Analysis of potential biomarkers and risk factors for rheumatoid arthritis with sarcopenia-osteomalacia based on 1H NMR technique: a case-control study

BackgroundControversial experimental and clinical evidences have raised questions regarding the role of B12 and insulin-like growth factor 1 (IGF-1) on osteoblast function and bone health. In this study, we aimed to determine if the serum levels of B12, IGF-1 and procollagen type 1 N-terminal propeptide (P1NP) are associated with different degrees of bone mineral density (BMD).MethodsA total of 287 subjects (190 women and 97 men; mean age 53 years) volunteered for evaluation of BMD and serum levels of B12, IGF-1 and P1NP; BMD at lumbar spine and proximal femur was evaluated by means of dual-energy X-ray absorption (DEXA) and expressed as T-score; serum concentrations of vitamin B12 and IGF1 were measured with a chemiluminescent immunoassay on Access II Beckman Coulter and DiaSorin Liaison XL analyzers, respectively; P1NP was assessed in 61 women and 35 men with reduced T-score on Roche Modular platform.ResultsA total of 101 subjects (66 women and 35 men) had a reduced BMD (T-score < -1) or osteoporosis with a T-score < -2.5, while 186 (124 women and 62 men) had a normal BMD. No significant difference in the B12 levels was observed between the subjects with reduced BMD (mean 265.15 pg/mL, 95% CI: 236 - 294.25) and those with normal BMD (mean 243.91, 95% CI: 225.78 - 262.03) (P = 0.1990); lower levels of IGF-1 were observed in the group with reduced BMD (mean 138.7 pg/mL, 95% CI: 126.75 - 150.83) than in that with normal BMD (mean 167.34, 95% CI: 136.49 - 198.18) (P< 0.001); serum levels of P1NP were significantly lower in 22 subjects younger than 50 years (mean 44.8 ng/mL, 95% CI: 36.4 - 53.1) vs. 74 subjects > 50 years old (mean 53.3, 95% CI: 34.3 - 72.3) (P < 0.001), and in women (mean 45.3, 95% CI: 37.6 - 52.9) vs. men (mean 62, 95% CI: 23 - 101) (P < 0.001).ConclusionWe found no significant association between B12 levels and BMD, but significant associations of lower levels of IGF1 with reduced BMD and lower levels of P1NP with younger age and female sex were found; additional studies to further investigate the association of serum levels of B12, growth factors and biochemical turnover markers with human bone health are needed.

Objective To investigate the relationship between bone metabolic indicators and non-alcoholic fatty liver disease (NAFLD) in healthy middle-aged men. Patients and methods The bone metabolic indicators of 232 healthy middle-age men with NAFLD (NAFLD group) and 308 healthy controls without fatty liver (Control group) were measured, including non-collagenous osteocalcin, the procollagen type 1 N-terminal propeptide (P1NP), beta-C-terminal telopeptide of type I collagen (β-CTX). The Student's t-test was used to analyze the differences in the bone metabolic indicators, age, clinical data, biochemical indicators, and the indicators of glucose and lipid metabolism between the two groups. The correlation of fatty liver-related indicators was detected using the logistic regression analysis. Results The body mass index (BMI), diastolic blood pressure, and heart rate in NAFLD group were significantly higher than those in Control group. Among the indicators of glucose and lipid metabolism in NAFLD group, the levels of blood glucose [fasting plasma glucose, postprandial blood glucose and hemoglobin A1c (HbA1c)] were significantly higher than those in Control group. In addition, the insulin resistance and secretion indexes were also significantly higher than those in Control group. The levels of lipid metabolic indicators such as triglyceride were higher, but high-density lipoprotein cholesterol was lower than that in Control group. From logistic regression analysis, the BMI, Homeostasis model assessment (HOMA)-β, HOMA-IR, HbA1c and P1NP were positively associated with the occurrence of NAFLD. Conclusions The bone metabolic indicator P1NP might be a potential predicator for the diagnosis of NAFLD in clinical application.

