Clinical Briefs
By Louis Kuritzky, MD, Clinical Assistant Professor, University of Florida, Gainesville
Dr. Kuritzky is a consultant for GlaxoSmithKline and is on the speaker’s bureau of GlaxoSmithKline, 3-M, Wyeth-Ayerst, Pfizer, Novartis, Bristol-Myers Squibb, AstraZeneca, Jones Pharma, and Boehringer Ingelheim.
Dark Chocolate and Arterial Function
Chocolate enthusiasts, take heart! Evidence that dark chocolate benefits more than just the palate is presented in this study from Greece.
Vlachopoulos et al studied 17 healthy non-smoking adults (mean age 29), who were free from vasculopathies such as diabetes, hyperlipidemia, or family history of premature vascular disease. Subjects were asked to abstain from caffeine, alcohol and flavonoid-containing foods for 24 hours or more prior to testing. Endothelial function was measured by means of forearm flow-mediated dilation, which is dependent primarily on nitric oxide derived from the endothelium. Subjects received either active intervention (dark chocolate) or sham-procedure (chewing without chocolate), both followed by 8 ounces of water. Endothelial function was measured at 30, 60, 90, 120, and 150 minutes after intervention.
Brachial artery diameter and arterial flow were significantly increased by dark chocolate. Normally, as arteries dilate their vasodilator response to stimulation decreases. In this trial, vasodilator responses increased even in the face of arterial dilation.
They comment that the salutary effects of chocolate could be attributable to improved nitric oxide bioavailability, prostacyclin increase, a direct effect of chocolate upon sooth muscle cells, or some central mechanism. And for the ultra-scientists amongst us, the ‘bar of choice’ (the study bar, that is) was Noir Intense, a 100 g dark chocolate bar manufactured by Nestle of Vevey, Switzerland.
Vlachopoulos C, et al Am J Hypertens. 2005;18:785-791.
Tetanus, Diphtheria, and 5-Component Pertussis Vaccine
Many clinicians still think of pertussis as a disorder limited to childhood. In 2004, more than 18,000 cases of adolescent or adult pertussis were reported to the CDC, and it is likely that this number is only a fraction of the actual number of cases, since pertussis is often not recognized, or presents in an atypical fashion. In the current vaccination schema, there is no provision for enhancing the waning pertussis immunity that appears to allow adolescent and adult pertussis to occur after appropriate childhood vaccination.
A new vaccine containing pertussis, tetanus, and diphtheria suitable for administration as a booster for adults has been recently developed. This trial examined the tolerability and efficacy in mounting a booster antibody response to pertussis. End points with the new vaccine were compared with the already established tetanus-diphtheria vaccine alone, and with pertussis antibody levels achieved in children after a complete immunization series.
The study population consisted of healthy adults and adolescents (n > 4,000) who were randomized to either the new pertussis-containing vaccine, or traditional tetanus-diphtheria vaccine.
These data suggest that providing an added component of pertussis may meaningfully reduce the incidence and consequences of adolescent and adult pertussis.
Pichichero ME, et al. JAMA. 2005; 293:3003-3011.
Lung Cancer Screening
Lung cancer (LCA) is currently responsible for 30% of cancer deaths in the United States. The majority of LCA cases have metastasized at the time of diagnosis, resulting in a 15% survival rate at 5 years. Recent studies have applied screening with increasingly sophisticated and sensitive tools amongst high-risk individuals (current and former smokers), and do indeed discover LCA at an overall earlier stage than by traditional clinical means: more than 50% are stage 1 at the time of screening diagnosis. Lead-time bias (the apparent lengthening of life seen in persons diagnosed by screening rather than by onset of symptoms simply due to natural history), length bias (slow-growing tumors, less like to cause symptoms may be preferentially discerned by screening), and overdiagnosis bias (some small tumors would be destined to never impact life, yet if discovered on screening would artificially inflate the benefit of screening) can contribute to an overly sanguine appraisal of screening benefits.
Because no randomized controlled trials of screening with a mortality end point have been completed (some are in process), there remains the possibility that screening may improve, be neutral towards, or even may worsen LCA outcome (ie, harms of intervention to complete the diagnostic process such as transthoracic needle biopsy increases morbidity and mortality). Until such data are in evidence, clinicians should convey to their interested patients the as-yet indefinite risk-to-benefit ratio of screening.
Mulshine JL, et al. Engl J Med. 2005;352:2714-2720.
Chocolate enthusiasts, take heart! Evidence that dark chocolate benefits more than just the palate is presented in this study from Greece.
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