Vitamin D deficiency related to physical capacity during cardiac rehabilitation

Abstract

Background: Vitamin D deficiency is a frequent pathology associated with cardiovascular diseases and physical performance.

Objective: To study the link between 25-hydroxyvitamin D (25OHD) level and physical performance and gain in physical performance after cardiovascular rehabilitation (CVR) with vitamin D deficiency.

Methods: 25OHD level was assessed in a retrospective cohort of patients admitted for CVR. Data were collected on physical fitness [6-min walk test distance (6MWD) in percentage of predicted, maximal power (Pmax)]. The threshold of vitamin D deficiency was 20ng/ml chosen according to the literature.

Results: Among the 131 patients included, as compared with those with nondeficiency (n=83; 63%), patients with vitamin D deficiency (n=48, 37%) had lower initial 6MWD (82±18 vs 89±12% predicted, P=0.009) and Pmax (100±58 vs 120±39W, P=0.006). After CVR, this difference was maintained. The improvement in 6MWD and Pmax was significantly lower with deficiency than nondeficiency, for an increase of 11±8% versus 14±9% predicted (P=0.048) and 10±30 versus 32±30W (P=0.00001), respectively.

Conclusion: Vitamin D deficiency may be associated with impaired physical fitness before CVR and a smaller gain in physical fitness with CVR, probably related to the action of vitamin D on the muscle.

Keywords: 6-min walking test; Cardiovascular rehabilitation; Maximal power; Vitamin D deficiency.