title: Effect of L-thyroxine replacement on apolipoprotein B-48 in overt and subclinical hypothyroid patients.
abstract: Apolipoprotein B-48 (ApoB-48) is a constituent of chylomicrons and chylomicron remnants, and is thought to be one of the risk factors for atherosclerosis.  We evaluated the effect of L-thyroxine (L-T(4)) replacement on serum ApoB-48 levels in patients with primary hypothyroidism.  Eighteen patients with overt hypothyroidism (OH) and 18 patients with subclinical hypothyroidism (SH) participated in the study.  The lipid profiles, including ApoB-48, were measured in patients with hypothyroidism before and 3 months after L-T(4) replacement.  After L-T(4) replacement, the serum concentrations of all lipoproteins, exclusive of lipoprotein(a) (Lp(a)), were significantly decreased in patients with OH.  In patents with SH, the serum levels of total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C), remnant-like particle cholesterol (RLP-C), apolipoprotein B (ApoB), and ApoB-48 decreased significantly after L-T(4) replacement.  The serum levels of triglycerides (TG), HDL-C, low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA-1), and Lp(a) did not change significantly.  In all 36 patients, the reduction in the ApoB-48 levels correlated significantly with the reduction in TSH levels (r = 0.39, P<0.05).  This study showed clearly that L-T(4) replacement might reduce serum levels of ApoB-48 in both OH and SH patients.  Such altered serum levels of ApoB-48 in patients with OH and SH may be related to the disturbed metabolism of chylomicron remnants in patients with hypothyroidism.
authors.affiliation: Kuma Hospital, Kobe 650-0011, Japan. ito02@kuma-h.or.jp
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ito
authors.forename: Akira
authors.initials: A
authors.lastname: Kitanaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Arishima
authors.forename: Takumi
authors.initials: T
authors.lastname: Kudo
authors.forename: Eijun
authors.initials: E
authors.lastname: Nishihara
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Kubota
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Amino
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hiraiwa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hanafusa
authors.forename: Akira
authors.initials: A
authors.lastname: Miyauchi
mesh_terms: D000328:Adult; D000368:Aged; D053283:Apolipoprotein B-48 / Q000097:blood*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D053283:Apolipoprotein B-48; D008055:Lipids; D013974:Thyroxine