Iodine nutrition in adults on long-term home parenteral nutrition

OBJECTIVE: The aim of this study was to evaluate iodine nutrition in adults on long-term home parenteral nutrition (HPN) and to compare it with iodine supplemented with PN, categorized as below or according to the European Society for Clinical Nutrition and Metabolism guidelines (ESPEN-GL) recommendation. METHODS: Iodine nutrition was evaluated retrospectively in 31 stable adults on long-term HPN. We analyzed urinary iodine concentration (UIC) and serum thyroid-stimulating hormone (TSH). A median UIC value ≥100 μg/L was considered indicative of adequate iodine intake, a value between 50 and 100 was indicative of moderate iodine deficiency, and a value <50 μg/L was indicative of overt iodine deficiency. RESULTS: PN iodine amount was according to ESPEN-GL in 26% of patients and lower in 19%; 55% did not receive iodine with PN. The median UIC was 63 μg/L (95% confidence interval [CI], 26-99 μg/L) in the whole group of patients, 56 μg/L (95% CI, 24-100) in the group including patients who did not receive any PN iodine supplementation and those who received PN iodine supply lower than the ESPEN-GL recommendation, and slightly higher (77 μg/L) in eight patients with PN iodine supply according to the ESPEN-GL (P = 0.42). TSH was normal in 74% of patients, increased in 23%, and reduced in 3%. Results did not change when patients with reduced glomerular filtration rate were excluded from the analysis. CONCLUSIONS: The analyzed patients on long-term HPN had a low iodine intake as shown by low median UIC level, as did the group of patients who received PN iodine supplementation according to ESPEN-GL. A condition of subclinical hypothyroidism was observed in a small percentage of patients.