EFFECT OF VITAMIN D LEVELS ON ASTHMA CONTROL IN ADULTS Astımlı Hastalarda D Vitamini Düzeyinin Astım Kontrolü Üzerine Etkisi

ABSTRACT Objective: The aim of this study is to evaluate the effects of serum vitamin D level and body mass index (BMI) on asthma control and pulmonary functions in asthmatic patients. Material and Methods: Thirty-five healthy normal controls and 60 patients with asthma were included in the study between December 2016 and February 2017. At initial admission, demographic characteristics and pulmonary function tests (PFT) were recorded and laboratory tests including serum vitamin D, calcium, phosphorus, parathormone and alkaline phosphatase levels were measured. Asthma control test (ACT) was performed to asthmatic patients. Fifty-three patients with asthma and 32 healthy controls with decreased vitamin D level were consulted with Endocrinology Department for vitamin D replacement therapy. ACT and PFT were repeated after therapy at third month in asthmatic patients. Results: There were totally 95 individuals; 76 females (80%) and 19 males (20%), There were no significant difference between age, gender and demographic characteristics between asthmatics and control group. Smoking status and passive smoking rates were similar. There was no significant difference between daily sun exposure, calcium containing diet and menopausal status. Serum phosphorus, calcium, alkaline phosphatase, parathormone and 25-hydroxyvitamin D levels were similar in both groups. Vitamin levels were low in about 90% of both groups. On the first admission, 71.7% of asthmatic patients were uncontrolled, while the rate of uncontrolled patients decreased to 13.2% after the post-replacement evaluation. There was a significant increase of ACT with respect to vitamin D replacement therapy (22.4 ± 2.7 vs 16 ± 5.4, p=0.001). The mean BMI were high in both groups (≥30 kg/m²). The mean ACT score was lower in obese asthmatics than in non-obese patients, but the difference was not significant (15.3 ± 5.4 vs. 17.5 ± 4.8, p= 0.1). Presence of controlled or uncontrolled disease was similar between the obese and non-obese groups (p = 0.744). Conclusion: It is suggested that vitamin D replacement therapy had positive effects on asthma control and pulmonary functions but further multicenter, prospective studies with large number of cases are needed to evaluate the effect of vitamin D replacement therapy on these parameters. Keywords: Asthma; Vitamin D; Asthma Control Test (ACT); Pulmonary Function Test (PFT)

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