Aspirin in Diabetics for Asymptomatic PAD

Aspirin in Diabetics with asymptomatic Peripheral arterial disease?
In examining why aspirin may have been ineffective, the question was asked as to whether these patients were at sufficient risk, in terms of peripheral arterial disease, as the cut-off point of an ankle brachial pressure index of 0.99 or less is higher than that used to define peripheral arterial disease in the population (<0.9). A subgroup analysis did not, however, find evidence of a difference in effect of aspirin between those with an index of 0.91-0.99 and those below this level. Furthermore, one of the current major interventions in the specialty of diabetes mellitus is statin therapy. Calculations by two of the centres (DM and CK) in over 10 000 people with diabetes showed a mean total cholesterol level of 6.0 mmol/l in 1996 decreasing to 4.3 mmol/l in 2007.
As aspirin was the first drug to have an evidence base for secondary prevention of cardiovascular disease it is always given to patients in subsequent trials and it might be asked if aspirin does indeed provide additional benefit when statins are used to good effect.The importance of the neutral effect of aspirin on cardiovascular events is that this drug is not without side effects. Aspirin is the most commonly prescribed drug in Scotland, with about 544 438 person years exposure per year in 2002. The number of prescriptions is increasing. The overwhelming majority of this, in the region of Tayside at least, is prescription based, with only about 7% being from over the counter use. Aspirin is one of the top 10 causes of adverse drug events reported to the Commission on Human Medicines. Gastrointestinal bleeding is associated with general use of non-steroidal anti-inflammatory drugs in over 80%of reported cases, and87%of that use is associated with aspirin, either alone or with other non-steroidal anti-inflammatory drugs. The risk of a bleeding event increases with age and also continuous exposure. Although the calculated risk of major bleeding is relatively small,35 the number of people taking aspirin is relatively large and therefore in population terms aspirin induced bleeding is a major problem. In a meta-analysis the number needed to treat to cause an adverse event has been calculated as 248, and this is relevant to the large and increasing population with diabetes.Of concern was the fact that there was a tendency to harm in the antioxidant group. It should be noted that the increase in number of deaths in the antioxidant groups seems to partly reflect better survival than expected of the groups who did not receive antioxidants, rather than just an obvious negative effect of the antioxidants. Thus this may at least in part be a difference achieved by chance. This agrees with recently published work, and these data should be added to future systematic reviews and meta-analyses. Anecdotally, many people with diabetes supplement with antioxidants after major publicity in the lay press of a deficiency in antioxidants in such people. We found no evidence for this perceived benefit from study.In the POPADAD trial (BMJ 2008) - it was found that Aspirin may have been ineffective in the prevention of cardiovascular events when used as primary prophylaxis!