Relationship between serum osteocalcin level and carotid intima-media thickness in a metabolically healthy Chinese population

Age- and sex-specific differences in the association of serum osteocalcin and cardiometabolic risk factors in type 2 diabetes

BACKGROUND

Serum osteocalcin levels are closely related to metabolic syndrome and cardiovascular disease. This study aimed to investigate the relationship between serum osteocalcin levels and cardiometabolic risk factors in patients with type 2 diabetes (T2D) according to age and sex.

METHODS

This cross-sectional study included 1500 patients with T2D (991 men and 509 women) aged ≥ 18 years old. The age- and sex-specific disparities in glycemic and lipid control, as well as cardiometabolic risk factors were evaluated.

RESULTS

The levels of serum osteocalcin were significantly higher in women aged > 50 years compared with women aged ≤ 50 years (15.6 ± 6.5 ng/mL vs. 11.3 ± 4.5 ng/mL, p < 0.0001). However, this was lower in men aged > 50 years than men aged ≤ 50 years (12.2 ± 4.2 ng/mL vs. 12.9 ± 4.3 ng/mL, p = 0.0081). We performed correlation analyses of serum osteocalcin and cardiometabolic parameters. Serum osteocalcin concentrations were negative associated with FBG and HbA1c levels in women and men ≤ 50 years old, but not in men aged > 50 years old. Serum osteocalcin were negatively correlated with TG and positively correlated with HDL-C and LDL-C only in men aged ≤ 50 years. In binary logistic regression analysis, serum osteocalcin levels were associated with multiple cardiovascular risk factors, as follows: overweight/obese (odds ratio [OR], 0.944; 95% confidence interval [CI], 0.9-0.991, p = 0.02) in men aged > 50 years; high HbA1C and high FBG in women and men aged ≤ 50 years, but not in men aged > 50 years; after adjustment for confounding factors, high TG (OR, 0.905; 95% CI 0.865-0.947, p < 0.0001), metabolic syndrome (OR, 0.914; 95% CI 0.874-0.956, p < 0.0001), and low high-density lipoprotein cholesterol (OR, 0.933; 95% CI, 0.893-0.975, p = 0.002) were seen in men aged ≤ 50 years only.

CONCLUSIONS

Serum osteocalcin level has significant relationships with cardiometabolic risk factors and several age- and sex-related differences in patients with T2D. Decreased serum osteocalcin levels are associated with a worse cardiometabolic risk profile.

Relationships of Serum Bone Turnover Markers With Metabolic Syndrome Components and Carotid Atherosclerosis in Patients With Type 2 Diabetes Mellitus

Objective

This study aimed to investigate the association of serum bone turnover markers (BTMs) with metabolic syndrome components and carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM).

Methods

We performed a cross-sectional based study in T2DM populations. Serum BTMs including N-terminal osteocalcin (N-MID), β-cross-linked C-telopeptide of type I collagen (β-CTX), and procollagen type I N-terminal propeptide (PINP) were measured by immunoassay method. Carotid artery intima-media thickness and carotid artery plaque (CAP) were measured by B-mode ultrasound.

Results

The serum N-MID, PINP, and β-CTX levels significantly lower in the CAP group compared with the non-CAP group. N-MID and PINP levels were inversely associated with fasting blood glucose, HOMA-IR, CRP, eGFR, and triglycerides (all P < 0.05), whereas β-CTX levels were negatively associated with triglycerides (P < 0.05). After multiple adjustment, the odds ratios (ORs) were substantially higher for CAP with decreased N-MID level (OR = 0.958; 95% CI = 0.926–0.991; P = 0.013). However, serum levels of PINP and β-CTX were not associated with the presence of CAP. Multivariate logistic regression analysis further revealed that serum N-MID, PINP, and β-CTX levels were significantly associated with hypertriglyceridemia, whereas serum N-MID and β-CTX levels were associated with overweight/obesity risk.

Conclusions

These findings indicated that serum N-MID level was an independent risk factor for carotid atherosclerosis, whereas BTM levels were associated with other metabolic syndrome components in a T2DM population.

The mediating role of the visceral fat area in the correlation between the serum osteocalcin levels and a prolonged QTc interval

AIMS

Osteocalcin, a bone-derived factor, could be a feasible marker for metabolic disorders and adverse cardiovascular outcomes. This study aimed to explore the correlation between serum osteocalcin levels and correct QT interval (QTc) interval prolongation, a risk factor of cardiac morbidity and mortality.

