By Jill Stein
CHICAGO, IL -- May 24, 2007 -- Aliskiren represents an effective and well-tolerated treatment for obese patients with hypertension who do not achieve blood pressure control with first-line hydrochlorothiazide (HCTZ) therapy, according to data released here at the 22nd Annual Meeting of the American Society of Hypertension (ASH).
Jens Jordan, MD, professor, division of medicine, Franz-Volhard Clinical Research Center, Berlin, Germany, and colleagues elsewhere compared the blood pressure-lowering effects and tolerability of aliskiren/HCTZ, irbesartan/HCTZ, amlodipine /HCTZ, and continued HCTZ monotherapy in obese patients with hypertension who did not respond to first-line treatment with HCTZ monotherapy.
Hypertension is a common comorbidity in obese patients, Dr. Jordan commented. "Almost 75% of patients who are obese also have hypertension, however less than 20% have their blood pressure controlled to less than 140/90 mm Hg. Obese patients are known to have difficulty in achieving blood pressure control and are at increased risk of cardiovascular disease and type 2 diabetes."
He also noted that in patients with hypertension, current Joint National Committee (JNC) 7 guidelines recommend first-line treatment with a thiazide diuretic but do not provide specific guidance for obese patients. "Given the low rates of blood pressure control in patients with obesity, there is a clear need for a new antihypertensive treatment option for obese patients who do not achieve blood pressure control with a thiazide diuretic alone," he said.
After a 2 to 4-week washout, 560 obese patients whose mean sitting diastolic blood pressure was greater than or equal to 95 mmHg and less than 110 mmHg received single-blind HCTZ 25 mg for 4 weeks.
The 489 non-responders were randomised to receive additional double-blind aliskiren 150 mg, irbesartan 150 mg, amlodipine 5 mg, or placebo for 4 weeks, followed by 8 weeks on twice the starting dose of aliskiren, irbesartan, or amlodipine.
After 8 weeks of double-blind treatment, the aliskiren/HCTZ combination reduced mean sitting diastolic blood pressure and mean sitting systolic blood pressure significantly more than placebo/hydrochlorothiazide. That is, the change in mean sitting diastolic blood pressure at week 8 was -11.9 mmHg in the aliskiren/HCTZ group and -7.9 mmHg in the HCTZ alone group. The change in mean sitting systolic blood pressure was -15.8 mmHg and -8.6 mmHg in the two groups, respectively.
The study found that the combination of aliskiren with HCTZ significantly improved blood pressure control rates over HCTZ alone and enabled over half of the patients to achieve blood pressure control (56.6% vs 34.2% for the two groups, respectively). Aliskiren/HCTZ also improved responder rates compared with HCTZ alone.
Blood pressure reductions with irbesartan/HCTZ and amlodipine/HCTZ were similar to those with aliskiren/HCTZ.
The aliskiren/HCTZ combination was well tolerated and was associated with a similar rate of adverse events as HCTZ alone. Aliskiren/HCTZ was not associated with the increased rate of peripheral oedema observed with amlodipine/HCTZ. "This side effect of amlodipine may limit its usefulness in obese patients," Dr. Jordan suggested.
Finally, he said that the study is the first to examine the use of antihypertensive therapies in combination with HCTZ in obese patients with hypertension who did not achieve blood pressure control with HCTZ alone.
Aliskiren is the first in a new class of direct renin inhibitors for the treatment of hypertension.
The study was sponsored by Novartis.
[Presentation title: Direct Renin Inhibition with Aliskiren Improves Blood Pressure Control in Obese Patients with Hypertension Who Do Not Respond to First-Line Hydrochlorothiazide Treatment. Abstract P-401]
E-Mail this DGDispatch to a colleague
