RESULTS:
Thyrotropin and free
thyroxine confirmed
hypothyroidism; low
thyroglobulin and radioiodine uptake indicated near absence of thyroid tissue.
LDL cholesterol (125 ± 35 vs. 167 ± 40 mg/dL; p = 0.0002),
HDL cholesterol (HDL-C; 39 ± 8 vs. 46 ± 10 mg/dL; p = 0.0025), non-HDL-C (149 ± 38 vs. 201 ± 46 mg/dL; p < 0.0001), unesterified
cholesterol (53 ± 10 vs. 70 ± 16 mg/dL; p = 0.0003),
apolipoprotein (
apo) A-I (1.32 ± 0.19 vs. 1.44 ± 0.22 g/L; p < 0.04), and
apo B (0.97 ± 0.25 vs. 1.31 ± 0.28 g/L; p < 0.0001) plasma concentrations were all higher in
hypothyroidism compared to values in the euthyroid state, but
triglycerides and Lp(a) were unchanged. There were no changes in HDL particle size and
lipid composition,
cholesteryl ester transfer protein and
lecithin cholesterol acyltransferase concentrations and in
paraoxonase-1 activity. Regarding the in vitro assay to estimate
lipid transfer to HDL, there were no changes when comparing the euthyroid to the hypothyroid state, but when adjusted for HDL-C, the unesterified
cholesterol (0.14 ± 0.03 vs. 0.11 ± 0.02; p < 0.0001),
triglycerides (0.11 ± 0.02 vs. 0.09 ± 0.02; p < 0.0001),
phospholipids (0.44 ± 0.09 vs. 0.40 ± 0.07; p = 0.0205), and esterified
cholesterol (0.14 ± 0.03 vs. 0.13 ± 0.03; p = 0.0043) transfer to HDL were all diminished in
hypothyroidism.
CONCLUSIONS: