LCAT-dependent conversion rate is a determinant of plasma prebeta1-HDL concentration in healthy Japanese.
BACKGROUND
Prebeta1-HDL acts as a primary acceptor of cellular cholesterol. Prebeta1-HDL is converted into alpha-migrating high-density lipoprotein (HDL) by lecithin/cholesterol acyltransferase (LCAT). We examined whether the LCAT-dependent conversion rate of prebeta1-HDL is a determinant of the plasma prebeta1-HDL concentration in healthy Japanese.


METHODS
We measured the conversion half time (CHT(prebeta1)), the time required for 50% of baseline prebeta1-HDL to be changed into alpha-migrating HDL by LCAT, in 100 healthy Japanese (47 men, 53 women, 22-88 years).


RESULTS
Prebeta1-HDL concentration, as determined by immunoassay, was significantly lower in younger women (<50 years, n=24) than in older women (>or=50 years, n=29) (16.8+/-3.3 vs. 21.7+/-8.0 mg/l apolipoprotein AI (apoAI), p<0.01). There was no significant difference in prebeta1-HDL concentration between younger (n=24) and older (n=23) men (21.2+/-6.8 vs. 22.5+/-6.6 mg/l apoAI). The mean CHT(prebeta1) for all subjects was 47.4+/-13.0 min, and was not influenced by gender or age. Prebeta1-HDL concentration was positively correlated with CHT(prebeta1) in both men and women, suggesting that high prebeta1-HDL levels may reflect delayed conversion of prebeta1-HDL.


CONCLUSIONS
LCAT-dependent conversion rate is a determinant of plasma prebeta1-HDL concentration in healthy Japanese. We speculate that prebeta1-HDL concentration may be used as a metabolic marker for HDL maturation.
Miida
Takashi
T
Division of Clinical Preventive Medicine, Department of Community Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Niigata, Niigata 951-8510, Japan. miida@med.niigata-u.ac.jp
Obayashi
Konen
K
Seino
Utako
U
Zhu
Ying
Y
Ito
Takako
T
Kosuge
Keiichiro
K
Hirayama
Satoshi
S
Hanyu
Osamu
O
Nakamura
Yuichi
Y
Yamaguchi
Toshio
T
Tsuda
Takashi
T
Saito
Yuji
Y
Miyazaki
Osamu
O
Nakamura
Yasushi
Y
Okada
Masahiko
M
D000328:Adult; D000367:Age Factors; D000368:Aged; D016632:Apolipoprotein A-I / Q000378:metabolism; D044466:Asian People; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D053442:High-Density Lipoproteins, Pre-beta; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000378:metabolism*; D012016:Reference Values; D012737:Sex Factors; D002785:Sterol O-Acyltransferase / Q000378:metabolism*
D016632:Apolipoprotein A-I; D008078:Cholesterol, LDL; D053442:High-Density Lipoproteins, Pre-beta; D008075:Lipoproteins, HDL; D002785:Sterol O-Acyltransferase; D007862:Phosphatidylcholine-Sterol O-Acyltransferase