A low-calorie diet improves endothelium-dependent vasodilation in obese patients with essential hypertension.

Abstract

BACKGROUND:

Both obesity and hypertension are associated with endothelial dysfunction. The purpose of this study was to investigate the effects of a low-calorie diet on endothelial function in obese patients with essential hypertension.

METHODS:

We measured forearm blood flow (FBF) during intra-arterial infusion of acetylcholine (ACh; 7.5, 15, 30 microg/min), an index of endothelium-dependent vasodilation, and isosorbide dinitrate (ISDN; 0.75, 1.5, 3.0 microg/min), an index of endothelium-independent vasodilation, in obese patients with essential hypertension before and after 2 weeks on a low-calorie diet (800 kcal/d). The study included 11 obese hypertensive Japanese patients (mean body mass index, 30.8 +/- 3.6 kg/m2). Fifteen healthy Japanese normotensive individuals were recruited as a control group.

RESULTS:

In obese patients with hypertension, the response of FBF to ACh was attenuated compared to healthy individuals (P < .001). Caloric restriction reduced body weight from 77.5 +/- 15.0 to 73.2 +/- 13.5 kg (P < .01), the mean blood pressure from 118.4 +/- 8.7 to 105.7 +/- 8.5 mm Hg (P < .01), fasting plasma insulin from 85.8 +/- 22.8 to 64.8 +/- 27.0 pmol/L (P < .05), serum total cholesterol from 5.30 +/- 0.76 to 4.67 +/- 0.58 mmol/L (P < .05), and low density lipoprotein cholesterol from 3.80 +/- 0.48 to 3.29 +/- 0.44 mmol/L (P < .05). Basal FBF was similar before and after weight reduction. Caloric restriction enhanced the response of FBF to ACh (P < .05), but did not alter the response to ISDN. The intra-arterial infusion of NG-monomethyl-L-arginine (8 micromol/min), a nitric oxide synthase inhibitor, decreased the enhanced ACh-induced blood flow response induced by caloric restriction.

CONCLUSIONS:

The present findings suggest that the caloric restriction improves endothelial-dependent vasodilation through an increased release of nitric oxide in obese hypertensive patients.

• Authors: Shota Sasaki, Yukihito Higashi, Keigo Nakagawa, Masashi Kimura, Kensuke Noma, Satoshi Sasaki, Keiko Hara, Hideo Matsuura, Chikara Goto, Tetsuya Oshima, Kazuaki Chayama
• Journal: American journal of hypertension (Am J Hypertens) Vol. 15 Issue 4 Pt 1 Pg. 302-9 (Apr 2002) ISSN: 0895-7061 [Print] United States
• PMID: 11991214 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cholesterol, LDL
• omega-N-Methylarginine
• Nitric Oxide
• Acetylcholine

Topics

• Acetylcholine (pharmacology)
• Adult
• Aged
• Cholesterol, LDL (blood)
• Endothelium, Vascular (physiology)
• Energy Intake
• Female
• Forearm (blood supply)
• Humans
• Hypercholesterolemia (physiopathology)
• Hypertension (physiopathology)
• Male
• Middle Aged
• Nitric Oxide (physiology)
• Obesity (physiopathology)
• Regional Blood Flow (drug effects)
• Vascular Resistance (drug effects)
• Vasodilation
• omega-N-Methylarginine (pharmacology)