High dietary fat intake increases renal cyst disease progression in Han:SPRD-cy rats

The effect of a high level of dietary fat on renal cyst disease was examined in the Han:SPRD-cy rat model of polycystic kidney disease. Control and diseased rats at 4 wk of age were fed either a low fat or high fat diet (5 or 20 g/100 g diet) for 6 wk. In rats with kidney disease fed the high fat rather than the low fat diet, kidneys were 17% larger, renal fluid content was 19% higher and cyst scores were 30% higher, indicating greater disease progression. In diseased rats fed the high fat diet, serum urea was 25% higher, indicating worsened renal function. Serum creatinine was 49% higher only in males. To examine whether high dietary fat worsened renal cyst disease by altering sex hormone concentrations, serum testosterone and estrogen concentrations were determined. In normal compared with diseased male rats, serum testosterone concentrations were one to three times higher. Serum testosterone concentrations were higher in normal male rats fed the high compared with the low fat diet, but were not affected by diet in diseased rats. Serum estrogen concentrations were unaffected by dietary fat levels or by disease state. Although it remains to be elucidated how dietary fat influences sex hormone concentrations in this disease, the current study demonstrates that a high dietary fat intake increases kidney disease progression in Han:SPRD-cy rats.