The Use of Cilostazol in Patients With Diabetic Nephropathy

Hypothesis:

Cilostazol reduces the rate of decline in renal function in Chinese patients with type 2 diabetes and mild to moderate renal impairment secondary to diabetic nephropathy.

Objectives:

To assess the suppressive effect of Cilostazol on the progression of diabetic nephropathy, as defined by rates of decline in glomerular filtration rate, serum creatinine and urinary albumin excretion rate.

The rising prevalence of diabetes in Asia imposes a heavy burden on the health care system. Given the increasingly early onset of disease, patients with type 2 diabetes have long duration of disease for the development of complications. Among all complications, microangiopathic complications are major causes of mortality and morbidity in diabetic patients. In Asia, patients with type 2 diabetes are particularly susceptible to the development of nephropathy. Among dialysis patients, the primary disease is diabetic nephropathy in about 40 to 50 % of patients. Despite the inhibition of the renin angiotensin system using either ACE inhibitor or AII receptor blocker (ARB) as well as introduction of tight glycaemic and blood pressure control, the prevalence of diabetic nephropathy remains high. More importantly, patients with nephropathy have more adverse metabolic profiles and increased risk of having other complications such as retinopathy, macrovascular diseases and neuropathy than those without. Indeed, according to the RENAAL Study, despite receiving the best of care, the combined event rate of death, cardiovascular disease and end stage renal disease in diabetic patients with renal impairment remained as high as 10% per year.

Cilostazol exerts antiplatelet, antithrombotic and vasodilating effects by inhibiting phosphodiesterase type 3 in platelets and vascular smooth muscle cells. Furthermore, cilostazol treatment has been shown to reduce serum triglyceride concentrations and increase HDL-cholesterol levels. In Japanese patients with type 2 diabetes, cilostazol therapy was associated with regression of carotid intimal media thickness and could prevent the onset of silent brain infarction. On the other hand, abnormal metabolism of prostaglandins in renal glomeruli has been postulated to modulate renal haemodynamics. Elevated levels of platelet-derived microparticles and soluble adhesion molecules may further contribute to the development of diabetic nephropathy. Cilostazol treatment had been shown to reduce serum levels of PMP, activated platelet subsets, soluble adhesion molecules and urinary excretion of thromboxane B2 in patients with type 2 diabetes. These changes were accompanied by a reduction in urinary albumin excretion and an increase in creatinine clearance.