Dear Editor, The metabolic effects of insulin and rosiglitazone combination therapy in Chinese Type 2 diabetic patients with nephropathy I am afraid that thiazolidinedione (TZD) could not stastically ameliorate lipid metabolism in type 2 diabetic patients with nephropathy. As to the effect of TZD on diabetic nephropathy, I would like to offer a comment. It has been reported that TZD had the renoprotective effect, containing attenuation of glomerular hyperfiltration and decrease of urinary albumin excretion rate(UAE) in experimental diabetic rats as well as diabetic patients [1–3], as the author would mention in the present article. Recently, the mechanism by which TZD improved renal dysfunction was determined [2,4]. TZD was indicated to have the renoprotective effect through inhibiting activation of DAG-PKC-ERK pathway which leaded to renal dysfunction in diabetes. In previous reports, it has been shown that TZD ameliorated microalbuminuria, treated with TZD only or TZD and the angiotensin converting enzyme inhibitor [1–3]. The feature of cases in the present paper is, first, that the degree of nephropathy was moderate or severe, although the level of UAE and the value of glomerular filtration rate were not shown. Second, the angiotensin II receptor blocker (ARB) was treated in all of the patients before combination therapy with TZD. I should like to know the effect of ARB and TZD combination therapy on moderate or severe diabetic nephropathy. The effects of TZD on other organs as well as the fat tissue and the kidney are expected.

Keywords: Albumins - analysis, Diabetic Nephropathies - complications, Diabetic Nephropathies - drug therapy, Diabetic Nephropathies - metabolism, Kidney Diseases - complications, Kidney Diseases - drug therapy, Kidney Diseases - metabolism, Lipid Metabolism, Thiazolidinediones - pharmacology, Thiazolidinediones - therapeutic use, Albumins - analysis, Diabetic Nephropathies - metabolism, Kidney Diseases - metabolism, Lipid Metabolism, Thiazolidinediones - therapeutic use