Dairy Modulation of Oxidative and Inflammatory Stress in Overweight and Obese Subjects

Obesity Clinical Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00948038
• Other study ID #: DMI-033
• Status: Completed
• Phase: N/A
• First received: July 28, 2009
• Last updated: July 28, 2009
• Start date: January 2007
• Est. completion date: May 2009

Study information

• Verified date: July 2009
• Source: University of Tennessee
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

The objective of this study is to determine the acute effects of a dairy supplement compared to a soy supplement on oxidative and inflammatory stress in overweight and obese subjects in the absence of any changes in adiposity.

Description:

Obesity is associated with sub-clinical chronic oxidative and inflammatory stress, both of which are major contributors to obesity-associated co-morbidities. Calcitriol (1, 25-(OH)2-D3) regulates adipocyte lipid metabolism, while dietary calcium inhibits obesity by suppression of calcitriol. We have recently shown calcitriol to increase oxidative stress and to stimulate the expression and release of inflammatory cytokines, while inhibiting the expression and release of anti-inflammatory cytokines. We have also shown that inhibition of calcitriol with high calcium diets decreases both adipose tissue and systemic oxidative and inflammatory stress in a mouse model of obesity. Moreover, dairy exerted a greater effect on both oxidative and inflammatory stress. These mice also exhibited significant reductions in adiposity, which could lead to confounding, as this reduction will independently reduce oxidative and inflammatory stress. However, the supporting cellular/mechanistic data indicate an effect which is independent of adiposity reduction. Consequently, we propose that low calcium diets exacerbate oxidative and inflammatory stress and that high dairy diets can attenuate both independently of changes in adiposity, thereby significantly reducing the risk of obesity-associated co-morbidities. Accordingly, the objective of this study is to determine the acute effects of a dairy-rich diet on oxidative and inflammatory stress in overweight and obese subjects in the absence of any changes in adiposity.

Twenty subjects (10 obese and 10 overweight) will undergo a randomized crossover study of low dairy and high dairy eucaloric diets. Each dietary period will be four weeks, and the two dietary periods will be separated by a four-week washout period. Primary outcomes will be circulating indices of oxidative stress and of inflammation. Secondary outcomes include blood pressure, circulating glucose, insulin, lipids, calcium-regulatory hormones and body composition.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: May 2009
• Est. primary completion date: December 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 50 Years

Eligibility

Inclusion Criteria:

• Body mass index (BMI) 25-29.9 (n=10); 30-34.9 kg/m2 (n=10)

• Age 18-50 years

• Weight stable: no more than 3 kg weight loss during past three months

Exclusion Criteria:

• BMI < 25 or >35

• Type II diabetes requiring the use of any oral antidiabetic agent and/or insulin (because of confounding effects on ROS)

• Adverse response to study foods (lactose intolerance, dairy intolerance, dairy allergy); this will be determined by self-report.

• history or presence of significant metabolic disease which could impact on the results of the study (i.e. endocrine, hepatic, renal disease)

• history of eating disorder

• presence of active gastrointestinal disorders such as malabsorption syndromes

• pregnancy or lactation

• use of obesity pharmacotherapeutic agents within the last 6 months

• use of over-the-counter anti-obesity agents (e.g. those containing phenylpropanalamine, ephedrine and/or caffeine) within the last 6 months

• Recent (current or past 12 weeks) use of any psychotropic medication

• Recent (past four weeks) initiation of an exercise program

• Recent (past twelve weeks) initiation of hormone replacement therapy or change in HRT regimen

• Recent (past twelve weeks) initiation of hormonal birth control or change in hormonal birth control regimen

• Recent (current or past 12 weeks) history of smoking

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Obesity
• Overweight

Intervention

Dietary Supplement:
• Milk
Milk-based smoothie containing 170 kcal, 10 g protein, 1 g fat, 30 g carbohydrate adn 350 mg Ca. Three consumed each day.
• Soy
Soy-based smoothie containing 170 kcal, 10 g protein, 1 g fat, 30 g carbohydrate and 30 mg Ca. Three consumed each day for 28 days,

Locations

Country	Name	City	State
United States	The University of Tennessee	Knoxville	Tennessee

Sponsors (2)

Lead Sponsor	Collaborator
University of Tennessee	Dairy Management Inc.

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Plasma malondialdehyde		28 days	No
Primary	Plasma 8-isoprostane F2-alpha		28 days	No
Primary	Plasma tumor necrosis factor alpha		28 days	No
Primary	plasma interleukin 6		28 days	No
Primary	Plasma C-reactive protein		28 days	No
Primary	Plasma MCP-1		28-days	No
Primary	Plasma interleukin 15		28 days	No
Primary	Plasma adiponectin		28 days	No
Secondary	Plasma lipids		28 days	No
Secondary	Plasma insulin		28 days	No
Secondary	vitamin D		28 days	No
Secondary	Body composition		28 days	No