Physiological Evaluation of Vitamin D Status in Relation to Pulmonary Function Parameters (FEV1/FVC) in Asthmatic Patients in Wasit Province, Iraq

Abstract

Asthma is a persistent (chronic) lung disease which is accompanied by variable (fluctuating) symptoms of the respiratory tract and a limitation of air flow during expiration. There has been some research into the physiological factors that may be related to respiratory function, including vitamin D status, but results have been inconsistent.  The purpose of this cross-sectional study is to evaluate the correlation between serum 25-hydroxyvitamin D [25(OH)D] levels and pulmonary function parameters in adult asthmatics in Wasit Province, Iraq, with a particular emphasis on the FEV1/FVC ratio.  Serum 25(OH)D was one of the study variables and the standardized spirometric parameters FEV1, FVC, FEV1/FVC, FEV1% predicted and FVC% predicted. For manuscript development 60 adults were used, 30 vitamin D deficient and 30 vitamin D sufficient. The manuscript-development analysis showed mean 25(OH)D concentrations of 15.5 ± 3.5 and 31.8 ± 6.2 ng/mL and mean FEV1/FVC values of 70.5 ± 6.1% and 76.8 ± 5.4%, respectively.  FEV1/FVC was somewhat favorably correlated with the 25(OH)D level (r = 0.47, P < 0.001).  The numerical results obtained were kept as examples of manuscript development, and were not patient observations. There was still some evidence published after the intervention and some before the intervention, which were not consistent with each other.