Lipoprotein(a) Concentration in Subclinical Hypothyroidism before and after Levo-Thyroxine Therapy


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Yildirimkaya M. M. , Özata M., Yilmaz K., Kilinç C., Gündoǧan M. A. , Kutluay T.

Endocrine Journal, vol.43, no.6, pp.731-736, 1996 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 6
  • Publication Date: 1996
  • Doi Number: 10.1507/endocrj.43.731
  • Title of Journal : Endocrine Journal
  • Page Numbers: pp.731-736
  • Keywords: subclinical hypothyroidism, lipoprotein(a), levo-thyroxine therapy, CORONARY-ARTERY DISEASE, B MESSENGER-RNA, RISK FACTOR, HEART-DISEASE, APOLIPOPROTEIN, PLASMA, THYROTROPIN, CHOLESTEROL, HORMONE, LP(A)

Abstract

Subclinical hypothyroidism is a frequent disorder in populations and has been shown to be a risk factor for coronary heart disease (CHD). Less is known about the contribution of lipoprotein (a) [Lp(a)] to the development of CHD in this disorder. Therefore this study was designed to evaluate Lp(a) and other lipoprotein concentrations before and after L-T4 therapy in 20 patients with subclinical hypothyroidism and 20 normal healthy subjects matched for sex, age and BMI. In the basal state of subclinical hypothyroidism, a significant increase in total cholesterol, LDL-cholesterol and apolipoprotein (apo) B concentrations was observed in patients compared with those in the control group. The mean Lp(a) concentration before treatment was 163 ± 15 mg/L. This is slightly but not significantly higher than those in the control group (131 ± 15 mg/L). Treatment of subclinical hypothyroidism with a low dose of L-T4 (25 μg daily) for 3 months after restoration of euthyroidism led to decreases in levels of Lp(a) from 163 mg/L to 126 mg/L (23% reduction, P<0.001), total cholesterol from 5.5 mmol/L to 5.1 mmol/L (7% reduction, P<0.001), LDL-cholesterol from 4.14 mmol/L to 3.63 mmol/L (12%, P<0.001), and apo B from 98 mg/dL to 86 mg/dL (12% reduction, P<0.05), but triglyceride, HDL-cholesterol and apo A-I concentrations were unchanged. These data suggest that L-T4 replacement therapy in patients with subclinical hypothyroidism has beneficial effects on the lipid profile since L-T4 replacement therapy lowered the concentrations of Lp(a) and other atherogenic lipid particles.