Low body mass index is a risk factor for impaired endothelium-dependent vasodilation in humans: role of nitric oxide and oxidative stress.
OBJECTIVE
The purpose of this study was to evaluate the relationship between body mass index (BMI), including low BMIs, and endothelial function.


BACKGROUND
Epidemiologic study has demonstrated that not only obesity but also a low BMI may be a risk factor for cardiovascular disease.


METHODS
The forearm blood flow (FBF) response to acetylcholine (ACh) and isosorbide dinitrate (ISDN) was measured in 87 healthy young men (15 low BMI, 51 normal, 14 obese, and 7 extremely obese).


RESULTS
Plasma concentrations of 8-hydroxy-2'-deoxyguanosine and serum concentrations of malondialdehyde-modified low-density lipoprotein were higher in low BMI, obese, and extremely obese subjects than in normal subjects and were similar among the low BMI, obese, and extremely obese groups. The FBF response to ACh was greater in the normal group than in the other groups (p < 0.001), and was lower in the extremely obese group as compared with the other groups (p < 0.001). The ACh-stimulated vasodilation was similar between the low BMI group and the obese group. The ISDN-stimulated vasodilation was similar in all four groups. There were no significant differences in ACh-stimulated vasodilation between the four groups after the nitric oxide (NO) synthase inhibitor NG-monomethyl-L-arginine infusion. Co-infusion of vitamin C augmented the FBF response to ACh in low BMI, obese, and extremely obese groups--but not in normal BMI group.


CONCLUSIONS
These findings suggest that not only obesity but also a low BMI may be a risk factor for impaired endothelium-dependent vasodilation through the increased oxidative stress, leading to the reduced bioavailability of NO.
Higashi
Yukihito
Y
Department of Cardiovascular Physiology and Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan. yhigashi@hiroshima-u.ac.jp
Sasaki
Shota
S
Nakagawa
Keigo
K
Kimura
Masashi
M
Noma
Kensuke
K
Sasaki
Satoshi
S
Hara
Keiko
K
Matsuura
Hideo
H
Goto
Chikara
C
Oshima
Tetsuya
T
Chayama
Kazuaki
K
Yoshizumi
Masao
M
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D001783:Blood Flow Velocity / Q000187:drug effects; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D005542:Forearm / Q000098:blood supply; D006801:Humans; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D018384:Oxidative Stress / Q000187:drug effects; D010991:Plethysmography; D012307:Risk Factors; D013851:Thinness / Q000150:complications* / Q000503:physiopathology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D000975:Antioxidants; D014665:Vasodilator Agents; D009569:Nitric Oxide; D007548:Isosorbide Dinitrate; D000109:Acetylcholine; D001205:Ascorbic Acid