# Ketogenic dietary interventions for autosomal-dominant polycystic kidney disease (ADPKD): a systematic review and synthesis without meta-analysis (SWiM) of observational and interventional studies

## TL;DR

This review examines how ketogenic diets affect autosomal-dominant polycystic kidney disease, finding they help with weight and body metrics but more research is needed on kidney outcomes.

## Contribution

The study is the first to synthesize evidence on ketogenic diets for ADPKD using a systematic review without meta-analysis.

## Key findings

- Ketogenic diets are associated with weight loss and improved anthropometric profiles.
- Renal outcomes like eGFR are either improved or stable, but structural changes remain uncertain.
- More long-term trials are needed to assess the effectiveness of ketogenic diets for ADPKD.

## Abstract

The purpose of this systematic review was to synthesize available human studies, present and weigh the evidence regarding the efficacy of ketogenic dietary interventions (KDIs) for ADPKD, and provide a direction for future research and relevant recommendations.

Three databases were searched and risk of bias (RoB) of the studies was assessed using Cochrane's RoB 2.0, the Newcastle-Ottawa scale and the ROBINS-IΙ tool. The Synthesis Without Meta-analysis (SWiM) extension was used to present the results.

Eight studies were identified delivering interventions with ketogenic diets, intermittent fasting, time-restricted feeding, etc. KDIs were generally associated with weight loss and a more favorable anthropometric profile in most interventions (nine). Blood pressure remained unchanged in most interventions (five), similar to blood cholesterol, HDL-cholesterol, triglycerides and LDL concentrations. Regarding renal outcomes, eGFR was either higher (4 interventions) or remained stable post-intervention. htTKV remained unchanged in most of the studies. Evidence for renal structural change was inconsistent and limited by short intervention duration and small sample sizes.

The evidence on KDIs for ADPKD is still limited. However, KDIs, particularly caloric-restriction diets, appear promising tools for managing ADPKD. Current human data support metabolic feasibility more consistently than renal disease modification. The effects of KDIs on renal structural outcomes remain uncertain and longer trials with appropriate comparators, namely the standard of care diet for ADPKD, are required before KDIs can be recommended for ADPKD.

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•Ketogenic interventions can reduce body weight and improve the anthropometric profile of patients.•Blood pressure, total cholesterol, HDL- and LDL-cholesterol, and triglycerides levels remain unaffected. Concerning renal outcomes, eGFR is either improved or remains stable post-intervention. htTKV also remains unchanged.•Ketogenic interventions are feasible for ADPKD, however, research is still limited. More research is required in order to understand the potential of ketogenic diets to act as an adjuvant treatment for ADPKD.

Ketogenic interventions can reduce body weight and improve the anthropometric profile of patients.

Blood pressure, total cholesterol, HDL- and LDL-cholesterol, and triglycerides levels remain unaffected. Concerning renal outcomes, eGFR is either improved or remains stable post-intervention. htTKV also remains unchanged.

Ketogenic interventions are feasible for ADPKD, however, research is still limited. More research is required in order to understand the potential of ketogenic diets to act as an adjuvant treatment for ADPKD.