To investigate the relationship between bone metabolic indicators and non-alcoholic fatty liver disease (NAFLD) in healthy middle-aged men. The bone metabolic indicators of 232 healthy middle-age men with NAFLD (NAFLD group) and 308 healthy controls without fatty liver (Control group) were measured, including non-collagenous osteocalcin, the procollagen type 1 N-terminal propeptide (P1NP), beta-C-terminal telopeptide of type I collagen (β-CTX). The Student's t-test was used to analyze the differences in the bone metabolic indicators, age, clinical data, biochemical indicators, and the indicators of glucose and lipid metabolism between the two groups. The correlation of fatty liver-related indicators was detected using the logistic regression analysis. The body mass index (BMI), diastolic blood pressure, and heart rate in NAFLD group were significantly higher than those in Control group. Among the indicators of glucose and lipid metabolism in NAFLD group, the levels of blood glucose [fasting plasma glucose, postprandial blood glucose and hemoglobin A1c (HbA1c)] were significantly higher than those in Control group. In addition, the insulin resistance and secretion indexes were also significantly higher than those in Control group. The levels of lipid metabolic indicators such as triglyceride were higher, but high-density lipoprotein cholesterol was lower than that in Control group. From logistic regression analysis, the BMI, Homeostasis model assessment (HOMA)-β, HOMA-IR, HbA1c and P1NP were positively associated with the occurrence of NAFLD. The bone metabolic indicator P1NP might be a potential predicator for the diagnosis of NAFLD in clinical application.

Bone Metabolism in Cholestatic Children Before and After Living-Related Liver Transplantation—a Long-Term Prospective Study

Introduction: Procollagen type 1 N-terminal Propeptide (P1NP) is a precursor protein of collagen type 1, a major component of cardiac extracellular matrix. The association of P1NP to clinical outcome in patients with suspected acute coronary syndrome (ACS) has so far not been investigated. The objective of the present study was to assess the predictive value of P1NP concerning adverse clinical outcome in patients admitted for suspected ACS. Methods: Plasma P1NP was measured with an enzyme immune assay in samples taken upon admission from patients enrolled in the Risk markers in Acute Coronary Syndrome (RACS) study (NCT00521976), a Norwegian single center study including patients with suspected ACS from November 2002 to September 2003. The primary endpoint was a composite of all-cause mortality, myocardial infarction (MI), or stroke within 1 year. Additional analyzes included the composite and its individual components at 1, 2, and 7 years, and cardiac death at 1 and 2 years. Associations between quartiles of P1NP and the endpoints were assessed in both univariate analyzes and in stepwise multivariable Cox regression analyzes fitted with significant clinical variables, past medical history, medication, TnT, BNP, and eGFR before P1NP was introduced. Results: Samples were available from 813 patients (Mean age 69.6 years, 61.4 % males, 52.9% elevated TnT). Mean P1NP levels was 46.2 ng/mL (CI 44.8-47.6). In multivariable Cox analyzes, P1NP was found to be significantly associated with the composite of all-cause mortality, MI, or stroke at 1 year (HR [Q4vsQ1] 1.82, CI 1.12-2.98; p=0.017). This association did not remain significant beyond 1 year. No association was seen for any of the individual components, or cardiac death, at any timepoint, or in patients with elevated TNT (p&gt;0.05 for all). Conclusions: This first study on P1NP in suspected ACS revealed a significant association with adverse clinical outcome (all-cause death, MI, or stroke) at 1 year. However, no predictive value was found concerning outcome for the individual components of the primary endpoint, or cardiac death, at any timepoint, or in patients with elevated TNT.