METHODS

We recruited 1210 subjects (age range: 26-80 years) in communities in Shanghai. Serum osteocalcin levels were determined using an electrochemiluminescence immunoassay. The QTc interval was measured using a 12-lead electrocardiogram and was calculated by the Bazett formula. A prolonged QTc interval was defined as QTc > 440 ms. Visceral fat area (VFA) was assessed by magnetic resonance imaging. A VFA of 80 cm² was applied as a cut-off point for central obesity.

RESULTS

Subjects with diabetes, overweight/obesity, or central obesity had significantly lower serum osteocalcin levels than those without (all P < 0.01). In subjects with a normal QTc interval, QTc interval lengthening accompanied decreasing osteocalcin levels (P_{for trend} = 0.033), and the decline was more obvious in subjects with a prolonged QTc interval (P_{for trend} = 0.022). Serum osteocalcin levels were correlated with the QTc interval (standardized β = -0.082, P = 0.005). Neither diabetes nor overweight/obesity was correlated with the QTc interval, whereas central obesity was positively correlated (P = 0.032). In addition, the correlation between osteocalcin levels and the QTc interval was attenuated when central obesity was included in the model simultaneously (standardized β = -0.075, P = 0.010). Mediation analysis revealed that VFA played a mediating role in the aforementioned correlation, and the estimated percentage of the total effect mediated by VFA was 20.9% (P = 0.007).

CONCLUSIONS

VFA partially mediated the inverse correlation between the serum osteocalcin levels and QTc interval, suggesting that improving fat metabolism may be a mechanism by which osteocalcin protects against cardiovascular diseases.

Serum osteocalcin level is associated with the mortality in Chinese patients with Fibrodysplasia ossificans progressiva aged ≤18 years at diagnosis

Background

Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder characterized by extraskeletal heterotopic ossification. It is well recognized that FOP can lead to a devastating condition of disability. However, the mortality rate of FOP patients in China and risk factors for mortality are still largely unclear.

Methods

We conducted a retrospective research on a cohort of 65 cases of FOP patients in China from 2008 to 2018. We reviewed medical records of these FOP patients to retrieve information such as date of birth/death, gender, clinical features, genotypes and biochemical parameters and analyze the correlation of these parameters with the mortality.

Results

92.3% (60/65 cases) patients were classic FOP patients, 3.1% (2/65 cases) were FOP-plus and 4.6% (3/65 cases) were FOP variants. 9 cases of this cohort were dead during the ten-year period, and the overall mortality rate was 13.8%. c.617G > A mutation was confirmed in all non-survivors. In FOP patients≤18 years at diagnosis, non-survivors demonstrated significantly lower blood osteocalcin and alkaline phosphatase levels compared with survivors (P < 0.05), and spearman correlation and logistic regression analysis indicated that serum osteocalcin and alkaline phosphatase levels were negatively correlated with the mortality. Furthermore, the receiver-operating characteristic curve analysis showed serum osteocalcin had the largest area under the curve of 0.855 among four biochemical parameters, and serum osteocalcin < 65.9 ng/ml displayed a good capacity to discriminate the non-survivors from survivors in FOP patients aged 18 years and younger at diagnosis.

Conclusions

Our findings showed that the mortality rate of FOP was 13.8% in China. Serum OC level was negatively correlated with the mortality in Chinese FOP patients ≤18 years at diagnosis.

Osteocalcin value to identify subclinical atherosclerosis over atherosclerotic cardiovascular disease (ASCVD) risk score in middle-aged and elderly Chinese asymptomatic men

BACKGROUND

Our study examined whether osteocalcin contributed to identifying carotid intima-media thickness (C-IMT) over the atherosclerotic cardiovascular disease (ASCVD) risk score.

METHODS

We recruited 618 middle-aged and elderly men from communities in Shanghai. Serum osteocalcin levels were determined using an electrochemiluminescence immunoassay. C-IMT was measured by ultrasonography.

