Diabetes Care, Vol 19, Issue 12 1399-1403, Copyright © 1996 by American Diabetes Association
Androgen activity as a risk factor for impaired glucose tolerance in postmenopausal women
H Larsson and B Ahren
Department of Medicine, Lund University, Malmo, Sweden. hillevi.larsson@medforsk.mas.lu.se
OBJECTIVE: Low sex hormone-binding globulin (SHBG) has been proposed as a
risk factor for NIDDM development in women. Our aim was to study the
relationship between SHBG and androgen activity and glucose tolerance, as
well as insulin sensitivity, in women with impaired glucose tolerance
(IGT). RESEARCH DESIGN AND METHODS: We studied 22 women with IGT and 46
women with normal glucose tolerance (NGT) aged 57-59 years. Free
testosterone (androgen activity) was determined as the testosterone-to-SHBG
ratio. A World Health Organization 75-g oral glucose tolerance test (OGTT)
was performed, and insulin sensitivity was measured with a
euglycemic-hyperinsulinemic clamp. RESULTS: Fasting glucose (P = 0.021),
2-h blood glucose after the OGTT (P < 0.001), and fasting insulin (P =
0.009) were higher in the IGT group, while insulin sensitivity did not
differ significantly between the two groups (P = 0.065). We found that SHBG
levels were lower in the IGT group (P = 0.004), while the
testosterone-to-SHBG ratio was higher in the IGT than in the NGT group (P =
0.004). Insulin sensitivity correlated negatively with testosterone-to-SHBG
ratio in both groups. The correlation was higher in the IGT (r = -0.67, P =
0.001) than in the NGT group (r = -0.29, P = 0.047). In contrast, the 2-h
blood glucose correlated with testosterone-to-SHBG ratio in the IGT (r =
0.66, P = 0.001) but not the NGT group (r = -0.04, NS). CONCLUSIONS:
Postmenopausal women with IGT have higher androgen activity than women with
NGT, and the androgen activity correlates with the degree of glucose
intolerance in IGT. Furthermore, in women with IGT, who have a high risk of
NIDDM development, androgen activity seems to have an enhanced negative
influence on insulin sensitivity. Therefore, androgen activity appears to
be a risk factor for IGT.