Children with atopic dermatitis (AD) are at risk for lower bone mineral density (BMD) and lower alkaline phosphatase (ALP) levels than healthy children. Low BMD and ALP in children could contribute to a higher lifetime prevalence of fractures, osteopenia and osteoporosis. Dupilumab is a fully humanized monoclonal anti-interleukin (IL)-4R antibody approved for the treatment of AD in children. The objective of this analysis is to report the impact of dupilumab treatment on markers of bone mineralization in children aged 6–12 years with moderate-to-severe AD vs. reference intervals (RIs). Analysis was performed retrospectively on sera from participants in LIBERTY AD PEDS, a phase III placebo-controlled trial of 16 weeks (NCT03345914) and LIBERTY AD PED-OLE (NCT02612454), an open-label extension trial in which eligible patients received dupilumab until week 52. Biomarkers, including bone ALP (BALP), procollagen type 1 N-terminal propeptide (P1NP), C-terminal crosslinking telopeptide of β-1 collagen (β-CTX), osteocalcin (OC) and insulin-like growth factor 1 (IGF-1), were analysed at baseline, 8, 12 and 16 weeks; only BALP was measured at 52 weeks. Both dupilumab dosing regimens led to significant increases in geometric mean (SE) levels of BALP at 8, 12 and 16 weeks compared with placebo. For the 100/200-mg Q2W group, at week 8 the BALP level was 72.7 (1.03) μg L−1 vs. 62.0 (1.05) μg L−1 (P &amp;lt; 0.0001), at week 12 it was 74.7 (1.03) μg L−1 vs. 64.3 (1.05) μg L−1 (P &amp;lt; 0.001) and at week 16 it was 78.0 (1.03) μg L−1 vs. 65.0 (1.04) μg L−1 (P &amp;lt; 0.001). For the 300-mg Q4W group, at week 8 the BALP level was 76.7 (1.03) μg L−1 vs. 62.0 (1.05) μg L−1 (P &amp;lt; 0.001), at week 12 it was 73.3 (1.04) μg L−1 vs. 64.3 (1.05) μg L−1 (P = 0.002) and at week 16 it was 77.3 (1.03) μg L−1 vs. 65.0 (1.04) μg L−1 (P &amp;lt; 0.001). At 52 weeks, BALP levels were statistically significantly increased compared with baseline [placebo vs. placebo transitioned to dupilumab: 64.2 (1.04) μg L−1 vs. 82.9 (1.04) μg L−1 (P &amp;lt; 0.001); 100/200 mg Q2W: 62.0 (1.05) μg L−1 vs. 83.8 (1.03) μg L−1 (P &amp;lt; 0.001); 300 mg Q4W: 64.1 (1.04) μg L−1 vs. 78.7 (1.04) μg L−1 (P &amp;lt; 0.001)] and also increased within RIs. From baseline to week 16, OC, P1NP and β-CTX levels improved from below to within the RIs, and levels of IGF-1 increased from the lower limit of the RI. However, data points were limited due to insufficient sera volumes, preventing statistical analyses for these biomarkers. The overall results suggest an increase in bone mineralization biomarkers in paediatric patients with moderate-to-severe AD following dupilumab treatment. Funding sources:research sponsored by Sanofi and Regeneron Pharmaceuticals Inc.

