SMOOTH - Blood Pressure Control in Diabetic/Obese Patients

• Changes following treatment in blood pressure during the last 6 hours of the 24-hour dosing interval as measured by automated blood pressure monitor. See Detailed Description for additional information.
  

• Various secondary outcomes related to 1) automated blood pressure monitoring; 2) in-clinic seated trough measurements and blood pressure-related response rates. See Detailed Description for additional information.
  

Methodology:

Prospective, randomised, open-label, blinded end-point, forced-titration, parallel group comparison using Ambulatory Blood Pressure Monitoring (ABPM).

Planned/Actual Number of Subjects:

Enrolled: 1500/2085; Randomised: 750/840; Complete: 680/752

Diagnosis and Main Criteria for Inclusion:

1) Mild-to-moderate hypertension defined as a baseline mean seated cuff DBP of 95 - 109 (inclusive) mmHg, and/or SBP of 140-179 (inclusive) mmHg, and a baseline 24-hour ABPM mean DBP >= 85 mmHg, and/or SBP >= 130 mmHg. 2) Overweight or obese as defined by a Body Mass Index (BMI) >= 27 kg/m2 in non-Asians and >= 24 kg/m2 in Asians 3) Type-2 diabetes mellitus. 4) At least 30 years of age.

Duration of Treatment:

10 weeks total: telmisartan (80 mg) or valsartan (160 mg) for 4 weeks followed by telmisartan (80 mg) plus hydrochlorothiazide (12.5 mg) or valsartan (160 mg) plus hydrochlorothiazide (12.5 mg) for an additional 6 weeks.

Criteria for Efficacy:

Primary Endpoint:

Reductions in blood pressure during the last 6 hours of the 24-hour dosing interval as measured by ABPM. The primary analysis will consist of comparing telmisartan combined with hydrochlorothiazide 80 mg/12.5 mg to valsartan combined with hydrochlorothiazide 160 mg/12.5 mg at the end of the 10-week study using a closed testing procedure first testing for non-inferiority based on SBP; if significant, testing for non-inferiority based on DBP; if significant, testing for superiority based on SBP; and if significant, testing for superiority based on DBP.

Secondary Endpoints:

Statistically greater reductions in ambulatory blood pressure for patients treated with telmisartan combined with hydrochlorothiazide 80 mg/12.5 mg compared to patients treated with valsartan combined with hydrochlorothiazide 160 mg/12.5 mg at the end of the 10-week study as measured by: 1) Changes from baseline in the last 6 hours of the 24-hour dosing interval for pulse pressure; 2) Changes from baseline in the 24-hour ABPM mean (relative to dose time) for SBP, DBP, and pulse pressure; 3) Changes from baseline in the ABPM mean SBP, DBP, and pulse pressure (relative to clock time) during other periods (i.e., morning, daytime, night time) of the 24-hour dosing interval; 4) Change from baseline in systolic and diastolic blood pressure load during the 24-hour dosing interval; and 5) Percentage of patients responding to treatment based on the 24-hour ABPM mean SBP and DBP (relative to dose time).

Statistically greater reduction in mean seated trough blood pressure patients treated with telmisartan combined with hydrochlorothiazide 80 mg/12.5 mg compared to patients treated with valsartan combined with hydrochlorothiazide 160 mg/12.5 mg at the end of the 10-week study as measured by: 1) Changes from baseline in mean seated trough SBP and DBP as determined by electronic or manual device in-clinic; and 2) Percentage of patients responding to treatment based on electronic or manual in-clinic trough cuff blood pressures.

Evaluation of other endpoints comparing telmisartan combined with hydrochlorothiazide 80 mg/12.5 mg to valsartan combined with hydrochlorothiazide 160 mg/12.5 mg, respectively, including: 1) Changes from baseline in metabolic markers: serum TG, LDL-C, HDL-C, total cholesterol, potassium, fasting glucose and HbA1C, and for urine: Na, K, Cl, proteinuria (as measured by spot urine for protein:creatinine ratio); and 2) inflammatory markers: serum high sensitive C-reactive protein, serum homocysteine and plasma fibrinogen.

Criteria for Safety:

Evaluation of adverse events, physical examinations, laboratory assessments, pulse rate and cuff blood pressure monitoring.

Statistical Method:

Analysis of covariance with treatment and centre as main effects and baseline as a covariate; Mantel-Haenszel test controlling for centre.

Study Hypothesis:

Null Hypothesis:

The overall mean change from baseline in the automated blood pressure monitor mean blood pressure during the last 6 hours of the 24-hour dosing interval for telmisartan (80 mg) plus hydrochlorothiazide (12.5 mg) is less than or equal to that for valsartan (160 mg) plus hydrochlorothiazide (12.5 mg).

Alternative Hypothesis:

The overall mean change from baseline in the automated blood pressure monitor mean blood pressure during the last 6 hours of the 24-hour dosing interval for telmisartan (80 mg) plus hydrochlorothiazide (12.5 mg) is greater than that for valsartan (160 mg) plus hydrochlorothiazide (12.5 mg).

Comparison(s):

Telmisartan (80 mg) plus hydrochlorothiazide (12.5 mg) vs. valsartan (160 mg) plus hydrochlorothiazide (12.5 mg)