Prospective association between body mass index at midlife and healthy aging among French adults.

Objective: To assess the association between midlife body mass index (BMI) and healthy aging (HA) in the French SU.VI.MAX cohort.

Methods: HA was assessed in 2007 to 2009 among 2,733 individuals, aged 45 to 60 years and free of diabetes, cardiovascular disease and cancer at baseline (1994-1995). HA was defined as not developing any major chronic disease, good physical and cognitive functioning, no limitations in instrumental activities of daily living, no depressive symptoms, no health-related limitations in social life, good overall self-perceived health, and no function-limiting pain. Associations between anthropometric indicators (measured in 1995-1996) and HA were assessed using robust-error-variance Poisson regression.

Results: After adjustment for potential confounders, BMI (continuous) was negatively associated with HA: relative risk (RR) = 0.97 (95% confidence interval = 0.96-0.99). Moreover, the detrimental role of obesity (RR  = 0.67 [0.51-0.88]) was substantially stronger than that of overweight (RR  = 0.91 [0.81-1.01]). Furthermore, while metabolically healthy individuals with overweight had a similar HA probability as metabolically healthy individuals with normal weight, metabolically unhealthy overweight individuals had a substantially lowered HA probability.

Conclusions: This study provides novel evidence that an elevated BMI at midlife may jeopardize the preservation of health during aging. Our results also highlight the importance of maintaining a healthy metabolic profile during midlife.