us to discuss about osteoporosis based only on bone mineral density densitometric data. There may be more factors leading to an increased risk of bone fractures in children with cerebral palsy that require further study.

Education and cooking methods in the management of calcium and PTH serum levels in patients on hemodialysis: a randomized controlled study.

Chronic kidney disease associated mineral bone disorder (CKD-MBD) is one of the major causes of excess morbidity and mortality in hemodialysis patients. The purpose of this study was to investigate whether education about dietary intakes and specific food processing methods affect serum calcium and PTH concentrations in hemodialysis patients. Forty-seven hemodialysis patients were randomly divided into a control and an intervention group. All participants were on individualized phosphate binder therapy. Both groups received education on dietary intake by a trained dietitian. The intervention group received additional education on specific preparation methods of different foodstuffs and consumed two hospital meals prepared according to these methods during hemodialysis. Serum calcium and PTH levels, and vitamin D analog therapy dosage were periodicallymonitored during the 1-year study period. At the baseline of the study, there were no differences between control and intervention groups in serum calcium (p = 0.078), serum PTH (p = 0.670), and vitamin D analog therapy dosage (p = 0.184). At the end of the study, serum calcium was better regulated in the intervention group, resulting in a significant differencebetween thestudy groups (p = 0.013). This was also confirmed by serum PTH levels in the intervention group, which remained stable until the end of the study (p = 0.110). Additional education on specific food processing techniques mayresult in improved management of serum calcium and PTH levels, which could ultimately provide better control of secondary hyperparathyroidism in hemodialysis patients.

Genome-Wide Interaction Analyses of Serum Calcium on Ventricular Repolarization Time in 125 393 Participants.

Ventricular repolarization time (ECG QT and JT intervals) is associated with malignant arrhythmia. Genome-wide association studies have identified 230 independent loci for QT and JT; however, 50% of their heritability remains unexplained. Previous work supports a causal effect of lower serum calcium concentrations on longer ventricular repolarization time. We hypothesized calcium interactions with QT and JT variant associations could explain a proportion of the missing heritability. We performed genome-wide calcium interaction analyses for QT and JT intervals. Participants were stratified by their calcium level relative to the study distribution (top or bottom 20%). We performed a 2-stage analysis (genome-wide discovery [N=62 532] and replication [N=59 861] of lead variants) and a single-stage genome-wide meta-analysis (N=122 393, [European ancestry N=117 581, African ancestry N=4812]). We also calculated 2-degrees of freedom joint main and interaction and 1-degree of freedom interaction P values. In 2-stage and single-stage analyses, 50 and 98 independent loci, respectively, were associated with either QT or JT intervals (2-degrees of freedom joint main and interaction P value <5×10-8). No lead variant had a significant interaction result after correcting for multiple testing and sensitivity analyses provided similar findings. Two loci in the single-stage meta-analysis were not reported previously (SPPL2B and RFX6). We have found limited support for an interaction effect of serum calcium on QT and JT variant associations despite sample sizes with suitable power to detect relevant effects. Therefore, such effects are unlikely to explain a meaningful proportion of the heritability of QT and JT, and factorsincluding rare variation and other environmental interactions need to be considered.