Subclinical Hypothyroidism with TSH>7 mIU/l and≤10 mIU/l and Coronary Artery Disease.

The association of subclinical hypothyroidism (SCH) with increased cardiovascular risk is controversial when thyroid-stimulating hormone (TSH) concentration is<10 mIU/l, as well as its association with a higher coronary artery calcium score (CACS) in individuals with low cardiovascular risk. This study evaluated coronary artery disease (CAD) by CACS in asymptomatic, low-cardiovascular risk women with SCH and TSH>7 mIU/l and≤10 mIU/l untreated for 5 years after diagnosis. The CACS was obtained for two groups of women with low cardiovascular risk. Group A consisted of 32 women with mild SCH (TSH>7 mIU/l and≤10 mIU/l) who remained untreated for 5 years, and group B consisted of 32 euthyroid women matched for age and body mass index to group A. The CACS ranged from 0 to 350 (median 0, 25-75% interval: 0-10) in group A and from 0 to 280 (median 0, 25-75% interval: 0-0) in group B. Scores>0 and≥10 were significantly more frequent in group A (40.6 vs. 12.5% and 25 vs. 3.1%, respectively). A CACS≥100 was also more frequent in group A (18.75 vs. 3.1%), but the difference was not significant (p=0.1). The results of the study suggest that long-term SCH with TSH>7 mIU/l and ≤ 10 mIU/l is associated with a higher risk of CAD in individuals≤65 years, even in those with low cardiovascular risk.