Objective: To describe the effects of menopause on resting metabolic rate, body composition, fat distribution, physical activity during leisure time, and fasting insulin levels.
Design: A longitudinal comparison of metabolic changes in women who experienced menopause with changes in age-matched women who did not experience menopause.
Setting: General clinical research center.
Patients: An initial cohort of 35 sedentary healthy premenopausal women (age range, 44 to 48 years). After 6 years of follow-up, 18 women had spontaneously stopped menstruating for at least 12 months and 17 women remained premenopausal. No women received hormone replacement therapy.
Results: Women who experienced menopause lost more fat-free mass than women who remained premenopausal (-3.0 +/- 1.1 kg and -0.5 +/- 0.5 kg, respectively), had greater decreases in resting metabolic rate (-103 +/- 55 kcal/d and -8 +/- 17 kcal/d) and physical activity during leisure time (-127 +/- 79 kcal/d and 64 +/- 60 kcal/d), and had greater increases in fat mass (2.5 +/- 2 kg and 1.0 +/- 1.5 kg), fasting insulin levels (11 +/- 9 pmol/L and -2 +/- 5 pmol/L), and waist-to-hip ratios (0.04 +/- 0.01 and 0.01 +/- 0.01) (P < or = 0.01 for all comparisons). Menopause did not affect energy intake, fasting glucose levels, or peak oxygen consumption.
Conclusions: Natural menopause is associated with reduced energy expenditure during rest and physical activity, an accelerated loss of fat-free mass, and increased central adiposity and fasting insulin levels. These changes may indicate a worsening cardiovascular and metabolic risk profile.