# Muscular Strength and Mortality in Women Aged 63 to 99 Years

## TL;DR

Stronger muscles in older women are linked to longer life, even after considering physical activity and other aging factors.

## Contribution

The study shows that muscular strength independently predicts mortality in older women beyond traditional activity and health markers.

## Key findings

- Higher grip strength and faster chair stands were associated with significantly lower mortality risk.
- Muscle strength remained a strong predictor of mortality even in women not meeting activity guidelines.
- Associations held across subgroups like age, race, and physical activity levels.

## Abstract

This cohort study evaluates associations between muscular strength and mortality in women aged 63 to 99 years accounting for accelerometer-measured physical activity and sedentary behavior, systemic inflammation, and other markers of aging.

Is muscular strength associated with mortality in older women after controlling for aerobic activity, sedentary time, and fitness level?

In this cohort study of 5472 women aged 63 to 99 years, 2 common strength tests were associated with significantly lower mortality risk after controlling for sociodemographic and clinical characteristics, accelerometer-measured physical activity and sedentary behavior, and timed walk. Muscle strength was associated with lower mortality even in women not meeting guideline-recommended activity levels.

These findings suggest that strength can be easily assessed in the clinical setting, and promoting its maintenance could play a key role in optimal aging.

Muscular strength is an important resilience marker relevant to maintaining functional independence and longevity.

To examine associations between muscular strength and mortality in women aged 63 to 99 years accounting for accelerometer-measured physical activity and sedentary behavior, systemic inflammation, and other markers of aging.

The Objective Physical Activity and Cardiovascular Health study was a prospective cohort study from baseline (March 2012 to April 2014) through February 19, 2023. Participants were ambulatory women aged 63 to 99 years who completed physical performance testing and 7 days of accelerometer wear.

Dominant hand grip strength,measured in kg by quartile (1: <14, 2: 14-19, 3: 19-24, and 4: >24) and time in seconds to complete 5 unassisted chair stands by quartile (standard criteria: 1: >16.7, 2: 16.6-13.7, 3: 13.6-11.2, and 4: ≤11.1).

All-cause mortality.

The present study included 5472 women (mean [SD] age, 78.7 [6.7] years; 1851 [33.8%] Black; 915 [16.7%] Hispanic/Latina; 2706 [49.5%] White) followed up for a mean (SD) of 8.4 (2.4) years. There were 1964 deaths during the study period. Controlling for age and sociodemographic, lifestyle, and clinical factors, significant inverse trends in mortality were evident across quartiles 2 through 4 of grip strength (quartile 2: hazard ratio [HR], 0.94; 95% CI, 0.85-1.06; quartile 3: HR, 0.85; 95% CI, 0.75-0.97; quartile 4: HR, 0.67; 95% CI, 0.58-0.78; P for trend < .001) and chair stand time (quartile 2: HR, 0.79; 95% CI, 0.69-0.88; quartile 3: HR, 0.76; 95% CI, 0.67-0.87; quartile 4: HR, 0.63; 95% CI, 0.54-0.73; P for trend < .001). Further controlling simultaneously for sedentary time and moderate to vigorous physical activity attenuated associations (grip strength: quartile 2: HR, 0.95; 95% CI, 0.86-1.07; quartile 3: HR, 0.87; 95% CI, 0.76-0.99; quartile 4: HR, 0.70; 95% CI, 0.61-0.82; P for trend < .001; chair stands: quartile 2: HR, 0.82; 95% CI, 0.73-0.92; quartile 3: HR, 0.82; 95% CI, 0.71-0.93; quartile 4: HR, 0.69; 95% CI, 0.59-0.79; P for trend < .001). Similar inverse associations were observed when controlling for walking speed and the inflammatory marker C-reactive protein. Magnitudes of association did not differ across subgroups defined by age, race and ethnicity, body mass index, moderate-to-vigorous physical activity, sedentary time, or timed walk.

In this study of ambulatory older women, greater muscular strength was associated with lower mortality even when controlling for accelerometer-measured PA and sedentary time, walking speed, and systemic inflammation. These findings suggest that assessing strength and promoting its maintenance are instrumental for optimal aging.