The effect of intentional weight loss on all-cause mortality in older adults: results of a randomized controlled weight-loss trial

Abstract

Background: Despite the reported benefits, weight loss is not always advised for older adults because some observational studies have associated weight loss with increased mortality. However, the distinction between intentional and unintentional weight loss is difficult to make in an observational context, so the effect of intentional weight loss on mortality may be clarified in the setting of a randomized controlled trial.

Objective: The objective was to determine the effect of intentional weight loss on all-cause mortality by using follow-up data from a randomized trial completed in 1995 that included a weight-loss arm.

Design: The Trial of Nonpharmacologic Intervention in the Elderly (TONE) used a 2 × 2 factorial design to determine the effect of dietary weight loss, sodium restriction, or both on blood pressure control in 585 overweight or obese older adults being treated for hypertension (mean ± SD age: 66 ± 4 y; 53% female). All-cause mortality was ascertained by using the Social Security Index and National Death Index through 2006.

Results: The mortality rate of those who were randomly assigned to the weight-loss intervention (n = 291; mean weight loss: 4.4 kg) did not differ significantly from that of those who were not randomly assigned to this group (n = 294; mean weight loss: 0.8 kg). The adjusted HR was 0.82 (95% CI: 0.55, 1.22).

Conclusions: Intentional dietary weight loss was not significantly associated with increased all-cause mortality over 12 y of follow-up in older overweight or obese adults. Additional studies are needed to confirm and extend our findings to older age groups. This trial is registered at clinicaltrials.gov as NCT00000535.

FIGURE 1.

Participation and death ascertainment in the Trial of Nonpharmacologic Intervention in the Elderly (TONE). NDI, National Death Index; SSI, Social Security Index.

FIGURE 2.

Cumulative all-cause mortality associated with randomization to dietary weight loss in the Trial of Nonpharmacologic Intervention in the Elderly (TONE). ¹Based on Cox proportional hazards regression.

FIGURE 3.

The effect of intentional weight loss on all-cause mortality over 8 y of follow-up in participants in the Trial of Nonpharmacologic Intervention in the Elderly (TONE); in the Arthritis, Diet, and Activity Promotion Trial (ADAPT); and in the studies combined. ^aAdjusted for age, sex (unless stratified), race, study site, history of cardiovascular disease (CVD), diastolic blood pressure, smoking status, and random assignment to a low-sodium intervention. ^bAdjusted for age, sex (unless stratified), history of CVD, and random assignment to exercise intervention. ^cAdjusted for age, sex (unless stratified), race, history of CVD, and study (TONE or ADAPT).