New-Onset Diabetes Increases Cardiac Morbidity in Hypertensive Patients

New published study results suggest that patients who develop type 2 diabetes while they are on treatment for essential hypertension have a higher cardiac morbidity than their counterparts without diabetes.

Dr. Tonje A. Aksnes, of Ullevaal University Hospital, Oslo, Norway writes, "There has been a lot of interest in the development of diabetes mellitus in recent hypertension trials, because differences in new-onset diabetes between ‘old’ and ‘new’ antihypertensive treatments have been seen."

"Although it is well established that the coexistence of diabetes and hypertension portends a 2- to 3-fold higher risk of cardiovascular disease, surprisingly few data exist on the prognostic impact of new-onset diabetes in initially nondiabetic patients, and the implications have been debated," they add.

The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial compared cardiac outcomes between the angiotensin II receptor blocker valsartan and the calcium channel blocker amlodipine in a cohort of hypertensive patients. A total of 15,245 high-risk patients were followed for an average of 4.2 years.

In the current study, the researchers examined the impact of new-onset diabetes on cardiac outcomes in the VALUE trial population.  At baseline, 5250 patients were diabetic according to the 1999 World Health Organization criteria. Among the 9995 nondiabetic patients, 1298 developed diabetes during follow-up (average incidence of 3.1% per year).

Patients who were diabetic at baseline had the highest cardiac morbidity, which was defined as myocardial infarction and heart failure (hazard ratio 2.20). Patients who developed diabetes during follow-up had significantly higher cardiac morbidity, especially more congestive heart failure, than nondiabetics (HR 1.43).

Patients with diabetes at baseline also had a highly significantly increase in all-cause and cardiac mortality compared to those without diabetes and a significant increase compared with patients with new-onset diabetes.

Overall, the findings suggest that "patients who develop diabetes during antihypertensive treatment have cardiac morbidity intermediate between diabetic subjects and those subjects who never had diabetes," Dr. Aksnes’s group concludes.
It is therefore important "to find these patients at risk of diabetes development and optimize lifestyle and medical treatment," they add.

Hypertension 2007;50:467-473.