ATLANTA—The home base of Coca-Cola and Ted Turner’s media empire also played host to the American Thoracic Society’s 98th International Conference. Highlights of the myriad of research presentations include studies on how to reduce cockroach allergens by pairing two novel cleaning methods and why menthol may cause cigarettes to be more addictive.

Other talks described research on the effects of red versus white wine on lung function and whether the use of continuous positive airway pressure (CPAP) results in long-term weight loss. In addition, investigators inquired into living wills and found significant misunderstandings on the part of both patients and doctors.

“SUPERCLEANING” REDUCES COCKROACH ALLERGEN

A bane of city life, cockroach allergen levels are difficult to control. Gehret et al combined a detergent steam-cleaning method used in lead abatement programs, called supercleaning, with conventional pheromone-based traps and mint aerosols to test their effectiveness in eliminating the allergen.

Researchers studied 10 inner-city apartments for six months, during which five apartments received the combination cleaning method and five apartments received standard pest control as provided by the tenants or landlord. In the test apartments, supercleaning was performed once and conventional methods were performed four times.

After one week, dust samples showed that levels of Blatella germanica allergens 1 and 2 (the two major cockroach allergens, Bla g1 and Bla g2) in the test apartments decreased by 63% and 93%, respectively. Levels in control apartments decreased by only 10% and 35%, respectively. In addition, the number of cockroaches decreased by 88% in test apartments and increased by 5% in control apartments. After six months, test apartments still showed a 90% reduction in Bla g2 concentrations and a 38% reduction in cockroach number, while control apartments showed an increase in Bla g2 concentrations of 227% and in cockroach number of 237%.

MENTHOL METABOLITES’ SHORT HALF-LIFE KEY TO ADDICTION?

Menthol smokers have higher levels of nicotine byproducts in the bloodstream and feel the need to have their first cigarette earlier in the day than do non-menthol smokers. But why this is so has not been clear. To measure plasma levels of menthol glucuronide (MG), Ahijevych et al studied six African-American women who had been smoking an average of 15 menthol cigarettes per day for 13 years. Studies show that African-Americans are three times more likely to smoke menthol cigarettes than whites are.

Each subject smoked two menthol cigarettes consecutively, and venous blood samples were drawn at various times afterward. Peak plasma levels of MG ranged from 93 to 134 ng/mL and occurred three to 15 minutes after the second cigarette. The mean half-life of menthol was 11.3 minutes. The investigators hypothesized that this short half-life may be the reason menthol smokers crave cigarettes more frequently.

In addition, the participants described menthol cigarettes as both “stronger” and “more filling.” Ahijevych et al suggested that unique chemical and physical responses of menthol smokers point to the need for tailored tobacco dependence treatment programs.

WHITE WINE BOLSTERS LUNG FUNCTION

While many studies have shown that drinking wine benefits the heart, evidence now suggests that the same holds true for the lungs. To analyze possible associations between wine consumption and lung function, Schünemann et al studied the drinking habits of 1,555 adults in relation to forced expiratory volume in one second (FEV1) and forced vital capacity (FVC).

Participants answered a questionnaire on both lifetime and recent (during the previous 30 days) alcohol consumption. Investigators then used multiple linear regression analysis after adjusting for mitigating factors, such as smoking habits, weight, education, and nutritional habits.

Although they found no significant correlation between total alcohol intake and lung function, they did find positive associations for both recent and total wine intake with FEV1 and FVC. The association was stronger for white wine than for red wine. Researchers theorized that the high levels of antioxidants in white wine may account for the apparent benefit.

EFFECTS OF CPAP ON WEIGHT

Because CPAP decreases daytime sleepiness and fatigue and increases patients’ sense of well-being, one hypothesis is that it could also result in long-term weight loss. Kendrick et al set out to investigate this possibility in a retrospective analysis of data from 54 patients using CPAP. These patients had been examined at six-month intervals, at which time weight was recorded.

At the first review, 29 had gained weight and 16 had lost weight (the remaining patients showed no change). Advice to lose weight was given at this time to those who had gained weight. At the second follow-up, 31 patients were heavier than they were at baseline and 16 were thinner. Of the 31 patients whose weight increased, 20 had continued to gain weight after the first follow-up visit.

No obvious reasons were given as to why about one third of the patients continued to gain weight. Investigators warned that this increase would probably worsen obstructive sleep apnea and cancel out the benefits of CPAP. Treatment should therefore include a more aggressive approach to weight loss.

LIVING WILLS COMMONLY MISUNDERSTOOD

Living wills are supposed to give voice to the patient who is unable to state his or her wishes about medical care at the end of life. However, a study by Upadya et al has revealed that many patients, family members, and doctors are not clear on the meaning or intent of these documents.

Researchers used a questionnaire to survey 68 patients, their family members, and doctors. Patients and doctors disagreed on the meaning of the living will in 11 cases. In three of these cases, the patients had wanted intubation, but the doctor thought it was precluded. Similar results were shown for cardiopulmonary resuscitation (CPR).

Of the 58 patients who correctly understood their living wills, 33 (57%) did not want intubation if there was only a 10% chance of survival. However, 84% of doctors and 55% of family members would have decided in favor of intubation. The statistics were similar for CPR. Upadya et al concluded that living wills often do not reflect the true wishes of patients and that patients’ intent is often misunderstood.

—Lisa Pallatroni

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