Renal complications in eating disorders with metabolic risk factors: a systematic review

Bulimia nervosa can have serious physiological and psychological effects in obese patients. Electrolyte disturbances, dehydration, and metabolic burden caused by bulimia nervosa can cause kidney injury. Furthermore, obesity, as an independent risk factor for kidney disease, may exacerbate renal complications in this population. The aim of the present systematic review was to evaluate renal disorders in patients with bulimia nervosa, with particular focus on obese individuals. A total of ten studies (including case reports and observational studies) published between 2001 and 2024 in PubMed, Scopus, Web of Science, and Cochrane Library were included. The results suggest that the most common pathway of renal injury in bulimia nervosa is chronic hypokalemia and dehydration, which may lead to hypokalemic nephropathy, tubulointerstitial nephritis, and acute or chronic kidney injury. Electrolyte and acid-base disturbances, along with decreased renal function, are frequent, and the risk of chronic kidney disease may be higher in obese patients. Limitations of the available evidence include the predominance of case reports and small observational studies, which restrict generalizability and preclude definitive causal conclusions. These findings highlight the need for cautious clinical monitoring, early renal assessment, and consideration of obesity as a compounding factor in managing patients with bulimia nervosa.