Obesity in youth and its relatıonship with the diagnosis of vıtamin D deficiency and insulin resistance according to pubertal status ‒ A retrospective study from Turkey

Introduction: Introduction: as children progressed into puberty, a notable escalation in the prevelance of obesity and insulin resistance was observed. Specifically during this developmental stage, both obesity and insulin resistance exhibited a pronounced surge. Objective: this study aimed to determine the relationships between serum 25(OH) vitamin D deficiency and insulin resistance in overweight and obese children and adolescents. Methods: a total of 418 individuals aged 6-18 years (11.9 ± 3.23) diagnosed with obesity or overweight retrospectively were included in the study. Data including gender, age, body weight, height, anthropometric measurements, and biochemical parameters were recorded from files between 2020-2022. Body mass index (BMI) for age values were evaluated using WHO 5-19 years Growth Reference. Results: among participants, 37.5 % of them were prepubertal and the mean age was 11.94 ± 3.32 years. Vitamin D insufficiency was found 43.9 % in prepuberty and 51.3 % in pubertal stage. While the presence of insulin resistance in the prepubertal stage was 36.8 %, it was 25.7 % in the pubertal stage. In the pubertal group, HOMA-IR values significantly increased as serum 25-OH vitamin D levels decreased (p = 0.002). Mean 25-OH Vitamin D was negatively associated with HDL-C and positively associated with BMI for age and HOMA-IR. Conclusion: a noteworthy corrrelation was established between vitamin D deficiency and the incidence of insulin resistance, alongside obesity. As a result, this study, which included a limited number of cases, showed significantly lower levels of vitamin D especially in obese patients with insulin resistance. There is a need for prospective, large-scale and long-term studies to verify our results.