Analysis of vitamin D metabolism, thyroid and autoimmune markers in the vitiligo pathways and their possible interaction with sleep.

Abstract

Vitiligo is an autoimmune skin disease that can be influenced by stress, including that resulting from sleep deprivation and sleep disturbances. Sleep is essential in the regulation of several hormonal, metabolic and autoimmune pathways that may have important roles in vitiligo. This study aimed to investigate the potential interplay between hormonal, metabolic, and autoimmune markers in vitiligo patients, and the possible influence of sleep quality in these vitiligo pathways. A cohort of 30 vitiligo patients and 26 healthy controls were assessed for various laboratory markers, including thyroid-stimulating hormone (TSH), parathyroid hormone (PTH), serum calcium, 1.25(OH)2D, 25(OH)D, anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG), and antinuclear antibodies (ANA). The study evaluated sleep quality using the Pittsburgh Sleep Quality Index (PSQI). Positive anti-TPO were found in the vitiligo group, but did not in the control group. Vitamin D 25(OH)D mean levels were clinically insufficient in both groups (< 30mg/dL). Reactive ANA was analyzed with 2 variables related to vitiligo: phototherapy and skin activity. No statistical correlation was found in the chi-square test on this relationship. Descriptive findings have shown that the positivity to anti-TPO and anti-TG, associated or not with reactive ANA, was higher in vitiligo group. Great part (85.7%) of vitiligo group were "poor sleepers" (PSQI > 5), which has increased (88.2%) when considering only individuals with signs of vitiligo activity. Autoimmune hypothyroidism and positive anti-TPO are expected in vitiligo, although this marker is not usually measured in the first laboratory screening to this disease. Adequate vitamin D levels may be a key adjuvant in skin pigmentation, and be related to sleep quality and immune regulation, as this vitamin can be related to better sleep and immunomodulation in autoimmune diseases. Evaluating ANA before phototherapy can be controversial, but it should be considered in cases with a poor response to this treatment, or when there is a higher risk of other autoimmune diseases. Poor sleep predominated in the vitiligo group, based on PSQI scores that reported worse subjective sleep in these patients. Worse sleep predominated in individuals with signs of skin activity and reactive autoimmune markers. Screening these components could be important in the management of vitiligo, as maintaining body homeostasis can help to improve the disease course. Sleep should be considered as a potential modulator of several multidirectional vitiligo pathways.