Decreased leg glucose uptake during exercise contributes to the hyperglycaemic effect of octreotide.
OBJECTIVE
During prolonged infusion of somatostatin, there is an increase in arterial glucose concentration, and this increase persists even during prolonged exercise. The aim of the study was to measure glucose uptake in the leg muscles during infusion of the somatostatin analogue octreotide before and during leg exercise.


METHODS
Eight healthy male subjects were investigated twice in the fasting state: during 3 h infusion of octreotide [30 ng (kg min)(-1)] or sodium chloride with exercise at 50% of maximal VO(2) in the last hour. Glucose uptake and oxygen uptake in the leg were measured using Fick's principle by blood sampling from an artery and a femoral vein. Blood flow in the leg was measured using the indicator (indocyanine green) dilution technique.


RESULTS
After an initial decrease during rest, octreotide infusion resulted in a significant increase in arterial glucose concentrations compared to control conditions during exercise (mean +/- SEM: 7.6 +/- 0.6 versus 5.6 +/- 0.1 mmol l(-1), P<0.01). During rest, octreotide did not change the leg glucose uptake (59 +/- 10 versus 55 +/- 11 micromol min(-1)). In contrast, leg glucose uptake was significantly lower during exercise compared to control conditions (208 +/- 79 versus 423 +/- 87 micromol min(-1), P<0.05). During exercise, leg oxygen uptake was not different in the two experiments (20.4 +/- 1.3 versus 19.5 +/- 1.1 micromol min(-1)).


CONCLUSIONS
In conclusion, infusion of octreotide reduced leg glucose uptake during exercise, despite the same leg oxygen consumption and blood flow compared to control conditions. The hyperglycaemic effect of octreotide can partly be explained by the reduction in leg glucose uptake. Furthermore, the results suggest that a certain level of circulating insulin is necessary to obtain sufficient stimulation of glucose uptake in the exercising muscles.
Department of Clinical Physiology, Bispebjerg Hospital, Copenhagen, Denmark.
Peter
P
Hovind
Lene
L
Simonsen
Jens
J
Bülow
D000328:Adult; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005263:Femoral Artery; D005268:Femoral Vein; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D006943:Hyperglycemia / Q000139:chemically induced* / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007866:Leg / Q000098:blood supply / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000008:administration & dosage / Q000009:adverse effects*; D010101:Oxygen Consumption / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D055815:Young Adult
D001786:Blood Glucose; D005765:Gastrointestinal Agents; D007328:Insulin; D015282:Octreotide