Are there sex differences in the influence of insomnia symptoms and sleep duration on the trajectory of neuromuscular strength decline?
A new longitudinal analysis of more than 6,400 older adults reveals that poor sleep does not weaken muscles equally in men and women, insomnia accelerates strength loss in men, while sleeping too long does the same in women.
Lead
Sleep problems are known to harm physical function in aging, but whether those harms affect men and women differently has been unclear. A study published July 2 in Age and Ageing now provides some of the clearest evidence yet that the relationship between sleep and muscle strength is sex-specific.
Researchers analyzed 8 years of data from the English Longitudinal Study of Ageing (ELSA), tracking grip strength, a standard measure of neuromuscular strength (NMS), in 6,429 adults aged 50 and older. They found that men who reported more insomnia symptoms lost grip strength significantly faster than those who slept well, while women who slept 9 hours or more per night experienced accelerated decline. The patterns did not cross over: insomnia did not significantly affect women’s strength trajectories, and long sleep did not significantly affect men’s.
What they found
The study, led by Leticia Coelho Silveira of the Federal University of São Carlos in Brazil, stratified all analyses by sex and adjusted for a broad set of sociodemographic, behavioral, clinical, and anthropometric confounders.
Men: insomnia drives faster decline
Among men, each additional reported insomnia symptom was associated with an extra 0.02 kg per year in grip strength loss (95% CI: -0.04 to -0.01). While that figure may appear modest in isolation, it represents a meaningful acceleration when projected over a decade or more of aging. The effect was independent of sleep duration, body composition, chronic conditions, and lifestyle factors such as physical activity and smoking.
Women: long sleep, not insomnia, is the risk factor
In women, the picture was different. Insomnia symptoms showed no statistically significant association with strength decline. Instead, women who reported sleeping 9 hours or more per night lost grip strength at a rate 0.14 kg per year faster than women who slept between 6 and 9 hours (95% CI: -0.26 to -0.03). Short sleep (6 hours or fewer) did not show a significant effect in either sex.
The researchers assessed insomnia using an adapted version of the Jenkins Sleep Problems Questionnaire and categorized sleep duration into three groups: short (6 hours or fewer), ideal (more than 6 to fewer than 9), and long (9 hours or more). Grip strength was measured with a hand dynamometer at multiple waves over the 8-year follow-up, with participants required to have a baseline strength of at least 27 kg (men) or 16 kg (women) to ensure a floor effect did not drive the results.
Why it matters
Age-related loss of muscle strength is a major contributor to frailty, falls, loss of independence, and mortality in older adults. Identifying modifiable risk factors that can be targeted differently by sex could lead to more personalized prevention strategies.
The findings suggest that screening and intervention guidelines for sleep-related physical decline may need to be sex-aware. In clinical practice, a man reporting worsening insomnia may warrant closer monitoring of physical function, while a woman who habitually sleeps 9 hours or more, particularly if that represents a change from her usual pattern, may be at elevated risk for accelerated strength loss, even if she does not report insomnia symptoms.
The study also adds to a growing body of evidence that sleep health is not a one-size-fits-all construct. Duration, quality, and sex all interact in ways that simple guidelines about “getting 8 hours” do not capture.
Limits
The observational design means causality cannot be firmly established. Residual confounding is possible despite extensive adjustment. Sleep duration was self-reported rather than measured objectively with actigraphy or polysomnography, which may introduce misclassification, particularly at the extremes. The ELSA cohort is predominantly white and British, so generalizability to other populations is uncertain. Grip strength, while a validated proxy for overall neuromuscular strength, does not capture lower-body function, which is also critical for mobility and fall risk.
Bottom line
Sleep problems affect neuromuscular aging differently in men and women. In men, the key driver is insomnia symptoms; in women, it is long sleep duration. Clinicians and researchers should consider sex when evaluating sleep as a risk factor for strength decline in older adults.
Source
Silveira LC, de Maio Nascimento M, de Campos Fonseca Goncalves CG, et al. Are there sex differences in the influence of insomnia symptoms and sleep duration on the trajectory of neuromuscular strength decline? Age and Ageing. 2026;55(7):afag201. doi:10.1093/ageing/afag201. PMID: 42407094.