JAMA news releases are made available to the public after 3 pm US Central time on the first 4 Tuesdays of each month. The Archives Journals news releases are made available to the public after 3 pm Central time on Mondays. We also provide a list of previous news releases.
THIS WEEK'S CONTENT
JAMA NEWS RELEASES
(Embargoed for Release: 3 p.m. CT Tuesday, November 11, 2008)
JAMA NEWS RELEASES
STUDY SHOWS DECLINING NUMBER OF CASES OF EXTENSIVELY DRUG-RESISTANT TUBERCULOSIS REPORTED EACH YEAR IN THE U.S., BUT NEW CASES STILL
INCREASED NONFASTING TRIGLYCERIDE LEVELS ASSOCIATED WITH HIGHER RISK OF STROKE
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Embargoed for Release: 3:00 p.m. CT, Tuesday, November 11, 2008
Media Advisory: To contact J. Peter Cegielski, M.D., M.P.H., call the CDC National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention News Media Office at 404-639-8895.
STUDY SHOWS DECLINING NUMBER OF CASES OF EXTENSIVELY DRUG-RESISTANT TUBERCULOSIS REPORTED EACH YEAR IN THE U.S., BUT NEW CASES STILL
CHICAGO—A new report suggests that the number of cases of extensively drug-resistant tuberculosis (XDR-TB) in the U.S. has declined in the past fifteen years, but new cases continue to be reported, according to the study published in the November 12 issue of JAMA. The researchers note the decrease in the number of XDR-TB cases coincides with improved TB and HIV/AIDS control.
"Tuberculosis remains the leading cause of infectious disease death among adults worldwide," the authors provide as background information. "In recent years, drug-resistant TB has emerged as an expanding threat, with an estimated 489,000 new cases in 2006. Treatment of multidrug-resistant TB (MDR-TB) is more than 100 times as costly as treatment of drug-susceptible TB, requiring intensive case management for its prolonged (18-24 months) and more toxic treatment course." Treatment success rates are lower for patients with MDR-TB as compared to those with drug-susceptible TB. In 2005, a new category of TB disease was defined—extensively drug-resistant TB (XDR-TB)—because TB cases with even great drug resistance had emerged, especially in settings of high human immunodeficiency virus (HIV) prevalence throughout the world.
J. Peter Cegielski, M.D., M.P.H., from the Centers for Disease Control and Prevention, Atlanta, and colleagues, analyzed 15 years of national surveillance data to describe the epidemiology of XDR-TB in the U.S. and to identify its unique characteristics as compared to MDR-TB and drug-susceptible TB cases. The analysis was based on all culture-confirmed cases of TB reported by the 50 states and the District of Columbia from 1993 through 2007. XDR-TB was defined as resistance to isoniazid, a rifamycin, a fluoroquinolone, and at least one of amikacin, kanamycin, or capreomycin based on drug susceptibility test results from initial and follow-up specimens.
"A total of 83 cases of XDR-TB were reported in the United States from 1993 to 2007," the authors report. "The number of XDR-TB cases declined from 18 (0.07 percent of 25,107 TB cases) in 1993 to 2 (0.02 percent of 13,293 TB cases) in 2007..." The authors note that of the "40 XDR-TB cases reported during 1993-1997, 25 (62 percent) were known to be HIV-infected. During 1998-2007, only 6 (14 percent) of 43 XDR-TB cases were known to be HIV-infected." Of the 83 XDR-TB cases, the majority were between the ages of 25 to 44 years, 64 percent male, U.S.-born, and unemployed (53 percent). Forty-percent (33 patients) were Hispanic and three cases (4 percent) occurred among health care workers. Patients with XDR-TB were more likely to be Hispanic and correctional facility residents compared with drug-susceptible TB cases.
"Twenty-six XDR-TB cases (35 percent) died during treatment, of whom 21 (81 percent) were known to be HIV-infected. ... Death rates were nearly two times greater than among MDR-TB cases and more than six-times greater than among drug-susceptible TB cases. Infection with HIV played an important role in both the occurrence and outcomes of XDR-TB cases," the authors state.
"Preventing the further emergence of drug resistance is paramount and must include not only TB program strengthening to ensure that patients complete their treatment regimen but also general health system interventions to improve infection control. Greater vigilance regarding drug resistance must include systematic second-line drug susceptibility testing according to published guidelines. Lessons gained from MDR-TB in the 1990s should be applied: Patients must be identified early, treated effectively, and assisted to complete treatment, and infection control precautions must be in place to prevent further emergence and transmission of XDR-TB," the authors conclude.
