Effect of thyroid function status in hemodialysis patients on erythropoietin resistance and interdialytic weight gain.

Thyroid function abnormalities are common in hemodialysis (HD) patients. Here, we investigated their frequency and impact on intradialytic hemodynamics and erythropoietin resistance index (ERI). Demographic and laboratory data including thyroid-stimulating hormone (TSH), interdialytic weight gain, and intradialytic blood pressure (BP) changes were measured, and ERI was calculated. The prevalence and causes of abnormities in TSH and free thyroxine (FT4) and their effects on ERI and intradialytic hemodynamics were then assessed. One hundred and thirty patients (mean age, 57.1 ± 19.2 years; 66.4% diabetic, 86.7% hypertensive) were enrolled. Among them, 16.7% had hypothyroidism, 2.3% had hyperthyroidism, and 10.9% had subclinical hypothyroidism. TSH level was significantly associated with higher BP (P <0.05), lower albumin (3.6 ± 4.4 and 2.6 ± 1.8, respectively; P = 0.05), lower dialysis hours (3.9 ± 5.3 and 2.6 ± 1.8, respectively), and lower ERI (3.7 ± 4.4 and 2.4 ± 1.9, respectively; P = 0.05). FT4 was significantly associated with higher interdialytic weight gain (13.4 ± 4.3 and 11.8 ± 2.2 pmol/L, respectively; P = 0.009) and higher pre-HD diastolic BP (13.2 ± 4.0 and 12.0 ± 2.9 pmol/L, respectively; P = 0.05). A negative correlation was seen between TSH level and urea reduction ratio (r = 0.29, P = 0.002), serum albumin (r = 0.304, P = 0.001), hemoglobin level (r = 0.26, P = 0.005), and ERI (r = 0.2, P = 0.002). A higher TSH level was associated with hypertension, lower albumin level, fewer dialysis hours, and increased resistance to erythropoietin. TSH level was negatively correlated with dialytic adequacy, serum albumin level, hemoglobin level, and ERI.