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.