Low-Dose Aspirin Helps Heart Only in Some Diabetes Patients

Dr. Yoshihiko Saito stated that, "Low-dose aspirin therapy is effective in patients with type 2 diabetes and mild renal dysfunction, not in all patients with type 2 diabetes as primary prevention." 

Dr. Saito of Nara Medical University, Kashihara, and colleagues note that it appears low-dose aspirin is effective in the secondary prevention of cardiovascular events in general, but its role in primary prevention in diabetics is controversial. 

To investigate further, the team conducted a subgroup analysis of a randomized, controlled, open-label trial of 81 or 100 mg of aspirin daily or no aspirin in 2,539 patients with type 2 diabetes. None had had previous cardiovascular disease. At baseline, 326 patients were treated with insulin, 1,750 with oral hypoglycemics and 463 with diet alone. The insulin group had the worst glycemic control and the longest diabetes history. 

Over a median follow-up of 4.4 years, the incidence of atherosclerotic events was 26.6 cases per 1,000 person-years in the insulin group. Corresponding values in the oral hypoglycemic and diet groups were 14.6 and 10.4. Although the event rates were lowest in the patients on diet alone, aspirin use had a significant protective effect (hazard ratio, 0.21). 

There was no such effect in the insulin group (hazard ratio, 1.19) or the oral hypoglycemic group (hazard ratio, 0.84). 

Overall, say the investigators, the agent "was not beneficial in patients with advanced stages of renal dysfunction and with high event rates but rather in those with early stages of renal dysfunction and with low event rates." The results are in keeping with those of another study. 

Despite these encouraging findings, the researchers note that the number of hemorrhagic events was very low in both the aspirin and thus firm conclusions couldn't be made "about the safety of low-dose aspirin based on our results." 

The approach is of value in patients with mildly reduced renal function Dr. Saito concluded, adding that the findings "give physicians the information necessary for further research to find a new prevention strategy for cardiovascular events for type 2 diabetes patients with reduced renal function." 

Diabetes Care April 22, 2011