Association of Skeletal Muscle Oxidative Capacity and Cardiometabolic Health in an Overweight Population

Abstract

Background: Cardiometabolic health factors are becoming increasingly front and center in prevalence and cost of treatment in the U.S.. Incidence rates and complications from diseases related to these factors including obesity, heart disease, type 2 diabetes and certain types of cancers have not only cost over $1 trillion annually but are increasing mortality rates across the country. Skeletal muscle mitochondrial function has been connected to these factors, and research has shown that it can be used as an in vivo assessment of cardiometabolic health. Near Infrared Spectroscopy has recently seen an increase in interest for being used as a non-invasive method of assessing in vivo-mitochondrial function providing a simpler, cheaper and accurate way to determine cardiometabolic health both for practitioners and researchers. Studies have shown that NIRS assessments are similar in accuracy to other more expensive standards of assessment, such as 31P-MRS. Thus, we aim to examine the relationship between factors of cardiometabolic health and assessment of mitochondrial function using NIRS. Purpose: To examine how indices of cardiometabolic health, and VO2max associate with NIRS assessment of mitochondrial function. Methods: Overweight subjects (n=17) with a body mass index (BMI) of 25.0-29.9 kg/m2 were screened for varying factors of cardiometabolic health. Body composition was measured by a DEXA scan, 3-D body scan, and participants also underwent a maximal exercise test on a cycle ergometer and measures of resting metabolic rate. For a measure of mitochondrial function, subjects performed a NIRS assessment before and after three days of a high-fat diet. Results: Measures of cardiometabolic health were not statistically significant with mitochondrial function assessment with NIRS pre- or post- three day high-fat diet. Conclusion: The results from the current study show that mitochondrial function as assessed by NIRS has no statistically significant relationships with factors of cardiometabolic health or following an acute high-fat diet.