Serum high density lipoprotein cholesteral (HDL-C) levels were measured in 103 hyperthyr- oid and 16 hypbthyroid patients.HDL-C was reduced in 81 female hyperthyroid patients as co- mpared to 151 euthyroid women as control:52.9±16.1 vs 65.5±20.2mg%(mean±SD)P<0.01
and 22 male patients as compared to 157 healthy men:52.7±14.3vs 61.6±13.9mg% P<0.01. When 31 female patients were restudied after restoration of normal thyroid function
serum HDL-C increased from 50.1±13.3 to 70.5±14.1(P<0.01).In addition 16 hypothyroid women HDL-C levels were increased as compared to the euthyroid group:75.4±13.0 vs 65.5±20.2mg% P<0.05;ten of them were restudiced after throid hormone replament therapy