Muscle Insulin Resistance In Aging — MIRAGE  

Aging Clinical Trial

Official title: Muscle Insulin Resistance In Aging

Status Recruiting

Clinical Trial Summary

The overall objective of this project is to thoroughly investigate the effects of diet-induced weight loss in the absence of or in combination with exercise on skeletal muscle IR, energy metabolism and function. These studies will significantly improve our understanding of the fundamental biochemical and molecular factors linking intervention-induced changes in mitochondria, oxidative stress, lipotoxicity, IR, and loss of muscle function in aging humans.

Clinical Trial Description

Aging is associated with alterations in skeletal muscle energy metabolism, insulin resistance and a higher prevalence of type 2 diabetes mellitus (T2DM). Aging is also associated with a progressive loss of muscle mass and increased adiposity, known as sarcopenic obesity, which leads to mobility limitations and disability. However, the causes of insulin resistance and sarcopenia in humans are not known. This project will provide novel information regarding potential factors underlying both metabolic dysfunction and sarcopenia in aging muscle - namely, mitochondria and the accumulation of intramyocellular lipids. Within this conceptual framework we will help elucidate the biological underpinnings of these two significant health problems related to aging. In addition, we will provide intervention-based evidence to better understand these complex age-related disorders and whether mitochondria or intramyocellular lipids are modifiable targets for improved prevention or treatment strategies for metabolic and muscle dysfunction. Therefore, our overall objectives are to employ highly innovative methods in muscle biopsy specimens in order to determine the functional and clinically relevant consequences of these interventions as well as alterations in several novel biochemical and molecular factors potentially underlying these intervention effects on human skeletal muscle. Our primary approach to address all aims of the proposed studies is to conduct a 6-month randomized controlled trial in obese (BMI ≥ 30 kg/m2) sedentary older men and women 65-80 years of age.

1. Control (health education) group (CON): Subjects will not receive specific exercise or dietary education or prescription, but will be asked to participate in biweekly health education sessions.

2. Diet-induced weight loss (DIWL): The goal will be to achieve a goal of 10% weight loss.

3. Weight Loss + Exercise (WLEX): This group will receive exactly the same dietary intervention as the respective DIWL group. In addition, subjects will be complete a progressive, moderate intensity supervised This is a single-site randomized controlled trial. The analysis of each of the aims will involve multiple steps and draw on statistical methods ranging from simple descriptive statistics to the modeling of repeated measures outcome data accounting for potential missing observations.

The major outcomes of the study, the muscle biopsy parameters, insulin sensitivity, muscle mass, strength, power and quality, will be measured at entry into the study and at the end of the study. ;

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Factorial Assignment, Masking: Open Label, Primary Purpose: Health Services Research

Related Conditions & MeSH terms

• Aging
• Insulin Resistance

• NCT number: NCT01808924
• Study type: Interventional
• Source: University of Pittsburgh
• Contact: Nicole L Helbling, MS, RN
• Phone: 412-692-2285
• Email: nlr8@pitt.edu
• Status: Recruiting
• Phase: N/A
• Start date: December 2011
• Completion date: September 2016