Good glycemic control in patients with type 2 diabetes reduces the risk of kidney stones. The better the glycemic control of diabetic patients, the lower their risk of stone formation. Some of this may be related to the fact that good glycemic control prevents the lowering of urinary pH and prevents stone formation. However, insulin may also have some direct effect on kidney stone formation, which we just don’t know yet. Both diabetes and kidney stones are common in the United States, with a prevalence of 8.3% for both diseases (about 26 million patients). In addition, there is a significant overlap between the two diseases, with about 21% of people with diabetes having kidney stones. This population’s vulnerability to kidney stones is partly due to impaired ammonia synthesis in diabetics and higher acid excretion than in non-diabetics due to lower urinary pH. The study found that people who were more active had a lower risk of kidney stones, and that exercise, along with diet, was a key factor in HbA1c (glycated hemoglobin) control.