Associations between obesity, self-reported weakness and their combinations with mortality in nursing home residents

ABSTRACT

Objectives

There are studies on associations between obesity and mortality in nursing home (NH) residents, but the presence of concomitant muscle weakness has not been examined. We considered that self-reported weakness might be a low muscle strength proxy marker. We aimed to examine associations of obesity alone, self-reported muscle weakness alone, and their combination with mortality in NH residents.

Methods

This is a retrospective longitudinal follow-up study. We noted age, sex, nutritional status, functionality, number of chronic diseases, and regular medication. Obesity was assessed by the body fat-percentage method estimated by bioimpedance analysis. Weakness was identified by self-reported muscle weakness. Survival was evaluated with a univariate log-rank test and multivariate Cox regression analyses.

Results

We included 214 participants. In a median follow-up time of 46 months, mortality occurred in 37.4%. In multivariate analysis adjusted by age, sex, undernutrition, number of chronic diseases, and regular medication, functional scores; ‘non-weak non-obese’ participants or ‘weak alone’ participants or ‘weak+obese’ participants had higher mortality risk when compared with the ‘obesity alone’ participants [hazard ratio (HR) = 2.6, 95% confidence interval (CI) = 1.2–5.5, p = 0.01; HR = 2.6, 95% CI = 1.2–5.9, p = 0.02; HR = 3.0, 95% CI = 1.2–7.7, p = 0.02].

Conclusion

This is the first report showing that obesity was associated with lower mortality risk if the weakness was not present in NH residents. However, obesity with concomitant weakness was associated with mortality risk similar to non-weak non-obese or weak alone participants. Our study suggests a simple consideration of weakness that can easily be integrated into everyday practice.

KEYWORDS:

• Mortality
• Nursing home
• obesity
• self-reported
• muscle weakness

List of Abbreviations

ADL: Activities of daily living

BIA: Bioimpedance analysis

CI: Confidence interval

EWGSOP: The European Working Group on Sarcopenia in Older People

FFM: Fat-free mass

HR: Hazard ratio

IADL: Instrumental activities of daily living

MMSE: Mini-Mental State Examination

MNA-SF: Mini nutritional assessment short-form

NH: Nursing home

S: Sarcopenia

SMM: Skeletal muscle mass

SO: Sarcopenic obesity

SPSS: Statistical package for social sciences

WHO: World Health Organization

Acknowledgments

The authors certify that they comply with ethical guidelines for authorship and publishing of the Acta Clinica Belgica.

Availability of data and material

The data is available from the authors upon reasonable request.

Consent for publication

We received informed consent from all participants.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethics approval

We obtained ethical approval from the Istanbul University Istanbul Medical School’s ethical

Board.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.