Clinical Context

The body changes as we move into older age, and a review by Gaddey and Holder examined some of the causes and consequences of weight loss among older adults. Their work was published in the July 2021 issue of American Family Physician.^[1]

Weight loss among older adults is not due to changes in appetite or psychosocial reasons alone, although these are important points of pathology for many senior citizens. Inflammatory biomarkers are elevated among adults with weight loss, suggesting another pathological mechanism.

The result is a loss of lean body mass, which is normal among adults. Lean body mass can start declining by an average of 0.3 kg/y even between the ages of 20 and 30 years. Meanwhile, fat mass generally increases until age 65 to 70 years. Therefore, body weight rarely increases substantially after age 60 years.

Nonetheless, these changes alone should not result in an unintentional body weight loss in excess of 5% over 12 months, at which time a workup for a secondary cause of weight loss should be investigated. Weight loss and cachexia have been associated with negative health outcomes among older adults, and the current study by Hussain and colleagues uses a large cohort to assess the effects of weight changes on mortality among older adults.

Study Synopsis and Perspective

Weight loss in otherwise healthy older adults is linked to an increased risk for mortality, even from conditions not typically associated with weight change, with a substantially stronger link in men vs women, suggesting the need for clinicians to be alert to such changes.

"Our study emphasizes the importance of weight loss even in relatively healthy individuals who are free from evident cardiovascular disease (CVD), dementia, physical disability, or life-limiting chronic illness," first author Monira Hussain, MBBS, MPH, PhD, told Medscape Medical News.

"Clinicians should be aware that even minor weight loss of 5% or more in older adults without life-limiting illnesses can increase mortality risk," Hussain said. "Regular monitoring of weight changes can help early identification of associated risks."

The study was published April 3 in JAMA Network Open.^[2]

The researchers noted that data on the significance of weight changes among older individuals who are otherwise relatively healthy and not diagnosed with life-limited diseases are limited, with the exception that "it is widely acknowledged that weight loss may precede a diagnosis of cancer," they said.

Still, the association with the other types of non--cancer-related premature death is notable.

"In our study, weight loss also preceded an increased mortality from CVD and other causes, [such as] deaths from trauma, dementia, Parkinson disease, and other less common causes," the authors continued.

Therefore, "a likely explanation for these findings is that weight loss can be an early prodromal indicator of the presence of various life-shortening diseases," wrote Hussain, of the School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia, and colleagues.

In terms of why weight loss shows such a stronger link to mortality in older men compared with women, Hussain speculated that this may be due to "differences in body composition" between the two sexes.

"Men have a higher proportion of muscle and bone mass, and weight loss [in men] primarily involves loss of these tissues," she observed.

To investigate this phenomenon, the researchers conducted a post hoc analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) randomized trial, which included information on a variety of body size parameters, such as weight and waist circumference, measured annually, from a large population of healthy individuals with no evident CVD, dementia, physical disability, or life-limiting chronic illness.

The 16,523 participants included in the study had a mean age of 75 ± 4.3 years, and 55.6% were women. During a mean follow-up of 4.4 ± 1.7 years, 1256 deaths occurred in the cohort.

Looking at rates of all-cause mortality, stratified by gender, the results showed that among men who had a 5% to 10% decrease in weight over the course of the study, the risk for all-cause mortality was 33% higher than among men who had a stable weight (< 5% change; hazard ratio [HR] 1.33).

Among men who had a more than 10% decrease in weight, the mortality risk was as much as 289%, or nearly 4 times higher compared with men with a stable weight (HR 3.89).

For women, the mortality risk was also increased, however, to a lesser degree. A 5% to 10% loss of body weight was associated with a 26% increased mortality risk (HR 1.26), and a loss of more than 10% was linked to a 114% increased risk for all-cause mortality (HR 2.14).

In terms of cancer-specific deaths, the risk was significantly increased only among men who had a greater than 10% weight decrease (HR 3.49), whereas the increased risk in women was observed with a 5% to 10% decrease in weight (HR 1.44) as well as a more than 10% decrease (HR 2.78).

The risk for CVD-specific death was significantly increased with a more than 10% decrease in weight in both sexes, but the risk was again higher among men (HR 3.14) than among women (HR 1.92) compared with stable weight groups.

And the non-cancer, non--CVD-specific mortality risk was nearly 5 times higher among men who had a more than 10% decrease in weight vs stable weight (HR 4.98); however, the association was not significant among women (HR 1.49).

Looking at the effects of change in waist circumference, a decrease of more than 10% was associated with a higher risk in all-cause mortality that was again higher for men (HR 2.14) vs women (HR 1.34); however, no link with all-cause mortality was observed with a less than 10% decrease in either sex.

A greater than 10% decrease in waist circumference was also associated with higher risk for cancer death for men and women, and higher non-cancer, non-CVD death among men, but not women, whereas there was no association between waist circumference and CVD mortality in men or women.

The results persisted after adjustment for age, frailty status, baseline body mass index (BMI), country of birth, smoking, hypertension, diabetes, and hospitalization in the previous 24 months.

The adjustment for recent hospitalization was especially important for ruling out weight loss that may have occurred due to hospitalization for acute conditions that could have contributed to mortality, the authors noted.

The authors have reported no relevant financial relationships.

Implications for the Healthcare Team

• Lean body mass can start declining by an average of 0.3 kg/y even between the ages of 20 and 30 years. Meanwhile, fat mass generally increases until age 65 to 70 years. Therefore, body weight rarely increases substantially after age 60 years.
• In the current study by Hassain and colleagues, weight loss among older adults was significantly associated with higher risks for overall, cancer-related, and CV mortality. This effect was more profound among men compared with women, and weight gain did not confer a similar higher risk for mortality. Reductions in waist circumference beyond 10% were also associated with a higher risk for mortality.
• The healthcare team should monitor body weight in older adults and investigate cases of unintentional weight loss.

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