Serum levels of undercarboxylated osteocalcin are related to cardiovascular risk factors in patients with type 2 diabetes mellitus and healthy subjects

Abstract

Aim: To determine a potential relationship between serum undercarboxylated (ucOC) concentration and cardiovascular risk factors in type 2 diabetes (T2D) patients and healthy subjects (HS).

Methods: A cross-sectional study was conducted on 140 subjects classified into two groups, 70 with T2D and 70 HS. Medical history and physical examination with anthropometric measurements were obtained from all subjects. Body fat percentage was determined by bioelectrical impendency analysis. Serum ucOC concentration was determined by enzyme immunoassay, while serum levels of insulin and hsCRP were obtained using high sensitivity enzyme-linked immunosorbent assay. Insulin resistance was determined using the homeostasis model assessment-IR. Lipid profile [triglycerides, total cholesterol (TC), high-density lipoproteins (HDL-c), low density lipoproteins (LDL-c), very low-density lipoproteins] was determined by spectrophotometry and standard formulas when applicable.

Results: The T2D patient group showed significantly higher values of waist circumference, waist-to-hip ratio, systolic blood pressure (SBP), diastolic blood pressure (DBP), current smoking, and alcohol use when compared to the HS group (P < 0.05). We observed a significantly lower serum ucOC concentration in T2D than in HS (1.5 ± 1.4 vs 2.3 ± 1.8, P < 0.05). In the whole study population, ucOC concentration was inversely correlated with body mass index (BMI) (r = -0.236, P < 0.05), fasting plasma glucose (r = -0.283, P < 0.01) and HDL-c (r = -0.255, P < 0.05); and positively correlated with LDL-c/HDL-c ratio (r = 0.306, P < 0.05) and TC/HDL-c ratio (r = 0.284, P < 0.05). In the T2D group, serum ucOC concentration was inversely correlated with BMI (r = -0.310, P < 0.05) and body-fat percentage (r = -0.311, P < 0.05), and positively correlated with DBP (r = 0.450, P < 0.01). In HS group a positive correlation between serum levels of ucOC and SBP (r = 0.277, P < 0.05) was observed.

Conclusion: Serum ucOC is a potential marker for cardiovascular risk in Mexicans because it is related to adiposity parameters, blood pressure and lipid profile.

Keywords: Bone; Cardiovascular risk; Diabetes; Glucose metabolism; Osteocalcin.

Figure 1

Correlation between undercaboxylated osteocalcin and diastolic blood pressure by quartiles. A: ucOC serum levels by DBP quartiles in type 2 diabetes; B: DBP (mmHg) by quartiles of serum ucOC. ucOC: Undercaboxylated osteocalcin; DBP: Diastolic blood pressure.