Low-intensity Resistance Exercise and Diet on Arterial Function and Blood Pressure

Not Applicable

Completed

• Conditions: Pre-hypertension; Obesity; Hypertension
• Interventions: Other: Resistance exercise training; Other: Hypocaloric diet; Other: Resistance exercise training & diet

• Registration Number: NCT01371370
• Lead Sponsor: Florida State University

Brief Summary

* 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.

Detailed Description

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.

Study Timeline

• Study Start: 2010-12
• Study First Submitted: 2011-06-09
• Study First Submitted QC: 2011-06-09
• Study First Posted: 2011-06-10
• Primary Completion: 2011-12
• Study Completion: 2012-06
• Status Verified: 2014-08
• Last Update Submitted: 2014-08-04
• Last Update Posted: 2014-08-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 41

Inclusion Criteria

• Female
• 40 to 65 years of age
• Body mass index of 27-39.9
• Sedentary or low active (less than 2 hr per wk)

Exclusion Criteria

• Younger than 40 or older than 65 years of age
• Body mass index lower than 27, or 40 or higher
• Physically active or competitively active
• Smoker
• Systolic blood pressure higher than 140 mmHg
• Use of hormone replacement therapy of less than 1 yr
• Use of calcium channel blocker or beta blockers
• Type 1 diabetes
• Uncontrolled type 2 diabetes

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Resistance exercise training	Resistance exercise training	Lower-body exercises 3 times per wk for 12 wk
Hypocaloric diet	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.
Resistance exercise training & diet	Resistance exercise training & diet	Lower-body exercise training and diet

Primary Outcome Measures

Name	Time	Method
Blood pressure	12 weeks	Non-invasive measures of brachial and aortic blood pressure

Secondary Outcome Measures

Name	Time	Method
Autonomic Function	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
Arterial Stiffness	12 weeks	Using pulse wave velocity of the aorta, systemic, and legs
Endothelial Function	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	12 weeks	By measuring fat mass and lean soft tissue mass from dual-energy x-ray absorptiometry and waist circumference
Pressure Wave Reflection	12 weeks	Using the augmentation index from radial tonometry

Trial Locations

Locations (1)

Florida State University; 🇺🇸 Tallahassee, Florida, United States