Subclinical hypothyroidism and vascular risk: Αn update

Abstract

subclinical hypothyroidism (scH), defined as elevated serum thyroid-stimulating hormone (tsH) in the presence of normal circulating free thyroxine (Ft4) and triiodothyronine (t3), is a relatively common condition. replacement treatment with levothyroxine is justified only for individuals with tsH levels >10 mIU/l. serum lipid levels are influenced by thyroid status and there is evidence pointing to a link between scH and an unfavorable lipid profile. Despite some conflicting data, most studies suggest that levothyroxine treatment may exert a beneficial effect on the lipid profile in scH regarding mainly total cholesterol and low-density lipoproteincholesterol. Moreover, it appears that treatment may also improve some other markers associated with cardiovascular (cV) disease such as carotid intima media thickness ( 17-03-201317-03- , Accepted 20-10-2013 Review (FT4) and triiodothyronine (T3) levels within the reference range.1 This is a relatively common condition with a prevalence ranging from 4 to 15% in the general population and up to 20% among females aged >60 years. [2][3][4][5]

Statin intolerance – an attempt at a unified definition. Position paper from an International Lipid Expert Panel

“…Data suggests that subclinical hypothyroidism (SCH) (TSH levels > 4 and < 10 mIU/l) is related to an unfavorable lipid profile, and levothyroxine replacement therapy may also be prescribed in these patients [100]. Some data suggest that levothyroxine replacement therapy may exert a beneficial effect on total cholesterol (TC), LDL-C and other predictors of vascular risk in SCH [100].…”

“…Some data suggest that levothyroxine replacement therapy may exert a beneficial effect on total cholesterol (TC), LDL-C and other predictors of vascular risk in SCH [100]. Furthermore, it appears that in SCH, statins with or without levothyroxine, can improve endothelial function and reduce carotid intima media thickness, reliable markers associated with CVD risk [101].…”

Correlation between Thyrotropin and Fasting Lipid Profile in Patients of Sub Clinical Hypothyroidism

“…2,9,13,14,15 However, studies on the abnormalities in lipid ratios are better markers of cardiovascular risk than conventional lipid profile are rare. With this background, we conducted a cross sectional-control study, where we studied patient who were asymptomatic for Hypothyroid, but their TSH levels were below 10 ImU/L to investigate the status of their fasting lipid profile and compared them with 50 persons with normal TSH levels as controls.…”

“…2017 and free Tetriodothyronine (T 4 ), is a common disorder having a prevalence of about 7.5-8.5% in females and 2.8-4.4% in males, worldwide. 1,2 Numerous studies have shown that overt hypothyroidism is associated with abnormalities of lipid metabolism such as elevated lipids viz. VLDL( Very low density Lipoprotein) LDL (Low Density Lipoprotein) TC (Total Cholesterol) and Triglycerides (TG) thereby predisposing individuals to vascular diseases.…”

Thyroid Hormone: A Therapy for Diabetic Vascular Complications?

“…There is evidence indicating that the onset of vascular complications occurs in the early stages of hypothyroidism [14,15]. Importantly, TH therapy largely restores vascular performance, including improvement of endothelial dysfunction and restoration of coronary blood flow while delaying the progression of atherosclerosis [11,16].…”