Background: More studies have revealed role of vitamin D(VD) in chronic diseases. Our study aimed to investigate its association with thyroid function in Type 2 Diabetes Mellitus(T2DM).
Methods: 730 patients with T2DM were enrolled. Thyroid and VD levels were measured. Patients were divided into lower VD and higher VD groups according to the median. Thyroid function was compared between groups and their association was investigated.
Results: BMI, TCH, TG and FFA were significantly higher in higher VD group than lower VD group (all P<0.05). FT3 was significantly higher while TT4 and TSH were significantly higher in higher VD group than lower VD group (4.45±0.93 vs. 4.95±1.52 pmol/l, P<0.001; 104.84±21.17 vs. 99.99±23.64 nmol/l, P=0.008; 2.88±7.03 vs. 2.06±1.72 mU/l, P=0.046). VD was significantly negatively associated with BMI, HGB, LDL-C and FFA (r=-0.093, P=0.016; r=-0.082, P=0.036; r= -0.099, P=0.011; r= -0.125; P=0.001). VD were significantly positively FT3 and FT4 and negatively associated with TSH (r=0.248, P<0.001; r=0.086, P=0.025; r=-0.080, P=0.033). Adjusted for height, BMI, HGB, TCH, TG, FFA and LDL, FT3 and FT4 were still significantly positive while TSH was still significantly negatively associated with VD (r=0.227, P<0.001; r=0.089, P=0.030; r=-0.081, P=0.049). Liner Regression analysis also showed that VD was significantly associated with FT3 and negatively with TSH (β=4.144, P<0.001; β= -0.412, P=0.020). Logistic regression analysis showed that VD was a protective factor for SCH (OR: 0.987, 95%CI:0.974-0.999, P=0.035) and even adjusted for BMI, FBG, FINS, TCH and HDL (OR: 0.986, 95%CI:0.974-0.999, P=0.041). T2DM patients with SCH had lower VD levels than those without SCH(46.45±4.76 vs. 45.40±5.84nmol/l, P=0.029).
In conclusion, there was a negative relationship between VD and thyroid function in patients with T2DM. T2DM patients with SCH had lower VD levels.
X. Wang: None. Y. Huang: None. S. Qu: None.
