eMJA: In Other Journals, 15 October 2007

Oral health does appear to have an association with mortality patterns, although the exact relationship is difficult to determine due to the presence of confounding factors such as smoking. Using data from the large, ongoing Glasgow Alumni Cohort study, researchers set out to investigate whether oral health in young adults is independently associated with cardiovascular disease later in life. Over 15 000 participants were followed for up to 57 years. Those with nine or more missing teeth at baseline had a significantly increased risk of cardiovascular disease mortality compared with those with fewer than five missing teeth, after adjusting for potential confounders. The association was not linear, suggesting the relationship is complex and affected by many variables. The authors comment that, as pathological pathways between oral health and systemic disease remain unclear, prospective studies are needed to unravel this complex relationship.

Weight loss — longer life

Weight loss after bariatric surgery may reduce mortality in previously obese people, according to a Swedish study. The prospective, controlled study involved over 4000 obese subjects, almost half of whom underwent bariatric surgery. Surgical procedures included gastric bypass, banding, and vertical-banded gastroplasty. The remaining individuals received non-standardised, conventional treatment. Weight losses in all surgical groups remained significant and stable (up to 27%) after 15 years. The non-surgical group showed weight changes of only ± 2% over the observation period. The hazard ratio for overall mortality for the surgery group was 0.76 as compared with the control group. Myocardial infarction and cancer were the most common causes of death. A drawback of the study is the lack of randomisation in the trial, but the authors comment that this may be difficult to achieve due to the risk of selection bias.

N Engl J Med 2007; 357: 741-752

Diabetes and heart failure —between a rock and a hard place

How to treat diabetic patients who also have heart failure is an important clinical question and one that is fraught with difficulty. A Canadian systematic review and meta-analysis of controlled studies has revealed that metformin appears to be the only anti-diabetic agent not associated with harm in patients with both conditions. Thiazoli-dinediones were associated with a reduced all-cause mortality, but an increase in hospital admissions for heart failure. The results from the two studies addressing sulfonylureas were contradictory, reflecting the controversy surrounding use of this class of drugs in diabetic patients with comorbid cardio-vascular disease. The authors comment that the presence of bias may have affected the results of the included studies and call for further randomised controlled trials analysing the use of metformin or thiazolidinedione in patients with heart failure and diabetes.

BMJ Online, 30 August 2007

Unravelling the MS mystery

A central nervous system (CNS) protein with anti-apoptotic and neuroprotective functions may be a key player in the autoimmune assault on myelin that underlies the pathogenesis of multiple sclerosis (MS). The heat shock protein αβ-crystallin (CRYAB) is the major target of CD4+ T cells in the MS brain. Using mouse models, researchers have shown that the autoimmune attack on CRYAB, rather than causing damage directly, worsens tissue injury by abolishing the protein’s role in impeding the inflammatory process. CRYAB also has a function as an inhibitor of glial apoptosis, or programmed cell death. When subjected to experimental autoimmune encephalitis, mice that lacked the CRYAB gene showed worse disease with more severe CNS inflammation and damage than their wild-type counterparts. In addition, antibody to the protein can be found in the cerebrospinal fluid of patients with MS. The implications for treatment of MS are promising, with CRYAB a possible protective agent if administered early in the disease process.

Nature 2007; 448: 474-483

Meningococcus targets bonny babies

Morbidity and mortality associated with meningococcal disease appear to be linked to nutritional status in a surprising way, according to Argentinean researchers. Anecdotally, physicians have noted that lethal invasive meningococcaemia is extremely rare in malnourished children. A prospective, observational study of 127 children aged 1 month to 4 years with invasive menin-gococcal infection was performed, with severity of disease and survival as clinical endpoints. Anthropometrical parameters were recorded prospectively for each child. Patients who died, had amputations, or required reparative surgery were considered to have severe disease. When anthro-pometrical data were compared, children who had a higher weight for age and height for age were significantly more likely to have severe meningococcal infection. The authors comment that malnutrition may confer a protective status through modulation of inflammatory mediators in poorly nourished children.

Arch Dis Child 2007; 92: 790-794

Dr Tanya Grassi, MJA

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