Incidence and Characteristics of Kidney Stones in Patients on Ketogenic Diet: A Systematic Review and Meta-Analysis

Abstract

Very-low-carbohydrate diets or ketogenic diets are frequently used for weight loss in adults and as a therapy for epilepsy in children. The incidence and characteristics of kidney stones in patients on ketogenic diets are not well studied. Methods: A systematic literature search was performed, using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the databases’ inception through April 2020. Observational studies or clinical trials that provide data on the incidence and/or types of kidney stones in patients on ketogenic diets were included. We applied a random-effects model to estimate the incidence of kidney stones. Results: A total of 36 studies with 2795 patients on ketogenic diets were enrolled. The estimated pooled incidence of kidney stones was 5.9% (95% CI, 4.6–7.6%, I2 = 47%) in patients on ketogenic diets at a mean follow-up time of 3.7 +/− 2.9 years. Subgroup analyses demonstrated the estimated pooled incidence of kidney stones of 5.8% (95% CI, 4.4–7.5%, I2 = 49%) in children and 7.9% (95% CI, 2.8–20.1%, I2 = 29%) in adults, respectively. Within reported studies, 48.7% (95% CI, 33.2–64.6%) of kidney stones were uric stones, 36.5% (95% CI, 10.6–73.6%) were calcium-based (CaOx/CaP) stones, and 27.8% (95% CI, 12.1–51.9%) were mixed uric acid and calcium-based stones, respectively. Conclusions: The estimated incidence of kidney stones in patients on ketogenic diets is 5.9%. Its incidence is approximately 5.8% in children and 7.9% in adults. Uric acid stones are the most prevalent kidney stones in patients on ketogenic diets followed by calcium-based stones. These findings may impact the prevention and clinical management of kidney stones in patients on ketogenic diets.

A Review of the Multi-Systemic Complications of a Ketogenic Diet in Children and Infants with Epilepsy

“…Renal calculi have been reported in 3–7% of children on a ketogenic diet, consisting of both uric acid and calcium [ 13 , 57 , 58 , 59 , 60 ]. In addition, three studies of over 200 children on a KD, showed that potassium citrate led to a reduced incidence of renal calculi [ 58 , 61 , 62 ].…”

Possible Nonneurological Health Benefits of Ketogenic Diet: Review of Scientific Reports over the Past Decade

“…eir prevalence in adults using KD is about 7.9% [43]. Current reports still do not provide complete data to determine whether the long-term regimen of carbohydrate intake demonstrated over periods of 5, 10, and 15 years is safe.…”

“…Using KD requires constant health monitoring as well as selecting proper macronutrients and hydration, due to the possible occurrence of disorders such as kidney stones. Their prevalence in adults using KD is about 7.9% [ 43 ].…”

Shockwaves and the Rolling Stones: An Overview of Pediatric Stone Disease

“…37 In one meta-analysis including 2795 patients on a ketogenic diet, the incidence of stone disease was about 6%. 38 Interestingly, the majority (w50%) of stones consisted of uric acid, than approximately 40% calcium-containing stones and the rest being mixed, likely reflecting low urine pH, a key risk factor for uric acid precipitation.…”