Primecuts – This Week In The Journals

September 13, 2010

By Karin Warltier, MD 

Faculty Peer Reviewed

 This past Thursday the US Court of Appeals ruled that the federal financing of embryonic stem cell research could continue while the court reconsiders last month’s ruling by Chief Judge Lambert of the Federal District Court for the District of Columbia (see Primecuts August 30, 2010 by Ha Na Kim, MD). As Gardiner Harris of the New York Times stated, this ruling “could save research mice from being euthanized, cells in petri dishes from starving and scores of scientists from a suspension of paychecks.” Not to mention saving the critical research that could improve the lives of those suffering from diseases.  However, the back and forth court battle is far from over and further hearings are expected in the next few weeks. [1]

 Both the Economist and Time Magazine had interesting articles this week on mental stimulation and dementia based upon worked by Robert Wilson published online in the journal Neurology.  In the longitudinal cohort study 1,157 patients were followed for six years to determine if cognitive activity predicted cognitive decline before and after the onset of dementia.  Patients rated their own frequency of participation in cognitively stimulating events. The results suggest that “late-life cognitive activity compresses the cognitive morbidity of Alzheimer’s disease by delaying its onset and by hastening cognitive decline after dementia onset.”  Hastening cognitive decline?  One theory is that those who stave off dementia through cognitive stimulation may actually have a larger burden of disease (plaques and neurodegenerative lesions). When dementia does set in, the cognitive decline is more rapid.  As the Economist puts it, “carry on with the crosswords.” [2,3,4]

 Interestingly, exercising the body may be just as important as exercising the brain, according to a paper currently in press in NeuroImage. [5]  In this study patients were divided into four groups based upon their level of physical activity and risk for Alzheimer’s disease due to the presence of the APOE-epsilon 4 allele.  Using functional magnetic resonance imaging, the authors concluded that physical activity increased brain activity in areas related to memory in cognitively intact at-risk elderly patients.  Further studies are needed, though, to determine if this increased MRI activity has clinical significance.

 As if that wasn’t reason enough to increase our exercise program, the Archives of Internal Medicine reported on the importance of slimming our waistlines to improve overall mortality. [6] In this prospective cohort of 48,500 males and 56,343 females, the authors examined the association of waist circumference with mortality, independent of BMI.  Patients were followed for nearly ten years. Greater waist circumference was associated with higher mortality in all BMI ranges. Very high waist circumferences (> 120cm in men or > 110cm in women) were associated with a two-fold higher risk of mortality (RR 2.02; 95% CI in men and RR 2.36; 95% CI in women).  Now, if only I could find the time to exercise while on Bellevue floors.

 Speaking of Bellevue, a new test will soon allow us to rule out TB in less than two hours. The New England Journal of Medicine published the results of a new diagnostic test that could detect drug-resistant tuberculosis in hours, not weeks. [7] The study assessed the performance of Xpert MTB/RIF, developed by the company Cepheid.  In 1,739 patients with suspected pulmonary TB, the test proved to be highly sensitive for detecting both tuberculosis and rifampin resistance in less than two hours. Among culture-positive tuberculosis patients, the overall sensitivity of the test was found to be 97.6%.  The specificity was over 99.2% in patients without tuberculosis. The test was also able to identify 97.6% of patients with rifampin-resistant bacteria. According to New York Times writer Donald McNeil, the “machines cost $30,000 and each test is about $60”, but by reducing length of stay in hospitals for rule out TB and over-treatment of sensitive TB, perhaps this test could be a valuable resource for New York City hospitals. [8]

 JAMA published a study this week looking at pay-for-performance. [9] Dr. Celemns Hong led a team of physicians investigating the relationship between patient characteristics and physician performance rankings.  The results of the article suggest that patients of primary care physicians in the bottom tertile for quality were more likely to be minorities, non-English speaking, and to lack insurance.  This was consistent with prior data. The authors’ results provide caution that with the growing trend to evaluate physicians via “performance measures”, policymakers must take into account which patients the physicians are actually providing care for as this could affect their quality ratings. Incentive programs that use pay-for-performance models “could erroneously distribute resources away from high-quality physicians caring for more vulnerable patients” and could encourage some physicians to cherrypick patients to improve their own quality scores.

 Dr. Warltier is a first year resident at NYU Langone Medical Center

Peer reviewed by Ishmeal Bradley MD, Section Editor, Clinical Correlations

Image courtesy of Wikimedia Commons. 

References:

 [1]  Harris G.  Stem Cell Financing Ban Ends, for Now.   The New York Times 2010.  http://www.nytimes.com/2010/09/10/health/policy/10stem.html?_r=1&ref=health

 [2] Mental Stimulation and dementia.  Brain gain.  The Economist. September 2, 2010 http://www.economist.com/node/16941143.

 [3] Park, Alice. Brain Exercises Delay, but Can’t Prevent Dementia.  Time Magazine.  September 1, 2010. http://www.time.com/time/health/article/0,8599,2015622,00.html.

 [4]  Wilson RS, Barnes LL, Aggarwal NT, Boyle PA, Hebert LE, Mendes de Leon CF, Evans DA.  Cognitive activity and the cognitive morbidity of Alzheimer disease.  Neurology 75;2010:990 – 6. http://www.neurology.org.ezproxy.med.nyu.edu/cgi/content/abstract/WNL.0b013e3181f25b5ev1?maxtoshow=&hits=10&RESULTFORMAT=&author1=Wilson&fulltext=Dementia&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

 [5]  Smith JC, Nielson KA, Woodard JL, Seindenberg M, Durgerian S, Antuono P, Butts AM, Hantke NC, Lancaster MD, Rao SM.  Interactive affects of Physical Activity and APOE-epsilon4 on BOLD semantic memory activation in healthy elders.  Neuroimage 2010.  Article currently in press, available through ScienceDirect.

 [6] Jacobs ER, Chrisitna CN, Wang Y, Patel AV, McCullough ML, Campbell PT, Thurn MJ, Gapstur SM.  Waist Circumference and All-Cause Mortality in a Large US Cohort.  Archives of Internal Medicine 2010; 170 (15): 1293-1301.  http://archinte.ama-assn.org/cgi/content/abstract/170/15/1293.

 [7] Boehme CC, Nabeta R, Hillemann D et.al.  Rapid Molecular Dectection of Tuberculosis and Rifampin Resistance.  The New England Journal of Medicine 2010; 363 (11): 1005 – 15. http://www.nejm.org.ezproxy.med.nyu.edu/doi/full/10.1056/NEJMoa0907847.

 [8]  McNeil DG.  Tuberculosis:  Automated Test for Drug Resistant TB Gives Results in Hours, Not Weeks.  The New York Times 2010.  http://www.nytimes.com/2010/09/07/health/07global.html?ref=research.

 [9]  Hong CS, Atlas SJ, Chang Y, Subramanian SV, Ashburner JM, Barry MJ, Grant RW.  Relationship Between Patient Panel Characteristics and Primary Care Physician Clinical Performance Rankings.  JAMA 2010; 304 (10): 1107 – 13.  http://jama.ama-assn.org/cgi/content/abstract/304/10/1107.

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