Effect of pioglitazone on urinary liver‐type fatty acid‐binding protein concentrations in diabetes patients with microalbuminuria

Urinary liver‐type fatty acid‐binding protein (L‐FABP) is a useful marker for renal tubulointerstitial injury. Pioglitazone is reported to be effective in early diabetic nephropathy. The aim of the present study was to determine whether pioglitazone affects urinary L‐FABP levels in diabetic nephropathy patients with microalbuminuria.

Sixty‐eight patients with type 2 diabetes and microalbuminuria were randomized to a 12‐month treatment with pioglitazone (30 mg/d, n = 17), glibenclamide (5 mg/d, n = 18), voglibose (0.6 mg/d, n = 17), or nateglinide (270 mg/d, n = 16). Pre‐ and posttreatment urinary albumin excretion (UAE) and urinary L‐FABP concentrations were compared between the four treatment groups and 40 age‐matched healthy subjects.

Pretreatment UAE and urinary L‐FABP levels differed little between the four groups. UAE and urinary L‐FABP levels were significantly greater in the diabetes patients than in the healthy subjects (UAE: p < 0.001; L‐FABP: p < 0.01). After 6 and 12 months, UAE and urinary L‐FABP were significantly lower in the pioglitazone treatment group than in the other treatment groups (UAE: 6 months, p < 0.01 and 12 months, p < 0.001; L‐FABP: 6 months, p < 0.05 and 12 months, p < 0.01).

Pioglitazone, but not glibenclamide, voglibose, or nateglinide, appears to be effective in reducing UAE and the urinary L‐FABP level, suggesting that pioglitazone has a specific role in ameliorating both glomerular and tubulointerstitial lesions associated with early diabetic nephropathy. Copyright © 2006 John Wiley & Sons, Ltd.