Re: CVD in diabetes

I suspect that the article by Dr David Wood, et al, “Prevention, diagnosis, and treatment of cardiovascular disease in patients with diabetes” (BCMJ, (2005;47(8):424-428), may be misleading for many physicians, especially those primary care physicians, like me, who take care of the bulk of patients in BC with diabetes.

The authors state, “patients with diabetes who are either symptomatic or have abnormal screening test results should be started immediately on ASA, beta blockers, ACE inhibitors and, where indicated, statins or other lipid lowering agents.” They also state that “all asymptomatic diabetic patients should be sent for a baseline ECG” and “if this is normal and the patient does not meet [certain other] criteria” then no further treatment is required. My question is, Why delay pharmacological intervention when we know most of these individuals are already at very high risk?

It is now widely accepted that diabetes is a coronary risk equivalent, i.e., the magnitude of cardiovascular risk is the same as that of someone who does not have diabetes but has already had a myocardial infarction.[1] Why then hold back on vascular protection until the patient is symptomatic, has an abnormal ECG, or has other identified risk factors? What is the rationale for withholding aspirin, an ACE, and a statin in a person with type 2 diabetes even when there are no identifiable risk factors? With very few exceptions, are these drugs not indicated at diagnosis in someone with type 2 diabetes regardless of BP or lipid levels.[2-4] Furthermore, in obese patients—the vast majority of type 2—metformin, in addition to improving glycemic control, also has proven cardiovascular benefits[5] and should be part of what I call the “longevity cocktail” for type 2 diabetes, i.e., metformin, aspirin, ACE, statin. Why delay the use of these drugs until the person is symptomatic or has abnormal screening tests as is suggested in the article? How many persons newly diagnosed with type 2 diabetes are at such low cardiovascular risk that they would not immediately benefit from the vascular protection offered by this longevity cocktail?

While retinopathy, neuropathy, and nephropathy continue to exert their grim toll, most people with diabetes (up to 80%) will eventually succumb to a cardiovascular event. In an effort to prevent my patients from ever seeing a cardiologist, I unapologetically encourage the vast majority of my newly diagnosed type 2 patients to take the longevity cocktail and to exercise regularly, eat a heart healthy diet, and not smoke.

—Andrew Farquhar, MB 
Kelowna

The authors respond

We appreciate Dr Farquhar’s letter which emphasizes the need for treating all patients with diabetes. We would like to point out a number of things.

Not all patients with diabetes are at high risk for coronary heart disease.[1] In fact, in the large NHANES study,[1] patients who had diabetes but did not have the metabolic syndrome (13% of all these surveyed) were at the same risk as individuals without diabetes.

The question is whether people with diabetes are really a coronary risk equivalent. While the study by Haffner and colleagues[2] suggested that this is the case, it was criticized for not allowing for gender differences, low fatality rates, relatively short follow-up, and only considering prior myocardial infarction and not other vascular disease.

An 18-year follow-up of this study[3] shows diabetes to be much less than a coronary equivalent risk in the men in this study, though the results of the study suggest that it may be a CVD equivalent for women.

A number of other studies, particularly those by Eberley and colleagues,[4] Evans and colleagues,[5] the placebo subgroup of the HPS Diabetes cohort,[6] Lotufo and colleagues,[7] and others,[8-10] suggest that diabetes is not a CVD equivalent in men and may also be less than full equivalent of CVD in some of the women’s groups studied. On the other hand, some of these studies suggest that it is the case in women.

In addition to these findings, it is important to consider the possible side-effects of medications used. As is generally known, aspirin itself causes a number of bleeding complications. Similarly, betablockers, statins, and ACE inhibitors are not without side effects. Taken together with the economic impact and the fact that many patients with diabetes are not CVD equivalent, the formula “one size fits all” may cause both medical and economic problems.

—Jiri Frohlich MD,
Andrew Ignaszewski MD
Healthy Heart Program, St. Paul’s Hospital
David Wood, MD
University of British Columbia