High Body Adiposity Drives Glucose Intolerance and Increases Cardiovascular Risk in Normoglycemic Subjects

The objective of this study was to assess the utility of the 2-hour oral glucose tolerance test (OGTT) value to discriminate between different cardiometabolic profiles and examine the role of body composition in predicting the associated increased risk for glucose impairment, beta-cell dysfunction, and cardiovascular disease (CVD).

Subjects with normal fasting glucose completed a 2-hour OGTT and were categorized to the carbohydrate metabolism alterations (CMAs) or the control group based on a 2-hour glucose threshold of 7.8 mmol/L. Body composition, visceral adipose tissue, OGTT-based parameters, and cardiovascular risk factors (CVRFs) such as hypertension, dyslipidemia, obstructive sleep apnea, nonalcoholic fatty liver disease, and smoking status were measured.

Subjects with CMAs exhibited a significantly higher 1-hour postload glucose level and a greater decline in beta-cell function and CVRF profiles. After multivariate adjustment, an excess of total body and visceral fat was associated with an increased risk of CMAs, beta-cell dysfunction, CVRFs, and lower whole-body insulin sensitivity.

These data support the etiopathogenic role of body and visceral fat in the development of glucose derangements and CVRFs early on in the metabolic dysregulation process. Thus, body composition analysis and OGTT assessment performed in individuals with normal fasting glucose enable a better identification of patients at risk of developing type 2 diabetes and CVD.