Effects of catheter-based renal denervation on glycemic control and lipid levels: a systematic review and meta-analysis.

Aims: As an emerging interventional technique to treat resistant hypertension, renal denervation (RDN) has also attracted considerable attention due to its potential beneficial effects on glucose and lipid metabolism. Given that inconsistent results were documented among studies, we aimed to perform a systematic review and meta-analysis to elaborate on this issue.
Methods: The PubMed, EMBASE, Web of Science (SCI) and ClinicalTrials.gov databases were comprehensively searched from their inception date to June 18, 2020, for relevant clinical studies evaluating the efficacy of RDN on glucose and lipid levels. The outcomes of interest were changes in fasting glucose, insulin, C-peptide, hemoglobin A1C (HbA1C), homeostatic model assessment-insulin resistance (HOMA-IR), cholesterol and triglyceride (TG) levels before versus after RDN and also RDN versus the control group. The mean differences (MDs) of the outcomes measured before versus after RDN and RDN versus the control group were pooled by a randomized effects model. Heterogeneity was quantified with Chi-square (χ ² ) and inconsistency index (I ² ). Assessment of publication bias was performed by the funnel plot and Egger's test.
Results: A total of 1600 studies were initially identified. Nineteen of the identified studies (six randomized controlled studies, one non-randomized controlled studies and 12 observational cohort studies) involving 2245 subjects were included in the final analysis. No significant change was observed after RDN in fasting glucose (weighted mean difference [WMD]  - 0.19 mmol/L; 95% CI  - 0.37, 0.00 mmol/L), insulin (standardized mean difference [SMD]  - 0.01; 95% CI  - 0.41, 0.39), C-peptide (SMD  - 0.05; 95% CI  - 0.30, 0.21), HbA1C (SMD  - 0.05; 95% CI  - 0.17, 0.07), HOMA-IR (SMD  - 0.29; 95% CI  - 0.72, 0.14), total cholesterol (TC) (WMD  - 0.11 mmol/L; 95% CI  - 0.37, 0.15 mmol/L), and low-density lipoprotein cholesterol (LDL-C) levels (WMD  - 0.18 mmol/L; 95% CI  - 0.59, 0.24 mmol/L) during follow-up. Changes in fasting glucose, insulin, HbA1C and TC levels in RDN groups were not significantly different from those in the control group. High-density lipoprotein cholesterol (HDL-C) and TG were slightly improved after RDN (WMD 0.07 mmol/L, 95% CI 0.01, 0.14 mmol/L; WMD - 0.26 mmol/l, 95% CI  - 0.51,  - 0.01 mmol/L, respectively). The funnel plot and Egger's test demonstrated the absence of potential publication bias.
Conclusions: Catheter-based RDN appeared to have no impact on glucose metabolism. There was a statistically significant but clinically negligible improvement in HDL-C and TG levels based on the current evidence. Future research with more rigorous designs is warranted to draw definitive conclusions.
Registration Details: The protocol of this meta-analysis was registered on PROSPERO (CRD42020192805). ( https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=192805 ).