ABSTRACT
Background: Fasting is practiced by various religions in the world. The previous studies show the effect of fasting on biochemical markers in healthy subjects; however, no study is available on its effect on gene expression or epigenetic markers. In the present study, miR126, a microRNA, was measured in serum samples of healthy adult subjects, and their correlation with biochemical profile was carried out during the short-term fasting of the Navratri festival. Methods: A total of 30 subjects who underwent fasting for 07 days during the Navratri festival were recruited for the study. The fasting blood samples were obtained at three different time points; day 1 of fasting, day 7 of fasting, and day 7 after completion of fasting period. The miR126 expression, fasting plasma glucose, and lipid profile were measured in all the three samples. Results: The miR126 levels showed a decreasing trend with a significant difference across the three time points (p-value = 0.006). Fasting plasma glucose increased continuously across three time points without showing any statistical significance. Serum total cholesterol (p = 0.001) and triglycerides (p = 0.001) levels were decreased initially and then increased after resuming normal diet. There was a medium-level negative correlation (-0.332) between baseline fasting glucose level and miR126 level (p = 0.068). Conclusion: The study revealed that serum levels of total cholesterol and triglyceride were more dynamic than the miR126 levels. A significant decrease in the miR126 expression across three time points is a promising outcome of this pilot study and indicates its role in short-term fasting. However, the fasting plasma glucose showed heterogeneous values without significant correlation with miR126 levels.
ABSTRACT
Background & objectives: Despite being a tropical country, vitamin D deficiency is highly prevalent in India with studies indicating 40-99 per cent prevalence. Apart from calcium and phosphate metabolism, vitamin D is involved in cell cycle regulation, cardiovascular, hepatoprotection. The metabolism of vitamin D is regulated by vitamin D tool genes (CYP2R1/CYP27B1/CYP24A1/VDR). The promoter regions of some of these genes have CpG islands, making them prone to methylation induced gene silencing, which may cause a reduction in circulating vitamin D levels. Epigenetic basis of vitamin D deficiency is yet to be studied in India, and hence, this pilot study was aimed to analyze whether methylation levels of CYP2R1 gene were correlated with the levels of 25(OH)D in healthy, adult individuals in Indian population. Methods: In this cross-sectional study, healthy adults of 18-45 yr of age with no history of malabsorption, thyroidectomy, chronic illness or therapeutic vitamin D supplementation were recruited. DNA methylation analysis was carried out by methylation specific quantitative PCR. Serum calcium, phosphate and vitamin D levels were also quantified. Statistical analysis was done by R 4.0.5 software. Results: A total of 61 apparently healthy adults were analyzed. The serum vitamin D levels did not correlate with CYP2R1 methylation levels in our study population. Significant positive correlation was observed between age and serum vitamin D levels. Significant association of gender was found with CYP2R1 methylation levels. Interpretation & conclusions: This study found no significant correlation between levels of CYP2R1 methylation and circulating 25(OH)D deficiency. Further studies on the Indian population having a larger sample size including entire vitamin D tool genes, among different ethnic groups may be conducted to elucidate molecular etiology of circulating 25(OH)D deficiency. The high prevalence of normal serum calcium and phosphate levels among vitamin D deficient subjects in this study coupled with the strikingly high prevalence of the deficiency at the national level, may suggest the need to revise the cut-off criteria for vitamin D deficiency in the Indian population.
