Clinical trial NCT00742456: Microvascular Dilatation After Endogenous Induced Hyperinsulinemia
Official title: Insulin-induced Microvascular Dilatation During a Physiological Stimulus - Studies in Hypertension and Obesity.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypertension
Obesity
Keywords: Microcirculation
Insulin
Hypertension
Obesity
Lead sponsor: Maastricht University Medical Center
Sponsor class: OTHER
First posted: 2008-08-27
Enrollment: 48
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: In this study we will examine if the insulin-induced microvascular effects will occur after a physiological stimulus (i.e. a oral glucose tolerance test). With that the physiological importance of the insulin-induced microvascular dilatation can be elucidated. In this study we hypothesize that oral glucose intake and consequently the endogenous induced hyperinsulinemia will lead to insulin-induced microvascular dilatation in healthy normotensive subjects. Furthermore, we suggest that the insulin-mediated microvascular dilatation, resulting from this physiological induced hyperinsulinemia, will be less in hypertensive and obese subjects compared to healthy controls.


Eligibility criteria: Inclusion Criteria:

healthy normotensive subjects:

1. 18-60 years
2. Caucasian
3. Blood pressure \<140/90 mmHg

obese normotensive subjects:

1. 18-60 years
2. Caucasian
3. Blood pressure \<140/90 mmHg
4. BMI 30-38kg/m2

hypertensive subjects:

1. 18-60 years
2. Caucasian
3. Untreated hypertension \>140/90mmHg.

Exclusion Criteria for healthy normotensive and hypertensive subjects:

1. Obesity (BMI\>27kg/m2)
2. Cardiovascular disease (stroke, coronary artery disease, peripheral vascular disease, heart failure)
3. Diabetes mellitus according to the criteria of the ADA
4. Smoking
5. Alcohol use \>4U/day
6. Use of medication (antihypertensive drugs, lipid lowering drugs, corticosteroids, NNSAIDs)
7. Pregnancy
8. Wearing contact lenses

for normotensive obese subjects:

1. Cardiovascular disease (stroke, coronary artery disease, peripheral vascular disease, heart failure)
2. Impaired glucose tolerance or diabetes mellitus according to the criteria of the ADA
3. Smoking
4. Alcohol use \>4U/day
5. Use of medication (antihypertensive drugs, lipid lowering drugs, corticosteroids, NNSAIDs)
6. Pregnancy
7. Wearing contact lenses

Primary outcomes:
measure: Functional recruitment of capillaries in the skin.
timeFrame: January 2009 - January 2010
Secondary outcomes:
measure: Perfused capillary density in the nailfold.
timeFrame: January 2009 - January 2010
measure: Endothelium- (in)dependent vasodilatation of finger skin microcirculation
timeFrame: January 2009 - January 2010
measure: Density of arterioles, capillaries and venules in the bulbar conjunctiva.
timeFrame: January 2009 - January 2010
measure: Diameter of arterioles and venules in the bulbar conjunctiva.
timeFrame: January 2009 - January 2010
measure: Insulin sensitivity (HOMA-IR)
timeFrame: January 2009 - January 2010
Other outcomes:
Locations:
city: Maastricht
country: Netherlands
facility: University Hospital Maastricht
Study officials:
affiliation: Univeristy Hospital Maastricht
name: CDA Stehouwer, Prof.
role: STUDY_CHAIR
References: