Acarbose treatment increases serum total adiponectin levels in patients with type 2 diabetes

Adiponectin is an anti-diabetic and anti-atherogenic adipokine that serves as a major determinant of insulin sensitivity. Thiazolidine derivatives increase circulating adiponectin, particularly the high molecular weight isoform, which has been shown to well correlate with amelioration of insulin resistance by thiazolidines in diabetic patients. alpha-glucosidase inhibitors are another class of anti-diabetic agents that specifically reduce postprandial blood glucose elevations, but its effect on adiponectin is largely unknown. In the present study we investigated effect of an alpha-glucosidase inhibitor, acarbose, together with pioglitazone, the only thiazolidine derivative available in Japan, on serum concentrations of adiponectin. Seventeen patients with type 2 diabetes were treated with acarbose and sixteen with pioglitazone for three months. Treatment with acarbose and pioglitazone decreased HbA1c values by 0.49% and 0.63%, respectively. Pioglitazone, as expected, increased serum levels of total adiponectin by 2.1 fold and its high molecular weight isoform by 3.6 fold. We found that acarbose also caused a small but significant increase in serum concentrations of total adiponectin. However, in contrast to pioglitazone, no appreciable changes were observed in the levels of high molecular weight adiponectin. In conclusion, acarbose increases serum concentrations of total adiponectin without preference of the high molecular weight isoform in type 2 diabetic patients. Clinical relevance of the increased adiponectin to the acarbose effects remains to be elucidated.