BACKGROUND: Periodontitis was shown to have an impact on glucose levels in prediabetic and diabetic rats. The Zucker fatty rat (ZFR) is a well-characterized model of prediabetes presenting with impaired glucose tolerance, hyperinsulinemia, dyslipidemia, and moderate hypertension. The aim of the present study was to investigate whether periodontitis influences kidney changes in ZFRs. METHODS: Male adult ZFRs (N = 19) and their lean littermates (N = 18) were studied. Periodontitis was induced with ligatures in half of the ZFRs and lean rats, whereas the other half served as controls. After 4 weeks, the rats were sacrificed, and the kidneys, liver, and heart were removed and weighed. Kidneys were evaluated histologically for glomerular volume and renal mRNA levels of vascular endothelial growth factor (VEGF), VEGF receptor 2, transforming growth factor-beta, connective tissue growth factor, collagen IValpha1, fibronectin, and nephrin. Urinary albumin excretion and creatinine clearance were also evaluated. RESULTS: In prediabetic ZFRs, periodontitis was associated with kidney hypertrophy (P = 0.03) and a tendency for increased glomerular volume (P = 0.06). In lean littermates, elevated fibronectin mRNA levels (P = 0.03) were noted in the presence of periodontitis. CONCLUSION: Our findings suggest the participation of periodontitis in the development of early renal changes in ZFRs.