Irbesartan Versus Amlodipine: The OBI Study

Double Blind Study of Irbesartan vs. Amlodipine in Obese Hypertensive Subjects- The OBI Study

Status

Withdrawn

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00987662

Acronym

OBI

Enrollment

Registered

2009-10-01

Start date

2012-01-31

Completion date

2014-01-31

Last updated

2014-02-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypertension, Obesity

Keywords

irbesartan, amlodipine, obesity, ambulatory blood pressure monitoring, new onset diabetes

Brief summary

Objective: 1. To study the effectiveness of irbesartan 300mg and amlodipine 10 mg in 24h ambulatory blood pressure values in obese subjects 2. To study the drug specific effect in arterial stiffness 3. To study possible drug mechanisms in obesity (reduction of central adiposity and changing the ratio of leptin to adiponectin)

Detailed description

Study Objectives 1. Primary: * Reduction of 24h BP in obese hypertensives * Reduction in arterial stiffness 2. Secondary * Drug specific effect on new onset of diabetes * Drug specific effect on reduction in central fat deposition and the leptin to adiponectin ratio Study design Study drugs: Irbesartan 300mg vs. amlodipine 10mg Tx duration and follow-up: 12 months Collected data: * 24h SBP and DBP in time 0, 1, 12. * Pulse wave velocity in time 0,1,12. * Central obesity (total, visceral, abdominal fat) in time 0,1,12. * Leptin/adiponectin in time 0,1,12. * BMI, waist/hip ratio in time 0,1, 12. * Glu, HbA1c, insulin in time 0, 1,12. * K, Na, Cr, BUN, Chol, Tg, HDL, LDL,ALT, AST in time 0, 1,12. Number of patients: The reduction in mean SBP expected to be 15 mmHg. Previous studies from our group reported an 14mmHg SD for mean SBP. The sample size required at the two sided 5% significance level and 80% power is 40 patients (Lehr's formula) Number of centers: 1

Interventions

DRUGIrbesartan

Treatment with irbesartan 300mg for 4 weeks. IF ABP\>135/85 mmHg add hydrochlorothiazide 12.5 mg.

DRUGAmlodipine

Treatment with amlodipine 10 mg for 4 weeks. If ABP\>135/85 mmHg add hydrochlorothiazide 12.5 mg

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

DIAGNOSTIC

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 60 Years

Healthy volunteers

Inclusion criteria

1. Age between 18 and 60 years. 2. All patients are going to give their informed consent to participate in the study. 3. Stage I hypertension. 4. BMI \> 30.

Exclusion criteria

1. Known oversensitiveness, 2. Chronic renal disease (GFR \< 50 ml/min) or ESRD, 3. Heart or respiratory failure, OR 4. Recent MI, shock, liver deficiency (ALT or AST \> 3 times normal and pregnancy or lactation.

Design outcomes

Primary

Measure	Time frame
Reduction of 24h BP and arterial stiffness in obese hypertensives	12

Secondary

Measure	Time frame
New onset of diabetes	12
Drug specific effect on reduction in central fat deposition and the leptin to adiponectin ratio	12

Countries

Greece

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026