Diabetes raises incidence of kidney stones

Diabetes may be a predisposing factor, particularly for kidney stones composed of uric acid. A kidney stone is a solid mass consisting of tiny crystals made of calcium oxalate, uric acid or cysteine. Pain in the back, flank or abdomen is a common feature, along with bloody urine, excessive or painful urination, nausea and vomiting, and other symptoms. Researchers from the Mayo Clinic in Rochester, Minnesota identified all Olmsted County residents diagnosed with kidney stones between 1980 and 1999. The 3,561 patients were matched by age and gender with an equal number of individuals without kidney stones. The researchers also examined patients diagnosed with diabetes, high blood pressure and obesity. After taking into account the effects of age, time of year, high blood pressure, and obesity, diabetes was significantly associated with a diagnosis of kidney stones. The researchers also analysed the cases according to stone type, and the prevalence of diabetes was 40 percent among the 10 individuals with uric acid stones, versus 9 percent among the 112 patients with calcium oxalate stones and 7 percent in those without kidney stones. After accounting for the patients' body mass index (the ratio between height and weight) patients with uric acid kidney stones had five times the risk of diabetes. Despite these findings, it's unlikely that diabetes is the only factor driving the increased incidence of kidney stones, which may also be partly attributed to improved diagnostic techniques.