Inclusion Criteria:  Control - BMI<30, age 30-55 Hypertensive - BMI<30, age 30-55, diagnosis of hypertension by 24-hour ambulatory blood pressure monitoring Obese- BMI>30, age 18-70 Obese-hypertensive- BMI>30, age 30-55, diagnosis of hypertension by 24-hour ambulatory blood pressure monitoring  Exclusion Criteria:  All groups - presence of other significant cardiovascular disease, renal disease, history of smoking, diabetes,