The association between vitamin D and inflammation with the 6-minute walk and frailty in patients with heart failure

OBJECTIVES: To identify relationships between anabolic hormones, inflammatory markers, and physical function. DESIGN: Cross-sectional. SETTING: Outpatient university heart failure program in Connecticut. PARTICIPANTS: Sixty patients with an ejection fraction of 40% or less. MEASUREMENTS: The 6-minute walk distance and frailty phenotype were measured. The relationship between physical measures of hormones and inflammatory mediators were examined. Linear and ordinal logistic regression analyses were performed for the physical measures. RESULTS: Forty-three men (mean age 77 +/- 9) and 17 women (mean age 78 +/- 12) participated. Longer 6-minute walk distance was correlated with higher 25-hydroxyvitamin D (25OHD) level, and a shorter walk was correlated with higher cortisol: dehydroepiandrosterone sulphate (DHEAS) ratio, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL6), and intact parathyroid hormone (PTH) (all P < .05). Percentage of free testosterone, DHEAS alone, and N-terminal pro-brain natriuretic peptide (NTpro-BNP) did not correlate with 6-minute walk distance. Higher frailty phenotype score (more frail) was correlated with higher high-sensitivity CRP, higher IL6, and lower 25OHD levels (all P < .05). Linear regression with the 6-minute walk distance as the dependent variable and independent variables of age, sex, percentage of free testosterone, DHEAS, 25OHD, intact PTH, hsCRP, IL6, cortisol/DHEAS ratio, and NTpro-BNP, revealed age, sex, 25OHD and hsCRP to be significant (coefficient of determination = 53.5%). Ordinal logistic regression with the frailty phenotype and hormonal levels revealed that age, 25OHD, and hsCRP also predicted frailty status. CONCLUSION: Twenty-five-hydroxyvitamin D and hsCRP levels may contribute to lower aerobic capacity and frailty in patients with heart failure. A longitudinal study will further define the role of 25OHD and hsCRP on muscle strength and functional decline.