A canonical correlation analysis on the relationship between functional fitness and health-related quality of life in older adults

Highlights

• There are positive and moderate relationships between overall FF and overall HRQoL in older adults.

• FF has a significant influence on HRQoL particularly physical functioning dimension.

• Key FF variables influencing relationship between FF and HRQOL are different between men and women.

Abstract

Objective

This study aimed to explore the relationship between the functional fitness (FF) and health-related quality of life (HRQoL) in older adults, and to identify the key subdimensions of FF and HRQoL influencing their overall relationship.

Methods

This cross-sectional study was performed among 851 independent community members (65–84 years; men = 402). The Senior Fitness Test and the Short Form 36 Health Survey were used to measure FF and HRQoL, respectively. A canonical correlation analysis was conducted using seven fitness variables as predictors of eight HRQoL variables to examine the relationship between FF and HRQoL.

Results

The overall FF was positively correlated with the overall HRQoL in both men (canonical correlation = 0.350) and women (canonical correlation = 0.456). The up-and-go and 2-min step contributed the most to FF, and physical functioning contributed the most to HRQOL among men. Conversely, the up-and-go and 30-s chair stand contributed the most to FF, and physical functioning contributed the most to HRQoL in women.

Conclusions

There were positive and moderate relationships between overall FF and overall HRQOL in older adults. The FF has a significant influence on HRQoL, particularly physical functioning. The main FF components influencing the relationship between FF and HRQoL in men are balance and agility and aerobic endurance, whereas in women they are balance and agility and lower extremity muscle strength. Results from this study facilitate comprehensively understanding the relationship between FF and HRQoL, and generating critical insight into HRQoL improvement from the perspective of FF enhancement.

Introduction

With the progress of civilisation and industrialisation, the average life expectancy has increased dramatically during the 20th century (World Health Organization, 2011). However, this dramatic increase in life expectancy did not come with a proportionate increase in quality of life, particularly in older adults (Brown, 2015). One of the strongest determinants to maintain a high quality of life among older adults is the maintenance of good health (Forsén et al., 2010). Because of the ageing-related degradations in physical and cognitive functioning (Chung, Zhao, Liu, & Binh, 2016; James, Wilson, Barnes, & Bennett, 2011), older adults are often reported with social difficulties, mental problems (e.g., depression), chronic disease, and declined ability to live independently (Charles & Carstensen, 2010; Clegg, Young, Iliffe, Rikkert, & Rockwood, 2013; Hung, Ross, Boockvar, & Siu, 2011).This would detrimentally influence older adults’ health and quality of life.

Among various definitions on quality of life, health-related quality of life (HRQOL) is a multi-dimensional concept involving both physical and mental functioning (Wanderley, Silva, Marques, Oliveira, Mota, & Carvalho, 2011). Functional fitness (FF), which is defined as having the physical capacity to perform normal daily activities safely and independently without undue fatigue (Rikli & Jones, 2013), has been determined crucial for maintaining HRQOL in older adults (Takata et al., 2010). Additionally, there is a burgeoning popularity of FF complementing HRQOL in ageing-related studies (Chou, Hwang, & Wu, 2012). Both these findings to some extent indicate the close relationship between FF and HRQOL. Moreover, ageing-associated declines have been reported in both FF (Chung et al., 2016) and HRQOL (Hsu, Chen, Kuo, Fan, Lee, & Hsu, 2014), and a comprehensive understanding about their relationship would facilitate developing and implementing specific interventions.

A review of the extant literature indicated that most research has focused on the associations between each fitness component and the subdimensions of HRQoL. For example, Wanderley et al. (2011) found that older adults with higher aerobic endurance capacity reported higher scores in physical functioning, role limitations due to physical problems, and vitality, whereas those with superior upper arm muscle strength were more likely to score higher on RP and VT. Additionally, Samuel, Rowe, Hood, and Nicol (2012) reported moderate correlations between muscle strength and some specific dimensions of HRQoL (e.g. physical functioning) among older adults in the community. All of the preceding evidence has indicated specific associations between the various subdimensions of FF and HRQoL. However, both HRQoL and FF are multidimensional concepts, necessitating examination of relationships between overall FF and overall HRQoL, and exploration of the key subdimensions that would influence their overall relationships. To date, few studies have performed such examinations, hampering the understanding of relationships between overall FF and overall HRQoL.

Additionally, because the samples in previous studies mainly comprised women (Hsu et al., 2014, Wanderley et al., 2011), the generalisability of the results may be compromised as a consequence of potential sex differences. According to the limitations of existing research findings, this study was conducted to explore the relationship between overall FF and overall HRQoL in older men and women separately, and to identify the key subdimensions of FF and HRQoL influencing their overall relationship. Results from this study can facilitate comprehensively understanding the relationships between FF and HRQOL and generating critical insight into HRQOL improvement from the perspective of FF enhancement.