RESULTS

The study included 245 men with low ASCVD risk and 373 men with moderate-to-high ASCVD risk. Serum osteocalcin levels were lower in the moderate-to-high risk vs. low risk men (p=0.042). Multivariate stepwise regression analysis showed that body mass index (BMI) and glycated hemoglobin were predictors for reduced osteocalcin levels (both p<0.001). Among all subjects, the proportion with an elevated C-IMT was higher in the low-osteocalcin group than in the high-osteocalcin group (p=0.042), and the significance of this result was greater when considering only subjects with a moderate-to-high ASCVD risk (p=0.011). The recognition rate of elevated C-IMT was superior with both low osteocalcin and moderate-to-high ASCVD risk vs. either parameter alone (p<0.001 and p=0.015, respectively). Osteocalcin was independently and inversely associated with elevated C-IMT after adjusting for the 10-year ASCVD risk score (p=0.004). The negative relationship remained statistically significant in subjects with a moderate-to-high ASCVD risk in particular (standardized β=-0.104, p=0.044).

CONCLUSIONS

In middle-aged and elderly men, serum osteocalcin levels strengthen identifying subclinical atherosclerosis over ASCVD risk score, especially among subjects with a moderate-to-high ASCVD risk.

Low serum osteocalcin levels are correlated with left ventricular systolic dysfunction and cardiac death in Chinese men

Osteocalcin is a newly identified type of cytokine secreted by osteoblasts, which has an endocrine function, mediates energy and glycol-lipid metabolism, and is closely related to cardiovascular diseases. In this study, we investigated the value of serum osteocalcin levels in predicting left ventricular systolic dysfunction and cardiac death. A total of 258 patients in the Department of Cardiology were included. Two-dimensional echocardiography was performed in all the subjects. The cardiac death of subjects occurring with a median follow-up of 4.6 years was informed via phone calls or the electronic medical records. The serum osteocalcin levels were measured using electrochemiluminescent immunoassay. We found that the median left ventricular ejection fractions (LVEFs) were 62% in men and 63% in women. In the men with a LVEF > 62%, the serum osteocalcin levels were significantly higher than in those with LVEF ≤ 62% (P = 0.042), whereas this difference was absent in the women. Both the serum osteocalcin (β = 0.095, P = 0.028) and serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP; β = -0.003, P < 0.01) levels remained independently significantly correlated with LVEF in the men but not in the women. Receiver operating characteristic (ROC) analyses of the men revealed that the serum osteocalcin (P = 0.007), serum NT-pro-BNP (P = 0.018) and serum osteocalcin + NT-pro-BNP (P < 0.01) levels were all significant in identifying left ventricular systolic dysfunction at baseline, but the pairwise comparisons of the three areas under the curves (AUCs) were all non-significant. The men in the lower osteocalcin level group at baseline suffered a greater risk of future cardiac death than those in the higher osteocalcin level group, whereas the result for NT-pro-BNP exhibited the opposite pattern. In conclusion, lower serum osteocalcin levels in the men could identify left ventricular systolic dysfunction and cardiac death in a manner that was not inferior to high serum NT-pro-BNP levels.

Osteocalcin‑GPRC6A: An update of its clinical and biological multi‑organic interactions (Review)

Osteocalcin is no longer regarded as a molecule exclusive to bone remodeling and osteogenesis, but as a hormone with manifold functions. The discovery of the interaction of osteocalcin with the G protein‑coupled receptor family C group 6‑member A (GPRC6A) receptor has accompanied the characterization of several roles that this peptide serves in body regulation and homeostasis. These roles include the modulation of memory in the brain, fertility in the testis, fat accumulation in the liver, incretins release in the intestine and adaptation to exercise in muscle, in addition to the well‑known effects on β‑cell proliferation, insulin release and adiponectin secretion. The aim of the present review was to provide a practical update of the multi‑organ effects that osteocalcin exerts through its interaction with GPRC6A and the clinical implications of this.

Relationship between Serum Osteocalcin and Carotid Atherosclerosis in Middle-Aged Men in China: A Cross-Sectional Study

BACKGROUND AND PURPOSE

Numerous investigations found that there exists a close relationship between serum osteocalcin and incurrence of atherosclerosis, but studies investigating the effect of serum osteocalcin on carotid atherosclerosis are very limited. Our study is aimed at investigating the role of osteocalcin in carotid atherosclerosis in middle-aged men in China.

METHODS

A total of 335 male middle-aged participants (40-60, 52.4 ± 3.87 years averagely) were enrolled from the institute. The carotid intima-media thicknesses (CIMT) of each subject were measured. All subjects were included either in the carotid atherosclerosis (AS) group or the control group according to the CAS diagnosis criteria. Serum osteocalcin and other markers of each patient were assessed following standard laboratory tests protocol.

