First-degree family history of diabetes and its relationship with serum osteocalcin levels independent of liver fat content in a non-diabetic Chinese cohort.

BACKGROUND: First-degree relatives of patients with diabetes (FDR) tend to have impaired insulin activity, which lead to the alternation of circulating cytokine levels. Liver is a main target tissue of insulin action; therefore, liver fat content (LFC) has a close relationship with insulin resistance. This study aimed to find the alteration in serum osteocalcin levels in FDR and the relationship of serum osteocalcin levels with FDR and non-alcoholic fatty liver disease (NAFLD). METHODS: In total, 1206 subjects including 413 men and 793 women from the communities, aged 59.7 (range, 54.8-64.3) years, were enrolled. An electrochemiluminescence immunoassay was performed to measure the levels of serum osteocalcin. LFC was measured using quantitative ultrasonography. RESULTS: A significant decrease was found in serum osteocalcin levels in subjects with NAFLD (P < 0.001) as well as in FDR (19.8 ± 5.7 ng/mL versus 20.7 ± 6.8 ng/mL, P = 0.028). Furthermore, among the subjects with NAFLD, those with FDR had lower levels of osteocalcin than those without FDR (P = 0.011). The presence of FDR remained a predictor for decreased serum osteocalcin levels after adjusting for body mass index, blood glucose, blood lipids, and LFC (standardized ß = - 0.057, P = 0.028). CONCLUSIONS: FDR had lower serum osteocalcin levels than non-FDR. The inverse association between FDR and serum osteocalcin levels was independent of metabolic factors.

Role of hyperglycaemia in the relationship between serum osteocalcin levels and relative skeletal muscle index.

BACKGROUND & AIMS: Studies have shown that osteocalcin is involved in energy metabolism and is sufficient to prevent age-related muscle loss. The present study investigated the association of serum osteocalcin levels with muscle mass and the influence of metabolic factors on this association in humans. METHODS: A total of 1742 middle-aged and elderly subjects (median age: 61.2 years; interquartile range: 56.9-65.3 years) were enrolled from Shanghai communities, including 775 men and 967 postmenopausal women. Serum osteocalcin levels were measured by an electrochemical immunoluminescence assay. An automatic bioelectric impedance analyser (BIA) was used to measure body compositions. Relative skeletal muscle index (SMI) was calculated using the BIA equation from Janssen et al. RESULTS: SMI was significantly higher in men than in postmenopausal women (37.30% [35.14%-39.63%] versus 27.72% [25.99%-29.66%], p < 0.001). Increasing SMI was associated with decreases in the frequency of overweight/obesity, central obesity, dyslipidaemia, elevated blood pressure, and hyperglycaemia (all p < 0.001). Serum osteocalcin levels were positively correlated with SMI in both men and women, regardless of treatment as a categorical or continuous variable (all p < 0.001). However, after accounting for confounding variables, the relationship remained only in men with hyperglycaemia (standardized ß = 0.068, p = 0.024). Among men with isolated impaired glucose tolerance, the odds ratio of increased SMI was 2.861 in the fourth osteocalcin quartile compared with the lowest (p = 0.046). Multiple stepwise regression revealed that each standard deviation (SD) increase of serum osteocalcin levels resulted in an increase of 0.131 SD in SMI (p = 0.024). CONCLUSION: Serum osteocalcin levels were positively related to SMI in men with hyperglycaemia, especially in those with isolated impaired glucose tolerance. No association was detected between serum osteocalcin levels and SMI in postmenopausal women.

Traceability to a primary reference measurement procedure (ID-LCMS); A key step in validating the clinical accuracy and safety of hospital blood glucose monitoring systems.