Objectives: The aim of this study was to evaluate the change of bone metabolism and bone remodelling balance in active and biochemical controlled acromegalic patients. Methods: We recruited 68 consecutive patients diagnosed as acromegaly in Nanjing Drum Tower Hospital. Of those, 39 patients after treatments with complete follow-up data were included. 30 sex-, age- and BMI-matched healthy persons were also included as normal controls. Serum calcium, phosphorus, parathyroid hormone (PTH), 25-hydroxy-vitamin D, bone turnover markers [osteocalcin, C-terminal telopeptide of type 1 collagen (CTX) and procollagen type 1 N-terminal propeptide (P1NP)], and bone remodelling index were investigated at baseline and after treatment. Univariate and multivariate linear regression analysis was used to determine the independent predictors of bone turnover markers. Results: At baseline, acromegalic patients had higher serum calcium, phosphorus and lower PTH levels than controls (all P < 0.01). Acromegalic patients had higher serum osteocalcin [45.98(31.98, 60.27) vs 15.83(12.74, 19.96) ng/ml, P < 0.01], P1NP [115.50(72.64, 145.90) vs 36.45(30.45, 44.28) ng/ml, P < 0.01] and CTX than controls [1.12(0.79, 1.56) vs 0.37(0.30, 0.50) ng/ml, P < 0.01], and the bone remodelling index of acromegaly patients is significantly increase compared to healthy controls [4.27(1.31, 5.99) vs 0.03(-0.38, 0.63), P < 0.01]. Multivariate linear regression analysis revealed that serum insulin-like growth factor 1 (IGF-1) was an independent predictor for osteocalcin (r = 0.610, P = 0.000), P1NP (r = 0.601, P = 0.000) and CTX (r = 0.596, P = 0.000). After treatment, serum calcium and phosphorus decreased, while PTH increased in acromegalic patients. Serum levels of bone turnover markers osteocalcin, PINP, CTX and bone remodelling index were also significantly decreased after treatment (all P < 0.05). In patients with biochemical control after treatment, bone turnover markers and bone remodelling index almost decreased to normal level (all P > 0.05). Conclusion: Acromegalic patients exhibited PTH-independent calcium-phosphate alterations, enhanced bone turnover state and positive bone remodeling balance. The abnormal bone metabolism is reversible after biochemical control of acromegaly. [Key words]Acromegaly; Bone turnover markers; Bone remodelling index; Growth hormone; Insulin-like growth factor 1

A Radioimmunoassay for the N-terminal Propeptide of Rat Procollagen Type III: Application to the Study of the Uptake of the N-terminal Propeptide of Procollagen Type III in Isolated Perfused Rat Liver

Background : Secondary osteoporosis is a significant problem, especially in patients with endocrine pathology, which is not accompanied constantly by distinct clinical symptoms. Markers of bone origin are needed, which could be used in osteoporosis diagnosis to clarify its genesis, especially in young people who have secondary osteoporosis more often than older patients. In Cushing’s disease (CD), such a marker, in addition to osteocalcin, could be another bone formation marker, procollagen type 1 N-terminal propeptide (P1NP). Aims : To study the diagnostic potential of P1NP as an additional marker of endogenous hypercortisolism (Cushing’s disease) compared to osteocalcin. Materials and methods : The study involved patients with Cushing’s disease and healthy volunteers, matched by gender, age, and body mass index. The levels of osteocalcin and P1NP were assessed in both groups, the electrochemiluminescence method for P1NP (Cobas e411 (Roche, Switzerland)) and for osteocalcin (Cobas 6000 Module e601 (Roche, Switzerland)) was used. ROC analysis was performed with the calculation of sensitivity and specificity of the method to determine the cut-off point for P1NP in CD diagnosis. Results : 29 patients with Cushing’s disease and 27 healthy individuals from the control group were included in the study. There were no differences in age, sex and body mass index (p = 0.488, 0.426 and 0.531, respectively). Both studied bone formation markers (osteocalcin and P1NP) were reduced in patients with CD: 8.53 ng/ml (Q25%;Q75% 5.40; 12.41) versus 22.45 ng/ml (Q25%;Q75% 17.36; 26.31) (p <0.001) and 28.50 ng/ml (Q25%;Q75% 18.00; 44.00) versus 56.50 ng/ml (Q25%;Q75% 39.50; 65.50) (p <0.001), respectively. The area under the receiver operating characteristic curve (AUC) was 0.808 (95% CI 0.693–0.924) for P1NP and 0.925 (95% CI 0.857–0.992) for osteocalcin, that indicates the greater diagnostic value of osteocalcin for CD verification in healthy controls. Optimal cut-off points were obtained: 53.4 ng/ml (values below are more typical for patients with CD; sensitivity of the method is 96.55%, specificity 57.69%) for P1NP and 15.285 ng/ml (below for patients with CD; sensitivity was 92.59%, specificity 77.78 %) for osteocalcin. Conclusions : The diagnostic potential of osteocalcin to detect Cushing’s disease in the population is higher compared to P1NP. However, applying of P1NP can be useful because, unlike osteocalcin, it is a direct indicator of the formation of bone matrix collagen structures, that is important for assessing the degree of inhibition of collagen type 1 synthesis in CD and deterioration of bone tissue due to glucocorticoid-induced osteoporosis.

