Renal denervation improves blood pressure, but also insulin and glucose metabolism
Mahfoud F, Schlaich M, Kindermann I et al.
Effect of Renal Sympathetic Denervation on Glucose Metabolism in Patients With Resistant Hypertension - A Pilot Study
BackgroundSympathetic overactivity induces insulin resistance, while hyperinsulinemia produces sympathetic activation, thus yielding a vicious cycle . Renal sympathetic afferent and efferent activity can be reduced by a percutaneous, catheter-based approach applying intra-arterial radiofrequency energy, thus treating drug-resistant hypertension. It also reduces muscle sympathetic nerve activity and renal an total body noradrenaline spillover [2-4].
Since the sympathetic nervous system is involved in metabolic control, reduction of its activity might have a substantial effect on glucose metabolism in hypertensive patients. This pilot study aimed to evaluate the relation between sympathetic activity and glucose metabolism and the effect of therapeutic renal denervation in patients with resistant hypertension. All patients remained on baseline antihypertensive medication. 37 were assigned to the treatment group following protocols of ongoing therapeutic renal denervation trials, whereas 13 control individuals would undergo renal denervation 6 months later. Follow-up was up to 3 months.
- Renal denervation significantly reduced systolic (-28.+2 mmHg, P<0.001) and diastolic (-10+2 mmHg, P<0.001) blood pressure at 1 month after the procedure. These reductions persisted until the 3-month follow-up (-32 +4 for SBP, -12+2 for DBP respectively, P<0.001). Control subjects did not show a significant change in blood pressure from baseline sitting office systolic (178+2.7) and diastolic (96+2.2) BP.
- Fasting glucose levels were significantly reduced after treatment, from 118+3.4 to 108+3.8 mg/dL (P=0.039), while no changes were seen in the control group. Insulin levels decreased from 20.8+3.0 to 9.3+2.5 µIU/mL (P=0.006), which was associated with reduced C-peptide levels (5.3+0.6 to 3.0+0.9 ng/mL, P=0.002).
- Insulin sensitivity increased significantly after renal denervation (HOMA-IR reduction from 6.0+0.9 to 2.4+0.8, P=0.001, and ISQUICKI increased from 0.32+0.01 to 0.36+0.01, P=0.001).
- No significant changes in glucose or insulin metabolism were seen during follow-up in the control group..
- During an oral glucose tolerance test (OGTT) after 3 months, glucose levels were significantly reduced after 120 minutes (-27+10.1 mg/dL, P=0.012) in the treatment but not in the control group.
ConclusionThis study identifies the renal sympathetic nervous system as an important regulator of insulin resistance. Ablation of the renal nerve can substantially improve insulin sensitivity and glucose metabolism, in addition to reducing blood pressure. Thus, selective denervation of the renal sympathetic nerves can improve glucose metabolism and blood pressure control simultaneously in patients with resistant hypertension.
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