New research, based on data from the Women’s Health Initiative, has highlighted the significant implications of unintentional weight loss on the life expectancy of older women. The study, published in The Journals of Gerontology, underscores the importance of monitoring weight changes, particularly when they are unintentional, as they can serve as indicators of underlying health issues and predictors of reduced life span among older women.
Aladdin H. Shadyab, PhD, an associate professor at the Herbert Wertheim School of Public Health and Human Longevity Science at the University of California, San Diego, emphasized the significance of these findings. He mentioned that the data support the need for close monitoring of both the amount and speed of weight loss, particularly when it occurs unintentionally, as it can signify compromised health and foreshadow a decreased life span for older women. However, it’s important to note that these findings should not affect clinical recommendations for moderate weight loss aimed at achieving health benefits.
Shadyab and his colleagues conducted a comprehensive analysis using longitudinal data from 54,437 women participating in the Women’s Health Initiative. These women had a mean age of 69.8 years, with 89.5% of them being of white ethnicity. The study examined the associations between weight changes, the intentionality of weight loss, and the probability of surviving to ages 90, 95, and 100 years. Weight measurements were taken at the study’s baseline, as well as at the 3-year and 10-year marks. Participants were categorized into three groups: those with weight loss defined as a 5% or more decrease from baseline, those with weight gain defined as a 5% or more increase from baseline, and those with stable weight defined as having less than a 5% change from baseline. Participants also reported their weight loss intentionality at the 3-year mark.
The study’s overarching findings showed that 56.3% of the women managed to survive to the age of 90 years or older. When compared to women with stable weight and after adjusting for relevant covariates, the study revealed that a 3-year weight loss of 5% or more was associated with reduced odds of survival to age 90 years (odds ratio [OR] = 0.67; 95% confidence interval [CI], 0.64-0.71), 95 years (OR = 0.65; 95% CI, 0.60-0.71), and 100 years (OR = 0.62; 95% CI, 0.49-0.78).
Interestingly, unintentional weight loss was found to be more strongly correlated with decreased odds of reaching the age of 90 years (OR = 0.83; 95% CI, 0.74-0.94) when compared to intentional weight loss (OR = 0.49; 95% CI, 0.44-0.55).
Conversely, a 3-year weight gain of 5% or more was not associated with survival to ages 90, 95, or 100 years when compared to individuals with stable weight (OR = 0.95; 95% CI, 0.9-1, 95 years [OR = 0.94; 95% CI, 0.86-1.02], 100 years [OR = 0.94; 95% CI, 0.73-1.22]).
These findings held true across women with varying weight classifications, including normal weight, overweight, and obesity.
While these results provide critical insights into the impact of unintentional weight loss on the life expectancy of older women, further studies are necessary to confirm whether similar findings apply to older men. The current study primarily focused on older women, and additional research will be required to determine the potential gender-specific differences in the relationship between weight changes and life expectancy.