Objective To assess associations of bone turnover markers with metabolic syndrome (MS) among men in Henan Province. Methods From December 2015 to March 2016, a total of 697 male subjects were selected from the TIDE (Thyroid Disorders, lodine status and Diabetes: a National Epidemiological Survey-2014) research--Henan sub-center survey using multistage stratified cluster random sampling. All included subjects received standard oral glucose tolerance test, a physical examination (height, weight, waist circumference and blood pressure), a collection of blood samples to determine the level of plasma glucose, glycated hemoglobin A1c, total cholesterol, triglyceride (TG), high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, osteocalcin, pro-collagen type 1 N-terminal propeptide (PⅠNP), C-terminal-cross-linking telopeptide of type 1 collagen (β-CTX), 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH), and all of them completed the questionnaire. The associations between bone turnover markers and MS were analyzed using Spearman correlation and binary logistic regression, respectively. Results A total of 697 men with an age of (46.6±15.9) years were included in the study. The average body mass index (BMI) was (25.97±3.69) kg/m2 (17.1-39.0 kg/m2). After adjusted for age, PTH, 25(OH)D, BMI and smoke, BMI was found as a risk factor for MS (OR=1.263, 95%CI 1.198-1.332). Spearman correlation analysis showed that OC and PⅠNP was negatively associated with MS (r=-0.154, -0.107, both P<0.01), but there was no significant correlation between β-CTX and MS. The results of the binary logistic regression analysis showed that OC was a protective factor for MS, abdominal obesity, hyperglycemia, hypertension and high TG; after adjusted for age, PTH, 25(OH) D and BMI, osteocalcin was also a protective factor for hyperglycemia (OR=0.971, 95%CI 0.947-0.995) and high TG (OR=0.955, 95%CI 0.931-0.980); further adjusted for smoke, the results were same as before. PⅠNP was a protective factor for MS, abdominal obesity, hyperglycemia and hypertension; after adjusted for age, PTH and 25(OH)D, PⅠNP was also a protective factor for abdominal obesity (OR=0.993, 95%CI 0.988-0.999); further adjusted for BMI and smoke, there was no significant correlation between PⅠNP and abdominal obesity. Conclusion Weight control is important to prevent adult males from MS, and higher levels of osteocalcin and PⅠNP may help prevent MS. Key words: Osteocalcin; Pro-collagen type 1 N-terminal propeptide; C-terminal-cross-linking telopeptide of type 1 collagen; Metabolic syndrome; Males

Like rheumatoid arthritis, ankylosing spondylitis (AS) is also an inflammatory disease associated with accelerated atherosclerosis and the presence of metabolic syndrome (MeS) features. AS patients often display osteoporosis as well as new bone formation. Insulin-like growth factor 1 (IGF-1) is a protein involved in both inflammation and bone metabolism. In the present study we assessed whether disease activity, systemic inflammation, MeS features, adipokines, and biomarkers of endothelial activation were associated with IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels in a series of 30 nondiabetic AS patients without CV disease undergoing TNF-α antagonist-infliximab therapy. All determinations were made in the fasting state, immediately before an infliximab infusion. Although no association of IGF-1 and IGFBP-3 levels with angiopoietin-2 or osteopontin was found, an inverse correlation between IGF-1 levels and asymmetric dimethylarginine (ADMA), an endogenous endothelial nitric oxide synthase inhibitor that impairs nitric oxide production and secretion promoting endothelial dysfunction, was found (r = −0.397; P = 0.04). However, no significant association was found between IGF-1 and IGFBP-3 levels and disease activity, systemic inflammation, metabolic syndrome features, or adipokines. In conclusion, in nondiabetic patients with AS undergoing periodic anti-TNF-α therapy, IGF-1 and ADMA are inversely correlated.

