The treatment of hypertension is the most common reason in the United States for the use of prescription medications and for office visits by nonpregnant adults. Effective treatments get us the numbers that we need and assure us that we are reducing patient risk for future adverse cardiovascular and cerebrovascular events.
Interestingly, epidemiologic studies have shown that lean patients with hypertension have a higher incidence of adverse cardiovascular outcomes, compared with obese individuals. This has been associated with a so-called "obesity paradox."
Most of us are aware of the decreased clinical efficacy of particular drug agents in certain racial groups. But how many of us are making decisions about antihypertensives based upon body weight?
To explore this question, investigators conducted a subgroup analysis with data from the ACCOMPLISH (Avoiding Cardiovascular Events Through Combination Therapy in Patients Living With Systolic Hypertension) trial (Lancet 2013;381:537-45).
ACCOMPLISH was a transnational, multicenter trial designed to compare combination angiotensin-converting enzyme (ACE) inhibitor (benazepril) and calcium channel blocker (CCB) (amlodipine) therapy with the effects of benazepril plus hydrochlorothiazide (HCTZ). The primary endpoint was reduction of a composite endpoint of cardiac death, nonfatal myocardial infarction, or nonfatal stroke among patients at risk for cardiovascular disease.
In the current analysis, patients were divided into obese (body mass index at least 30 kg/m2), overweight (from 25 to less than 30), or normal weight (less than 25).
Among obese subjects, no differences in risk for any outcome were observed between benazepril plus amlodipine or benazepril plus HCTZ. Within the overweight group, benazepril plus amlodipine was associated with a lower risk for the composite endpoint (hazard ratio, 0.76; 95% confidence interval, 0.59-0.94).
Within the normal-weight category, benazepril plus amlodipine was associated with significantly decreased risk for the composite endpoint (HR 0.57; CI, 0.39-0.84) and for MI (HR, 0.50; CI, 0.26-0.96), compared with benazepril plus HCTZ.
So, how do we put these findings into practice?
The evidence here supports the hypothesis that hypertension may be mediated by different mechanisms in obese patients (i.e., increased plasma volume) and nonobese patients (i.e., vasoconstriction). Drug selection, therefore, has a different impact on outcome based upon body weight.
Thus, CCB-based antihypertensive therapy may be the best first-line treatment for patients who are nonobese.
Dr. Ebbert is professor of medicine and a primary care clinician at the Mayo Clinic in Rochester, Minn. He reports having no conflicts of interest. The opinions expressed are those of the author. Reply via e-mail at imnews@frontlinemedcom.com.