[13C]glucose breath testing provides a noninvasive measure of insulin resistance: calibration analyses against clamp studies.

Background: Exhaled (13)CO2 following ingestion of [(13)C]glucose with a standard oral glucose tolerance load correlates with blood glucose values but is determined by tissue glucose uptake. Therefore exhaled (13)CO2 may also be a surrogate measure of the whole-body glucose disposal rate (GDR) measured by the gold standard hyperinsulinemic euglycemic clamp.

Subjects And Methods: Subjects from across the glycemia range were studied on 2 consecutive days under fasting conditions.

Impaired cardiometabolic responses to glucagon-like peptide 1 in obesity and type 2 diabetes mellitus.

Glucagon-like peptide 1 (GLP-1) has insulin-like effects on myocardial glucose uptake which may contribute to its beneficial effects in the setting of myocardial ischemia. Whether these effects are different in the setting of obesity or type 2 diabetes (T2DM) requires investigation. We examined the cardiometabolic actions of GLP-1 (7-36) in lean and obese/T2DM humans, and in lean and obese Ossabaw swine.