Denervation of the Renal Arteries in Metabolic Syndrome

Abstract

Chronic elevation of sympathetic nervous system is a key factor in metabolic syndrome. Because renal denervation (RDN) is thought to modulate sympathetic activity, we performed the Denervation of the Renal Arteries in Metabolic Syndrome (DREAMS)–study to investigate the effects of RDN on insulin sensitivity and blood pressure (BP) in patients with metabolic syndrome. Twenty-nine patients fulfilling the criteria for metabolic syndrome and who used a maximum of 1 antihypertensive or 1 antidiabetic drug or 1 of both gave informed consent and were treated by RDN. Glucose tolerance tests and 24-hour ambulatory BP measurements were performed at baseline, at 6 and 12 months of follow-up. Moreover, we performed self-monitored BP measurements at home every month. To assess sympathetic activity, we performed muscle sympathetic nerve activity and heart rate variability measurements at baseline and follow-up. The majority of the included patients was men (57%), mean body mass index was 31±5 kg/m 2 . Median insulin sensitivity as assessed by the Simple Index assessing Insulin Sensitivity oral glucose tolerance test did not change at 6- and 12-month follow-up ( P =0.60 and P =0.77, respectively). Mean 24-hour BP decreased by 6±12/5±7 mm Hg 12 months after RDN ( P =0.04/0.01). However, self-monitored BP measurements data showed no reduction over time. Measurements of sympathetic activity showed no reduction in systemic sympathetic activity. In conclusion, RDN did not lead to a significant improvement of insulin sensitivity ≤12 months after treatment. Although a significant reduction in ambulatory BP was observed in this nearly drug-naïve population, the self-monitored BP measurements data suggest that this may be explained by regression to the mean. Moreover, no effect in systemic sympathetic activity was observed.

Should the sympathetic nervous system be a target to improve cardiometabolic risk in obesity?

“…It was shown that the procedure was associated with improvement in glucose metabolism (100), diastolic function (17), health-related quality of life (89) and arterial stiffness (64), and a reduction in left ventricular mass (17) in those with resistant hypertension. On the other hand, a recent study (173) showed no improvement in insulin sensitivity after one year following renal denervation in hypertensive patients with the metabolic syndrome despite a reduction in blood pressure. Chronic baroreflex activation.…”

“…The consequences of renal ablation may be due to blockade of both afferent and efferent neural pathways. One study (65) showed that ablation of afferent renal nerve activity leads to decreased MSNA, indicating a suppression of overall sympathetic vasoconstrictor drive that contributes to the antihypertensive actions; however, two recent reports (19,173) are inconsistent with this possibility. Likewise, in dogs with obesity-related hypertension, renal denervation did not decrease global sympathetic nervous activity (98).…”

Renal denervation for the treatment of resistant hypertension: review and clinical perspective

“…Although producing a modest fall in arterial pressure in 29 obese patients with metabolic syndrome treated with a maximum of one antihypertensive drug, renal nerve ablation failed to decrease MSNA at a 6 mo follow-up (84). In an ovine model of heart failure, catheter-based renal denervation did not reduce elevated levels of cardiac sympathetic nerve activity when measured 24 h after renal denervation (7).…”

Renal denervation in the era of HTN-3. Comprehensive review and glimpse into the future

“…83 This disruption of the SNS has the potential to influence many other clinical entities highly dependent on SNS hyperactivity, such as the sleep apnea syndrome, chronic heart failure, atrial fibrillation (AF) and ventricular arrhythmias, metabolic syndrome, chronic kidney disease, and polycystic ovary syndrome. [84][85][86][87][88][89] Most of these studies are small and purely observational. Regarding cardiac arrhythmias, SYMPLICITY AF is a prospective, randomized, multicenter, feasibility clinical study investigating pulmonary vein isolation and renal denervation compared to pulmonary vein isolation alone, for the treatment of paroxysmal or persistent AF in patients with both AF and HT.…”