Tooth Loss Linked to CHD
Loss of permanent teeth may raise the risk for coronary heart disease, and the risk could increase as the extent of tooth loss worsens, reported Catherine A. Okoro and her associates at the Centers for Disease Control and Prevention, Atlanta.
Epidemiologic studies have shown a link between coronary heart disease (CHD) and tooth loss due to periodontal or other oral disease, but other studies have cast doubt on this association. Ms. Okoro and her colleagues assessed tooth loss and CHD prevalence using data from a surveillance study involving 41,891 people aged 40–79 years in the general U.S. population.
The rate of CHD was 4.7% in subjects who had all their natural teeth but was 5.7% in those who were missing 1–5 teeth, 7.5% in those missing 6–31 teeth, and 8.5% in those missing all of their teeth due to tooth decay or gum disease.
In addition, patients with CHD were more likely to be missing several teeth (29.4%) or all of their teeth (23.6%) than were people who didn't have CHD (17.6% and 10.1%, respectively). Like other local infections, periodontal infections are thought to raise systemic levels of inflammatory mediators and thus promote inflammation-associated atherosclerotic processes, the investigators said (Am. J. Preventive Med. doi:10.1016/j.amepre.2005.07.006).
This study was not designed to identify any possible causal links between tooth loss and CHD. It is possible that the findings simply indicate that people who are more health conscious have better oral health and lower CHD risk, they noted.
Diesel Fumes Harm Vascular Function
Inhaling diesel exhaust impairs two complementary aspects of vascular function: the regulation of vascular tone and the performance of endogenous fibrinolysis.
This may be the mechanism by which air pollution exerts its well-known adverse effects on the cardiovascular system, reported Dr. Nicholas L. Mills of Edinburgh University and his associates.
Noting that transient exposure to road traffic appears to raise the risk of MI and that long-term residence near major highways increases cardiopulmonary mortality, Dr. Mills and his associates assessed the effects of diluted diesel exhaust inhalation on endothelial function in a study involving 30 healthy male nonsmokers aged 20–38 years.
Half of the subjects were randomly assigned to breathe diesel exhaust in a specially designed chamber while performing moderate exercise and resting. The other 15 subjects breathed normal room air and performed the same activities in the chamber. In a second session 2 weeks later, all subjects were crossed over to the other group. The exhaust was produced by an idling diesel engine. Over 90% of it was shunted away, and the remainder was diluted with room air and fed into the testing chamber, the researchers said (Circulation 2005;112:3930–6).
Breathing diesel fumes was found to impair the vasomotor responses in the forearm vascular bed to both endothelium-dependent and endothelium-independent vasodilators, but it had no effect on the vasomotor response to a calcium channel antagonist. This suggests that the mechanism of vascular dysfunction involved increased consumption of nitrogen oxides, the investigators said.
Binge Drinking Imperils MI Survivors
Binge drinking doubles short-term mortality in patients who have survived an MI, regardless of their usual level of drinking and the type of alcohol they consume, reported Dr. Kenneth J. Mukamal of Beth Israel Deaconess Medical Center, Boston, and his associates.
The researchers assessed mortality in a subset of patients who had participated in a multicenter cohort study on the causes of MI. The 1,919 patients had been interviewed about their drinking habits and other factors while they were hospitalized for an initial MI between 1989 and 1994.
A total of 318 of the patients died during a median of 3.8 years of follow-up. As expected, light and moderate drinking were found to protect against cardiovascular mortality and total mortality, as has been reported in previous studies, the investigators said (Circulation 2005:112:3839–45).
In contrast, binge drinking (consuming 3 or more drinks in 1–2 hours) was linked to a twofold increase in cardiovascular mortality and total mortality. This association held true for subjects who binged on beer, wine, liquor, or any combination of these drinks. It also persisted after the data were adjusted to account for differences in infarct size and severity; smoking status; and intake of coffee, tea, marijuana, and cocaine.
There also appeared to be a dose-response relationship, with mortality risk rising as the frequency of binge drinking episodes increased.
Binge drinking raised mortality among people who customarily were light drinkers as well as those who drank more heavily. This suggests that “any potential benefits of moderate drinking must be weighed against the risks of even occasional binge drinking,” Dr. Mukamal and associates said. “In our analyses, the apparent benefit associated with otherwise light drinking among patients with acute MI was completely eliminated by episodes of binge drinking.”