Effect of Weight Loss on Cardiovascular Disease Risk Factors in Obese Women
Condition: Obesity; Cardiovascular Diseases
MeSH terms: Cardiovascular Diseases; Weight Loss
Study type: Interventional

Summary: 
      The purpose of this study is to examine the effect of weight loss and exercise on
      cardiovascular disease risk factors, specifically inflammation as measured by C-Reactive
      Protein and cardiac structure and function as measured by cardiac MRI, in Class II and III
      obese women during a 12 week training intervention.
    

Detailed description: 
      To date, research investigating obesity, inflammation, and cardiovascular disease has
      utilized lifestyle interventions focused on weight loss and exercise among groups with BMI
      classifications of normal, overweight and mildly obese. A limitation of recent investigations
      is the failure to utilize participants who are significantly overweight. Those whose BMI
      classification extends to Class II and Class III obesity (BMI > 35.0, and BMI > 40.0) have
      not yet been studied at length, yet these individuals have been shown to be able to
      substantially improve their cardiovascular risk profiles without attaining a BMI below 25.
      Inactivity has been linked to increased adiposity and a trend toward higher levels of
      cardiovascular disease risk. It is necessary to study the relationships between weight loss
      and weight loss with added physical activity among Class II and Class III obese participants
      in order to gain a more thorough knowledge of the effects of BMI on circulating markers of
      inflammation and the cardiac structural and functional changes associated with weight loss
      among this population. A second limitation of the current research is the use of strictly
      progressive resistance training protocols. The protocols used have increased constantly in
      intensity or volume, if not both. Constant increases in intensity tend to lead to
      overtraining among participants, highlighting a need for more variation of intensity and
      volume in the training protocol in order to avoid stagnation and overtraining. Finally, no
      research has studied the specific impact of diet and resistance training on either CRP or
      cardiovascular adaptations.
    

Intervention name(s): Diet; Diet Plus Aerobic Training; Diet plus Resistance Training
Intervention type(s): Behavioral; Behavioral; Behavioral
Intervention description(s): Participants will be given a calorie and fat gram goal according to their initial bodyweight. The fat gram goals will be set at 20% to 30% of total caloric intake. Subject calorie and fat gram goals are as follows: Subjects weighing less than 175 pounds will receive a diet prescription of 1200 calories and 27 fat grams per day. Subjects weighing between 175 and 219 pounds will receive a diet prescription of 1500 calories and 33 fat grams per day. Subjects weighing between 220 and 249 pounds will receive a diet prescription of 1800 calories and 40 fat grams per day. Subjects weighing greater than 250 pounds will receive a diet prescription of 2100 calories and 47 fat grams per day.; Participants will receive all of the components as described for the DIET group. Additionally, this group will participate in supervised progressive aerobic training 3 days per week. Participants will be required to attend 3 sessions per week where they will participate in supervised exercise sessions progressing from 60 to 180 minutes per week of moderate-intensity (3.0-6.0 METS) aerobic exercise. 180 minutes per week of exercise will meet the American College of Sports Medicine and the American Heart Association recommendations of 450-750 METS.min.wk-1.; Participants will receive all of the components as the DIET group. Participants will also participate in supervised resistance training protocol 3 days per week in the form of an individual session. The protocol will start the participants at a low volume of exercise at an intensity of 50-55% of 1-repetition maximum, and oscillate in both volume and intensity during the intervention, with a general trend toward increases in intensity as outlined in the ACSM Position Stand.
Other intervention name(s): DIET+AT; DIET+RT
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Intervention Studies; Magnetic Resonance Imaging; C-Reactive Protein