Anosmia, dysgeusia and malnutrition in chronic kidney disease: A systematic review

Chronic kidney disease (CKD) is a prevalent health condition associated with numerous complications, including olfactory and taste dysfunction, and malnutrition. This systematic review focused on dysgeusia, smell disorders and malnutrition in CKD patients. The search included scientific databases such as PubMed, Cochrane Library, CINAHL, Scopus, and Web of Science, as well as sources of grey literature. Quality assessment and risk of bias were evaluated using JBI guidelines, while the certainty of evidence was assessed with the Oxford Centre methods. Seven studies were included: two focusing on anosmia and five on dysgeusia. Anosmia was associated with poorer nutritional status, and interventions such as intranasal theophylline showed promise in enhancing olfactory function. Dysgeusia studies highlighted the potential role of zinc deficiency in malnutrition among dialysis patients, with zinc supplementation showing mixed results to improve taste dysfunction. Taste alterations were correlated with upper gastrointestinal symptoms and malnutrition in CKD patients. The analysis of the interconnection between anosmia, dysgeusia, and malnutrition emerges as a crucial starting point for improving nutritional outcomes in chronic kidney disease (CKD) patients, emphasizing the need for accurate assessment and targeted therapeutic interventions to ensure better nutritional health and improved quality of life for these patients.