[Correlation of thyroid-stimulating hormone with metabolic syndrome in euthyroid male elders]

To explore the relationship between thyroid-stimulating hormone (TSH) and metabolic syndrome (MS) and its components in euthyroid male elders.

For this cross-sectional study, 307 euthyroid male elders aged over 60 years participating in a routine annual health screening examination at our hospital during May-June 2011 were enrolled. Their mean age was (72.6 ± 7.9) years. Height, weight, blood pressure, blood glucose, blood lipids, fasting insulin levels and thyroid functions (TT3, TT4, FT3, FT4, TSH, TgAb & TPOAb) were measured. And the association of thyroid functions and the presence of MS and its components was analyzed.

The prevalence of MS was 40.7% (125/307). The TSH level was significantly higher in the MS and obese group than that in control group ((2.6 ± 1.1) vs (2.4 ± 1.0) mU/L, P = 0.014; (2.7 ± 1.1) vs (2.3 ± 1.1)mU/L, P = 0.007). The prevalence of MS and obesity showed a gradual increase according to the TSH tertiles. When comparing subjects in the highest and lowest tertile of TSH, the former group demonstrated 1.872 and 1.904-fold increases in the odds ratio for obesity and MS after adjusting for age and homeostasis model assessment for insulin resistance (HOMA-IR) (95%CI: 1.051-3.332, P = 0.033; 95%CI: 1.070-3.387, P = 0.028) . Logistic regression analysis showed that the TSH levels were independent influencing factors for MS in male elders (OR = 1.324, 95%CI:1.042-1.683) .

High circulating TSH level, albeit normal, is associated with elevated risk for metabolic syndrome in male elders.