Smell and taste function in children with chronic kidney disease

Loss of appetite and poor growth are common in children with chronic kidney disease (CKD), and changes in smell and/or taste function may be responsible, but the hypothesis has not been proven. This aims of this prospective age- and gender-controlled study were to determine whether: (1) changes in smell and taste function occur in children with CKD; (2) smell or taste dysfunction are associated with estimated glomerular filtration rate (eGFR); (3) there is an association between smell or taste loss and body mass index (BMI). The study cohort consisted of 72 children of whom 20 were CKD stage 3-5 patients, 12 were CKD stage 2 patients, 20 were clinical controls (CC) and 20 were healthy children (HC). The CKD patients and clinical controls were recruited from Sydney Children's Hospital and The Children's Hospital, Westmead, and healthy controls were recruited from a local school. Scores for each group from taste and smell chemosensory function tests were compared, and their relationship with renal function and BMI investigated. The CKD stage 3-5 group had a significantly lower taste identification score (85.6%, P < 0.001) than the CC (94.8%) and HC (94.8%) groups, with almost one third of the children in the CKD stage 3-5 group exhibiting taste loss. Decreased taste function was associated with decreased eGFR (r = 0.43, P < 0.01), but no association between BMI and taste function was found (r = 0.001, P > 0.9). Odour identification scores were not different; however, there was a positive relationship with BMI (r = 0.427, P = 0.006). We conclude that a loss of taste can occur in children with CKD and that when it occurs, it worsens as eGFR declines and is found early in kidney disease.