A recent study published in Scientific Reports investigated the associations between sleep quality and health parameters in older adults with obesity.
Study: Sleep quality is a predictor of muscle mass, strength, quality of life, anxiety and depression in older adults with obesity. Image Credit: GroundPicture/Shutterstock.com
Background
The prevalence of obesity among older individuals has been increasing worldwide. Obesity may influence physiological processes and physical or mental health during aging. Further, the adverse aging effects on sleep disorders may be aggravated by obesity. Sleep has been recognized as a crucial determinant of well-being and health.
Sleep impairments are prevalent in older populations. Evidence suggests sleep deprivation can induce a pro-catabolic environment and anabolic resistance.
As such, low sleep quality may worsen anabolic resistance observed in older people, especially those with obesity, contributing to muscle weakness, body composition disturbances, and low quality of life.
About the study
In the present study, researchers explored the associations of sleep quality with muscle strength, quality of life, depression, anxiety, and body composition of older adults with obesity. This cross-sectional study was conducted from June 2021 to July 2022 in Sao Paulo, Brazil. Adults aged 65 or older with obesity were recruited through social media advertisements.
Sleep quality was assessed using the Pittsburgh sleep quality index (PSQI), which evaluates sleep quality over a month through a questionnaire. Participants were stratified as good and poor sleepers based on PSQI scores; lower PSQI scores reflect good sleep quality.
Body weight and height were determined from which body mass index (BMI) was derived. Participants underwent dual-energy X-ray absorptiometry for fat or lean mass quantification.
Appendicular lean mass (ALM) was estimated, and handgrip strength was assessed. The short-form health survey (SF36) was administered to examine health-related quality of life. Lower scores on SF36 indicate a worse condition.
The Geriatric Anxiety Index (GAI) and Depression Scale (GDS) were used to evaluate anxiety and depression, respectively.
Differences between poor and good sleepers were tested using independent t-tests. Linear regression models were built to verify associations of sleep quality with outcomes, such as quality of life, handgrip strength, and ALM.
One model was adjusted for sex and age, and the other was additionally adjusted for BMI and comorbidities (pulmonary diseases, hypertension, psychiatric diseases, type 2 diabetes, and rheumatic disease).
Findings
The study comprised 95 participants, including 46 good and 49 poor sleepers. The mean PSQI of good sleepers was 3.54 compared to 8.86 for poor sleepers. Poor sleepers had lower ALM, ALM-to-BMI ratio, and handgrip strength-to-BMI ratio than good sleepers. Besides, poor sleepers exhibited higher relative fat mass than good sleepers.
SF36 revealed lower scores on mental and physical domains in poor sleepers than in good sleepers. Poor sleepers also had lower scores on SF36 sub-scales such as general health, mental health, vitality, and body pain than good sleepers. The social and physical function and role-emotional aspects did not differ between the two groups.
Furthermore, poor sleepers had higher depression and anxiety than good sleepers. Crude models revealed an inverse relationship between sleep quality with quality of life for physical and mental domains, ALM-to-BMI ratio, anxiety, and depression.
These associations were significant even after adjusting for covariates. However, there were no significant associations between sleep quality and handgrip strength.
Conclusions
In sum, the researchers evaluated how sleep quality impacts muscle strength, body composition, depression, quality of life, and anxiety in older people with obesity. Participants with poor sleep had lower relative and absolute ALM and handgrip strength but a higher body fat percentage than good sleepers.
Further, poor sleepers had lower scores on depression, anxiety, and mental or physical health than good sleepers. The linear regression models showed poor sleep quality was associated with lower ALM, poor mental or physical health, and higher depression and anxiety.
The study’s limitations include the low sample size, inability to objectively assess sleep quality or disorders, and lack of controls.
Taken together, the findings link poor sleep quality to higher anxiety and depression, poor quality of life, and lower ALM and handgrip strength in older individuals with obesity, warranting further analyses to explore potential strategies for sleep quality improvements to prevent poor outcomes in this subset of the population.
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