Combined association of fitness and central adiposity with health-related quality of life in healthy Men: a cross-sectional study

BACKGROUND There is limited data examining the association of combined fitness and central obesity with health related quality of life (HRQoL) in adults. We examined the association of combined cardiorespiratory fitness (CRF) and waist-to-height ratio (WHtR) in the form of a fit-fat index (FFI) with the Physical Component Summary (PCS) and Mental Component Summary (MCS) HRQoL scores in United States Navy servicemen. METHODS As part of a health fitness assessment, a total of 709 healthy males aged 18-49 years completed a submaximal exercise test, WHtR measurement, and HRQoL survey (SF-12v2) between 2004 and 2006. FFI level was classified into thirds with the lowest FFI tertile serving as the referent group. PCS and MCS scores ≥50 were taken to indicate average or better. Logistic regression was used to obtain odds ratios (OR) and 95% confidence intervals (CI). RESULTS The prevalence of average or better HRQoL scores was lowest in the referent FFI tertile, PCS 60.2% and MCS 57.6%. Compared with the lowest FFI group in multivariate analyses, the OR (95% CI) of having average or better PCS was 1.63 (1.09-2.42) and 3.12 (1.95-4.99) for moderate and high FFI groups respectively; MCS was 1.70 (1.13-2.55) and 4.89 (3.03-7.89) for moderate and high FFI groups respectively (all P < 0.001). Consistent and progressive independent associations were observed between age and MCS, and also between CRF and MCS. CONCLUSION Among males in the United States Navy, higher levels of FFI were independently and more consistently associated with having average or better HRQoL (physical and mental) than other known predictors of HRQoL.