The unfavorable effects
raised sympathetic activity can be shown in normal persons after reflex
of the sympathetic nervous system. In the experiment by Jamerson et al.
a supraphysiological dose of insulin was infused using the euglycemic
clamp technique. The increased insulin resulted - as expected - in a
glucose utilisation. When a bilateral thigh compression was used to
the venous return to the heart, the glucose utilisation was impaired!
receptors monitor the venous filling of the heart and induce a rise in
outflow of the brain when venous return is reduced or the pressure
of the heart is depressed. As a consequence of the increased
activity, glucose utilization of the body is reduced. The study shows that reflex
sympathetic tone that are in the normal range of human physiological
responses can induce insulin resistance. It appears that a raised
sympathetic activity due to a high caloric intake has a similar action.
Since insulin resistance precedes diabetes mellitus type-2, interventions which interfere with progression of insulin resistance are of utmost importance. Since moxonidine interferes with various adverse mechanisms that promote insulin resistance, it is not unexpected that it increases insulin sensitivity also in overweight or obese subjects. In our opinion, hypertension therapy should include an intervention that reduces insulin resistance, as is the case with moxonidine.
1. Rupp H: Excess
catecholaminesyndrome. Pathophysiology and therapy. Ann N Y Acad Sci
2. Jamerson KA, Julius S, Gudbrandsson T et al. Hypertension 1993;21:618-623.