eMJA: In Other Journals, 3 November 2008

Diabetic retinopathy is a significant cause of vision loss. In an attempt to determine how renin-angiotensin system blockers might reduce the burden of diabetic retinopathy, international researchers designed two randomised double-blind placebo-controlled trials.1 In 309 centres worldwide, normotensive participants with and without retinopathy were randomly allocated to groups receiving candesartan or placebo. The aim was to ascertain if the angiotensin II receptor antagonist could reduce the incidence of diabetic retinopathy in diabetics without the complication or slow its progression in those who already had the diagnosis. The results in over 3000 patients followed for 4 years suggested a role for candesartan in reducing the incidence of retinopathy, but no apparent beneficial effect on the progression of the disease in early cases. However, an accompanying comment by two experts from Australia and Singapore2 discusses the findings and the post-hoc statistical analysis, which suggested that treatment could increase regression of retinopathy in patients with early disease.

Autism and urinary opiates

Contrary to previous claims, children with autism do not appear to have exogenously derived opioid peptides in their urine, say British researchers. In a case-control study of 65 boys with autism and 158 controls, urine samples were examined by high-pressure liquid chromatography (HPLC) and mass spectrometry for the presence of opioid peptides. The highly sensitive mass-spectrometry method used is able to identify molecules that may appear to be peptides on initial examination with HPLC. There were no significant differences between the urinary profiles of the children with autism and the control group. The authors comment that there appears to be no evidence that opioid peptiduria serves as a biochemical marker for autism, nor that it can be used to monitor the response to certain exclusion diets.

Arch Dis Child 2008; 93: 745-750

Read all about it

News articles reporting on medication studies may not always give a complete picture, especially when it comes to declaring pharmaceutical company funding, according to the results of a US study. With the aim of assessing the use of generic versus brand names, and the reporting of pharmaceutical company funding, researchers reviewed news articles from print and online sources about medication studies published in five major medical journals between 2004 and 2008. Editors at 100 newspapers with a wide circulation were also surveyed. Despite the majority (88%) of newspaper editors reporting they often or always disclosed when studies received company funding, 42% of the articles reviewed did not do so. Most of the articles were found to refer to medications by their brand names, once again in contrast to the large majority of editors’ belief that this was not the case. The authors suggest further education of journalists in these areas, and propose medical journals can assist by making funding declarations more prominent.

JAMA 2008; 300: 1544-1550

Suspicious fractures

Identifying childhood fractures that are due to child abuse can be difficult. The authors of a recent Welsh systematic review set out to identify characteristics of injury that may distinguish fractures resulting from abuse by reviewing comparative studies of fractures in children at different skeletal sites. Researchers found that fractures resulting from abuse were more common in infants less than 1 year old and toddlers aged 1-3 years, and that multiple fractures were more common in cases of abuse. After excluding major trauma, rib fractures had the highest probability of being caused by abuse, and humeral fractures, a one in two chance. The authors comment that no one fracture in isolation is specific for physical abuse, and that assessment must rely on an evaluation of the whole clinical and social picture at the time of presentation.

BMJ 2008; 337: a1518

Finding the occult

Although faecal occult blood testing has become an acceptable screening tool for colorectal cancer, new methods continue to be investigated as alternatives that may prove to be more sensitive and specific. Stool DNA studies, which test for cancer-related genes, are potentially superior, as the colonic mucosa is constantly shedding cells, and the bleeding detected by occult blood tests may be intermittent. In a US multicentre, cross-sectional study, including over 4000 adults, faecal blood testing and two types of stool DNA analyses have been compared. Over 3500 adults had a screening colonoscopy, faecal occult blood testing, and a first- and second-generation stool DNA test. Researchers found that the second-generation DNA analysis appeared to be substantially more sensitive than the faecal occult blood testing. Although the authors caution that they were unable to determine whether this gain in sensitivity was offset by a loss in specificity, it appears that assay refinements in molecular testing may be promising for the development of future tests.

Ann Intern Med 2008; 149: 441-450

Dr Tanya Grassi, MJA

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