Insulin resistance plays an important role in the pathophysiology of diabetes and is associated with obesity and other cardiovascular risk factors. The "gold standard" glucose clamp and minimal model analysis are two established methods for determining insulin sensitivity in vivo, but neither is easily implemented in large studies. Thus, it is of interest to develop a simple, accurate method fo...

Insulin resistance plays a major role in the pathophysiology of diabetes and is associated with obesity and cardiovascular disease. Excellent methods exist for the assessment of insulin sensitivity in the laboratory setting, such as the glucose clamp. However, these methods are not suitable for large population studies, and, thus, surrogate estimates of insulin sensitivity based on measurements...

OBJECTIVE We evaluated insulin sensitivity and insulin secretion across the entire range of fasting (FPG) and 2-h plasma glucose (PG), and we investigated the differences in insulin sensitivity and insulin release in different glucose tolerance categories. RESEARCH DESIGN AND METHODS A total of 6,414 Finnish men (aged 57 +/- 7 years, BMI 27.0 +/- 3.9 kg/m2) from our ongoing population-based M...

OBJECTIVE A drastic difference is evident in the prevalence of type 2 diabetes among ethnic groups. We examined the role of beta-cell function and insulin sensitivity in this disparity among 4 ethnic groups. RESEARCH DESIGN AND METHODS beta-Cell function and insulin sensitivity were assessed in 77 healthy glucose-tolerant subjects using a hyperglycemic clamp (18 Asian-Americans, 9 African-Ame...

To evaluate mechanisms underlying the close association between insulin secretion and insulin sensitivity, insulin sensitivity was evaluated by the euglycemic-hyperinsulinemic clamp technique (M/I(clamp)) and insulin secretion was determined from the 75-g oral glucose tolerance test (OGTT) and from the glucose-dependent arginine-stimulation test in 81 nondiabetic postmenopausal women, all aged ...

Intramyocellular lipid (IMCL) has been inversely associated with insulin sensitivity in some, but not all, studies. This study utilized fast, high-resolution, magnetic resonance spectroscopic imaging (MRSI) to: investigate relationships between muscle lipids (IMCL and extramyocellular lipid (EMCL)) and insulin sensitivity in muscles of varying oxidative capacity, explore ethnic differences in t...

OBJECTIVE To investigate whether features of the insulin resistance syndrome are associated with altered incretin responses to food intake. RESEARCH DESIGN AND METHODS From a population-based study, 35 men were recruited, representing a wide spectrum of insulin sensitivity and body weight. Each subject underwent a hyperinsulinemic-euglycemic clamp to determine insulin sensitivity. A mixed mea...

Numerous studies have suggested that ovarian hormones are able to modulate insulin sensitivity, but their exact role remains unclear. We have investigated whether different doses of 17beta-oestradiol mediate changes in insulin sensitivity and if these changes could be related to modifications of insulin receptor substrate-1 (IRS-1). Female rats were ovariectomized and later separated into three...

BACKGROUND AND AIMS The liver is the main source and insulin the main regulator of IGF binding protein 1 (IGFBP-1) in humans. Here we examined how serum IGFBP-1 concentrations are related to directly measured hepatic insulin sensitivity and liver fat content in humans. METHODS We measured fasting serum (fS) IGFBP-1 concentrations and liver fat content by proton magnetic resonance spectroscopy...

Introduction: Muscle sympathetic nerve activity (MSNA) may play a role in insulin resistance in obesity. However, the direction and nature of the relationship between MSNA and insulin resistance in obesity remain unclear. We hypothesized that resting MSNA would correlate inversely with both muscle and liver insulin sensitivity and that it would be higher in insulin-resistant vs. insulin-sensiti...