To determine the incidepce and clinicopathological characteristics of
hypouricemia in patients with diabetes mellitus, we studied 473 consecutive hospitalized
diabetic patients. The incidence of hypouricemia, defined as a serum urate concentration
below 2.0 mg/dl, was 1.9% (9 patients). In this group (2 males, 7 females), there were no
patients receiving drugs known to reduce serum urate concentration. Two of the 9 patients
had neoplastic disease, while the others suffered from no other disorder known to affect
serum urate levels. Four patients exhibited glomerular hyperfiltration. Three of the 9
patients were studied in more detail by renal biopsy, and all had mild to moderate glomerular diffuse lesions and tubulointerstitial lesions, such as interstitial fibrosis or mononuclear
cell infiltration. These findings suggest that the glomerular hyperfiltration which accompanies diabetic nephropathy and functional abnormality of tubular urate handling due to
tubulointerstitial involvement contribute to hypouricemia in diabetic patients
