The association between obesity and the frailty syndrome in older women: the Women's Health and Aging Studies.

OBJECTIVES: To determine whether obesity is associated with the frailty phenotype and, if so, whether comorbid conditions or inflammatory markers explain this association.

DESIGN: Cross-sectional analysis of baseline data from the Women's Health and Aging Studies I (1992) and II (1994), complementary population-based studies.

SETTING: Twelve contiguous ZIP code areas in Baltimore, Maryland.

PARTICIPANTS: Five hundred ninety-nine community-dwelling women aged 70 to 79 with a body mass index (BMI) greater than 18.5 kg/m(2).

MEASUREMENTS: The dependent variables were the frailty syndrome, including prefrailty, defined as presence of one or two of five frailty indicators (weakness, slowness, weight loss, low physical activity, exhaustion), and frailty, defined as three or more indicators. Independent variables included BMI, categorized using World Health Organization criteria as normal (18.5 to <25 kg/m(2)), overweight (25 to <30 kg/m(2)), and obese (>/=30 kg/m(2)); chronic diseases; C-reactive protein; and serum carotenoids.

RESULTS: Being overweight was significantly associated with prefrailty, and obesity was associated with prefrailty and frailty. In all frail women, regardless of BMI group, a similar pattern of three defining frailty indicators was found: slowness, weakness, and low activity (with the addition of weight loss in the normal weight group.) In multinomial regression models, obesity was significantly associated with prefrailty (odds ratio (OR)=2.23, 95% confidence interval (CI)=1.29-3.84) and frailty (OR=3.52, 95% CI=1.34-9.13), even when controlling for covariates.

CONCLUSION: Obesity is associated with the frailty syndrome in older women in cross-sectional data. This association remains significant even when multiple conditions associated with frailty are considered. Prospective studies are needed to confirm this finding.