Miss Mia Abdy1,2, Dr David Tunnicliffe1,2, Ms Kitty St Pierre3,4, Ms Brydee Cashmore1,2, Ms Kelly Lambert5, Ms Jessica Dawson6,7, Ms Helen MacLaughlin8,9, Ms Vanessa Cullen10
1Sydney School of Public Health, University Of Sydney, Sydney, Australia, 2Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, Australia, 3Faculty of Medicine, The University of Queensland, Brisbane, Australia, 4Pharmacy Department, Gold Coast University Hospital, Gold Coast, Australia, 5Discipline of Nutrition and Dietetics, School of Medicine, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia, 6NHMRC Clinical Trials Centre, The University of Sydney, Sydney, Australia, 7Department of Nutrition and Dietetics, St George Hospital, Sydney, Australia, 8School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia, 9Dietetics and Food Services, Royal Brisbane and Women’s Hospital, Brisbane, Australia, 10PKD Australia, Sydney, Australia
Biography:
Bio to come
Aim:
To evaluate the effect of ketogenic diet interventions on disease progression and harms for patients with autosomal-dominant polycystic kidney disease (ADPKD).
Background:
Ketogenic diets involve high fat and low carbohydrate intake, stimulating endogenous production of ketones (beta-hydroxybutyrate [BHB]) as alternative cellular energy sources. Despite uncertainty around the mechanism of action, some clinical evidence suggests that reduced carbohydrate intake and increased BHB levels may reduce cyst growth and slow disease progression in ADPKD.
Methods:
We included all human study types assessing nutritional (classical ketogenic diet, Atkins diet) or fasting (caloric restriction, time-restricted diets) ketogenic diets in people with ADPKD. Primary outcomes included cyst characteristics and kidney function (eGFR). The studies were summarised using narrative synthesis as meta-analysis was not possible. Risk of bias assessments were conducted according to study type; certainty of evidence was assessed using GRADE.
Results:
Our searches yielded eight studies: three randomised controlled trials, four non-randomised studies, and one case series (total n = 338). Five studies assessed nutritional ketogenic diets, while six studies assessed fasting ketogenic diets.
Ketogenic diets had limited effects on disease progression: only one RCT found that time-restricted diets may increase kidney volume (MD = 2.68%, 95% CI: 1.33%, 4.03%). No effects were seen for the remaining studies for any other outcome, and no between-groups differences were observed for any outcome in any study. All diets were associated with symptoms of “ketogenic flu”, including headache, dizziness, and nausea.
Conclusions:
Limited and inconsistent evidence indicates neutral or harmful effects of ketogenic diets for ADPKD patients (“ketogenic flu”, increased kidney volume). These findings should inform shared decision making; further trials should clarify these effects before clinical recommendations can be made.