Evaluation of salivary and serum ADMA levels in patients with periodontal and cardiovascular disease as subclinical marker of cardiovascular risk

The purpose of this study was to evaluate endothelial function in patients with periodontitis. We evaluated forearm blood flow responses to acetylcholine and sodium nitroprusside in patients with periodontitis who had no other cardiovascular risk factors (32 men; 25+/-3 years of age), in a normal control group (20 men; 26+/-3 years of age), and in hypertensive patients with periodontitis (28 men and 10 women; 56+/-12 years of age) and without periodontitis (control group; 18 men and 6 women; 54+/-13 years of age). Forearm blood flow was measured using strain-gauge plethysmography. Circulating levels of C-reactive protein and interleukin-6 were significantly higher in the periodontitis group than in the control group. Both in healthy and hypertensive subjects, forearm blood flow responses to acetylcholine were significantly smaller in the periodontitis group than in the control group. Sodium nitroprusside-stimulated vasodilation was similar in the 2 groups. Periodontal therapy reduced serum concentrations of C-reactive protein and interleukin-6 and augmented acetylcholine-induced vasodilation in periodontitis patients with and without hypertension. After administration of N(G)-monomethyl-L-arginine, an NO synthase inhibitor, forearm blood flow response to acetylcholine was similar before and after treatment. These findings suggest that periodontitis is associated with endothelial dysfunction in subjects without cardiovascular risk factors, as well as hypertensive patients, through a decrease in NO bioavailability and that systemic inflammation may be, at least in part, a cause of endothelial dysfunction, leading to cardiovascular diseases.

This Editors' Consensus is supported by an educational grant from Colgate-Palmolive, Inc., New York, New York, and is based on a meeting of the authors held in Boston, Massachusetts, on January 9, 2009. Dr. Friedewald has received honoraria for speaking from Novartis, East Hanover, New Jersey. Dr. Kornman is a full-time employee and shareholder of Interleukin Genetics, Waltham, Massachusetts, which owns patents on genetic biomarkers for chronic inflammatory diseases. Dr. Genco is a consultant to Merck, Whitehouse Station, New Jersey. Dr. Ridker has received research support from AstraZeneca, Wilmington, Delaware; Novartis; Pfizer, New York, New York; Roche, Nutley, New Jersey; Sanofi-Aventis, Bridgewater, New Jersey; and Abbott Laboratories, Abbott Park, Illinois. Dr. Ridker has received non-financial research support from Amgen, Thousand Oaks, California. Dr. Ridker is a co-inventor on patents held by Brigham and Women's Hospital that relate to the use of inflammatory biomarkers in cardiovascular disease. Dr. Ridker is a research consultant for Schering-Plough, Kenilworth, New Jersey; Sanofi-Aventis; AstraZeneca; Isis, Carlsbad, California; Novartis; and Vascular Biogenics, Tel Aviv, Israel. Dr. Van Dyke is a co-inventor on patents held by Boston University, Boston, Massachusetts, that relate to inflammation control, including consulting fees. Dr. Roberts has received honoraria for speaking from Merck, Schering-Plough, AstraZeneca, and Novartis. All other individuals in a position to control content disclosed no relevant financial relationships.

Preclinical studies have revealed that the endogenous nitric oxide synthase inhibitor, asymmetric dimethylarginine (ADMA), increases vascular tone in cerebral blood vessels. Marked elevations of ADMA blood levels were found in patients with diseases characterized by decreased cerebral perfusion, such as ischemic stroke. Arterial stiffness is an independent predictor of stroke and other adverse cardiovascular events. The aim of this study was to investigate the influence of a systemic subpressor dose of ADMA on arterial stiffness and cerebral perfusion in humans. Using a double-blind, vehicle-controlled study design, we allocated 20 healthy men in random order to infusion of either ADMA (0.10 mg ADMA/kg per min) or vehicle over a period of 40 minutes. Arterial stiffness was assessed noninvasively by pulse wave analysis. All volunteers underwent measurement of cerebral perfusion by dynamic contrast-enhanced perfusion magnetic resonance imaging of the brain. Infusion of ADMA significantly decreased total cerebral perfusion by 15.1+/-4.5% (P=0.007), whereas blood flow in the vehicle group increased by 7.7+/-2.8% (P=0.02). ADMA also increased arterial stiffness as assessed by measurement of the augmentation index (-12.6+/-1.9 to -9.6+/-1.5, P=0.007). Our results document for the first time that subpressor doses of ADMA increase vascular stiffness and decrease cerebral perfusion in healthy subjects. Thus, ADMA is an important endogenous modulator of cerebral vascular tone and may be involved in the pathogenesis of cerebrovascular disease.