Risk factors for cardiovascular disease in patients with subclinical hypothyroidism.
BACKGROUND
The relationship between subclinical hypothyroidism (SCH) and cardiovascular disease is not fully understood. We investigated risk factors for cardiovascular disease (lipid profile, lipoproteins, insulin resistance, C-reactive protein [CRP] homocysteine [Hcy] and fibrinogen levels) and their relationships with thyroid hormones in SCH patients and controls.


METHODS
Thirty-eight SCH patients and 44 controls were enrolled in this study. No patients had any substantial confounding medical conditions (including diabetes mellitus or coronary heart disease) or were taking thyroid-related medication.


RESULTS
Serum total cholesterol (P<0.05), low-density lipoprotein cholesterol (P<0.05) and triglycerides (P<0.001) were higher in patients with SCH than in controls. Serum lipoprotein(a) (Lp[a]) levels were higher in SCH subjects but this difference did not reach statistical significance (P=0.07). No significant differences were noted in CRP, Hcy, fibrinogen, high-density lipoprotein cholesterol, apolipoprotein A-1, apolipoprotein B (Apo B) or insulin resistance between patients with SCH and controls (in all cases, P>0.05). Free triiodothyronine (FT3) negatively correlated with Apo B (r=.0.46, P=0.005) and Lp(a) (r=.0.31, P=0.03) in patients with SCH and negatively correlated with Lp(a) (r=.0.30, P=0.04) in controls. All of these parameters were comparable between patients with thyroid-stimulating hormone (TSH) >10 microIU/ml and TSH <10 microIU/ml (in SCH patients, P>0.05).


CONCLUSIONS
Our results suggest that SCH is associated with some lipid and lipoprotein abnormalities. Our results also suggest that this association does not depend on the subject's TSH level.
Toruner
Fusun
F
Department of Endocrinology and Metabolism, Gazi University, Faculty of Medicine, Ankara, Turkey.
Altinova
Alev E
AE
Karakoc
Ayhan
A
Yetkin
Ilhan
I
Ayvaz
Goksun
G
Cakir
Nuri
N
Arslan
Metin
M
D000328:Adult; D050197:Atherosclerosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000150:complications; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D012307:Risk Factors
D008055:Lipids; D008074:Lipoproteins