Exercise-Induced Epigenetic Modifications in Obese Aging Women

Summary

Our greatest public health challenge is obesity and the co-morbidities of metabolic syndrome (MetS). Age is an established risk factor for MetS and specific to women, data indicates that the prevalence of MetS increases substantially with the menopausal transition with postmenopausal women having a 60% increased risk of MetS. Menopause also contributes to reductions in strength, physical function and often psychological well-being (e.g. fatigue). Obese individuals also have: a) impaired immune function and chronic inflammatory responses associated with changes in the white blood cell population in blood and fat tissues; and, b) increased secretion of and signaling by proteins in their fat cells. Weight loss, which requires an energy deficit through increased physical activity and/or caloric restriction (EX+CR), reduces risk for MetS in older sedentary obese women by reducing insulin resistance and chronic systemic inflammation. Science and clinical practice will be advanced by examining the molecular mechanisms by which EX+CR affects risk for MetS in older women. The primary aim is to determine if CD4+ T cells will report the differential epigenetic reprogramming of relevant gene expression associated with metabolic indices resulting from EX+CR induced weight loss in older women known to be at risk for MetS. This pilot data will be used to generate an NIH proposal of the same topic. A secondary aim is to assess the impact of weight loss on physical function and psychological well-being which will provide pilot data for an additional grant proposal regarding weight management in postmenopausal women.

Conditions

• Metabolic Syndrome

Interventions

BEHAVIORAL

High Protein Diet

All participants will be individually counseled by an RD for \~ 4 sessions (30 to 60 minutes)to meet weight loss goals. During the duration of the study, participants will be required to attend a 30 to 60 minute group educational/motivational meeting weekly (first 1 to 2 months) and then biweekly (for the remainder of the study). Diet recommendations will include high quality proteins with an emphasis on lean meats with protein being targeted for every meal and snack. Regarding beef intake specifically, the prescribed diet will include a minimum of one serving of beef per day, which is approximately 3 to 3.5 ounces or \~100 grams. This amount of lean cooked beef provides an average of \~25-30 grams of protein per day (www.beefnutrition.org/leanbeef.aspx). This combined with reducing energy from carbohydrates and fat from other sources will create an overall energy deficit of 500 kcal/day. This diet will also include 5 servings/day of vegetables and 2-3 servings/day of fruit

BEHAVIORAL

Exercise

Participants will be prescribed a supervised exercise program with required attendance of 3 nonconsecutive days per week (75 minutes each session). A program that combines flexibility and balance activities, weight bearing endurance exercise (walking) and resistance training to preserve lean mass will be prescribed. With specific regard to strength training, 50% of the resistance work will involve primary muscle groups of the lower body with the main focus being the gluteal and quadriceps groups (squats, lunges, etc.). The remaining 50% of work will dedicate 25% to the core stabilizers with the final 25% being the upper body. Transitions between segments of training will be used for recovery and social support enhancement. Note that all aspects of the exercise intervention will be progressive in intensity (i.e., starting at lower end of intensity or \~50% of maximal capacity), and duration (i.e., from 15 minutes to 35 minutes of exercise and adding a few minutes each session).

Sponsors & Collaborators

• University of Georgia

  lead OTHER

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

50 Years

Max Age

64 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-06-30

Primary Completion

2014-12-31

Completion

2014-12-31

Countries

• United States

Study Locations