Summary
Insulin sensitivity is impaired in overweight subjects with IGT and is accompanied
by hyperinsulinemia, a condition, that might promote early B-cell exhaustion. Twelve
subjects were recruited for a double-blind trial using either 100 mg of acarbose or
placebo for three months. Insulin sensitivity was measured by hyperglycémie clamp
and with the minimal model. Baseline characteristics such as body weight, BMI, blood
glucose, HB-Alc and serum lipids did not change throughout the study period. The steady
state glucose infusion rate (SSGIR) improved significantly following acarbose. The
insulin sensitivity as measured by clamp (MI) or minimal model, (SI), however, increased
only descriptively (p = 0.08).The fasting proinsulin was raised in all subjects during
pretreatment. Following acarbose, the proinsulin dropped from 20.3 ± 12.9 to 13.6
± 7.1 ng/ml, but remained unchanged in the placebo group. Due to the high variability
of values and the low number of subjects in this study, differences were only descriptive
and did not reach significance (p = 0.08). The proinsulin/insulin ratio, however,
significantly decreased after 3 months of acarbose treatment.
Acarbose might therefore be considered recommendable for the protection of the B-cell
function and for delaying the transition of IGT to overt NIDDM.
Key words
Impaired glucose tolerance - insulin resistance - hyper-insulinemia - proinsulin -
acarbose
