The relationship between uremic pruritus and 25-hdyroxy vitamin D in hemodialysis patients

Uremıc pruritus (UP) is the most common and the most important dermatological symptom in patients with chronic kidney failure (CKF). It's prevalance varies between %50-90. Despite the recent developments in hemodialysis (HD), the frequence of UP has been decreased but still common. Its etiology and pathogenesis is not clear and affects the quality of life and morbidity in a negative way. Vitamin D which is a multifunctional vitamin that has an important ımmunomodulator role. In CKF patients, 25 hydroxy vitamin D [25(OH)2D] deficiency as well as 1,25 dihydroxy vitamin D [1,25(OH)2D] is well-known phenomenon. This study aimed to invastigate the relationship between UP and the level of 25(OH)D in HD patients. To evaluate the pruritus, a questionnaire was answered by patients who received HD for 3 days and 4 hours for at least 6 months because of CKF in Ankara Başkent University Department of Nephrology. 47 patients with pruritus formed the study group and 47 patients without pruritus formed the control group. Severity of pruritus was evaluated by using Visual Analog Scale (VAS). Demographic features of patients (age, gender), etiology of CKF and duration of HD, parameters including hemoglobin, serum iron, serum iron binding capacity, ferritin, calcium, phosphor, magnesium, PTH, ALP, creatinine, ALT, CRP, albumine, total biluribin in the blood samples which was obtained in the last 6 months for the HD and the serological markers of hepatitis were recorded retrospectively. 25(OH)D was studied in the blood which was taken at the initiation of the HD for all patients. 94 patients were enrolled the study. 39 of all was female. The mean age was 59,2+13, 6 and varied between 24-88. The mean duration time for dialysis varied between 7-300 months. The most common etiology for CKF was diabetic nephropathy (%28,7) and hypertension (%14) respectively. There were no statically significant differences in means of age, duration of HD, creatinine, hemoglobin, serum iron, serum iron binding capacity, albumine, CRP, calcium, magnesium, ALT, ALP, PTH, total bilirubin, serology of hepatitis and the use of active vitamin D between the study and control groups. Ferritin level was found higher in the pruritic group but this was not found statically significant. Level of phosphor (p=0,08), calsiumxphosphor (p=0,08) were higher and 25(OH)D (p=0,045) were lower in study grup. Pruritus was more common in the female gender and ıt was statically significant (p=0,047). Skin dryness was found increased in the pruritic group (p=0,003). It was detected that pruritus was located in the back in the %29,8 of the patients and densified in the extremities in the 44,7% of the patients. Pruritus was common in the evenings and during the night time in the 34% and 34% of the patients respectively and may disturb the sleep in the 48,9% of the patients. 51,1% of the patients with pruritus, it had been lasting for at least one year and was seen both in summer and winter for 61,7% of them. It was established that HD was not effective on pruritus in 53,2% of the patients. Off all, 42,5% were treated with antihistaminic and 29,8% were treated with topical therapy. They had benefits from the treatment with the of 36,2% and 14,9% respectively. In conclusion; we think that there is a relationship between UP and 25(OH)D. deficiency. 25(OH)D could be a responsible factor in the UP pathogenesis. For this reason, we recommend to evaluate the 25(OH)D level in patients with pruritis and recommend to perform future studies about this hipothesis. Key words: Hemodialysis, 25-Hdyroxy Vitamin D, Uremic pruritus