RESULTS

135 subjects were included in AS group, and 199 subjects were included in control group. The average osteocalcin level in AS group was 18.71 ± 6.20 ng/ml and was significantly different from that in control group, which was 20.38 ± 7.19 ng/ml (p=0.039). Logistic regression analysis revealed that OCN (standardized β=-0.024, p=0.013) and FINS (standardized β=-0.065, p=0.010) were independently and inversely associated with the carotid atherosclerosis, while FPG (standardized β=0.538, p=0.006) was independently and positively associated with the carotid atherosclerosis.

CONCLUSION

Our study suggests that OCN is independently related to carotid atherosclerosis in middle-aged male individuals.

Relationship between Bone Health Biomarkers and Cardiovascular Risk in a General Adult Population

Purpose/Introduction: Osteoporosis (OP) and cardiovascular (CV) disease emerge as closely related conditions, showing common risk factors and/or pathophysiological mechanisms. The aim of this study was to evaluate the association between bone health markers (BHM) and individual CV risk factors and overall CV risk (FRAMINGHAM-FRS, and PROCAM scores) in a general adult population.

METHODS

In 103 subjects (21 males; age: 56 ± 12 years), vitamin D (25(OH)D), osteocalcin (OC), bone alkaline phospatase (BALP), procollagen I aminoterminal propeptide (P1NP), CTx-telopeptide, as well clinical history and life style were evaluated.

RESULTS

Aging (p < 0.001) and glycemia (p < 0.05) emerged as independent 25(OH)D predictors. Aging (p < 0.001), male sex (p < 0.05), and obesity (p < 0.05) represented independent OC determinants. Aging (p < 0.05) was the only independent BALP determinant. After multivariate adjustment, low 25(OH)D (<20 ng/mL) (Odds ratio OR (95% confidence intervals CI)) (5 (1.4-18) p < 0.05) and elevated OC (>75th percentile-16.6 ng/mL) (6.7 (1.9-23.8) p < 0.01) were found to be significant FRS predictors, while subjects with elevated OC and/or BALP (>75th percentile-9.8 μg/L) showed a higher CV risk as estimated by PROCAM (3.6 (1.2-10.7) p < 0.05). CTx and P1NP did not significantly correlate with CV risk factors or scores.

CONCLUSION

As we go further into bone and CV physiology, it is evident that a close relationship exists between these diseases. Further studies are needed to investigate mechanisms by which bone turnover markers are related to metabolic risk and could modulate CV risk. This knowledge may help to develop possible multiple-purpose strategies for both CV disease and OP prevention and treatment.

High density lipoprotein modulates osteocalcin expression in circulating monocytes: a potential protective mechanism for cardiovascular disease in type 1 diabetes

Background

Cardiovascular disease (CVD) is a major cause of mortality in type 1 diabetes (T1D). A pro-calcific drift of circulating monocytes has been linked to vascular calcification and is marked by the surface expression of osteocalcin (OCN). We studied OCN+ monocytes in a unique population with ≥50 years of T1D, the 50-Year Joslin Medalists (J50M).

Methods

CD45 bright/CD14+/OCN+ cells in the circulating mononuclear blood cell fraction were quantified by flow cytometry and reported as percentage of CD45 bright cells. Mechanisms were studied by inducing OCN expression in human monocytes in vitro.

Results

Subjects without history of CVD (n = 16) showed lower levels of OCN+ monocytes than subjects with CVD (n = 14) (13.1 ± 8.4% vs 19.9 ± 6.4%, p = 0.02). OCN+ monocytes level was inversely related to total high density lipoprotein (HDL) cholesterol levels (r = −0.424, p = 0.02), large (r = −0.413, p = 0.02) and intermediate (r = −0.445, p = 0.01) HDL sub-fractions, but not to small HDL. In vitro, incubation with OxLDL significantly increased the number of OCN+ monocytes (p < 0.01). This action of OxLDL was significantly reduced by the addition of HDL in a concentration dependent manner (p < 0.001). Inhibition of the scavenger receptor B1 reduced the effects of both OxLDL and HDL (p < 0.05).

