Effects of Intranasal Insulin Administration on Tissue Specific Insulin Sensitivity
Status:
Completed
Trial end date:
2016-12-01
Target enrollment:
Participant gender:
Summary
Recent research has suggested that intranasally administered insulin can reach the brain
quickly without passing through circulation and evoke increased insulin sensitivity and
tissue glucose consumption during insulin stimulation (low-dose hyperinsulinemic, euglycemic
clamp). It is still not known what mechanism causes these changes or what tissues are
involved in this.
In this study, the changes in tissue-specific insulin sensitivity and glucose uptake will be
investigated by using glucose-analogue radiotracer ([18F]-fluorodeoxyglucose) with positron
emission tomography (PET) imaging during insulin stimulation. Ten healthy males are studied,
each receiving nasal sprays containing insulin or placebo in a randomized order on two
separate days. After spray administration, glucose uptake in skeletal muscle, liver,
subcutaneous and visceral adipose tissue, myocardium, intestines, brown adipose tissue and
brain assessed by PET imaging and glucose uptake in these tissues is analyzed. Endogenous
glucose production is calculated facilitating the measurements glucose and radiotracer uptake
in tissues and tracer loss into urine.
As skeletal muscle consumes most of the glucose available, it is likely that administration
of insulin sprays will result in an increased uptake in this tissue. Some increase in glucose
uptake might also be seen in other tissue types after insulin spray versus placebo spray
administration.