Apolipoprotein E phenotype affects the malondialdehyde-modified LDL concentration and forearm endothelial function in postmenopausal women.
OBJECTIVE
We investigated whether the apolipoprotein E (apo E) phenotype affects the serum concentration of malondialdehyde-modified low-density lipoprotein (MDA-LDL) or forearm endothelial function in postmenopausal women.


METHODS
Individuals were divided into three groups according to their apo E phenotype: E2 (E2/2 and E2/3, n = 12); E3 (E3/3, n = 71); and E4 (E3/4 and E4/4, n = 27). The serum concentrations of lipids and MDA-LDL were measured. Forearm blood flow during reactive hyperaemia and after sublingual nitroglycerin administration was measured by strain-gauge plethysmography.


RESULTS
The serum concentrations of total and LDL cholesterol were significantly higher in the E4 group than in the E2 group (P < 0.05) or in the E3 group (P < 0.05). The serum apo B concentration was significantly higher in the E4 group than in the E2 group (P < 0.05). The serum concentrations of high density lipoprotein (HDL) cholesterol and nitrite/nitrate were significantly lower in the E4 group than in the E2 group (P < 0.05). Other lipid concentrations did not differ in the three groups. The serum MDA-LDL concentration was highest in the E4 group, and was lowest in the E2 group (E2: 91.1 +/- 6.9 IU/l, E3: 112.3 +/- 5.9 IU/l, E4: 128.8 +/- 9.9 IU/l; P < 0.05). The forearm blood flow response to reactive hyperaemia was lowest in the E4 group, and highest in the E2 group (E2: 52.2 +/- 5.8 ml/min per 100 ml tissue, E3: 40.7 +/- 1.7 ml/min per 100 ml tissue, E4: 33.4 +/- 2.4 ml/min per 100 ml tissue; P < 0.05). The forearm blood flow changes in response to nitroglycerine were similar between all three groups.


CONCLUSIONS
The apo E phenotype affects the serum MDA-LDL concentration and forearm endothelial function in postmenopausal women.
Tsuda
Mikio
M
Department of Obstetrics and Gynaecology, Graduate School of Biomedical Science, Hiroshima University, Hiorshima, Japan. mtsuda@hiroshima-u.ac.jp
Sanada
Mitsuhiro
M
Higashi
Yukihito
Y
Hara
Yoshiko
Y
Kodama
Ichiro
I
Chayama
Kazuaki
K
Yoshizumi
Masao
M
Ohama
Koso
K
D000368:Aged; D000704:Analysis of Variance; D001055:Apolipoproteins B / Q000032:analysis; D001057:Apolipoproteins E / Q000032:analysis* / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D007525:Isoelectric Focusing; D008077:Lipoproteins, LDL / Q000097:blood*; D008875:Middle Aged; D005996:Nitroglycerin; D010641:Phenotype; D010991:Plethysmography; D017698:Postmenopause / Q000097:blood*; D012039:Regional Blood Flow; D014665:Vasodilator Agents
D001055:Apolipoproteins B; D001057:Apolipoproteins E; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008077:Lipoproteins, LDL; D014665:Vasodilator Agents; D002784:Cholesterol; D005996:Nitroglycerin