Thyroid function profile and differential serum lipid and lipoproteins in Africans with endemic goitre.

Serum total thyroxine (TT4), total triiodothyronine (TT3), thyrotrophine (TSH), thyroxine binding globulin (TBG), total lipids, triglycerides, total cholesterol, beta lipoprotein and beta lipoprotein cholesterol level were measured in 68 goitrous subjects and 4 agoitrous cretins by the techniques based on enzyme immunoassay (ELISA) (for thyroid parameters) and enzyme substrate principle (for lipid and lipoproteins) using commercial test kits (Boehringer Mannheim, W. Germany) and the results were matched with those derived from 59 clinically normal control subjects. The mean values of serum TT3, TBG, TSH and T3/T4 ratio showed positive correlations with the goitre size (r > 0.8, P < 0.005) while mean serum TT4 was negatively correlated (r > -0.9, P < 0.005). Typical biochemical features of hypothyroidism on serum lipid and lipoprotein profile were seen throughout, the changes being more marked in cretins. However, the serum lipid and lipoproteins were also, to some extent, found to be positively related to the thyroid size. In addition, a number of patients also showed variations in the serum lipid and lipoprotein levels appropriate to their compensated thyroid functional status in endemic goitre (as reflected by low TT4, raised TT3 and raised T3/T4 quotients).