Korean J Intern Med.  2013 Mar;28(2):180-186. 10.3904/kjim.2013.28.2.180.

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

• Oh JY
• Sung YA
• Lee HJ

• KMID: 1501773
• DOI: http://doi.org/10.3904/kjim.2013.28.2.180

Abstract

BACKGROUND/AIMS
The 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.
METHODS
The 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).
RESULTS
The 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).
CONCLUSIONS
Healthy 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.

Keyword

Thyrotropin; Euthyroid; Metabolic syndrome; Young women

MeSH Terms

Adolescent
Adult
Age Factors
Biological Markers/blood
Female
Humans
Hypertension/blood/epidemiology
Hypertriglyceridemia/blood/epidemiology
Linear Models
Metabolic Syndrome X/*blood/diagnosis/epidemiology
Obesity, Abdominal/blood/epidemiology
Odds Ratio
Prevalence
Republic of Korea
Risk Factors
Sex Factors
Thyrotropin/*blood
Up-Regulation
Young Adult