Inspiratory Muscle Strength and Cardiorespiratory Fitness Association With Health-Related Quality of Life in Healthy Older Adults

The main purpose of this study was to explore similarities and differences in the association between two capabilities affecting the cardiorespiratory system (overall and multifactorial cardiorespiratory fitness and inspiratory muscle strength) and the health-related quality of life (HRQoL), in a group of active healthy seniors. Sixty-five individuals (age, 73.01 ± 5.27 years; 53 women) who participated regularly in a multicomponent training program completed the EuroQol 5D-5L questionnaire, the 6-min walking test (6MWT), and the maximum inspiratory pressure test (MIP). Non-parametric correlations (Spearman's rho) were conducted to analyze the association between HRQoL indices (EQindex and EQvas), MIP, and 6MWT, considering both, the whole sample and men and women separately. Furthermore, partial correlation was made by controlling age and sex. We found a moderate association between HRQoL and cardiorespiratory fitness (EQvas: r = 0.324, p = 0.009; EQindex: r = 0.312, p = 0.011). Considering sex, relationship EQvas-6MWT decrease to small (r = 0.275; p = 0.028) whereas EQindex-6MWT remained moderated (r = 0.425; p = 0.000). When we considered women and men separately, the association between HRQoL and 6MWT appeared only in women, while the observed strong trend (p = 0.051) toward a large and positive association between EQindex and MIP, mediated by the covariate age, appeared only in men. Conversely to the cardiorespiratory fitness, MIP is not a limiting factor of HRQoL in healthy active elderly. Moreover, MIP and HRQoL should be included in the assessment of exercise interventions because they provide different information about the cardiorespiratory system deterioration. Similarly, EQvas and EQindex confirm to be complementary in the assessment of HRQoL. Furthermore, like aging process is different for men and women, the association between MIP and cardiorespiratory fitness with HRQoL may behave differently, so keeping on research these associations could help to improve training programs for this population.