Low osteocalcin level is a risk factor for impaired glucose metabolism in a Chinese male population

AIMS/INTRODUCTION: This study was to assess the association between serum osteocalcin level and glucose metabolism in a Chinese male population. MATERIALS AND METHODS: We carried out a cross‐sectional study with a cohort of participants from the Fangchenggang Area Male Health and Examination Survey. The cross‐sectional study was carried out among 2,353 men, including 2,139 participants with normal glucose tolerance, 148 with impaired fasting glucose and 66 with type 2 diabetes. A subsample of 1,109 men with measurement of osteocalcin was observed in the cohort. After a 4‐year follow‐up period, 1,049 non‐diabetic and 983 participants with normal glucose tolerance who submitted the available information were enrolled in the cohort. Participants were divided into group‐H (≥23.33 ng/mL) and group‐L (<23.33 ng/mL) by osteocalcin level. RESULTS: In the cross‐sectional study, osteocalcin levels were highest in participants with normal glucose tolerance, followed by those with impaired fasting glucose and type 2 diabetes (P < 0.001). In partial correlation analysis adjusted for age, serum osteocalcin level was related to glucose level (r = −0.082, P < 0.001), insulin level (r = −0.079, P < 0.001) and insulin resistance (r = −0.065, P = 0.002). Compared with group‐H, group‐L was associated with an increased risk of type 2 diabetes (odds ratio 2.107, 95% confidence interval 1.123–3.955), impaired fasting glucose (odds ratio 2.106; 95% CI 1.528–2.902), and insulin resistance (odds ratio 1.359, 95% confidence interval 1.080–1.710) adjusted for age, education levels, cigarette smoking and lipid profiles. In the cohort study, the increased risk of impaired fasting glucose was significant in group‐L vs group‐H (3.3% vs 1.2%, P = 0.026). CONCLUSIONS: Low serum osteocalcin level was a risk factor for impaired glucose metabolism and subsequent type 2 diabetes.