Embargoed news from Annals of Internal Medicine

It is well-documented that lifestyle factors such as diet, weight, physical activity, smoking habits, and alcohol consumption affect a person's risk for diabetes. Studies have shown that individual lifestyle improvements, such as quitting smoking, can delay or prevent the onset of diabetes. However, it is less clear how multiple changes affect diabetes risk. Researchers surveyed more than 100,000 men and nearly 1000,000 women aged 50 to 71 without evidence of heart disease, cancer, or diabetes to determine how combinations of lifestyle risk factors relate to the 11-year risk for diabetes. Between 1995 and 1996, researchers surveyed participants and recorded demographic information and lifestyle factors, including dietary habits, body weight, physical activity, smoking, and alcohol consumption. Ten years later, researchers surveyed participants again to find out who was diagnosed with diabetes by a physician. Ten percent of men and almost as many women developed diabetes during the study. The researchers used original survey information to measure the association between lifestyle factors and onset of diabetes. Persons with the best lifestyle factors were about 80 percent less likely to develop diabetes than those with the worst lifestyle factors, and the risk for diabetes decreased for each additional good lifestyle factor.

2. EARLY RELEASE: CDC Identifies Babesiosis as a Threat to Nation's Blood Supply, Donor-screening Strategies Needed

Babesiosis is an uncommon, potentially life-threatening parasitic disease that is transmissible through tick bite or blood transfusion. Tickborne transmission mainly occurs in seven states in the Northeast and upper Midwest, but transfusion-associated cases can occur anywhere. Regardless of the transmission route, Babesia infection can range from asymptomatic to severe, depending on patient characteristics such as age and health. The infection can cause nonspecific flu-like symptoms, hemolytic anemia, and complications such as multiorgan dysfunction and death. There is no approved screening test for blood donors, and asymptomatic donors may not realize they are infected. Researchers reviewed data on U.S. transfusion-associated Babesia cases identified since 1979 (when the first transfusion case was documented). They identified 159 cases, which were dispersed in time (meaning infection occurred during all four seasons of the year) and place (19 states). Eighty–seven percent of U.S. cases occurred in the seven main babesiosis-endemic states, with 77 percent of cases occurring between 2000 and 2009. According to the study lead author, babesiosis should be considered in patients with unexplained fever or hemolytic anemia, regardless of region or time of year. Donor-screening strategies are needed to make the nation's blood supply even safer.

3. Even Mild Cognitive Decline Associated with Increased Mortality Risk

Previous studies of cognitive impairment and mortality have focused on patients with formally diagnosed Alzheimer's disease. For Alzheimer's patients, time between diagnosis and death is typically three to six years, but few studies address associations between different levels of cognitive impairment and mortality risk. During primary care appointments at community health clinics, 3,957 older adults aged 60 to 102 were screened for cognitive impairment to determine whether cognitive impairment is independently associated with increased long-term mortality. The proportion of adults with no, mild, and moderate to severe cognitive impairment who died during a more than 13-year follow-up period were 57 percent, 68 percent, and 79 percent, respectively. Median survival time for the three groups was 138, 106, and 63 months, respectively. The increased mortality risk for adults associated with cognitive impairment was independent of other risk factors for mortality, such as smoking and the presence of comorbid conditions.

4. Duodenal Switch Provides Greater Weight Loss, but More Adverse Events Compared to Gastric Bypass

Two types of bariatric surgery are commonly used to treat severe obesity: gastric bypass and duodenal switch. Researchers sought to determine whether duodenal switch leads to greater weight loss and more favorable improvements in cardiovascular risk factors and quality of life than gastric bypass. Sixty patients with a body mass index between 50 and 60 km/m2 were had either duodenal switch (n=29) or gastric bypass (n=31) at two academic medical centers. After two years, duodenal switch resulted in significantly greater reduction in body mass index than gastric bypass. Duodenal switch patients also had greater reductions in total and LDL cholesterol levels than gastric bypass patients; however, adverse events were much more common. Dietary factors, quality of life, and cardiovascular markers varied with each procedure. Patients benefited from both types of bariatric surgery. The choice should be individualized. However, according to the author of an accompanying editorial, the potential harms of duodenal switch surgery may negate the benefits. The author questions whether duodenal switch surgery should be offered as an option at all.