Obesity, Physical Fitness and Inflammation in the Elderly

Among the elderly, obesity is paradoxically associated with a lower mortality risk. Thus, this study describes fitness levels by Body Mass Index (BMI) category and the associations of high-sensitivity C-reactive protein (hs-CRP) and Vitamin D levels with muscle strength, in community-dwelling older adults. A cross-sectional study, with 1338 subjects having mean age of 78.3 years, were assessed in anthropometrics, muscle strength, and cardiorespiratory fitness. In a sub-sample, blood samples were collected and objective markers of inflammation were provided: high-sensitivity C-reactive protein (hs-CRP) and Vitamin D (25(OH) D). Obese women (BMI ≥ 30.0 kg/m²) showed significantly better results for grip strength than normal weight group (BMI between 18.5⁻24.9 kg/m²): 22.3 (7.0) vs. 20.0 (6.8); p = 0.002. After adjustment, higher levels of hs-CRP were an independent predictor of lower levels of grip strength (β = -0.213, 95% CI: -0.424; -0.002) and Vitamin D levels were positively associated with higher levels of muscle strength (β = 0.098, 95% CI: 0.008⁻0.189). The multivariate analysis found a significant and positive association between 25(OH) D and grip strength: (β = 0.098, 95% CI: 0.008⁻0.189). A positive pattern of higher levels of absolute strength among obese older subjects could have an important impact on morbidity and mortality risk, through the inverse association with acute inflammation and an increase in Vitamin D profile.