The association between insulin-like growth factor I and bone turnover markers in the general adult population

Individuals with type 2 diabetes (T2D) have an increased risk of bone fractures despite normal or increased bone mineral density. The underlying causes are not well understood but may include disturbances in the gut-bone axis, in which both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are regulators of bone turnover. Thus, in healthy fasting participants, both exogenous GIP and GLP-2 acutely reduce bone resorption. The objective of this study was to investigate the acute effects of subcutaneously administered GIP and GLP-2 on bone turnover in individuals with T2D. We included 10 men with T2D. Participants met fasting in the morning on 3 separate test days and were injected subcutaneously with GIP, GLP-2, or placebo in a randomized crossover design. Blood samples were drawn at baseline and regularly after injections. Bone turnover was estimated by circulating levels of collagen type 1 C-terminal telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), sclerostin, and PTH. GIP and GLP-2 significantly reduced CTX to (mean ± SEM) 66 ± 7.8% and 74 ± 5.9% of baseline, respectively, compared with after placebo (P = .001). In addition, P1NP and sclerostin increased acutely after GIP whereas a decrease in P1NP was seen after GLP-2. PTH levels decreased to 67 ± 2.5% of baseline after GLP-2 and to only 86 ± 3.4% after GIP. Subcutaneous GIP and GLP-2 affect CTX and P1NP in individuals with T2D to the same extent as previously demonstrated in healthy individuals.

Background: The procollagen type 1 N-terminal propeptide (P1NP), a byproduct of type I collagen synthesis, is useful in clinically monitoring anti-resorption medications. The role of P1NP in anti-resorption therapy in older bisphosphonate-taking individuals who have suffered another fracture is unclear.Objectives: This study aims to describe serum P1NP levels in patients aged ≥60 years who sustained a fragility neck of femur fracture while receiving osteoporosis therapy and to describe how P1NP results were associated with subsequent bone health management decisions, defined as documented decisions to continue, stop, or change osteoporosis therapy (including switch/escalation) and/or request additional investigations.Methods: This retrospective descriptive cohort study, conducted between March 2017 and September 2021, involved patients aged 60 years or older who experienced intra- or extracapsular femoral neck fractures while receiving osteoporosis therapy and had serum P1NP assessed before surgery. Routinely collected data were extracted from departmental databases and systems accessible through the NHS computers at East Surrey Hospital as part of an ongoing quality improvement project.Results: Out of the 2,303 total fractures during the study period, 58 patients (2.5%) had serum P1NP levels tested. The mean age was 84.6 ± 8.08 years, with a female-to-male ratio of 8.7:1; 34 (58.6%) had intracapsular and 24 (41.6%) had extracapsular types of fractures. Eighteen patients (31%) had P1NP levels of 40 ug/l or higher; six (10.3%) had P1NP levels between 36 and 39 ug/l, and 34 patients (58.6%) exhibited suppressed P1NP levels (below 35 ug/l). For those who had suppressed P1NP, five (55.6%) of the nine patients (who had been receiving treatment for over five years) had their treatment discontinued, two (22.2%) had their treatment plans modified because of DXA scan results, and two remained on the same treatment plan. Three patients on therapy for up to five years had P1NP levels above 40 ug/l owing to memory loss or inexperience with oral alendronate; therefore, adherence was low. Change to IV zoledronate or patient education was offered.Conclusion: In this selected cohort, measuring pre-operative P1NP levels supported patient-centred multidisciplinary (MDT) bone health planning. Clinicians considered P1NP alongside DXA findings and the broader clinical context when documenting MDT post-fracture bone health plans, with management changes commonly recorded among patients receiving long-term therapy (>5 years). Notably, in this long-term treated group, suppressed P1NP commonly coincided with documented decisions to stop or adjust therapy. Given the retrospective design, small sample size, lack of a comparator group, and absence of outcome data, these findings provide real-world insight into current practice and may support development of a more standardised approach to incorporating P1NP into post-fracture bone health pathways.

Role of the Growth Hormone/Insulin-like Growth Factor-1 Paracrine Axis in Rheumatic Diseases