Department of Health Sciences, Furman University, Greenville, SC.
Diabet Med. 2013 Nov;30(11):1324-32. doi: 10.1111/dme.12297. Epub 2013 Aug 29.
To determine the prevalence of plasma vitamin D (25-dihydroxyvitamin D) insufficiency in individuals with Type 1 diabetes and to determine the cross-sectional and longitudinal associations of plasma vitamin D with insulin resistance.
Participants from the SEARCH for Diabetes in Youth Study [n = 1426; mean age 11.2 years (sd 3.9)] had physician-diagnosed Type 1 diabetes [diabetes duration mean 10.2 months (sd 6.5)] with data available at baseline and follow-up (approximately 12 and 24 months after baseline). Insulin resistance was estimated using a validated equation. Cross-sectional and longitudinal multivariate logistic regression models were used to determine the association of plasma vitamin D with insulin resistance, adjusting for potential confounders.
Forty-nine per cent of individuals had plasma vitamin D < 50 nmol/l and 26% were insulin resistant. In cross-sectional multivariate analyses, participants who had higher plasma vitamin D (65 nmol/l) had lower odds of prevalent insulin resistance than participants with lower plasma vitamin D (25 nmol/l) (odds ratio 0.70, 95% CI 0.57-0.85). This association was attenuated after additional adjustment for BMI z-score, which could be a confounder or a mediator (odds ratio 0.81, 95% CI 0.64-1.03). In longitudinal multivariate analyses, individuals with higher plasma vitamin D at baseline had lower odds of incident insulin resistance, but this was not significant (odds ratio 0.85, 95% CI 0.63-1.14).
Vitamin D insufficiency is common in individuals with Type 1 diabetes and may increase risk for insulin resistance. Additional prospective studies are needed to determine the association between plasma vitamin D and insulin resistance, and to further examine the role of adiposity on this association.
确定 1 型糖尿病患者血浆维生素 D（25-羟维生素 D）不足的发生率，并确定血浆维生素 D 与胰岛素抵抗的横断面和纵向关联。
来自 SEARCH for Diabetes in Youth 研究的参与者[ n ＝ 1426；平均年龄 11.2 岁（标准差 3.9）]患有经医生诊断的 1 型糖尿病[糖尿病病程平均为 10.2 个月（标准差 6.5）]，并在基线和随访时（大约在基线后 12 和 24 个月）获得数据。使用经过验证的方程来估计胰岛素抵抗。使用横断面和纵向多变量逻辑回归模型，调整潜在混杂因素后，确定血浆维生素 D 与胰岛素抵抗的关联。
49%的个体血浆维生素 D<50nmol/L，26%存在胰岛素抵抗。在横断面多变量分析中，与血浆维生素 D 较低的参与者相比，血浆维生素 D 较高的参与者（65nmol/L）发生胰岛素抵抗的可能性较低（比值比 0.70，95%可信区间 0.57-0.85）。这种关联在进一步调整 BMI z 评分后减弱，BMI z 评分可能是混杂因素或中介因素（比值比 0.81，95%可信区间 0.64-1.03）。在纵向多变量分析中，基线时血浆维生素 D 较高的个体发生胰岛素抵抗的可能性较低，但无统计学意义（比值比 0.85，95%可信区间 0.63-1.14）。
维生素 D 不足在 1 型糖尿病患者中很常见，可能会增加胰岛素抵抗的风险。需要进一步的前瞻性研究来确定血浆维生素 D 与胰岛素抵抗之间的关联，并进一步研究肥胖在这种关联中的作用。
