Vitamin D as a biomarker of health in snoring children: a familial aggregation study.

BACKGROUND Hypovitaminosis D is a common health problem. The purpose of this study was to investigate the inter-relationship between serum 25(OH)D levels and paternal and maternal vitamin D status in a sample of snoring children. METHODS We selected 137 participants for whom serum 25(OH)D had been measured and underwent overnight polysomnography evaluation. Serum glucose, lipids, liver enzymes, parathyroid hormone, insulin, and glycated hemoglobin were also measured. Glucose and insulin levels were used to estimate insulin resistance with the homeostasis model assessment (HOMA-IR). RESULTS Vitamin D insufficiency (<30 ng/mL) and deficiency (<20 ng/mL) were found in 40.9 and 17.5% of children, respectively. After adjustments for age, BMI z-score and seasonality, the odds ratio for risk of vitamin D insufficiency according to the vitamin D status of parents were: OR (95% CI): paternal insufficiency 15.1 (2.7-35.7), p = 0.002; maternal insufficiency 7.2 (2.4-22), p = 0.001. When children with vitamin D deficiency were analyzed separately, serum 25(OH)D concentration was found to be associated with the apnea-hypopnea index (r = -0.647, p = 0.009) and respiratory arousal index (r = -0.669, p = 0.034). CONCLUSIONS Family patterns of vitamin D could be helpful for the early identification of children at risk of metabolic and/or sleep disturbances and when considering strategies to improve vitamin D status. IMPACT Family patterns of vitamin D could be helpful for the early identification of snoring children at risk of metabolic and/or sleep disturbances. Significant associations were found between serum 25-hydroxyvitamin D (25(OH)D) concentrations in children and their parents. An inverse association between 25(OH)D levels and OSA severity was detected in deficient vitamin D children. Children with insufficient and deficient vitamin D status tended to have a worse metabolic profile, so strategies are needed to improve vitamin D status.