Elevated thyroid stimulating hormone levels are associated with metabolic syndrome in euthyroid young women

Abstract

Background/AimsThe existence of an association between thyrotropin (thyroid stimulating hormone, TSH) levels and metabolic derangement in euthyroid subjects is controversial. We examined the association between high normal TSH levels and metabolic syndrome in healthy young women.MethodsThe study recruited 2,760 young female volunteers (age, 18 to 39 years) with TSH levels in the normal range (0.3 to 4.5 mU/L). We defined metabolic syndrome using the 2007 International Diabetes Federation criteria. Using a TSH level of 2.5 mU/L as an upper reference limit, as recommended by the National Academy of Clinical Biochemistry, we divided the subjects into high-(n = 453) and low-TSH groups (n = 2,307).ResultsThe prevalence of metabolic syndrome was significantly higher in the high-TSH group than in the low-TSH group (7.5% vs. 4.8%, p = 0.016). Central obesity (22.3% vs. 17.3%, p = 0.012) and hypertriglyceridemia (8.0% vs. 4.2%, p = 0.0007) were significantly more frequent in the high-TSH group than in the low-TSH group. Waist circumference, systolic and diastolic blood pressure, and triglycerides were significantly associated with the TSH level after adjusting for age and body mass index (BMI). Subjects in the high-TSH group had a 2-fold greater risk of metabolic syndrome than subjects in the low-TSH group after adjusting for age and BMI (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.2).ConclusionsHealthy young women with TSH levels > 2.5 mU/L should be assessed for the presence of metabolic syndrome, even if their TSH levels are in the normal range.

A Study on Association between Thyroid Stimulating Hormone Levels and Metabolic Syndrome Components

“…[20] A significant correlation between TSH and both the 2-hour post-load plasma insulin (2 hr-PG) and glucose area under the curve (AUC), suggests that elevated TSH levels are associated with hyperglycemia or impaired glucose tolerance. [21] Similar to our study, a positive, linear association between systolic and diastolic blood pressure and TSH levels was reported by Oh et al [21] The antinatriuretic effect of insulin stimulates renal sodium re-absorption, which may be increased in individuals with insulin resistance, and this effect may play an important role for development of hypertension in the metabolic syndrome. [22] …”

The prevalence of the metabolic syndrome increases through the quartiles of thyroid stimulating hormone in a population-based sample of euthyroid subjects

“…Oh and cols. reached somewhat similar conclusions in young women (18). Each one of those studies had a narrower age window of the target population in contrast to the wide age range of the current work (20-94 years).…”

Pattern of Thyroid Dysfunction in Patients with Metabolic Syndrome and Its Relationship with Components of Metabolic Syndrome

“…WC, systolic and diastolic blood pressure, and TG were significantly associated with TSH levels, though fasting hyperglycemia and low HDL-C levels were not significantly associated with TSH levels [26]. Similarly, a recent study in Taiwan by Lai et al [16] explored the relationship between serum TSH levels and components of MetS, concluding that even slight increases in TSH, as in SCH, may be a MetS risk factor; in that study, TSH levels were significantly higher in the MetS group than in the non-MetS group.…”