The clinical feature research of type 2 diabetes mellitus combined with subclinical hypothyroidism

Abstract

Objective To investigate the clinical feature of type 2 diabetes mellitus combined with subclinical hypothyroidism to provide the clinical evidence for treatment.Methods One hundred and twenty-eight type 2 diabetes mellitus patients combined with subclinical hypothyroidism were selected as observation group,200 type 2 diabetes mellitus patients combined with normal thyroid function were selected as control group.The clinical indexes such as body mass index (BMI),glycosylated hemoglobin (HbA1c),fasting plasma glucose (FPG),2-hour postprandial plasma glucose (2 h PPG),fasting C-peptide (FCP),2-hour postprandial C-peptide (2 h PCP),triglyceride (TG),total cholesterol (TC),low-density lipoproteincholesterol (LDL-C),high density lipoprotein-cholesterol (HDL-C),lipoprotein (a) [LP (a)],homocysteine (Hcy),24-hour microalbuminuria (24 h UMALB) were compared between two groups.10.0 mU/L thyroid stimulating hormone (TSH) was used as the cut point and patients in observation group were divided into two groups (＞ 10.0 mU/L group,4.0-10.0 mU/L group),the above indexes were compared between two groups,and the correlation of TSH and clinical indexes was analyzed.In TSH 4.0-10.0 mU/L group,the incidence of diabetic nephropathy,diabetic retinopathy,diabetic vascular disease between Hcy normal or abnormity was compared.Results The level of BMI,FPG,FCP,TG,TC,LDL-C,LP (a) and Hcy between observation group and control group had significant difference [(27.8 ± 2.8) kg/m2 vs.(24.6 ± 3.2) kg/m2,(8.64 ± 2.79) mmol/L vs.(6.71 ± 3.65) mmol/L,(1.99 ± 1.24) μ g/L vs.(2.56 ± 1.03) μ g/L,(3.26 ± 0.76) mmol/L vs.(2.04 ± 0.18) mmol/L,(6.08 ± 1.74) mmol/L vs.(4.95 ± 2.11) mmol/L,(3.86 ± 2.01) mmol/L 比 (2.45 ± 1.99) mmol/L,(0.64 ± 0.52) g/L vs.(0.44 ± 0.12) g/L,(20.68 ± 4.66) μ mol/L vs.(15.07 ± 3.45) μ mol/L] (P ＜ 0.05 or ＜ 0.01).The level of TG,TC,LP (a),Hcy and 24 h UMALB between TSH ＞ 10.0 mU/L group and TSH 4.0-10.0 mU/L group had significant difference [(3.88 ± 0.45) mmol/L vs.(2.12 ± 0.61) mmol/L,(6.88 ± 1.44) mmol/L vs.(5.79 ± 0.86) mmol/L,(0.88 ± 0.09) g/L vs.(0.50 ±0.10) g/L,(24.13 ±2.10) μmol/L vs.(19.54 ±3.18) μmol/L,(100.10 ±24.18) mg/24 h vs.(80.21 ± 18.99) mg/24 h](P＜0.01 or ＜0.05).In TSH ＞ 10.0 mU/L group,TG (r =0.681),TC (r =0.840),LP(a)(r =0.692),Hcy (r =0.774) and 24 h UMALB (r =0.722) was positively related with TSH by Spearman correlation analysis.In TSH 4.0-10.0 mU/L group,the incidence of diabetic nephropathy,diabetic retinopathy and diabetic vascular disease was significantly increased in patients with high Hcy [12.9％(4/31) vs.7/19、22.6％(7/31) vs.10/19、16.1％(5/31) vs.9/19](P＜ 0.05).Conclusions Type 2 diabetes mellitus combined with subclinical hypothyroidism may have more obvious lipid abnormity,more pronounced insulin resistance,and may be more likely to have macrovascular and microvascular complication.Patients of TSH ＞ 10.0 mU/L or TSH 4.0-10.0 mU/L with high Hcy should be given a small dose of thyroid hormone replacement therapy actively. Key words: Diabetes mellitus, type 2; Hypothyroidism; Thyroid stimulating hormone; Homocysteine