Hyperinsulinemia in nonobese women reporting a moderate weight gain at the beginning of menopause: a useful early measure of susceptibility to insulin resistance.

OBJECTIVE: At menopause, the frequent weight gain excess could be related to insulin resistance. This study evaluated the prevalence of hyperinsulinemia in nonobese women reporting a moderate increase in weight at the beginning of menopause.
METHODS: Women who were postmenopausal for 1 to 5 years and reporting a weight gain of 5 to 15 kg were evaluated for weight, eating habits, physical activity, body circumferences, fasting blood glucose level, insulin level, and lipid profile. An oral glucose tolerance test was performed in subgroups of 21 hyperinsulinemic women and 21 normoinsulinemic women matched for age, weight, height, body mass index, and hysterectomy.
RESULTS: Among 279 postmenopausal women reporting a weight gain of 8.7 +/- 4.4 kg, insulin level was increased in 49 (17.6%) women as compared with normoinsulinemic women (108.53 +/- 31.35 vs 58.96 +/- 14.52 pmol/L, respectively; P < 0.001). Differences were also found for glucose (5.24 +/- 0.37 vs 5.05 +/- 0.42 mmol/L, respectively; P = 0.003), insulin resistance as estimated by homeostasis model assessment HOMA-2-IR (2.01 +/- 0.53 vs 1.10 +/- 0.27, respectively; P < 0.001), weight (72.6 +/- 8.0 vs 69.9 +/- 7.1 kg, respectively; P = 0.023), body mass index (28.3 +/- 2.3 vs 27.2 +/- 2.3 kg/m2, respectively; P = 0.003), and waist circumference (89.8 +/- 5.8 vs 86.0 +/- 6.5 cm, respectively; P < 0.001). Triglyceride levels were higher (1.47 +/- 0.66 vs 1.17 +/- 0.61 mmol/L, respectively; P = 0.002) and high-density lipoprotein cholesterol level was lower (1.54 +/- 0.35 vs 1.72 +/- 0.42 mmol/L, respectively; P = 0.007) in the hyperinsulinemic and normoinsulinemic groups. Although insulin levels were higher in 21 hyperinsulinemic women at all times that oral glucose tolerance tests were performed, levels of glucose were also above those of 21 matched normoinsulinemic women at 1 and 2 hours and remained greater than 6.0 mmol/L at 2 hours.
CONCLUSIONS: Because insulin resistance is frequently associated with weight gain in nonobese women at menopause, the measurement of fasting insulin, along with glucose, lipids, and waist circumference, may help to identify those who are at higher risk of developing glucose intolerance, metabolic syndrome, diabetes, and cardiovascular diseases and to implement early preventive measures.