Weight change and physical function in older women: findings from the Nun Study.

OBJECTIVE

To investigate the association between change in weight and decline in physical function in older women.

DESIGN

Longitudinal study of a defined population of Catholic sisters (nuns) whose weight and function were assessed twice, an average of 584 days apart.

SETTING

Unique life communities (convents) located throughout the United States.

PARTICIPANTS

475 Catholic sisters who were 75 to 99 years of age (M = 82.1, SD = 4.8) and were independent in at least one Activity of Daily Living (ADL) at the first assessment of weight and function.

INTERVENTIONS

None.

MEASUREMENTS

At each assessment, weight, ADLs, and cognitive function were evaluated as part of the Nun Study--a longitudinal study of aging and Alzheimer's disease. Annual percent weight change was calculated using weights from the two assessments, as well as the number of days that elapsed between assessments.

RESULTS

Mean weight at first assessment was 140 pounds (range 78 to 232, SD = 27). The mean annual percent weight change was 0.1% (range 22% loss to 16% gain, SD = 3.8). Age- and initial weight-adjusted findings indicated that those participants with an annual percent weight loss of 3% or greater had 2.7 to 3.9 times the risk of becoming dependent in each ADL, compared to the sisters with no weight change. The elevated risk persisted in those who were mentally intact or were independent in their eating habits.

CONCLUSION

Monitoring of weight may be an easy and inexpensive method of identifying older individuals at increased risk of disability.