Low-intensity Resistance Exercise and Diet on Arterial Function and Blood Pressure
- Obesity is a major risk factor for premature arterial abnormalities including high blood pressure and increased stiffness. Previous studies have shown that weight loss via lifestyle modifications is associated with a decrease in large artery (aorta) stiffness. However, along with decreases in fat mass, hypocaloric diet reduces muscle mass. Low-intensity resistance exercise training (LIRET) results in similar increases in muscle mass and strength than those observed after high-intensity resistance exercise.
- The investigators hypothesis is that weight loss via diet combined with LIRET would additively reduce arterial stiffness and blood pressure (BP) in obese women. The investigators also hypothesize that the improved arterial function with weight loss would be associated with beneficial changes in the main mechanisms involved in BP regulation.
|Obesity Pre-hypertension Hypertension||Other: Resistance exercise training Other: Hypocaloric diet Other: Resistance exercise training & diet|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Investigator)
Primary Purpose: Basic Science
|Official Title:||Effects of Low-intensity Resistance Exercise Training and Diet on Central Hemodynamics and Arterial Stiffness in Obese Middle-aged Women With High Blood Pressure|
- Blood pressure [ Time Frame: 12 weeks ]Non-invasive measures of brachial and aortic blood pressure
- Autonomic Function [ Time Frame: 12 weeks ]Heart rate variability, vascular sympathetic activity [low-frequency power of systolic BP variability], and spontaneous baroreflex sensitivity will be assessed from electrocardiogram and beat-by-beat digital blood pressure
- Endothelial Function [ Time Frame: 12 weeks ]By measuring circulating levels of adipocytokines (adiponectin and leptin) and endothelial-derived vasodilators (NO metabolites [NOx] and prostacyclin) and vasoconstrictors (endothelin-1 and prostaglandin F2α)
- Body Composition [ Time Frame: 12 weeks ]By measuring fat mass and lean soft tissue mass from dual-energy x-ray absorptiometry and waist circumference
- Arterial Stiffness [ Time Frame: 12 weeks ]Using pulse wave velocity of the aorta, systemic, and legs
- Pressure Wave Reflection [ Time Frame: 12 weeks ]Using the augmentation index from radial tonometry
|Study Start Date:||December 2010|
|Study Completion Date:||June 2012|
|Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
Experimental: Resistance exercise training
Lower-body exercises 3 times per wk for 12 wk
Other: Resistance exercise training
The low intensity resistance exercise training intervention consists of lower-body resistance exercise (machines) 3 times per wk for 12 wk. Two sets the first 2 wk and 3 sets the rest of the intervention, at 40% of the estimated 1 repetition maximum, for 17 to 23 repetitions, with 1 minute of rest in between sets.
Experimental: Hypocaloric diet
This arm involves 12 wk of the standard Nutrisystem foods plan complemented by fresh produce and dairy. Subjects consume breakfast, lunch, dinner, and one (women) or two (men) snacks per day.
Other: Hypocaloric diet
The hypocaloric diet intervention consists of 12 wk of the standard Nutrisystem foods plan complemented by fresh produce and dairy. Subjects consume breakfast, lunch, dinner, and one (women) or two (men) snacks per day.
Experimental: Resistance exercise training & diet
Lower-body exercise training and diet
Other: Resistance exercise training & diet
Combination of low intensity resistance exercise training and hypocaloric diet
No Intervention: Control
This arm involves not making any change to the subject's lifestyle at the moment of the start of the intervention and for 12 wk.
The purpose of the study is to examine the effects of 12 weeks of low-intensity resistance exercise training (LIRET) and diet on arterial function, autonomic function, and body composition in obese women with high blood pressure (BP). Specific aims of the study are to:
- To evaluate the extent to which diet and LIRET will improve body composition assessed by changes in fat mass and lean mass using dual-energy x-ray absorptiometry and waist circumference.
- To investigate that combined diet and LIRET are more efficacious than either treatment alone in ameliorating cardiovascular disease risk factors by assessing arterial stiffness (aortic, systemic, and leg), aortic BP and wave reflection, and autonomic function (heart rate variability, vascular sympathetic activity [low-frequency power of systolic BP variability], and baroreflex sensitivity). Circulating levels of adipocytokines (adiponectin and leptin) and endothelial-derived vasodilators (NO metabolites [NOx] and prostacyclin) and vasoconstrictors (endothelin-1 and prostaglandin F2α) will be assessed as secondary outcome variables.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01371370
|United States, Florida|
|Florida State University|
|Tallahassee, Florida, United States, 32306|
|Principal Investigator:||Arturo Figueroa, M.D., Ph.D.||Florida State University|