Objective Vitamin D deficiency is common and has been associated with several non-bone/calcium related outcomes. The objective was to determine the association between serum 25-hydroxyvitamin D (25-OH-D) and fasting glucose, insulin and insulin sensitivity in obese and non-obese children.
Patients/setting/design Cross-sectional study of 85 children aged 4–18 years recruited from the local Philadelphia community and Sleep Center.
Main outcomes measures Fasting blood glucose, insulin and 25-OH-D were measured. Insulin resistance was calculated using homeostasis model assessment (HOMA). Body mass index standard deviation scores (BMI-Z) and pubertal stage were determined. Multivariable linear regression was used to determine factors associated with decreased 25-OH-D and to determine the association of vitamin D with HOMA.
Results Median 25-OH-D was 52 nmol/l (IQR 34–76). 26% of subjects were vitamin D sufficient (25-OH-D ≥75 nmol/l), 27% had intermediate values (50–75 nmol/l) and 47% were insufficient (25–50 nmol/l) or frankly deficient (<25 nmol/l). In the multivariable model, older age, higher BMI-Z and African–American race were all negatively associated with 25-OH-D; summer was positively associated with 25-OH-D. Lower 25-OH-D was associated with higher fasting blood glucose, insulin and HOMA after adjustment for puberty and BMI-Z.
Conclusion Low 25-OH-D, common in the paediatric population at risk for diabetes (older children, African–Americans, children with increasing BMI-Z) is associated with worse insulin resistance.
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Funding This work was supported by K-23-RR021973 (AK) and Institutional Clinical and Translational Science Award Research Grant (UL1-RR-024134) from the National Center for Research Resources.
Competing interests None.
Ethics approval This study was conducted with the approval of The Children's Hospital of Philadelphia.
Provenance and peer review Not commissioned; externally peer reviewed.