The correlation of metabolic syndrome with low triiodothyronine syndrome, subclinical hypothyroidism and hyperhomocysteinemia in the elderly

Abstract

Objective To explore the correlation of metabolic syndrome(MS)with low triiodothyronine(T3)syndrome(LT3S, or It is known as ESS: euthyroid sick syndrome), subclinical hypothyroidism(SCH)and a high serum total homocysteine(tHcy)level(hyperhomocysteinemia)in elderly patients. Methods We retrospectively analyzed thyroid function, serum glucose, lipids and homocysteine(Hcy)level in 83 MS patients(MS group), 30 patients with low T3 syndrome(low T3 group), 41 patients with SCH(SCH group)and 80 healthy individuals(control group)aged over 60 years from January 2015 to March 2017 in outpatient and inpatient departments of our hospital.The correlations of thyroid function and serum Hcy level with MS components were analyzed by multiple Logistic regression model. Results The incidence of low T3 syndrome and SCH in MS patients was 37.3%(31/83)and 49.4%(41/83), respectively.Low T3 group versus control group showed the lower levels in free triiodothyronine, FT4, folic acid, and Hcy, with statistically significant differences(all P 5.5 mU/L had decreased FT3 which occurred later than the rise of TSH(P<0.05). Univariate correlation analysis showed that FT3 was negatively correlated with Hcy(P<0.01), and TSH was negatively correlated with high-density lipoprotein cholesterol(P<0.01). Multivariate linear regression analysis found linear correlations of TSH with triglyceride, high-density lipoprotein cholesterol, and Hcy(all P<0.05). Logistic regression analysis showed that FT3, Hcy and TSH are highly associated with hypertension after adjustment for gender and body mass index(all P<0.05). Decreased FT3(P<0.01), elevated Hcy(P<0.05), and increased TSH(P<0.05)were independent risk factors for MS in elderly patients. Conclusions The incidences of low T3 syndrome and SCH are increased with aging.FT3, TSH, and Hcy are independent risk factors for MS in the elderly. Key words: Metabolic syndrome X; Low T3 syndrome; Hypothyroidism; Homocysteine