Medicine & Science in Sports & Exercise:
POST ACCEPTANCE, 23 June 2010
Farrell, Stephen W.; Cleaver, Joseph P.; Willis, Benjamin L.
Purpose: We examined the cross-sectional associations between cardiorespiratory fitness level (CRF), different measures of adiposity, and serum 25-dihydroxyvitamin D levels (SVD) in men.
Methods: 2317 men completed a baseline health examination between 2005 and 2009. Clinical measures included body mass index (BMI), waist circumference (WC), waist to hip ratio (W:Hip), percent body fat (%fat), CRF quantified as duration of a maximal treadmill exercise test, and measurement of SVD. Participants were classified by CRF as 'unfit' (lowest 20%) and 'fit' (remaining 80%) based on age, as well as by clinical cut points for BMI, WC, W:Hip, and %fat, and by categories of SVD. We examined trends of CRF and adiposity exposures across SVD categories. We also calculated odds ratios (OR) of abnormal SVD across levels of adiposity exposures prior to and following adjustment for CRF, as well as OR of abnormal SVD across levels of CRF prior to and following adjustment for each adiposity exposure.
Results: We observed a significant positive trend for CRF across incremental SVD categories (P < 0.001), with the highest mean age-adjusted CRF levels (11.9 +/- 1.9 METS) in the highest SVD category. When compared to normal weight men, ORs for abnormal SVD were significantly higher for overweight men within each adiposity exposure (P < 0.05). Joint associations between CRF, adiposity, and SVD revealed significantly lower SVD in unfit than in fit men within each stratum of each adiposity exposure.
Conclusion: SVD levels are positively associated with CRF and negatively associated with different measures of adiposity in men. Higher CRF attenuates the relationship between adiposity level and SVD. Because the observed associations are cross-sectional, future prospective studies are warranted.