Shelly S, Mielke MM, Mandrekar J, et al. - In the present study, the researchers determined the prevalence and natural history of sporadic inclusion body myositis (sIBM) and tested the assumption that patients with sIBM have higher cancer or mortality rates than the general population. They looked for patients with sIBM who met the 2011 European Neuromuscular Centre (ENMC) diagnostic criteria in Olmsted County, Minnesota, over a 40-year period. Based on ENMC criteria, 20 patients (10 clinicopathologically defined, 9 clinically defined, and 1 probable) were identified. Data reported that the prevalence of sIBM in 2010 was 18.20 per 100,000 people ≥ 50 years old. Dysphagia and female sex were also independent predictors of death. The highest prevalence of sIBM has been found in Olmsted County. When compared with matched patients without sIBM, those with sIBM have a similar cancer risk but a significantly reduced life span.