Relations of lysophosphatidylcholine in low-density lipoprotein with serum lipoprotein-associated phospholipase A2, paraoxonase and homocysteine thiolactonase activities in patients with type 2 diabetes mellitus.
OBJECTIVE
We studied the relations of lysophosphatidylcholine (lyso-PC) in LDL with serum lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), paraoxonase and homocysteine thiolactonase (HTLase) activities in patients with type 2 diabetes mellitus.


METHODS
Lyso-PC was measured by electrospray ionization-liquid chromatography/mass spectrometry. Paraoxonase and HTLase activities were measured with paraoxon and gamma-thiobutyrolactone as substrates, respectively.


RESULTS
Serum HTLase and paraoxonase activities were significantly suppressed in diabetic patients (n=96) compared with control (n=25), whereas serum Lp-PLA(2) did not differ in control and diabetic patients. Lyso-PC contents in LDL correlated with serum Lp-PLA(2) activity positively and with serum HTLase activity negatively. Stepwise regression analysis revealed that serum Lp-PLA(2) and HTLase activities independently contributed to lyso-PC contents in LDL. In patients with diabetic nephropathy, lyso-PC contents in LDL were increased with reduced serum HTLase and paraoxonase activities compared with control, while serum Lp-PLA(2) activity did not differ. On the other hand, 3-month treatment with simvastatin reduced both lyso-PC contents in LDL and serum Lp-PLA(2) activity in hypercholesterolemic diabetic patients, while serum HTLase or paraoxonase activities did not change.


CONCLUSIONS
Increased lyso-PC contents in LDL were associated with the suppressed HTLase activity, and serum Lp-PLA(2) and HTLase activities may be related to lyso-PC in type 2 diabetic patients.
Sonoki
Kazuo
K
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan.
Iwase
Masanori
M
Sasaki
Nobuhiro
N
Ohdo
Shigehiro
S
Higuchi
Shun
S
Matsuyama
Naoto
N
Iida
Mitsuo
M
D000328:Adult; D043303:Aryldialkylphosphatase / Q000097:blood*; D001794:Blood Pressure; D015992:Body Mass Index; D002265:Carboxylic Ester Hydrolases / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000201:enzymology*; D005260:Female; D006801:Humans; D054709:Lecithins / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood*; D008244:Lysophosphatidylcholines / Q000097:blood*; D008297:Male; D008875:Middle Aged; D054467:Phospholipases A2 / Q000097:blood*; D012016:Reference Values; D021241:Spectrometry, Mass, Electrospray Ionization
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D054709:Lecithins; D008077:Lipoproteins, LDL; D008244:Lysophosphatidylcholines; D002265:Carboxylic Ester Hydrolases; C502233:homocysteine-thiolactonase, human; D054467:Phospholipases A2; D043303:Aryldialkylphosphatase