OBJECTIVE: A key step in the evaluation of the accuracy of blood glucose monitoring systems (BGMS) is using a comparator method aligned to a high order definitive reference method. We describe how we achieved traceability to an isotope dilution liquid chromatography mass spectrometry (ID-LCMS) method. We used ID-LCMS to evaluate the accuracy and specificity of two hospital BGMS used in China. METHOD: ID-LCMS was used to verify the calibration alignment of the laboratory plasma hexokinase reference method using NIST standard reference material and clinical samples. The ID-LCMS aligned hexokinase method was used to evaluate the clinical accuracy of two BGMS in hospitalized patients. System accuracy was evaluated using Chinese consensus guidelines. BGMS accuracy was also assessed with interference factors known to be present in critically ill patients' blood. RESULTS: The laboratory plasma hexokinase reference method was shown to calibrate closely with ID-LCMS. Two BGMS demonstrated good correlation with this reference method. Only one BGMS met the Chinese guidelines. The interference factors didn't influence this BGMS but adversely affected the clinical accuracy of the other. CONCLUSIONS: We advocate that our IDMS calibration alignment approach for ensuring the accuracy of the glucose reference method should be adopted in evaluations assessing the accuracy of blood glucose monitoring systems.

Verification of a novel point-of-care HbA1c device in real world clinical practice by comparison to three high performance liquid chromatography instruments.

INTRODUCTION: A real world clinical study was designed and conducted to evaluate the performance of a novel point-of-care device for determination of glycated haemoglobin A1c (HbA1c), A1C EZ 2.0, in daily clinical practice. MATERIALS AND METHODS: Five hundred and fourteen subjects were included in this study, and divided into three groups. HbA1c was measured by A1C EZ 2.0 and three different high performance liquid chromatography (HPLC) devices: Bio-Rad Variant II Turbo, Tosoh HLC-723 G8 and Premier Hb9210 separately. Precision of A1C EZ 2.0 was also evaluated. RESULTS: Results obtained from A1C EZ 2.0 and all HPLC devices are correlated. Passing-Bablok regression analysis shows the equation of A1C EZ 2.0 results against the mean of HPLC devices with corresponding 95% confidence intervals (95% CI) for the intercept and slope is y = 0.10 (- 0.17 to 0.10) + 1.00 (1.00 to 1.04) x. Bland-Altman difference plot shows that the mean relative difference between A1C EZ 2.0 and Variant II Turbo, G8, Hb9210 and all HPLC results is 2.5%, 0.6%, 0.4% and 1.1%, respectively. In addition, 121 pairs of results determined by using both venous and capillary blood prove that the difference of two kinds of blood sample causes no notable variation when measured by A1C EZ 2.0. Precision study gives 2.3% and 1.9% of total coefficient of variation for normal and abnormal HbA1c sample in A1C EZ 2.0. CONCLUSIONS: HbA1c values measured by A1C EZ 2.0 were in good accordance with the results obtained with the reference HPLC devices.

Serum osteocalcin levels in relation to metabolic syndrome in Chinese postmenopausal women.

OBJECTIVE: It has been revealed that osteocalcin is a regulator of energy metabolism. We investigated the relationship between serum osteocalcin levels and metabolic syndrome (MetS) in Chinese postmenopausal women. METHODS: A total of 1,789 postmenopausal women, aged 41 to 78 years, were selected from four communities in Shanghai, China. Serum levels of osteocalcin were measured with an electrochemiluminescence immunoassay. The diagnostic definition of MetS followed the 2007 Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. RESULTS: Serum osteocalcin levels were significantly lower in participants with MetS than in non-MetS participants (median [interquartile range], 18.51 [15.52-23.46] vs. 21.09 [16.98-26.26] ng/mL, P < 0.01). The frequency of MetS and its components decreased with increasing increments of serum osteocalcin levels (all P for trend < 0.05), with the exception of the frequency of low levels of high-density lipoprotein cholesterol. Serum osteocalcin levels significantly decreased with increasing number of metabolic disorders (P for trend < 0.01). Furthermore, binary logistic regression analysis revealed that participants with higher serum osteocalcin levels had lower odds ratios (ORs) for MetS (OR, 0.123; 95% CI, 0.053-0.283), central obesity (OR, 0.134; 95% CI, 0.060-0.299), and hyperglycemia (OR, 0.142; 95% CI, 0.066-0.302). CONCLUSIONS: Serum osteocalcin levels are negatively associated with MetS, particularly central obesity and hyperglycemia, in Chinese postmenopausal women.