Diabetes diagnoses may be starting to plateau in the United States. The percentage of the population diagnosed with the disease and the rate of new cases per year rose sharply between 1990 and 2008 but haven’t grown quite as quickly between 2008 and 2012, a new study shows. The change may be linked to the slowing growth of obesity, a major risk factor for type 2 diabetes, the scientists suggest. The results appear in the September 24 JAMA.