Disability in obese elderly women: Lower limb strength and recreational physical activity

Disability in the obese may be a consequence of low muscle strength and inactivity.

We compared isometric knee extensor strength (KES) between obese (body mass index, BMI >29 kg/m(2)), normal (BMI [24-29]) and lean (BMI < 24) elderly and its association with disability. Then, we investigated the risk of disability in obese, normal, and lean participants according to their physical activity.

215 obese (80.0 ± 3.5 y, BMI 31.9 ± 2.6), 630 normal (80.2 ± 3.7 y, BMI 26.3 ± 1.4) and 598 lean (80.7 ± 4.1 y, BMI 21.6 ± 1.8) women with good functional ability were studied. A cross-sectional design was used. Anthropometric measures, KES (statometers), health status, self-reported difficulties for physical function, disability (Instrumental and Basic Activity of Daily Living), and recreational physical activities (RPA; walking, gymnastics, cycling, swimming, and gardening) were obtained.

KES was negatively and significantly associated with disability and functional difficulties. When KES was adjusted for age, RPA, pain, depression, visual impairment, steroid treatment, comorbidity, osteoporosis and, weight, an interaction effect between the BMI groups and RPA (p = 0.01) was found. KES significantly decreased in the sedentary women with increasing BMI but was not significantly different in active (≥1 h/week in ≥1 RPA for ≥1 month) women. Association between KES and self-reported difficulties for physical function was significantly lower in the active compared to the sedentary women and was not significantly higher in the active obese women.

Low KES is associated with disability and difficulties for physical function in elderly women. The higher level of KES in participants engaged in RPA may prevent disability related to obesity.