Bellan Mattia, Guzzaloni Gabriele, Rinaldi Maura, Merlotti Elena, Ferrari Carlotta, Tagliaferri Antonella, Pirisi Mario, Aimaretti Gianluca, Scacchi Massimo, Marzullo Paolo
Division of General Medicine, Ospedale S, Giuseppe, I,R,C,C,S, Istituto Auxologico Italiano, Verbania, Italy.
Cardiovasc Diabetol. 2014 Mar 11;13:57. doi: 10.1186/1475-2840-13-57.
The last decades have provided insights into vitamin D physiology linked to glucose homeostasis. Uncertainties remain in obesity due to its intrinsic effects on vitamin D and glucose tolerance.
To assess the relationship between vitamin D and glucose abnormalities in severely obese individuals previously unknown to suffer from abnormal glucose metabolism.
Tertiary care centre.
524 obese patients (50.3 ± 14.9 yrs; BMI, 47.7 ± 7.3 kg/m2) screened by OGTT, HbA1c and the lipid profile. Vitamin D status was assessed by 25(OH)D3, PTH and electrolyte levels. 25(OH)D3 deficiency/insufficiency were set at 20 and 30 ng/ml, respectively. All comparative and regression analyses were controlled for age, BMI and gender.
The prevalence of vitamin D deficiency/insufficiency and secondary hyperparathyroidism were 95% and 50.8%, respectively. Normal glucose tolerance (NGT), impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) were found in 37.8%, 40.5% and 21.7% of cases, respectively. Large variations in metabolic parameters were seen across categories of vitamin D status, but the only significant differences were found for C-peptide, tryglicerides, LDL- and HDL-cholesterol levels (p < 0.05 for all). The prevalence of vitamin D deficiency was documented to be slightly but significantly more frequent in glucose-intolerant patients (IFG + IGT + T2DM) compared to the -normotolerant counterpart (87% vs. 80%, p < 0.05). In partial correlation analyses, there was no association between vitamin D levels and glucose-related markers but for HbA1c (r = -0.091, p < 0.05), and both basal and OGTT-stimulated insulin levels (r = 0.097 and r = 0.099; p < 0.05 for all). Vitamin D levels were also correlated to HDL-cholesterol (r = 0.13, p = 0.002). Multivariate regression analysis inclusive of vitamin D, age, BMI, gender and fat mass as independent variables, showed that vitamin D was capable of predicting HbA1c levels (β = -0.101, p < 0.05).
Given the inherent effect of obesity on vitamin D and glucose homeostasis, current data suggest a potential independent role for vitamin D in the regulation of glucose metabolism in a setting of obese patients previously unknown to harbour glucose metabolism abnormalities.
过去几十年对与葡萄糖稳态相关的维生素D生理学有了深入了解。由于肥胖对维生素D和葡萄糖耐量的内在影响，仍存在不确定性。
评估在先前未知患有葡萄糖代谢异常的严重肥胖个体中，维生素D与葡萄糖异常之间的关系。
三级医疗中心。
524名肥胖患者（年龄50.3±14.9岁；体重指数，47.7±7.3kg/m²），通过口服葡萄糖耐量试验（OGTT）、糖化血红蛋白（HbA1c）和血脂谱进行筛查。通过25(OH)D3、甲状旁腺激素（PTH）和电解质水平评估维生素D状态。25(OH)D3缺乏/不足分别设定为20和30ng/ml。所有比较和回归分析均对年龄、体重指数和性别进行了校正。
维生素D缺乏/不足和继发性甲状旁腺功能亢进的患病率分别为95%和50.8%。正常糖耐量（NGT）、空腹血糖受损（IFG）或糖耐量受损（IGT）以及2型糖尿病（T2DM）分别在37.8%、40.5%和21.7%的病例中被发现。在不同维生素D状态类别中观察到代谢参数有很大差异，但仅在C肽、甘油三酯、低密度脂蛋白和高密度脂蛋白胆固醇水平方面发现了显著差异（所有p<0.05）。与糖耐量正常的患者相比，糖耐量异常的患者（IFG+IGT+T2DM）中维生素D缺乏的患病率略高但显著更高（87%对80%，p<0.05）。在偏相关分析中，除了HbA1c（r=-0.091，p<0.05）以及基础和OGTT刺激后的胰岛素水平（r=0.097和r=0.099；所有p<0.05）外，维生素D水平与葡萄糖相关标志物之间无关联。维生素D水平也与高密度脂蛋白胆固醇相关（r=0.13，p=0.002）。将维生素D、年龄、体重指数、性别和脂肪量作为自变量的多变量回归分析表明，维生素D能够预测HbA1c水平（β=-0.101，p<0.05）。
鉴于肥胖对维生素D和葡萄糖稳态的内在影响，目前的数据表明，在先前未知存在葡萄糖代谢异常的肥胖患者中，维生素D在调节葡萄糖代谢方面可能具有潜在的独立作用。
