Hypertension and Diabetes: Should We Treat Early Surrogates?

What are the cons?

Type 2 diabetes, a major public health problem of great concern, affects millions of patients in both developed and developing countries. These patients run a well-documented increased risk of cardiovascular disease (CVD), the risk of which is two- to threefold greater than that seen in nondiabetic subjects (1). Despite modern methods for treatment of diabetes and its risk factors and complications, the increased risk is still substantial. This is so even if data on risk factor control in national surveys, repeated on an annual basis, have shown improving trends for blood pressure and lipid control, e.g., in the National Diabetes Register in Sweden (2). Because hypertension and lipid disturbances are currently relatively easy to treat pharmacologically, this denotes that the majority of patients with diabetes are also to some extent receiving treatment for their CVD risk factors. Ideally, only studies that could prove the effect on clinical end points should be accepted as fundamental for evidence-based medicine in national or international guidelines. However, in addition, intermediate end points have been advocated for evaluation of intervention effects, as recently shown in studies evaluating drug effects on carotid or coronary atherosclerosis. This has provoked a clinical debate as that related in the following two sets of arguments, i.e., pro or con regarding the use of intermediate end points when hypertension in diabetes is treated.

On the pro side, arguments are concentrated in defense of using left ventricular hypertrophy, albuminuria, or arterial stiffness as useful surrogate markers, or intermediary end points, to guide the intensity and mode of treatment. However, on the con side, other more critical arguments are given to state that only drugs that are also able to decrease the rate of clinical events should be used, e.g., those shown to reduce CVD, including myocardial infarction and stroke, and in addition …