Resumo

Objectives: Vitamin D and insulin have an important role in the homeostasis and physiology of skin, hence this study assessed the association between 25-hydroxyvitamin D (25[OH]D) concentration and The Homeostasis Model of Insulin Resistance (HOMA-IR), with their impact on skin related disorders. Introduction: Vitamin D has a protective role against insulin resistance (IR) by up-regulating insulin receptors and increasing insulin sensitivity. Vitamin D receptors are also expressed in the beta cells of pancreas, where vitamin D binds and helps release of insulin. Being a fat soluble vitamin, it gets sequestered in adipose tissues leading to reduced bioavailability and low levels can produce inflammatory cytokines which can cause insulin resistance and eventually type 2 Diabetes mellitus. Research shows vitamin D supplementation may control glycaemic response and improve insulin resistance. Materials / method: This is a retrospective observational study in a dermatology clinic in South India, with 114 participants (86 females and 28 males), aged 18-45 years. HOMA-IR along with 25-hydroxyvitamin D (25[OH]D) and skin manifestations were analysed. Those having taken vitamin D supplementation, with diabetes and other chronic disorders were excluded due to their influence on vitamin D and insulin levels. Data analysis was done using IBM SPSS Statistics for Windows and for qualitative categorical data, Chi square test was done, with a probability value of 0.05 considered significant. Results: Vitamin D and HOMA IR were categorized as severe deficiency (12 and below in 57%), deficiency (12.1-20 - 26.3%), insufficiency (20.1-30 – 15.8%), sufficiency (Above 30 – 0.9%) and No Insulin Resistance (IR) - (<1 seen in 7%), Mild (1.1-1.9 in 27.2%), moderate (2.0-2.9 in 24.6%), Significant IR (>2.9 in 41.2%) respectively. The patient with sufficient vitamin D had no IR, whereas those with low vitamin D levels had mild to severe IR, with a statistically significant p value 0.022. FPHL, hidradenitis suppurativa, hirsutism, acrochordon, eczema, psoriasis were present only in the groups with IR. Conclusion: Vitamin D deficiency has an inverse association to insulin resistance. This is an important finding and it remains to be seen whether genetic susceptibility to vitamin D deficiency despite the status of sun exposure is the reason for early insulin resistance in Indians. Patients routinely check their vitamin D due to various skin and health complaints, however fail to check the insulin status. Hence, low vitamin D along with the skin manifestations can aid in diagnosing IR early, leading to decrease in global diabetes burden.