The obesity-stroke paradox: why do obese patients have milder strokes?

Over the weekend, the Sydney Morning Herald wrote of the ‘heavy cost’ of obesity to the Australian health system http://www.smh.com.au/nsw/the-heavy-cost-of-obesity-and-how-nsw-health-workers-are-responding-20150613-ghmxbu.html . The article featured a quote that “the new normal is to be overweight or obese”. The epidemic of obesity has presented major health challenges that are not just faced by the developed world but which are now increasingly also becoming part of the health dilemmas facing developing countries.

There are groups of obese patients however who do not seem to encounter the health problems that one might expect and these patients have been called the ‘obese well’ http://www.ncbi.nlm.nih.gov/pubmed/23491523 The reasons for why these people remain free of health problems remains unclear although a number of theories have been put forward including reduced inflammatory mediators in this group of patients. Accordingly, the possibility that anti-inflammatory drugs may improve outcomes such as glucose control and diabetes risk is an ongoing area of research.

In the current issue of JNNP, Kim and colleagues from Seoul have demonstrated that mild-moderate elevations of body mass index (BMI) are associated with reduced stroke severity http://jnnp.bmj.com/content/86/7/743.abstract . This backs up previous studies that have shown lower risk of mortality in obese patients who suffer haemorrhagic or ischaemic stroke. The importance of these observations is that it lays the foundation for further studies that may be able to address why this group is relatively protected from severe long-term disability. This will help in drilling down on the potential ways of improving outcomes in all stroke patients, regardless of BMI.