eMJA: In Other Journals, 4 June 2007

Sequential antibiotic therapy against Helicobacter pylori may result in a better eradication rate than standard triple-drug therapy, an Italian randomised controlled trial has shown. A total of 295 patients with proven H. pylori infection underwent endoscopy, biopsy, and bacterial culture of biopsy specimens. One group of patients received a 10-day sequential regimen of pantoprazole, amoxycillin, clarithromycin, and tinidazole. The other group was given standard 10-day therapy of pantoprazole, clarithromycin, and amoxycillin, each given twice daily. After treatment, patients underwent a second diagnostic 13C-urea breath test to detect presence of H. pylori. Sequential therapy resulted in a greater eradication rate and was significantly more effective in the treatment of clarithromycin-resistant strains.

Salt and the heart

Reducing dietary sodium intake can lower the risk of cardiovascular disease overall as well as leading to a significant reduction in blood pressure, according to US researchers. Two large randomised trials involving over 3000 patients were performed, and the incidence of myocardial infarction, stroke, coronary revascularisation, and cardiovascular death were recorded. The Trials of Hypertension Prevention studied adults aged 30–54 years with prehypertension, who were randomly assigned to a sodium reduction intervention group or a control group. The risk of a cardiovascular event was found to be 25% lower in the intervention group in the 10 to 15 years after the trial. The reduced risk persisted after adjustment for confounding factors such as age, race, and sex. The researchers comment that their study, despite being relatively small as a trial of clinical outcomes, has several strengths. These include objective measurement of dietary sodium intake, a heterogenous study population, and the use of a prehypertensive population at risk of negative cardiovascular outcomes.

BMJ Online, 20 April 2007

Chocoholic

Daily intake of cocoa can cause a significant reduction in blood pressure, according to a meta-analysis of 10 randomised controlled trials. In contrast, consumption of green or black tea is not shown to have a significant lowering effect on systolic and diastolic blood pressure. The review, which included trials performed over a 10-year period, reveals that an intake of between 46 and 100 mg of polyphenol-containing dark chocolate per day results in a pooled decrease of −4.7 mmHg in systolic blood pressure. Polyphenols, present in both cocoa and tea, act by causing arterial vasodilation. The authors of the meta-analysis comment that the reduction in blood pressure on the cocoa-including diet is similar to that achieved using β-blockers or angiotensin-converting enzyme inhibitors. The researchers hypothesise that the difference observed between cocoa and tea in blood-pressure lowering properties is due to the varying types of polyphenols present in chocolate and tea.

Arch Intern Med 2007; 167: 626-634

Killing pain softly

Morphine still suffers from “bad press”, despite its proven efficacy as a pain-relieving drug in the palliative care setting, according to a commentary by a UK palliative care physician. Dr Nigel Sykes, from St Christopher’s Hospice in London, gives a brief history of morphine use at the end of life and debunks some of the myths surrounding the risk of addiction and respiratory complications. Dr Sykes comments that morphine remains underused due to negative perceptions long held by both the medical community and the public, and that under-prescription of opioids remains a major barrier to effective pain management, particularly in the dying patient.

Lancet 2007; 369: 1325-1326

Right brain — right weight

Obesity may well prove to be all in the mind, or in the right prefrontal cortex (PFC), if new studies by US scientists continue to shed light on the complex aetiology of weight gain. Researchers from Beth Israel Medical Centre and Harvard Medical School claim that the right PFC is a critical area in the cognitive control of eating. The PFC is a centre in the brain where sensory, limbic and autonomic information converge, making it an essential area in the “top-down” control of behaviour. Using repetitive transcranial magnetic stimulation, which allows non-invasive interference with cortical activity, the neurologists were able to influence their subjects’ decision-making ability. Disrupting the activity of the right dorsolateral PFC induces a disregard for the adverse consequences of choices in the long term. Obese individuals are found to perform more poorly on tasks involving activation of such pathways, leading to the hypothesis that under-functioning of the PFC may result in an inability to project the consequences of poor food choices into the future. The role of the right PFC in mediating self-recognition and promoting physical activity over sedentarism and apathy may also support its role in the development of obesity.

JAMA 2007; 297: 1819-1822

Dr Tanya Grassi, MJA

The Medical Journal of Australia eMJA