The Effects of Renal Denervation on Insulin Sensitivity
Renal sympathetic nerves contribute to development of hypertension. Sympathetic overactivity also induces insulin resistance and it could therefore be assumed that a renal denervation might improve insulin sensitivity. Studies have shown that glucose metabolism is improved in patients with treatment resistant essential hypertension both 1 and 3 months after renal denervation compared to a control group with treatment resistant essential hypertension. Fasting glucose, insulin and C-peptide decreased significantly as did insulin resistance assessed by HOMA-IR. The investigators wish to investigate the effect of renal denervation on insulin sensitivity using the gold standard - the hyperinsulinemic euglycemic clamp and to investigate the degree of insulin resistance in muscle, liver and adipose tissue.
Treatment Resistant Essential Hypertension
Procedure: Renal denervation
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||The Effects of Renal Sympathetic Denervation on Insulin Sensitivity in Patients With Resistant Essential Hypertension|
- Insulin sensitivity expressed as an M-value [ Time Frame: 4 hours ] [ Designated as safety issue: No ]To assess insulin sensitivity the hyperinsulinemic euglycemic clamp is used. The patients are given 0.8 mU/kg/min insulin as an infusion for 2 hours and the blood glucose is clamped at 5 mmol/l. For assessment of endogenous glucose production (EGP) during the glucose clamps, a tracer (3-3 H glucose) is added to the glucose infusion. The patients will be examined by the hyperinsulinemic euglycemic clamp prior to the renal denervation and 6 months after.
- Insulin signaling [ Time Frame: 6 months ] [ Designated as safety issue: No ]Two biopsies from the lateral vastus muscle and two biopsies from the abdominal subcutaneous adipose tissue are obtained under local anesthesia. Biopsies are taken at baseline and during the clamp. Protein expression involved in the insulin signalling cascade is assessed using standard western blotting techniques.
|Study Start Date:||June 2012|
|Estimated Study Completion Date:||June 2014|
|Estimated Primary Completion Date:||February 2014 (Final data collection date for primary outcome measure)|
Experimental: Renal denervation
The patients will be examined prior to renal denervation and 6 months after. Thus the patients are their own controls.
Procedure: Renal denervation
The patients are examined prior to and 6 months after renal denervation. On the day of examination the patients will have blood samples taken and the hyperinsulinemic euglycemic clamp and muscle and adipose tissue biopsies will be performed.
|Medical Research Laboratories, Aarhus University Hospital|
|Aarhus, Denmark, 8000|
|Principal Investigator:||Per Løgstrup, MD Dr Sci||Department of Endocrinology and Internal Medicine, Aarhus University Hospital|