The Effect Of Subclinical Hypothyroidism On Insulin Resistance

Objective:To explore the effect of subclinical hypothyroidism,type 2 diabetes mellitus and subclinical hypothyroidism on insulin resistance.Methods:A total of 621 non-diabetic community populations in the community epidemiological survey in Shenyang in 2010 and 675 newly diagnosed type 2 diabetics in the MARCH study were selected as study subjects.Patients with type 2 diabetes were randomly distributed with hypoglycemic drugs(acarbose or metformin XR).According to the diagnostic criteria of thyroid disease,the subjects were divided into normal thyroid function group and subclinical hypothyroidism group.The normal group of thyroid function was further divided into three subgroups: 0.27 mU/L?TSH<1.0 mU/L,1.0mU/L?TSH?1.9 mU/L,1.9 mU/L<TSH?4.2 mU/L.Two groups of people(diabetics before and 24 weeks)received physical examination and blood sampling.Physical examination includes height,weight,waist circumference,hip circumference,and blood pressure.Blood sampling measurements included FPG,FINS,OGTT 2hPG,OGTT2 hINS,HbA1c,TC,TG,HDL-C,LDL-C,TSH,FT3,and FT4.Calculate HOMA-IR,HOMA-?,HOMA-IS,BMI,and WHR.Results: 1.There was no significant difference in age,gender composition,and blood pressure between the two groups(P>0.05).The body weight,BMI,waist circumference,hip circumference,WHR,TC,TG,FPG,OGTT2 hPG,HbA1c,and HOMA-IR in the diabetic population were significantly higher than those in the community(P<0.05).The HDL-C,FINS,OGTT2 hINS,HOMA-IS,and HOMA-? in the diabetic population were significantly lower than those in the community(P<0.05).2.The abnormal rate of thyroid dysfunction in patients with diabetes was significantly higher than that of the community group(16.6%vs11.3%),of which the proportion of subclinical hypothyroidism was the highest 14.7%(P < 0.05).3.The BMI,waist circumference,WHR,and HOMA-IR in the subclinical hypothyroidism group in the community were significantly higher than those in the normal population in the community(P<0.05).There was no significant difference between the normal group and the subclinical hypothyroidism group in the diabetic population(P>0.05).The FINS,OGTT2 hINS and HOMA-? in the subclinical hypothyroidism group in the community population were significantly higher than those in the normal population in the community population,normal group in the diabetes group and subclinical hypothyroidism group in the diabetic group(P<0.05).HOMA-IS in the subclinical hypothyroidism group of the community population was not significantly different with the normal group and subclinical hypothyroidism group in the diabetic group(P>0.05),which was significantly lower than that of the normal group(P<0.05).The BMI,waist circumference,hip circumference,WHR,TC,TG,HDL-C,LDL-C,FINS,OGTT2 hINS,HOMA-?,HOMA-IS,and HOMA-IR in the subclinical hypothyroidism group in the diabetic group was no significant difference with the normal group in the diabetic group(P>0.05).4.HOMA-IR,HOMA-?,and FINS in the various TSH subgroups in the normal population in the community population have a tendency to increase with the increasing of TSH.The FT3,FT4,FPG,OGTT2 hPG,and HOMA-IS in the various TSH subgroups in the normal population in the community have a tendency to decrease with increasing levels of TSH.5.Before medication: HOMA-? and HOMA-IR in TSH subgroups in the diabetic group with the normal thyroid group decrease with the increasing of TSH(P<0.05).FT4,FINS,OGTT2 hINS have a tendency to decrease with the increasing levels of TSH.After 24 weeks of treatment: There was no significant difference in HOMA-?,HOMA-IR,HOMA-IS,and FINS among the various TSH subgroups with normal diabetes mellitus(P>0.05).Comparison of improvement of each index before and after treatment: The improvement of HOMA-?,HOMA-IR,and FINS in the 0.27 mU/L?TSH<1.0 mU/L group was significantly better than that in the other two groups(P<0.05).Conclusion:1.The prevalence of thyroid disease in diabetics was significantly higher than that in the community,with subclinical hypothyroidism accounting for the largest proportion.2.The ability of subclinical hypothyroidism to cause insulin resistance is the same as the initial diabetic population.Due to the existence of insulin resistance,insulin is compensatoryly increased.Once it fails to compensate diabetes will occur.3.The insulin resistance of diabetic patients with subclinical hypothyroidism was the same as the people with simple diabetes.4.The lower TSH in the normal population ofdiabetic patients and the higher HOMA-IR,the better the improvement of insulin resistance after the treatment with hypoglycemic drugs.