An Investigation of the Oxidation of Carbohydrate versus Fat for Energy in Individuals with Type 2 Diabetes

Abstract

Impaired fat oxidation has been associated with increased plasma free fatty acid concentrations, ectopic fat deposition and insulin resistance, which may contribute to the development of Type 2 Diabetes (T2D). The objectives of this research were to determine whether individuals with T2D oxidized a greater proportion of carbohydrate (CHO oxidizers) versus fat (fat oxidizers) over a 24 hour period, measured by the cumulative respiratory quotient (RQ24), and to identify differences in metabolic variables between CHO and fat oxidizers. Ten participants spent two non-consecutive days in the Whole Body Calorimetry Unit to determine their RQ24. More (n=7) were classified as CHO oxidizers than fat oxidizers (n=3); and CHO oxidizers had a greater central fat distribution (P=0.041) and a higher resting systolic blood pressure (P=0.031) than fat oxidizers. Results of this pilot study suggest that differences in substrate oxidation exist in people with T2D and these differences may be clinically important.