Metabolic and Cardiovascular Effects of Renal Denervation

Renal denervation has recently shown to improve glucose metabolism and insulin sensitivity in addition to reducing blood pressure. The mechanisms are however unclear. The investigators hypothesize that renal denervation alters adipose tissue function by reduced sympathetic outflow, measured by fat biopsies and markers of inflammation and insulin sensitivity. 15 clinical patients undergoing renal denervation are recruited to the study investigating anthropometry, peripheral blood samples, body composition, heart rate variability and subcutaneous fat biopsies at baseline and 6 months after renal denervation.

Renal denervation, a catheter-based approach to reduce renal sympathetic afferent and efferent activity has been used successfully to treat drug-resistant hypertension. Previous studies has demonstrated a reduction of muscle sympathetic nerve activity and renal and total body noradrenaline spillover. In addition, renal denervation seems to improve glucose metabolism and insulin sensitivity, representing the first potential nonpharmaceutical approach for treating insulin resistance. However, the mechanisms are unclear. There is a clear relationship between sympathetic overactivity and insulin resistance. Activation of the sympathetic nervous systems contributes to insulin resistance and metabolic disorders and insulin itself induces sympathetic overactivity. One possible explanation to improved glucose metabolism after renal denervation is altered adipose tissue function (due to the reduction in sympathetic activity). Therefore,15 individuals undergoing renal denervation are recruited. The clinical study includes anthropometry, peripheral blood samples, body composition, heart rate variability and subcutaneous fat biopsies before renal denervation and after 6 months.

Secondary hypertension is excluded by an extensive preoperative clinical investigation and the renal artery anatomy is visualized by computer tomography (with contrast). By cannulating the femoral artery both renal arteries are treated by a radiofrequency-catheter, 4-6 ablations in each artery.

Inclusion Criteria: Essential hypertension Systolic blood pressure >160 mm Hg despite ≥3 antihypertensive drugs Clinical patients accepted for renal denervation Exclusion Criteria: Type 1 diabetes Pregnancy Glomerular filtration rate ≤45 ml/min/1,73 m2 Pacemaker/ICD Myocardial infarction/stroke the last 12 months