Serum osteocalcin level and its association with carotid atherosclerosis in patients with type 2 diabetes

We performed a cross-sectional community-based study in metropolitan area. Serum total osteocalcin was measured by radioimmunoassay in 382 men and 435 postmenopausal women. The carotid artery intima-media thickness (IMT) and carotid plaques (PLQ) were measured by B-mode ultrasound.The crude mean of serum osteocalcin concentrations were 4.52±2.43 ng/ml for men and 5.75±2.92 ng/ml for postmenopausal women (P <0.001), respectively. Osteocalcin levels were associated inversely with age, fasting serum insulin, HOMA-IR, ALT, triglycerides, total cholesterol, LDL- cholesterol, CRP (all P<0.001) and positively with adiponectin and HOMA-B (all P<0.05). After multiple adjustment, the odds ratios (ORs) were substantially higher risk for carotid plaques (OR 1.77 for 1 SD decrease in osteocalcin, 95% CI 1.23-2.76, p=0.005). These associations remained significant after further adjustment for potential confounder.Serum osteocalcin levels is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes.The increased cardiovascular risk in type 2 diabetes mellitus is reflected by atherosclerosis, which is an established predictor of coronary heart disease and stroke in older subjects [1-4]. This diabetes-associated increase in atherosclerosis is associated with conventional cardiovascular risk factors, such as central obesity, high blood pressure, and dyslipidaemia, as well as with insulin resistance [5,6].Osteocalcin is a 49-amino acid bone matrix noncollagen protein expressed mainly by osteoblasts [7]. It is a specific biochemical marker of bone turnover and bone formation involved in bone mineralization and calcium homeostasis [8]. Studies have verified that adipose tissue could regulate bone remodeling through the adipokine leptin by acting on osteoblasts [9,10]. In turn, bone modulates energy metabolism in a feedback loop. The novel function for the skeleton unraveled its importance as an endocrine organ. A bone-derived protein, osteocalcin, has raise