Letter: rising incidence of obesity in the coeliac population – a malady or maladaptation?

We read with interest the paper published by Kabbani et al. entitled 'Body mass index and the risk of obesity in coeliac disease treated with the gluten-free diet'.1 We would like to share the results of a similar study done in our unit. We are a large regional centre in North Queensland and have examined the data on body mass index (BMI) in our cohort of coeliac patients. The incidence of coeliac disease here in Australia has been on the rise, previously affecting 1 in 250 Australians, however, current reports suggest an incidence of 1 in 100.2 The primary objective of our study was to prove that the demographics of coeliac patients is evolving, in that coeliac disease is no longer a disease exclusive to the malnourished population, but is also affecting the overweight population and thus institution of a gluten-free diet (GFD) in these select individuals is not without ramifications. We performed a retrospective observational study, selecting 100 patients from both the public and private hospital who had coeliac disease diagnosed on duodenal biopsy between 2004 and 2010, and who were subsequently followed up in the gastroenterology out-patient clinic after institution of a GFD. Of the 100 patients included in the study, 40 patients were classified as overweight (BMI ≥ 25) at the time of diagnosis. Of these 40 patients, 18 patients were in the obese category (BMI ≥ 30). During the course of follow-up, an additional 10 patients were found to be in the overweight category after institution of a GFD, of which 2 of these patients were obese. The data suggested that among the 100 patients with coeliac disease observed, 50% of them were found to be obese collectively, either prior to diagnosis or during the course of follow-up. We too conclude that remedial treatment with GFD is not always without consequences, particularly in the overweight population that are predisposed to increased cardiovascular associated morbidity. We agree that weight maintenance counselling should be an integral part of coeliac dietary education. Although our study population is significantly smaller, we have found that 40% of our coeliac patients were overweight at the time of diagnosis compared with the Northeast US population. Similarly, none of our patients in the obese category returned to having a normal BMI after diagnosis. The rising prevalence of coeliac disease that we are witnessing in Western society could potentially be explained by the fundamentals of natural selection in reducing obesity, however, the evidence for this is lacking and difficult to prove. Although it is well established that GFD in coeliac disease reduces morbidity from malabsorption and lymphoma,3 the long-term negative impact on the cardiovascular and metabolic system in the overweight population with coeliac disease is yet to be assessed. Declaration of personal and funding interests: None.