The Mediating Role of Physical Activity and Physical Function in the Association between Body Mass Index and Health-Related Quality of Life: A Population-Based Study with Older Adults

• Published in: International journal of environmental research and public health 2022-10, Vol.19 (21), p.13718
• Main Authors: Nascimento, Marcelo de Maio, Gouveia, Élvio Rúbio, Gouveia, Bruna R, Marques, Adilson, Campos, Pedro, García-Mayor, Jesús, Przednowek, Krzysztof, Ihle, Andreas
• Format: Article
• Language: English
• Subjects: Adults; Age groups; Aged; Aging; Body composition; Body mass; Body Mass Index; Body size; Body weight; Cardiovascular disease; Comorbidity; Exercise; Humans; Metabolism; Middle Aged; Muscle strength; Obesity; Obesity - epidemiology; Older people; Overweight; Overweight - epidemiology; Physical activity; Physical fitness; Physiology; Population; Population studies; Population-based studies; Quality of Life; Questionnaires; Regression analysis; Sociodemographics; Underweight; Womens health
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph192113718

This study aimed (1) to investigate the association between body mass index (BMI), physical activity (PA), and physical function (PF) with health-related quality of life (HRQoL), and (2) to examine in-depth whether PA and PF mediate the relationship between BMI and HRQoL in older adults. We investigated 802 individuals (mean age 69.8 ± 5.6 years), residents of the Autonomous Region of Madeira, Portugal. Harmol and PA were assessed using the SF-36 and Baecke questionnaires, respectively, and PF by the Senior Fitness Test. The prevalence of overweight was 71.3%, 26.5% for normal weight, and 2.1% for underweight. We verified a small correlation between age and sex with BMI, PA, PF, and medium borderline with HRQoL. After adjusting for covariates (i.e., sex, age, comorbidities), the multivariate regression analysis indicated a 93.1% chance of improvement in HRQoL for low BMI, while PA and PF revealed a chance of increasing HRQoL by 91.8% and 60.0%, respectively. According to the serial mediation pathway, PA and PF partially mediated the association between BMI and HRQoL by 32.3% and 81.5%, respectively. The total variance of the model was 90%. It was concluded that BMI can negatively affect HRQoL. On the other hand, PA and PF are able to increase HRQoL levels during the aging process.