Serum osteoglycin is stable during various glycemic challenges in healthy men

PURPOSE: Osteoglycin is hypothesized to be metabolically active and may enhance insulin action. We hypothesized that osteoglycin levels increase during hyperglycemia as a physiological response to enhance the effects of insulin.

METHODS: Eight healthy males were included in a cross-over study consisting of three study days following an 8 h fast. First, we performed an oral glucose tolerance test (OGTT); second, an isoglycemic intravenous glucose infusion (IIGI); and third, a control period consisting of a three hour fast. We analyzed blood samples for circulating osteoglycin levels during the study days. Repeated measures ANOVA was performed to compare levels of s-osteoglycin between OGTT, IIGI, and the fasting control.

RESULTS: There were no differences in baseline osteoglycin levels among study days (p > 0.05). We observed no significant changes neither in absolute s-osteoglycin levels by time (p = 0.14) nor over time by study day (p = 0.99). Likewise, we observed no significant changes in percentage s-osteoglycin levels neither by time (p = 0.11) nor over time by study day (p = 0.89).

CONCLUSION: We found that s-osteoglycin levels were stable for three hours during OGTT, IIGI, and fasting in healthy males. Based on the present study, circulating s-osteoglycin levels may be measured independently of fasting or non-fasting conditions. Furthermore, circulating physiological levels of glucose and insulin did not affect s-osteoglycin levels.