Undercarboxylated osteocalcin can predict insulin secretion ability in type 2 diabetes.

It has been reported that there is an intimate relationship between diabetes and bone metabolism including undercarboxylated osteocalcin (ucOC). In contrast, data on the relationship between ucOC and glucose metabolism are limited in type 2 diabetes. We recruited 50 Japanese patients with type 2 diabetes, and examined the association with ucOC on the insulin secretion, evaluated by both glucagon loading test and meal tolerance test. UcOC was shown to correlate positively with the change in C-peptide response in the glucagon loading test and C-peptide response after eating a meal (P = 0.025, P = 0.047). Therefore, ucOC reflects the reserve capacity of β-cell function, such as the bolus insulin secretion ability in patients with type 2 diabetes.