Primecuts – This Week In The Journals

August 27, 2012

By Tracey Liebman, M.D.

Faculty Peer Reviewed

This week’s primecuts starts off with some other-worldly news [1]. The NASA rover, known as Curiosity, had landed on Mars on August 6 after a 352-million-mile trip from earth. Finally, this week, Curiosity successfully made its first, albeit short, journey on Mars, going all of 23 feet. In the coming months and years, it will continue to take more journeys through the craters and mountains on Mars. With the intent of finding evidence that some form of life could have existed in the past on Mars, Curiosity will take longer journeys and make use of lasers to evaluate the components of rocks, look for water using a tool that fires neutrons, and analyze Mars’ atmosphere.

Now onto some news from earth. In this week’s New England Journal of Medicine, Carlsson and colleagues published a study, ‘Bariatric Surgery and Prevention of Type 2 Diabetes in Swedish Obese Subjects’ [2]. In this non-randomized, prospective study based in Sweden, 1658 patients who underwent bariatric surgery were compared to 1771 obese matched controls. Inclusion criteria included age of 37 to 60, BMI of 34 or greater in men and 38 or greater in women, and intention to lose weight. The controls were based on 18 matching variables, and none of the patients had diabetes at baseline. The patients in the bariatric surgery group subsequently underwent either gastric banding, vertical banded gastroplasty, or gastric bypass, whereas the patients in the control group went through usual obesity treatment in a primary care setting. Fasting glucose was measured at baseline, at 2 years, 10 years, and 15 years. The median follow-up time was 10 years. In terms of weight loss, those who went through bariatric surgery lost approximately 20kg after 10 to 15 years, in comparison to the non-surgical group, with 0.6kg lost by those who attempted to lose weight with profession help versus 1.4kg gain in those who did not have professional help. With regards to diabetes, after 15 years there were only 6.8 cases of diabetes per 1000 person-years in the bariatric surgery group as compared to 28.4 cases of diabetes per 1000 person-years in the control group, which corresponded to an adjusted hazard ratio of 0.17 (95% confidence interval, 0.13 to 0.21; p<0.001). Each of the three types of bariatric surgery was associated with a decreased incidence of diabetes, with hazard ratios of 0.12 for gastric bypass, 0.20 for gastric banding, and 0.25 for vertical banded gastroplasty. Patients with impaired fasting glucose particularly benefited; the risk of developing type 2 diabetes was decreased by 87% when bariatric surgery was employed in these patients. Though the results of this study are of limited utility because the study was not randomized, it appears that bariatric surgery may have a role in preventing the development of type 2 diabetes.

Now, switching gears to some screening recommendations. The U.S. Preventive Services Task Force came out with an article, ‘Screening for Hearing Loss in Older Adults: U.S. Preventive Services Task Force Recommendation Statement’ outlining new screening recommendations for hearing loss. After reviewing the literature from 1950 to 2010, the USPSTF determined that the evidence of risks and benefits for screening asymptomatic adults ages 50 years and older is insufficient (Grade I) to allow them to provide a recommendation for or against screening. No randomized trials have been performed to evaluate any harm done by screening asymptomatic older adults and offering hearing aids. Furthermore, only one randomized-controlled trial has studied the effect of screening for hearing loss in those 50 years or older, and the study found that only 0 to 1.6% of those with no baseline perceived hearing impairment used a hearing aid at one year later. The new recommendation is a change from the prior recommendation on this matter from 1996, which encouraged periodic questioning of older patients regarding hearing, counseling patients about hearing aids, and subsequently making referrals for further evaluation. Since physicians following this recommendation will not be screening asymptomatic older individuals, hopefully patients who are experiencing hearing loss feel comfortable actively informing their physicians about the issue so they can undergo further workup and treatment.

Now onto another set of new recommendations. The Centers for Disease Control and Prevention (CDC) developed new recommendations for testing patients for Hepatitis C Virus (HCV) based on evidence in the literature from 1995 and 2012, ‘Hepatitis C Virus Testing of Persons Born During 1945 to 1965: Recommendations From the Centers for Disease Control and Prevention.’ There is now a strong recommendation with moderate-quality evidence that individuals born from 1945 to 1965 should be tested once for HCV, with no need to determine baseline risk for HCV. Individuals born during that time have a higher proportion of positive HCV antibody when compared to the general population. The second new recommendation, which is also a strong recommendation with moderate-quality evidence, has two parts. The first is that individuals with HCV should undergo brief alcohol screening and treatment. The second part is that the patients should be referred for appropriate services for treatment of HCV and related conditions. Since HCV is often asymptomatic, these guidelines may help to identify additional previously undiagnosed cases of HCV and also help to limit further liver damage, since alcohol counseling may help to lower the consumption of alcohol.

