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

Obesity Clinical Trial

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01371370
• Other study ID #: 2011.5485
• Status: Completed
• Phase: N/A
• First received: June 9, 2011
• Last updated: August 4, 2014
• Start date: December 2010
• Est. completion date: June 2012

Study information

• Verified date: August 2014
• Source: Florida State University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 41
• Est. completion date: June 2012
• Est. primary completion date: December 2011
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 40 Years to 65 Years

Eligibility

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

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Investigator), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Hypertension
• Obesity
• Pre-hypertension
• Prehypertension

Intervention

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.
• 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.
• Resistance exercise training & diet
Combination of low intensity resistance exercise training and hypocaloric diet

Locations

Country	Name	City	State
United States	Florida State University	Tallahassee	Florida

Sponsors (2)

Lead Sponsor	Collaborator
Florida State University	Nutrisystem, Inc.

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Blood pressure	Non-invasive measures of brachial and aortic blood pressure	12 weeks	No
Secondary	Autonomic Function	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	12 weeks	No
Secondary	Endothelial Function	By measuring circulating levels of adipocytokines (adiponectin and leptin) and endothelial-derived vasodilators (NO metabolites [NOx] and prostacyclin) and vasoconstrictors (endothelin-1 and prostaglandin F2a)	12 weeks	No
Secondary	Body Composition	By measuring fat mass and lean soft tissue mass from dual-energy x-ray absorptiometry and waist circumference	12 weeks	No
Secondary	Arterial Stiffness	Using pulse wave velocity of the aorta, systemic, and legs	12 weeks	No
Secondary	Pressure Wave Reflection	Using the augmentation index from radial tonometry	12 weeks	No