• the composite event rate in death (any cause), myocardial infarction and stroke
  

• Cardio-vascular: the composite event rate of unstable angina, transient ischemic attacks, peripheral arterial disease, other, consequent to atherosclerosis
  
• Lipid profile
  

Hemodialysed diabetic patients constitute a high-risk subset of patients for developing cardio-vascular disease, which accounts for nearly 50% of deaths. In those patients, mortality rates probably exceed 20% per year. After stratification for age, race and gender, cardio-vascular mortality is 10-20 times higher in these patients than in the general population. Thus cardio-vascular risk factors in these patients should be managed early, aggressively and in a multi-factorial manner in order to reduce their high cardio-vascular morbidity and mortality.

Low molecular weight heparin (LMWH) provides a safe and effective alternative to UFH for hemodialysis anticoagulation. While unfractionated (UF) heparin has been implicated in hyper-lipidemia, the effect of LMWHs on the lipid profile in non-diabetic patients on chronic hemodialysis remains controversial. The effect of LMWH in diabetic patients, a high risk group for developing hyper-lipidemia and cardio-vascular disease, has not been studied.

The study intends to examine the long-term effects of the replacement of UFH by LMWH (tinzaparin sodium) on cardio-vascular outcomes and on lipoprotein profiles in a large group of diabetic patients stable on HD.

Tinzaparin sodium is superior to UFH in terms of reducing cardio-vascular and cerebrovascular outcomes (primary end-point). Tinzaparin sodium is superior to UFH in terms of reducing the specified lipid parameters of stable diabetic patients on chronic hemodialysis.

A time-to-event analysis is the tool that will be used for recording events rate. Accordingly, the study will aim in enrolling 200 diabetic nephropathy patients, but allowing for a 10% drop-out rate, the number of evaluable patients in the study will be 180.

Therefore, for the primary triple end-point of death/MI/stroke (ischemic) with 180 evaluable patients, we will have an 80% power (at a two-sided alpha level of 0.05) to detect a statistical significant difference in the 2 groups if the rate of events in the UFH group is 30% and on tinzaparin is 13% or less.

For the secondary end-points in cardiovascular morbidity and mortality, if we assume that the event rate in the UFH group is 50%, then a statistical significance can be achieved if the rate in the tinzaparin group is at 30% or less.

For differences in average lipid values between the 2 groups, with 180 evaluable patients, a 2-sided alpha level at 0.05 and with 80% power, we can detect statistical significance if the difference is: for Total Cholesterol=19 mg/dL (SD of 46), for HDL-C = 4.6 mg/dL (SD=11), for TG = 30 mg/dL (SD=72), for LDL-C = 15 (SD=36) and for ApoB = 13 (SD=32).