Volume 194 - Issue 5
In Other Journals
Author: Peter Lavelle
Med J Aust 2011; 194 (5): 267. || doi: 10.5694/j.1326-5377.2011.tb02963.x
Published online: 7 March 2011
Published online: 7 March 2011
NO LAUGHING MATTER
Patients receiving nitrous oxide as part of general anaesthesia for surgery may be at increased long-term risk of myocardial infarction (MI), say Melbourne researchers. Leslie and colleagues analysed data from the ENIGMA trial of 2 050 patients undergoing non-cardiac surgery, who were randomly assigned to receive anaesthesia with or without nitrous oxide. They found that odds of MI were nearly 60% higher in those receiving nitrous oxide. However, there was no significant increase in the risk of death or of stroke. The significance of the link between nitrous oxide and MI is unclear, and the findings need to be confirmed by larger studies, the authors say.
Anesth Analg 2011; 112: 255-257
CANNABIS MADNESS
Cannabis use may bring forward the onset of psychosis in some people. Large and colleagues, from the University of New South Wales and the Emory University School of Medicine, Atlanta, Georgia, did a meta-analysis of 83 published studies which compared the age of onset of psychosis in people who used cannabis and other psychoactive substances with the age of onset of psychosis in those who did not. Those who used cannabis developed psychosis, on average, when they were aged 2.7 years younger than those who did not; while those who used other psychoactive substances developed psychosis about 2 years earlier. The use of alcohol alone was not associated with an earlier onset of psychosis. Reducing cannabis use could delay or prevent some cases of psychosis, the authors say. They say there’s a need for heightened public health warnings about the link between cannabis and psychosis.
Arch Gen Psychiatry 2011. Published online 7 Feb doi:10.1001/archgenpsychiatry.2011.5
MORE MAMMOGRAMS, YOUNGER?
In Australia, on cost-benefit grounds, breast screening is offered free and recommended every 2 years for women from the age of 50 years — though women aged 40-49 years are also screened free of charge. But perhaps they should be having annual mammograms from the age of 40. US researchers Hendrick and Helvie reviewed evidence obtained by the US Preventive Services Task Force, which recommends screening every other year in women aged 50-74 years (in contrast to the American Cancer Society, which recommends annual screening in women 40-84 years). After modelling different screening scenarios and outcomes, the authors found that annual mammograms beginning at age 40 reduce breast cancer deaths by 40%. In comparison, screening every 2 years, beginning at age 50, reduces breast cancer deaths by 23%. This equates to 71% more lives saved if annual screening begins at age 40, they say.
Am J Roentgenol 2011; 196: W112-W116
MÉMOIRE METABOLIC
Older people with metabolic syndrome may be at a higher risk for memory loss, say French researchers. Raffaitin, from the French National Institute of Health Research, and colleagues studied 4 323 women and 2 764 men aged 65 and older from three French cities. Participants were tested for metabolic syndrome and its individual components and were also tested for memory and cognitive function, verbal fluency, and visual retention. Those with metabolic syndrome were 20% more likely to show decline in memory and cognitive function (though not of verbal fluency). Higher serum triglyceride and low serum high-density lipoprotein cholesterol levels were associated with diminished memory and cognitive function; diabetes (but not higher fasting blood sugar level) was associated with diminished verbal fluency and visual retention.
Neurology 2011; 76: 518-525
POLYPILLOMANIA
A single pill to prevent heart disease? That’s the idea behind the “polypill”; a combination of statins, aspirin and antihypertensives designed as a low-cost alternative to traditional multidrug regimens, and promising better patient compliance. Now another version is being trialled. The Wolfson Institute of Preventive Medicine in London is conducting a trial to determine the effect on blood pressure and cholesterol of a combination of simvastatin and three antihypertensives on healthy people older than 50 years of age. In response, an editorial in the Drug and Therapeutics Bulletin, (published by the BMJ Group) has questioned the whole notion of the polypill. Trials of various polypills have measured short-term outcomes such as the effect on serum cholesterol level and blood pressure, rather than more important long-term outcomes such as reductions in heart attacks and strokes, or reduced death rates, the editorial says. There are too many combinations of different drugs, at different dosages, targeting different populations (some healthy, others with established heart disease). In short, the polypill is overhyped; a “solution that is desperately seeking a problem, rather than the other way round”, the editorial says.
Drug Ther Bull 2011; 49: 2