Handgrip Strength, Function, and Mortality in Older Adults: A Time-varying Approach

Abstract

Purpose To determine the time-varying associations between 1) decreased handgrip strength and disabilities in each activity of daily living (ADL) function, and 2) disaggregated ADL limitations and time to mortality in older adults. Methods A United States nationally representative sample of 17,747 older adults from the Health and Retirement Study were followed up for 8 yr. Maximal handgrip strength was measured with a hand-held dynamometer. Ability to perform ADL was self-reported. Date of death was identified by the National Death Index and exit interviews. Separate covariate-adjusted hierarchical logit models were used to examine the time-varying associations between decreased handgrip strength and each ADL outcome. Distinct covariate-adjusted Cox models were used to analyze the time-varying associations between disaggregated ADL limitations and time to mortality. Results Every 5-kg decrease in handgrip strength was associated with increased odds for the following ADL limitations: 20% for eating, 14% for walking, 14% for bathing, 9% for dressing, 8% for transferring, and 6% for toileting. The presence of a bathing, walking, toileting, eating, and dressing ADL disability was associated with a 47%, 43%, 32%, 30%, and 19% higher hazard for mortality, respectively. A transferring ADL disability was not significantly associated with mortality. Conclusions Decreased handgrip strength was associated with increased odds for each ADL limitation, and in turn, most individual ADL impairments were associated with a higher hazard for mortality in older adults. These findings provide insights into the disabling process by identifying which ADL limitations are most impacted by decreased handgrip strength and the subsequent time to mortality for each ADL disability.