Conclusions

Low OCN+ monocytes levels are associated with lack of CVD in people with long duration T1D. A possible mechanism for the increased OCN+ monocytes could be the elevated levels of oxidized lipids due to diabetes which may be inhibited by HDL. These findings suggest that circulating OCN+ monocytes could be a marker for vascular disease in diabetic patients and possibly modified by HDL elevation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0599-2) contains supplementary material, which is available to authorized users.

Osteocalcin as a potential risk biomarker for cardiovascular and metabolic diseases

Clear evidence supports a role for circulating and locally-produced osteocalcin (OC) in the pathophysiology of cardiovascular (CV) lesions and CV risk, also in combination with metabolic changes, including type 2 diabetes mellitus (T2DM). Reduced plasma OC levels are associated with greater incidence of pathological CV changes, like arterial and valvular calcification, coronary and carotid atherosclerosis and increased carotid intima-media thickness. The actual relationship between OC levels and incidence of major CV events is, however, still unclear. Moreover, reduced circulating OC levels have been mostly associated with insulin resistance, metabolic syndrome or T2DM, indicating relevant OC actions on pancreatic β-cells and insulin secretion and activity. Based on these observations, this review article will attempt to summarize the current evidence on the potential usefulness of circulating OC as a biomarker for CV and metabolic risk, also evaluating the currently open issues in this area of research.

Osteocalcin, Vascular Calcification, and Atherosclerosis: A Systematic Review and Meta-analysis

BACKGROUND

Osteocalcin (OC) is an intriguing hormone, concomitantly being the most abundant non-collagenous peptide found in the mineralized matrix of bone, and expanding the endocrine function of the skeleton with far-reaching extra-osseous effects. A new line of enquiry between OC and vascular calcification has emerged in response to observations that the mechanism of vascular calcification resembles that of bone mineralisation. To date, studies have reported mixed results. This systematic review and meta-analysis aimed to identify any association between OC and vascular calcification and atherosclerosis.

METHODS AND RESULTS

Databases were searched for original, peer reviewed human studies. A total of 1,453 articles were retrieved, of which 46 met the eligibility criteria. Overall 26 positive, 17 negative, and 29 neutral relationships were reported for assessments between OC (either concentration in blood, presence of OC-positive cells, or histological staining for OC) and extent of calcification or atherosclerosis. Studies that measured OC-positive cells or histological staining for OC reported positive relationships (11 studies). A higher percentage of Asian studies found a negative relationship (36%) in contrast to European studies (6%). Studies examining carboxylated and undercarboxylated forms of OC in the blood failed to report consistent results. The meta-analysis found no significant difference between OC concentration in the blood between patients with "atherosclerosis" and control (p = 0.13, n = 1,197).

CONCLUSION

No definitive association was determined between OC and vascular calcification or atherosclerosis; however, the presence of OC-positive cells and histological staining had a consistent positive correlation with calcification or atherosclerosis. The review highlighted several themes, which may influence OC within differing populations leading to inconclusive results. Large, longitudinal studies are required to further current understanding of the clinical relevance of OC in vascular calcification and atherosclerosis.

Association of Serum Osteocalcin with Insulin Resistance and Coronary Atherosclerosis

Background

To determine the associations between serum osteocalcin level and insulin resistance, coronary atherosclerosis by using dual-source coronary computed tomography angiography.

Methods

A total of 98 subjects (24 men and 74 women) were selected for this retrospective cross-sectional study who voluntarily visited a health examination center for routine health check-up including the blood test for serum osteocalcin level and coronary computed tomography angiography. Multiple regression analysis was used to determine which variables were independently related to osteocalcin levels and coronary atherosclerosis.

Results

Stepwise multiple regression analysis adjusted for age, sex, menopausal status, body mass index, serum alkaline phosphatase, serum calcium and phosphate showed that osteocalcin negatively correlated with serum glucose (β=-0.145, P=0.001) and homeostasis model assessment of insulin resistance (HOMA-IR) index (β=-1.794, P=0.027) independently. The age, serum glucose, smoking status but not osteocalcin level were independent risk factors for coronary atherosclerosis by use of multiple logistic regression analysis after controlling for other variables.

Conclusions

Serum osteocalcin level was inversely associated with fasting glucose level and insulin resistance measured by HOMA-IR, suggesting that osteocalcin is important for glucose metabolism. However, in this study, no significant difference was observed in the serum osteocalcin level according to the presence of coronary atherosclerotic plaques.