Cognitive impairment and the association between frailty and functional deficits are linked to abdominal obesity in the elderly.

OBJECTIVE: To evaluate whether specific obesity phenotypes in community-dwelling elderly: (a) affect differently the relationship between frailty and functional impairment and (b) are related to cognitive impairment.

STUDY DESIGN: A post-hoc cross-sectional analysis of the last Israeli national health and nutrition survey of the elderly (≥ 65 yrs.; n = 1619).

MAIN OUTCOME MEASURES: We implemented a previously validated frailty model based on frailty-related variables that were obtained in the survey. Mild cognitive impairment was defined using the Mini-Mental State Examination (a score <24 and >17). The Katz's scale of activities of daily living was used for functional assessment. Data were clustered according to different obesity phenotypes using measured body mass index (BMI) and waist circumference (WC).

RESULTS: The link between frailty and disability was most prominent in subjects with abdominal obesity who were non-obese by BMI: compared with non-obese subjects as defined by WC and BMI, the odds ratio (OR) for functional limitations in this phenotype was 8.34 (95 % CI, 2.14-32.48) for pre-frail subjects and 69.26 (10.58-453.55) for frail subjects. The rate of cognitive impairment was 3.3 times higher (p = .023) in women who were obese by WC but not by BMI.

CONCLUSIONS: In elderly people with a large WC and BMI < 30 kg/m2 , disability is more tightly linked to frailty than for any other form of obesity. Cognitive impairment was more prominent in women with central obesity and BMI < 30 kg/m2 than in the other anthropometric phenotypes. WC should be used for early detection of individuals at risk of progression of frailty to functional incapacity.