title: Physical activity, sedentary behavior, and vitamin D metabolites.
abstract: Physical activity is associated with circulating 25-hydroxyvitamin D (25(OH)D). However, the influence of activity and/or sedentary behavior on the biologically active, seco-steroid hormone 1α,25-dihydroxyvitamin D (1,25(OH)2D) is unknown. We conducted a cross-sectional analysis among ursodeoxycholic acid (UDCA) randomized trial participants (n=876) to evaluate associations between physical activity, sedentary behavior, and circulating vitamin D metabolite concentrations. Continuous vitamin D metabolite measurements and clinical thresholds were evaluated using multiple linear and logistic regression models, mutually adjusted for either 1,25(OH)2D or 25(OH)D and additional confounding factors. A statistically significant linear association between 1,25(OH)2D and moderate-vigorous physical activity per week was strongest among women (β (95% CI): 3.10 (1.51-6.35)) versus men (β (95% CI): 1.35 (0.79-2.29)) in the highest tertile of activity compared to the lowest (p-interaction=0.003). Furthermore, 25(OH)D was 1.54ng/ml (95% CI 1.09-1.98) higher per hour increase in moderate-vigorous activity (p=0.001) and odds of sufficient 25(OH)D status was higher among physically active participants (p=0.001). Sedentary behavior was not significantly associated with either metabolite in linear regression models, nor was a statistically significant interaction by sex identified. The current study identified novel associations between physical activity and serum 1,25(OH)2D levels, adjusted for 25(OH)D concentrations. These results identify the biologically active form of vitamin D as a potential physiologic mechanism related to observed population-level associations between moderate-vigorous physical activity with bone health and chronic disease risk. However, future longitudinal studies are needed to further evaluate the role of physical activity and vitamin D metabolites in chronic disease prevention.
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN; Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ; University of Arizona Cancer Center, University of Arizona, Tucson, AZ. Electronic address: Elizabeth.a.hibler@vanderbilt.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Hibler
authors.affiliation: Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York NY.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Sardo Molmenti
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Qi
authors.initials: Q
authors.lastname: Dai
authors.affiliation: Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ.
authors.forename: Lindsay N
authors.initials: LN
authors.lastname: Kohler
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Shaneda
authors.initials: S
authors.lastname: Warren Anderson
authors.affiliation: School of Mathematical and Natural Sciences, Arizona State University, Phoenix, AZ.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Jurutka
authors.affiliation: Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ; University of Arizona Cancer Center, University of Arizona, Tucson, AZ.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Jacobs
mesh_terms: D000368:Aged; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D057185:Sedentary Behavior; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 1α,25-dihydoxyvitamin D; 25-hydroxyvitamin D; Physical activity; sedentary behavior; vitamin D