Thyroid Function Markers in Patients Receiving Hemodialysis and Peritoneal Dialysis for Chronic Kidney Disease

A relationship between chronic kidney disease (CKD) and thyroid dysfunction has been previously suggested. This study compared serum levels of thyroid markers in patients receiving alternative treatments for CKD with those of healthy people. In 2012، sampling was performed from patients over 18 years of age who referred to dialysis centers in Isfahan، Iran. These patients had been on dialysis (hemodialysis: three times a week and peritoneal dialysis: four times a day) for at least three months before the study We measured serum levels of thyroxine (T4)، triiodothyronine (T3)، free thyroid hormone 4 (fT4)، thyroid-stimulating hormone (TSH)، triiodothyronine resin uptake (T3RU)، and albumin، in four groups of patients on hemodialysis، patients on peritoneal dialysis، and their control groups. A total number of 115 subjects، including 63 men (54. 5%) and 52 women (45. 5%)، participated in this study. The mean age of the participants was 54. 3 ± 11. 5 years. The mean levels of TSH، T4، and T3RU were higher in both groups of patients than in control groups. However، the difference was only significant in case of T3RU (P < 0. 001). The mean levels of T3، fT4، and albumin were lower in patients than in controls. The differences in levels of T3 and Albumin were statistically significant (P < 0. 001 for both). T4 levels were significantly higher in patients on peritoneal dialysis than in control groups (P = 0. 020). TSH levels were higher in patients on peritoneal dialysis than in controls، but the difference was not significant (P = 0. 09). As TSH levels of patients and healthy controls were not significantly different، hypo- or hyperthyroidism cannot be specifically determined in patients on dialysis. Lower T3 levels in patients on alternative treatments may indicate the inhibition of peripheral conversion of T4 to T3 because of uremia or drugs. Lower serum albumin level in patients on alternative treatments can be due to malnutrition or loss of albumin and thyroxine-binding globulin during peritoneal dialysis.