ABSTRACT Type 2 Diabetes (T2D) has several comorbidities such as cardiovascular disease, elevated lipid profile, microvascular complications, and impaired metabolic flexibility (MF: the ability to switch substrate use upon stimulation). Further, healthy Caucasians with a family history of T2D (FH+) have impaired MF similar to T2D, suggesting impaired MF could be an early-detection tool to identify at-risk populations. Hispanics of the Rio Grande Valley have ~3x the T2D rates as the US average, and have ~79% of the people in this region are either overweight or obese. However, patterns of MF in this population have not been addressed. Purpose: The purpose of this study was to quantify metabolic flexibility in this population, and determine if differences in MF are noted between FH+ and those with no history of T2D (FH-). Methods: To determine changes in metabolic flexibility we utilized a hooded metabolic cart to quantify substrate oxidation in FH+ and FH- participants while 1) fasted at rest, and 2) for 60-min after consumption of mixed composition meal challenge (MMC). Participants were matched according to BMI, age, weight and height (25.23 ±3.4, 74.1 ±14.9, 167.3 ±8.5 respectively). Blood draws and expired gas were taken before and after each state at intervals 0, 15, 30, 60, 90 and 120 min. Results: No differences were noted in RMR between FH+ and FH- groups (1588.90 ± 97.57 and 1540.87 ± 81.12, mean ± SD respectively, p=0.7), fasting RER (0.76 ± 0.04 and 0.80 ± 0.03 mean ± SD respectively, p=0.44), or max RER (0.85 ± 0.05 and 0.95 ± 0.04 mean ± SD respectively, p=0.1). However, MF in FH+ was lower than in FH- (0.24 ± 0.23 and 0.41 ± 0.20 mean ± SD respectively, p=0.03). Conclusion: In Hispanics of the RGV, healthy FH+ individuals display impaired MF when compared with matched FH- counterparts. Additional testing is warranted to compare ethnicities to determine differences between Caucasians and Hispanics, as well as additional variables that may affect MF.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.