Aim: To investigate the effect of a thiazolidinedione on proteinuria in patients with non-diabetic renal disease.
Methods: In an open-label randomized cross-over study, 40 adults with chronic non-diabetic renal disease completed the study. In a random fashion, one group was treated for 4 months with 4 mg of rosiglitazone first followed by a 4-month period of standard treatment. The opposite order was used for the second group.
Results: Baseline urinary protein excretion rate was 1.45 g/24 h. On rosiglitazone, there was a drop of urinary protein level of 0.24 g/24 h (P=0.045). In contrast, there was a trend for proteinuria to increase during the control period (0.12 g/24 h, P=0.18). The urine protein level on rosiglitazone was lower than on usual treatment (0.36 g/24 h, P=0.002, 95% CI 0.15-0.58). There was a similar beneficial effect on systolic blood pressure which was reduced by rosiglitazone by 7.8 mmHg (P=0.006, 95% CI 2.6-13.1). Although average fasting glucose was only 5.8 mmol/L, there was a significant Spearman correlation between fasting glucose and a reduction in urinary protein levels (r=0.34, P=0.045).
Conclusion: It is concluded that thiazolidinediones may have a role in the management of non-diabetic proteinuria of various aetiologies. In this study the average body mass index was 28.9 kg/m2. It will be important to repeat these studies in non-overweight subjects with non-diabetic proteinuria and in addition to trial maximal therapeutic doses of the thiazolidenedione.