Associations of Change in Body Size With All-Cause and Cause-Specific Mortality Among Healthy Older Adults

Published in JAMA Network Open on the 10^th of April, 2023, this study investigated the correlation between weight loss in a healthy older population and an increase in their all-cause mortality risk.

While weight loss's benefits for reducing risk have been well documented, very little research exists to determine whether weight loss, other than that associated with dread diseases such as cancer, was an indicator of future mortality risk.
 
Design, Setting and Measurements

 The cohort study analyzed data from 16 523 healthy participants who had taken part in the Aspirin in Reducing Events in the Elderly (ASPREE) randomized clinical trial and who had been recruited between March 1, 2010, and December 31, 2014. The participants had no evidence of CVD, dementia, physical disability, or life-limiting chronic illness at the time of the ASPREE trial collation.
 
Of the 16, 523 participants:

• 16 792 were Australian, aged 79 years and older
• 2 411 were from the US, aged 65 years and older
• The mean age of the group was 75 years [SD 4.3] years, and 55.6% (9193) participants were women

• Stable: within 5%
• Decrease by 5-10%
• Decrease by 10% or more.
• Increase by 5-10%
• Increase by 10% or more

The participant's data was measured at baseline and a second annual visit, and they were followed up for an average of 4.4 years.
 
The outcomes under consideration were all-cause mortality and cancer-specific, CVD-specific, and noncancer non-CVD–specific mortality
 
Findings

The findings of this study were significant. Of the 16 523 participants, 1256 died during the 4.4 years under review, most within 1.7 years of review.

In terms of risk, when compared to participants considered as stable ( 5% or less reduction in weight or waist circumference):
 

• Among the male participants, those with a "...5% to 10% weight loss had a 33% higher risk of all-cause mortality, and those with more than a 10% decrease in body weight had a 289% higher risk." 
• Among women, "...a loss of 5% to 10% of body weight and loss of more than 10% of body weight was associated with a 26% and 114% increase in mortality, respectively."

They further found that regardless of the individual's baseline weight, for example, those considered clinically obese, unanticipated weight loss was still related to increased mortality.

The researchers posit that the startling increase in mortality risk among men may be related to the different body compositions of men. Specifically, male body mass comprises muscle and bone compared to women, where body mass is more likely to have a higher fatty component. Furthermore, they note that weight loss in this age group is most frequently attributed to appetite loss and that it most often accompanies chronic illness.
 
Conclusion

The clinical implication of the findings of this cohort study is that physicians should be aware of the significant association with mortality of even relatively minor weight loss (≥5%), especially among older men.

Hussain SM, Newman AB, Beilin LJ, et al. Associations of Change in Body Size With All-Cause and Cause-Specific Mortality Among Healthy Older Adults. JAMA Netw Open. 2023;6(4):e237482. doi:10.1001/jamanetworkopen.2023.7482  (Accessed 19 April 2023) 

Contributor: Linda Ravenhill
Linda Ravenhill is a medical professional with an MA in Journalism. She has worked in the medical, technology and digital development spaces for over 25 years, & has a particular interest in the impact of technology on the delivery of healthcare in the Sub-Saharan Africa region.