Regulation of adipose tissue oxygen tension by adipose tissue blood flow.

Increasing evidence suggests that adipose tissue dysfunction plays a prominent role in the development of insulin resistance and type 2 diabetes mellitus. One aspect of adipose tissue dysfunction is an impaired adipose tissue blood flow (ATBF). We and others have demonstrated that ATBF is decreased in obese and type 2 diabetic subjects. It is tempting to speculate that adipose tissue hypoperfusion may induce hypoxia in this tissue, which in turn may contribute to insulin resistance via induction of adipose tissue inflammation.

A decreased adipose tissue blood flow results in adipose tissue hypoxia, which in turn may contribute to the development of insulin resistance.

In this cross-section study, blood samples are collected during the clamp (every 5min) and during the oxygen tension measurements (during the OGTT at time-points t0, t10, t20, t30, t60, t90 and t120).

Adipose tissue oxygen tension will be measured using an optochemical measurement system for the continuous monitoring of oxygen tension in vivo in humans using microdialysis. Adipose tissue oxygen tension will be mreasured during pharmacological (local angiotensin II and isoprenaline administration) and physiological (a standardized 75g oral glucose tolerance test (OGTT)) manipulation of adipose tissue blood flow. Insulin sensitivity will be assessed during a hyperinsulinemic-euglycemic clamp. An adipose tissue biopsy and blood samples will be taken under fasting (baseline) conditions and at several time-point during the protocol (e.g. during local administration of pharmacological agents and during the OGTT).