Adipokine Concentrations in Nonobese Women: A Study of Reproductive Aging, Body Mass Index, and Menstrual Cycle Effects

Objective: To explore the influence of reproductive aging, body mass index (BMI), and the menstrual cycle on adiponectin (AD) and leptin concentrations. Design: Cross-sectional comparison in age- and BMI-matched nonobese volunteers with regular cycles (CO, n = 19) or in early postmenopause (EPM, n = 19), aged 40-52 years, and a young cycling group (CY, n = 2 1), aged 20-30 years. Measures: Sex steroids, fasting AD, leptin, insulin, glucose, AD/leptin (A/L) ratio, and insulin resistance (IR) by homeostasis model assessment (HOMA-IR). In ovulatory women, AD, estradiol (E-2), and progesterone were assessed weekly across the same menstrual cycle. Results: Insulin, glucose, HOMA-IR, A/L ratio, and leptin values were similar across the three study groups. AD differed, with the highest concentrations in the EPM group (CY: 13.0 +/- 0.9 mu g/ml vs. CO: 14.0 +/- 1.1 mu g/ml vs. EPM: 17.7 +/- 1.5 mu g/ml; p = .05). Values among cycling women were similar. When the cycling groups were combined into a premenopausal (PRE) group and compared to EPM women by BMI (> or <= 25 kg/m(2)), leptin concentrations were higher and A/L ratios lower in PRE and EPM overweight (OW) subgroups versus normal-weight (NW) subgroups. AD was lower in OW, cycling women and higher in the NW EPM subgroup compared to NW PRE women. In cycling women, AD did not vary across the menstrual cycle. Conclusion: Nonobese, midlife women experience minimal adverse effects from reproductive aging on insulin sensitivity and adipokine secretion. The menstrual cycle is not a key mediator of AD. Early menopause has differential, BMI-dependent effects on adipokine secretion.