Comparison of Aliskiren and Amlodipine on Insulin Resistance and Endothelial Dysfunction in Patients With Hypertension and Metabolic Syndrome

Inclusion criteria: * Male or female adults aged 18 to 55 years, inclusive. * Sitting diastolic blood pressure ≥80 mm Hg and/or sitting systolic blood pressure ≥ 130 at screening. * Metabolic Syndrome as defined by the Adult Treatment Panel (ATP) III criteria. * Hypertension (defined above) and impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) plus one or more out of the remaining 3 criteria to satisfy entry into the study. IGT and IFG will be classified according to American Diabetes Association (ADA) guidelines: * IFG: Fasting plasma glucose of 100 mg/dl (5.6 mmol/l) to 125 mg/dl (6.9 mmol/l) * IGT: Two-hour plasma glucose of 140 mg/dl (7.8 mmol/l) to 199 mg/dl (11.0 mmol/l) * Abnormal Positron Emission Tomography (PET) results at baseline. (Myocardial Blood Flow (MBF) of less than or equal to 35%.) * Abnormal euglycemic clamp results at baseline. (Glucose infusion rate (GINF) of less than or equal to 4.2 mg/kg/min.) * Body mass index (BMI) of less than 40. Exclusion criteria: * Smokers (use of tobacco products in the recent past) * Cardiovascular abnormalities including myocardial infarction, angina pectoris, hypertensive encephalopathy, stroke, transient ischemic attack, valvular heart disease, ventricular arrhythmia, A-V block, atrial fibrillation or cardiac revascularization/angioplasty in the past 12 months. * Symptoms or clinical evidence of congestive heart failure or known left ventricular ejection fraction \< 40%. * Supine Blood pressure ≥ 160 mmHg systolic or ≥110 mmHg diastolic. * Clinically significant echocardiogram (ECG) abnormalities, including history of a prolonged QT-interval syndrome. * Significant autonomic dysfunction. * Severe bronchospastic disease (including asthma and chronic obstructive pulmonary disease, treated or not treated). * Clinically significant drug allergy, atopic allergy (asthma, urticaria, eczematous dermatitis). * Pregnant or breastfeeding females. Pre-menopausal females who are not practicing a non-hormonal method of birth control. * African Americans will not be eligible for this study. Other protocol-defined inclusion/exclusion criteria may apply.