Plasma homocysteine concentrations and serum lipid profile as atherosclerotic risk factors in subclinical hypothyroidism.
OBJECTIVE
Because subclinical thyroid dysfunction may be a risk factor for cardiovascular disease, we evaluated the atherosclerosis tendency in subclinical hypothyroid (SCH) patients.


METHODS
Fifty-three subclinical hypothyroid patients (serum thyrotropin [TSH] concentrations >4.12 mU/L) were compared with a control group of 50 euthyroid subjects whose age, sex and body mass indices were similar to the patient group. We tested whether serum TSH concentrations were correlated with plasma total homocysteine concentration (tHcy), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and triglycerides (TG).


RESULTS
There was a significant statistical difference between the patient and control groups for normal free T4 (1.02+/-0.17 vs. 0.86+/-0.13, P<.001), TSH (1.64+/-1.02 vs. 6.62+/-2.61, P<.001), TC (185+/-39 vs. 206 +/- 42, P=.01), TG (103+/-54 vs. 132+/-85, P=.04), LDL-C (114+/-33 vs. 127+/-36, P=.04), and TC/HDL-C (3.81+/-106 vs. 4.19+/-1.02, P=.04), respectively. No statistically significant difference was found between the two groups for HDL-C, VLDLC, LDL-C/HDL-C, and tHcy. Serum TSH was significantly correlated with plasma tHcy (r=0.55; P=.001), TC (r=0.52; P=.001), LDL-C (r=0.49; P=.001), TC/HDL-C (r=0.38; P=.002) and LDL-C/HDL-C (r=0.36; P=.004) across all participants.


CONCLUSIONS
Our study suggests that the atherogenicity of SCH is not mediated by hyperhomocysteinemia. Associated hyperlipidemia may explain the observed increased risk of coronary artery disease in patients with SCH.
Turhan
Serpil
S
Department of Clinical Biochemistry, Ankara Numune Education and Research Hospital, Ankara, Turkey.
Sezer
Sevilay
S
Erden
Gonul
G
Guctekin
Ali
A
Ucar
Fatma
F
Ginis
Zeynep
Z
Ozturk
Ozlem
O
Bingol
Sezin
S
D000328:Adult; D050197:Atherosclerosis / Q000209:etiology*; D002318:Cardiovascular Diseases / Q000209:etiology; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007037:Hypothyroidism / Q000150:complications*; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D008055:Lipids; D006710:Homocysteine; D013972:Thyrotropin; D013974:Thyroxine