Body weight dynamics and their association with physical function and mortality in older adults: the Cardiovascular Health Study

Abstract

Background: To estimate the associations of weight dynamics with physical functioning and mortality in older adults.

Methods: Longitudinal cohort study using prospectively collected data on weight, physical function, and health status in four U.S. Communities in the Cardiovascular Health Study. Included were 3,278 participants (2,013 women and 541 African Americans), aged 65 or older at enrollment, who had at least five weight measurements. Weight was measured at annual clinic visits between 1992 and 1999, and summary measures of mean weight, coefficient of variation, average annual weight change, and episodes of loss and gain (cycling) were calculated. Participants were followed from 1999 to 2006 for activities of daily living (ADL) difficulty, incident mobility limitations, and mortality.

Results: Higher mean weight, weight variability, and weight cycling increased the risk of new onset of ADL difficulties and mobility limitations. After adjustment for risk factors, the hazard ratio (95% confidence interval) for weight cycling for incident ADL impairment was 1.28 (1.12, 1.47), similar to that for several comorbidities in our model, including cancer and diabetes. Lower weight, weight loss, higher variability, and weight cycling were all risk factors for mortality, after adjustment for demographic risk factors, height, self-report health status, and comorbidities.

Conclusions: Variations in weight are important indicators of future physical limitations and mortality in the elderly and may reflect difficulties in maintaining homeostasis throughout older ages. Monitoring the weight of an older person for fluctuations or episodes of both loss and gain is an important aspect of geriatric care.

Figure 1.

Illustration of four weight measures. Points = observed weights; solid line = regression of weight on study year; dotted line = mean weight; squared distance from points to dotted line are components of the standard deviation, the numerator of the coefficient of variation. Top figure includes weight cycling; bottom figure does not.

Figure 2.

Hazard ratios (95% confidence intervals) for weight measures and comorbidities from multivariable models. (A) Incident activities of daily living (ADL) difficulty. (B) Incident mobility difficulty. (C) Mortality. CHF = congestive heart failure; CV = coefficient of variation; lbs = pounds. *32 lbs = 1 standard deviation. Also adjusted for age, sex, race, height and high school education.