posted 10/09/02
Obese individuals have delayed transcapillary transport of
insulin to muscle tissue, 25 minutes slower, Swedish researchers report in the
September issue of Diabetes.
Dr. Mikaela Sjostrand of Sahlgrenska University Hospital,
Goteborg, and colleagues note that insulin-resistant subjects have a slow onset
of insulin action. To determine whether delayed transcapillary action might be
involved, the researchers investigated the kinetics of infused insulin and
insulin in plasma and muscle interstitial fluid. A total of 10 insulin-resistant
obese subjects and 10 lean controls were evaluated.
The obese subjects had a significantly lower
steady-state glucose infusion rate. They also showed a delayed appearance of
insulin. The time to reach half-maximal plasma concentration was 72 minutes
versus 46 minutes for controls. In interstitial fluid, the corresponding figures
were 83 versus 53 minutes.
Onset of insulin action was 70 minutes in obese
subjects and 45 minutes in controls. Furthermore, the forearm blood flow rate in
obese subjects was significantly lower than that in controls.
Dr. Sjostrand feels that "the impaired vasodilative effect of insulin may result in the sluggish insulin transport to the muscle tissue in the obese group. Therefore, it would be interesting to study the effect of vasodilating agents on transcapillary insulin transport and muscle glucose uptake in insulin resistant obese and type 2 diabetes subjects.
Source: Diabetes In Control Dot Com: Diabetes 2002;51:2742-2748.