Why We Need A Cardiovascular Risk Model Exclusively For Type 1 Diabetes

I published this post last October on my personal blog (see here for details), but it seems that today, a number of bloggers have jumped on the bandwagon due to The New York Times article published in this morning’s edition entitled “Looking Past Blood Sugar to Survive With Diabetes”. Similarly, The Wall Street Journal’s Health Blog went even further, suggesting that statins be considered a class of “diabetes drug”. However, once again, in the rush to cover the story, many are overlooking that type 1 and type 2 diabetes are not the same disease, and have different risk factors for complications, including cardiovascular disease.

An October 17, 2006 Reuters article published provided some disturbing (although unsurprising) statistics which I felt were worth sharing. The study (available at the online journal Public Library of Science) showed that elderly participants with diabetes were twice as likely to die from cardiovascular disease as non-diabetics, and that the risk was particularly high for patients who treated their disease with insulin injections. Researchers also found that participants who were taking insulin were six times more likely to die from infectious diseases or kidney failure than non-diabetic participants. Women treated with insulin had a particularly high mortality risk.

The researchers noted that their results were adjusted for factors already known to affect heart disease risk including smoking, alcohol consumption and cholesterol levels, which is indeed useful. However, their study failed to acknowledge whether they even examined whether there were any clinical differences observed between type 1 and type 2 diabetes. We do know, however, that only 194 of 5,372 participants (3.3% of the cohort) with diabetes treated their condition with insulin only, so we can probably assume this tiny segment represented patients with type 1 diabetes.

In early 2006, researchers found that cardiodvascular risk models are not predictive for patients with type 1 diabetes; because risk models only exist for the general population, and patients with type 2 diabetes. In addition, last year researchers at UC Davis Medical Center in Sacramento, CA reported that the cause of cardiovascular inflammation in patients with type 1 diabetes appears to be autoimmunity, not the risk factors often observed in type 2 patients, which frequently includes hypertension and obesity.

The researchers noted that a major limitation of this particular study was the fact that participants on insulin may have had greater duration of diabetes since most patients with type 1 diabetes (which requires insulin treatment) are diagnosed at much younger ages than the typical type 2 patient. The editors also noted that elderly people often receive less-intensive treatment of risk factors for heart disease, such as high blood pressure and cholesterol, than younger people.

But perhaps even more important is the fact that it is probably time for researchers to do a comprehensive cardiovascular risk prediction model for type 1 diabetes because risk factors including younger age at diabetes onset and presence of diabetes complications are not considered in the existing models. With all the money being poured into such unnecessary studies as the effects of chili consumption on postprandial glucose insulin, and energy metabolism, or maybe lifestyle intervention associated with a lower prevalence of urinary incontinence (I kid you not, these were genuine studies published in prominent scientific and medical journals - read them for yourself using the links provided) it is about time researchers put their efforts (and our money) into something that might possibly benefit the type 1 diabetes community.

I sincerely hope that the NIH/NIDDK, JDRF and others are reading my recommendations on what types of studies they should be pursuing! We need our own cardiovascular risk model!