All ETDs from UAB

Advisory Committee Chair

Barbara A Gower

Advisory Committee Members

José R FernαNdez

Timothy R Nagy

Document Type

Thesis

Date of Award

2018

Degree Name by School

Master of Science (MS) School of Health Professions

Abstract

Current screening methods have failed to detect more than 50% of the 120 million U.S. adults with insulin resistance and/or metabolic syndrome, conditions that substantially increase one’s risk for cardiometabolic disease (CMD).1 Evidence exists that metabolic health is associated with cell membrane composition, which is reflected in the electrical properties of the body cell mass. The objective of this study was to determine whether bioimpedance spectroscopy can identify insulin resistance and/or metabolic syndrome by evaluating membrane capacitance (CM). We hypothesized that CM would be higher in individuals with insulin resistance and/or metabolic syndrome when compared to healthy individuals. This cross-sectional study used relatively healthy adults (n= 2,191 45% female, 43% Non-Hispanic white, aged 18 – 49 years) from the 1999 – 2004 National Health and Nutrition Examination Survey. First, we explored the associations of CM with relevant biomarkers (e.g., fasting glucose, fasting triglycerides) and clinical endpoints (e.g., hyperglycemia, hypertriglyceridemia) by linear regression. Second, we compared CM between men and women with normal CMD risk to those with homeostatic model assessment (HOMA) defined insulin resistance, NCEP: ATP III-defined metabolic syndrome, and those with both insulin resistance and metabolic syndrome, using analysis of (co)variance models. Third, we explored serum potassium as a potential mediator of the association between CM and metabolic dysregulation. Covariates included stature, electrical resistance, fat/lean mass (DXA), age, race, smoking, alcohol, and medication use. First, we found that CM was associated with insulin resistance independent of covariates in women, but CM was not associated with insulin resistance in men. CM was not associated with metabolic syndrome in either sex. Next, compared to those with normal risk, CM was higher in insulin-resistant women; there was no difference in CM for insulin-resistant men. CM was similar between women or men with normal-risk and those who had metabolic syndrome with normal insulin sensitivity. Finally, we found that insulin-resistant women, but not men had elevated serum potassium, which may have mediated the association between CM and insulin resistance in women, and explained the lack of association in men. In conclusion, CM may be a useful indicator of insulin resistance in relatively healthy women.

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