Vitamin D Receptor Gene Polymorphism FokI and 25-Hydroxy Vitamin D Levels among Indonesian Diabetic Foot Patients

Abstract

BACKGROUND: Vitamin D and VDRs FokI has been reported to be strongly associated with type 2 diabetes mellitus (T2DM) through controlling inflammation of endothelial cells in diabetic foot cases. 
 AIM: This study aimed to detect Vitamin D receptor FokI polymorphisms and to determine the Vitamin D levels among diabetic foot patients in sunlight-rich areas. 
 MATERIALS AND METHODS: A cross sectional study was conducted among diabetic foot patients who were treated as T2DM, from November 2016 to June 2018 in Padang city, Indonesia. There are an inclusion and exclusion criteria listed below. A questionnaire for symptoms-based screening, ankle brachial index (ABI) examination, fasting glucose, and HbA1c were measured. Electroimmunoassay (ECLIA) was used to determine Vitamin D levels as sufficiency, insufficiency, and deficiency. Polymerase chain reaction assay was addressed for VDR FokI genetic polymorphisms. Data were analyzed to evaluate the differences of explanatory variables (age, gender, duration of T2DM, fasting blood sugar, body mass index [BMI], HbA1c, and Vitamin D levels) across different genotypes of VDR FokI for three groups based on the absent T allele (ff: wild type homozygous, Ff: mutant heterozygous, and FF: mutant homozygous). 
 RESULTS: Among 36 eligible subjects, 52.8% were females, 61.1% were <50 years old, 63.9% had normal BMI, and 86.1% had normal ABI. Vitamin D deficiency, insufficiency, and sufficiency were shown in 19.4%, 33.3%, and 47.2% of the subjects, respectively. The majority of VDR FokI gene polymorphisms were mutant heterozygous Ff (44.4%), wild type homozygous ff (13.9%), and mutant homozygous FF (41.7%). Results of one-way ANOVA showed that there were no differences of BMI, ABI, fasting blood glucose, Vitamin D levels, and Hb1AC status with the VDR FokI gene polymorphisms. Based on Vitamin D levels, most of the Vitamin D deficiency subjects had 31.2% VDR FokI Ff allele, 13.3% had FF allele, and none of them had ff allele. 
 CONCLUSION: This study concluded that most of the individuals with diabetic foot in a sunlight-rich area tended to have mutant VDR FokI polymorphisms and Vitamin D insufficiency.