Moving into the realm of cardiology, in this week’s JAMA, the results of the COMFORTABLE AMI trial were published in the article,‘Effect of Biolimus-Eluting Stents With Biodegradable Polymer vs Bare-Metal Stents on Cardiovascular Events Among Patients With Acute Myocardial Infarction – The COMFORTABLE AMI Randomized Trial.’ In this prospective, randomized, single-blinded, multi-center controlled trial of 1161 patients (ages 18 and older) who presented with STEMI within 24 hours of symptom onset, patients were randomized to the biolimus-eluting stent or the bare-metal stent. Baseline characteristics of both groups were similar. The primary endpoint of adverse cardiac events which included cardiac death, target vessel-related reinfarction, and ischemia-driven target-lesion revascularization, was found to occur in 4.3% of individuals who were given the biolimus-leuting stent versus 8.7% of those who were given the bare-metal stent, with a hazard ratio of 0.49 (p=0.004). In particular, patients given the biolimus-eluting stent had lower risk of target vessel-related reinfarction with a hazard ratio of 0.20 and also had a lower risk of ischemia-driven target-lesion revascularization with a hazard ratio of 0.28. Also of note, patients who were treated with the biolimus-eluting stent had a lower rate of stent thrombosis (0.9% as compared to 2.1%), though this was not statistically significant (95% CI, 0.15-1.19). In all, there was a 51% relative reduction in the 1-year risk of adverse cardiac events when the biolimus stent was used instead of the bare-metal stent. The results show promise for the benefit of biolimus stent at one year after treatment, so it would be helpful to see more results a few years out.

Here are some other noteworthy articles to review this week:

Preoperative Diagnosis of Benign Thyroid Nodules with Indeterminate Cytology

http://www.nejm.org/doi/full/10.1056/NEJMoa1203208?query=featured_home A gene-expression classifier may help to identify benign thyroid nodules in cases of FNA with indeterminate cytologic findings, especially in patients with a low likelihood of thyroid cancer

Radiation dose to the pancreas and risk of diabetes mellitus in childhood cancer survivors: a retrospective cohort study http://www.thelancet.com/journals/lancet/article/PIIS1470-2045%2812%2970323-6/fulltext Evidence of dose-related risk of diabetes associated with radiation to the tail of the pancreas

Self-reported and observed risky driving behaviors among frequent and infrequent cell phone users. http://www.sciencedirect.com/science/article/pii/S0001457512002734 Car crashes in drivers using cell phones may be related to those drivers’ tendencies to engage in other risky driving behaviors other than just using their phones

Burnout and Satisfaction With Work-Life Balance Among US Physicians Relative to the General US Population. http://archinte.jamanetwork.com/article.aspx?articleid=1351351 This national survey study found that physicians were at higher risk for emotional exhaustion, depersonalization, and overall burnout relative to population controls. Individuals with bachelor degree or professional/doctoral degree other than MD or DO were at lower risk for burnout.

Antipsychotics in Adults With Schizophrenia: Comparative Effectiveness of First-Generation Versus Second-Generation Medications: A Systematic Review and Meta-analysis http://annals.org/article.aspx?articleid=1309704 In this meta-analysis, benefits/harms of first-generation antipsychotics versus second-generation antipsychotics were not fully elucidated

Dr. Tracey Liebman, Medicine Intern, NYU Langone Medical Center

Peer reviewed by Todd Cutler, MD, a 2nd year resident at NYU Langone Medical Center

Image courtesy of Wikimedia Commons

References:

1. http://www.nytimes.com/2012/08/23/science/space/nasas-curiosity-rover-gets-moving-on-mars.html?ref=science

2. Article 1: Lena M.S. Carlsson, Markku Peltonen, Sofie Ahlin, Asa Anveden, Claude Bouchard, et al. Bariatric Surgery and Prevention of Type 2 Diabetes in Swedish Obese Subjects. N Engl J Med 2012; 367:695-704. August 23, 2012 http://www.nejm.org/doi/full/10.1056/NEJMoa1112082

3. Article 2: Virginia A. Moyer and on behalf of the U.S. Preventive Services Task Force; Screening for Hearing Loss in Older Adults: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine. 2012 Aug http://annals.org/article.aspx?articleid=1309706

4. Article 3: Bryce D. Smith, Rebecca L. Morgan, Geoff A. Beckett, Yngve Falck-Ytter, Deborah Holtzman, John W. Ward; Hepatitis C Virus Testing of Persons Born During 1945 to 1965: Recommendations From the Centers for Disease Control and Prevention. Annals of Internal Medicine. 2012 Aug. http://annals.org/article.aspx?articleid=1310557

5. Article 4: Räber L, Kelbæk H, Ostoijc M, et al. Effect of Biolimus-Eluting Stents With Biodegradable Polymer vs Bare-Metal Stents on Cardiovascular Events Among Patients With Acute Myocardial Infarction: The COMFORTABLE AMI Randomized Trial. JAMA. 2012;308(8):777-787. http://jama.jamanetwork.com/article.aspx?articleid=1352112

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