Microvascular Dilatation After Endogenous Induced Hyperinsulinemia

Sponsor

Maastricht University Medical Center (Other)

Overall Status

Completed

CT.gov ID

NCT00742456

Collaborator

(none)

Enrollment

Location

Arms

Duration (Months)

2.5

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Hypertension Obesity	Dietary Supplement: Glucose solution Dietary Supplement: Placebo	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

48 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Single (Participant)

Primary Purpose:

Basic Science

Official Title:

Insulin-induced Microvascular Dilatation During a Physiological Stimulus - Studies in Hypertension and Obesity.

Study Start Date :

Jan 1, 2009

Actual Primary Completion Date :

Aug 1, 2010

Actual Study Completion Date :

Aug 1, 2010

Arms and Interventions

Arm	Intervention/Treatment
Experimental: I Glucose	Dietary Supplement: Glucose solution single oral intake of 250 ml glucose solution (75gr sugar in 250ml of water)
Placebo Comparator: II Placebo	Dietary Supplement: Placebo single intake of placebo solution (250ml of sweet flavored water, no sugar added), orally

Arm

Intervention/Treatment

Experimental: I

Glucose

Dietary Supplement: Glucose solution

single oral intake of 250 ml glucose solution (75gr sugar in 250ml of water)

Placebo Comparator: II

Placebo

Dietary Supplement: Placebo

single intake of placebo solution (250ml of sweet flavored water, no sugar added), orally

Outcome Measures

Primary Outcome Measures

Functional recruitment of capillaries in the skin. [January 2009 - January 2010]

Secondary Outcome Measures

Perfused capillary density in the nailfold. [January 2009 - January 2010]
Endothelium- (in)dependent vasodilatation of finger skin microcirculation [January 2009 - January 2010]
Density of arterioles, capillaries and venules in the bulbar conjunctiva. [January 2009 - January 2010]
Diameter of arterioles and venules in the bulbar conjunctiva. [January 2009 - January 2010]
Insulin sensitivity (HOMA-IR) [January 2009 - January 2010]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 60 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

healthy normotensive subjects:

18-60 years
Caucasian
Blood pressure <140/90 mmHg

obese normotensive subjects:

18-60 years
Caucasian
Blood pressure <140/90 mmHg
BMI 30-38kg/m2

hypertensive subjects:

18-60 years
Caucasian
Untreated hypertension >140/90mmHg.

Exclusion Criteria for healthy normotensive and hypertensive subjects:

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

for normotensive obese subjects:

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