Effects of ovarian failure and X-chromosome deletion on body composition and insulin sensitivity in young women

Abstract

Menopause is associated with increased visceral adiposity and reduced insulin sensitivity. It remains unclear whether these changes are due primarily to ovarian failure or aging. The aim of this study was to clarify the impact of ovarian failure on body composition and insulin sensitivity in young women. In a cross-sectional study, we compared main outcome measures (body mass index, body composition by dual-energy x-ray absorptiometry, and insulin sensitivity by Quantitative Insulin Sensitivity Check Index) in three groups: women with 46,XX premature ovarian failure (POF), women with premature ovarian failure associated with 45,X or Turner syndrome (TS), and normal control women (NC). Participants were enrolled in National Institutes of Health Clinical Center protocols between years 2000 and 2005. Mean body mass index (+/- SD) was lower in women with POF (n = 398): 24.3 +/- 5 kg/m versus 27.8 +/- 7 for women with TS (n = 131) and 26.6 +/- 4 for controls (n = 73) (both P < 0.001). Only 33% of women with POF were overweight or obese, compared with 56% of those with TS and 67% of NC women (P < 0.0001 for both). Despite less obesity, women with POF had lower insulin sensitivity (0.367 +/- 0.03) compared with those with TS (0.378 +/- 0.03, P = 0.003) and NC women (0.376 +/- 0.03, P = 0.04). In groups selected for similar age and body mass index, women with POF (n = 89), women with TS (n = 48), and NC women (n = 40) had similar total body and trunk adiposity. After adjustment for age and truncal adiposity, women with POF had significantly lower insulin sensitivity than women with TS (P = 0.03) and NC women (P = 0.049). In contrast to observations in middle-aged postmenopausal women, ovarian failure in young women is not associated with increased total or central adiposity. In fact, women with TS were similar to NC women, whereas women with POF were leaner. The lower insulin sensitivity observed in women with POF deserves further investigation.