Clinical Briefs

By Louis Kuritzky, MD

Glucose Metabolism and Coronary Heart Disease in Patients with Normal Glucose Tolerance

There is a clearly established relationship between frank diabetes (DM) and increased vascular risk, especially coronary heart disease. Whether more modest perturbations in glucose regulation might be reflected in coronary vascular pathology has not been satisfactorily elucidated. Results studying the association between cardiovascular risk and markers such as subsyndromal levels of hemoglobin A1c, fasting glucose, or postload glucose have not provided consistent results. The relationship between glucose metabolism amongst persons with coronary heart disease (CHD) but without frank evidence of glucose derangement (ie, diabetes, impaired fasting glucose, or postload glycemia) is unstudied.

Glucose metabolism was examined in patients admitted and underwent coronary angiography for suspected CHD (n = 234). Patients who met criteria for diabetes, impaired fasting glucose, or postload glycemia were excluded from evaluation.

The level of fasting glucose was similar amongst all subjects. The number of stenosed coronary vessels was associated in a linear fashion with the levels of post load glucose and hemoglobin A1c. Even amongst persons without demonstrable stigmata of deranged glucose metabolism, risk for CHD is associated with increasing A1c and postload glucose levels. These data suggest that the relationship between some markers of glucose metabolism and CHD may be linear and continuous, even below the currently recognized thresholds for intervention.

Sasso FC, et al. JAMA. 2004;291: 1857-1863.

Evidence of Airborne Transmission of the Severe Acute Respiratory Syndrome Virus

For the moment, the immediate threat of Severe Acute Respiratory Syndrome virus (SARS) appears to have passed in the United States. The serious morbidity and mortality of the virus mandate clarification of just how disease may be transmitted, which has been as yet incompletely understood.

A large outbreak of SARS cases (n = 187) in a single housing complex provided sufficient information to model potential transmission channels.

The place of residence of the SARS cases (Anoy Gardens, Honk Kong), was able to be stratified into distance between buildings in the complex, direction of prevailing winds, height of units from the ground (buildings were categorized into low, middle, and high distance off the ground), and presence or absence of a window admitting the prevailing wind. Computational fluid dynamics was utilized to model the airflow pattern in and around buildings in the complex.

Data analysis supports the hypothesis that there was a common source outbreak at this site, spread by virus-laden aerosol. Were SARS to recur, such knowledge may assist future disease prevention and containment.

Yu ITS, et al. N Engl J Med. 2004; 350:1731-1739.

Alcohol Intake and Risk of Incident Gout in Men: A Prospective Study

The association between gout and alcohol consumption has been oft quoted, though never previously established by a prospective trial. It has been confirmed that alcohol loading acutely induces elevations in blood uric acid; case-control studies and cohort studies have found an association between gout and alcohol, but suffer from retrospectively reported alcohol consumption.

Subjects from the Health Professionals Follow-up Study (n = 51,529) comprise an all-male, predominantly white cross-section of clinicians including dentists, optometrists, physicians, and veterinarians. At enrollment, 5.6% of these men reported gout, and were excluded from this analysis. Subjects were periodically monitored for nutrient and alcohol intake from 1986-1998.

Alcohol intake and gout were found to be related in a linear fashion. Men consuming more than 50g/d alcohol (1 beer was designated as containing 12.8 g alcohol in this study) demonstrated a 3-fold increased likelihood of developing gout than non-drinkers. The strongest relationship between alcohol and gout was found for beer; a lesser relationship was seen with spirits. Wine intake was not associated with subsequent gout, regardless of type (white vs red) or level of intake. This prospective study is the first to confirm an association between alcohol intake and gout.

Choi HK, et al. Lancet. 2004;363: 1277-1281.

Dr. Kuritzky, Clinical Assistant Professor, University of Florida, Gainesville, is Associate Editor of Internal Medicine Alert.