Obesity and Midlife Performance: A Cross-Sectional and Longitudinal Analysis of Women in the Menarche-To-PreMenopause Study.

BACKGROUND: The interplay between obesity and physical performance in women is poorly understood, especially before the fifties. OBJECTIVE: To assess associations between weight gain from early to mid-adulthood and midlife performance-based physical function. METHODS: 499 women from the Menarche-to-PreMenopause Study completed handgrip strength, chair rise, and standing balance tests at age 41-48. The lowest tertile was defined as the 'worse performance' group. Weight and height were self-reported across eight surveys, from ages 18-23 to 40-45, and used to determine body mass index (BMI) trajectories using group-based trajectory modelling, as well as to estimate annual weight gain percentages. Other obesity indicators included BMI, waist circumference (WC), and waist-to-hip ratio (WHR) measured cross-sectionally at age 41-48. RESULTS: Two BMI trajectories were identified: Normal-Increasing (75%) and High-Increasing (25%). The High-Increasing BMI trajectory showed approximately 40% higher prevalence of worse chair-rise and standing-balance performances compared to the Normal-Increasing group (95% CI: 9%-84%, p = 0.01; and 10%-84%, p = 0.008). Higher annual weight gain percentage showed a prevalence ratio (PR) 1.21 times higher for worse standing balance performance (95% CI: 1.06-1.38, p = 0.004). Midlife obesity (BMI ≥ 30 kg/m2), high-risk WC (≥ 80 cm) and WHR (≥ 0.8) were also associated with a higher prevalence of worse performance on the chair rise and standing balance tests, with PRs from 1.41 to 1.55. No consistent evidence was found for handgrip strength. CONCLUSIONS: Weight gain from early to mid-adulthood was associated with worse performance on the chair rise and standing balance tests in midlife, highlighting the potential of early weight-control strategies to preserve midlife performance.