(JAMA. 2008;300[18]:2153-2160. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: No specific funding was provided for this analysis. ... The CDC provides funding to state and local departments of health to conduct TB surveillance. Co-author Dr. Shah has received support from the Doris Duke Charitable Foundation while at Albert Einstein College of Medicine. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
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Embargoed for Release: 3:00 p.m. CT, Tuesday, November 11, 2008
Media Advisory: To contact corresponding author Borge G. Nordestgaard, M.D., D.M.Sc., email: brno{at}heh.regionh.dk.
INCREASED NONFASTING TRIGLYCERIDE LEVELS ASSOCIATED WITH HIGHER RISK OF STROKE
CHICAGO—Elevated nonfasting triglyceride levels, previously associated with an increased risk for heart attack, also appear to be associated with an increased risk for ischemic stroke, according to a study in the November 12 issue of JAMA.
Recent studies found a strong association between elevated levels of nonfasting triglycerides, which indicate the presence of remnant (a small portion that remains) lipoproteins, and increased risk of ischemic heart disease. "It is therefore possible that nonfasting triglyceride levels are also associated with increased risk of ischemic stroke," the authors write. "Triglyceride levels are usually measured after an 8- to 12-hour fast, thus excluding most remnant lipoproteins; however, except for a few hours before breakfast, most individuals are in the nonfasting state most of the time. Therefore, by mainly studying fasting rather than nonfasting triglyceride levels, several previous studies may have missed an association between triglycerides and ischemic stroke."
Jacob J. Freiberg, M.D., of Copenhagen University Hospitals, Denmark, and colleagues conducted a study to determine if increased levels of nonfasting triglycerides are associated with risk of ischemic stroke. The Copenhagen City Heart Study, a Danish population-based study initiated in 1976 with follow-up through July 2007, included 13,956 men and women age 20 through 93 years. Participants had their nonfasting triglyceride levels measured at the beginning of the study and at follow-up examinations.
Of the 13,956 participants in the study, 1,529 developed ischemic stroke. The researchers found that the cumulative incidence of ischemic stroke increased with increasing levels of nonfasting triglycerides. Men with elevated nonfasting triglyceride levels of 89 through 176 mg/dL had a 30 percent higher risk for ischemic stroke; for levels 177 through 265 mg/dL, there was a 60 percent increased risk; for 266 through 353 mg/dL, a 50 percent higher risk; for 354 through 442 mg/dL, a 2.2 times elevated risk; and for 443 mg/dL or greater, the risk of ischemic stroke was 2.5 times greater compared to men with nonfasting levels less than 89 mg/dL.
Corresponding values for women were a 30 percent increased risk of ischemic stroke for nonfasting triglyceride levels of 89 through 176 mg/dL; twice the risk for levels 177 through 265 mg/dL; a 40 percent higher risk for levels of 266 through 353 mg/dL; 2.5 times the risk for 354 through 442 mg/dL; and 3.8 times the risk for ischemic stroke for women with nonfasting triglyceride levels of 443 mg/dL or greater compared to women with nonfasting triglyceride levels less than 89 mg/dL.
Absolute 10-year risk of ischemic stroke ranged from 2.6 percent in men younger than 55 years with nonfasting triglyceride levels of less than 89 mg/dL to 16.7 percent in men age 55 years or older with levels of 443 mg/dL or greater. These values in women were 1.9 percent and 12.2 percent, respectively. Men with a previous ischemic stroke vs. controls had nonfasting triglyceride levels of 191 mg/dL vs. 148 mg/dL; for women, these values were 167 mg/dL vs. 127 mg/dL.
"By using levels of nonfasting rather than fasting triglycerides and by having more statistical power than any previous study, we detected a previously unnoticed association between linear increases in levels of nonfasting triglycerides and stepwise increases in risk of ischemic stroke...", the authors write. "Even the most recent European and North American guidelines on stroke prevention do not recognize elevated triglyceride levels as a risk factor for stroke."
"Our results, together with those from 2 previous studies, suggest that elevated levels of nonfasting triglycerides and remnant lipoprotein cholesterol could be considered together with elevated levels of low-density lipoprotein cholesterol for prediction of cardiovascular risk. However, these findings require replication in other populations."
(JAMA. 2008;300[18]:2142-2152. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
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