OBJECTIVE Recent work has shown that insulin stimulates its own secretion in insulin-sensitive humans, suggesting that insulin resistance in the β-cell could cause β-cell dysfunction. We have tested whether insulin exposure and insulin sensitivity modulate β-cell function in subjects with normal glucose tolerance (NGT) and whether they contribute to dysglycemia in impaired glucose regulation (I...

BACKGROUND We aimed to evaluate the predictive utility of common fasting insulin sensitivity indices, and non-laboratory surrogates [BMI, waist circumference (WC) and waist-to-height ratio (WHtR)] in sub-Saharan Africans without diabetes. METHODS We measured fasting glucose and insulin, and glucose uptake during 80/mU/m2/min euglycemic clamp in 87 Cameroonians (51 men) aged (SD) 34.6 (11.4) y...

AIMS To investigate the relationship between adiposity and plasma free fatty acid levels and the influence of total plasma free fatty acid level on insulin sensitivity and β-cell function. METHODS An insulin sensitivity index, acute insulin response to glucose and a disposition index, derived from i.v. glucose tolerance minimal model analysis and total fasting plasma free fatty acid levels we...

Glucagon levels are often moderately elevated in diabetes. It is known that glucagon leads to a decrease in hepatic glutathione (GSH) synthesis that in turn is associated with decreased postprandial insulin sensitivity. Given that cAMP pathway controls GSH levels we tested whether insulin sensitivity decreases after intraportal (ipv) administration of a cAMP analog (DBcAMP), and investigated wh...

BACKGROUND Insulin resistance, i.e. impaired insulin sensitivity, and type 2 diabetes are more prevalent in elderly humans. Both conditions relate to lower aerobic performance and increased body fatness, which have been linked to reduced mitochondrial oxidative capacity. Thus, lower insulin sensitivity in the elderly could result from age-related diminished energy metabolism or from lifestyle-r...

Ahrén, B., and G. Pacini. A novel approach to assess insulin sensitivity reveals no increased insulin sensitivity in mice with a dominant-negative mutant hepatocyte nuclear factor-1 . Am J Physiol Regul Integr Comp Physiol 291: R131–R137, 2006. First published February 9, 2006; doi:10.1152/ajpregu.00519.2005.—In phenotype experiments in mice, determination of dynamic insulin sensitivity often u...