Chronic insomnia in kidney transplant recipients.

BACKGROUND: Recent studies confirmed that sleep disorders have a significant impact on various aspects of health in patients at different stages of chronic kidney disease. At the same time, there is an almost complete lack of information on the prevalence and correlates of insomnia in kidney transplant recipients. METHODS: In a cross-sectional study, the Athens Insomnia Scale was used to assess the prevalence of insomnia in a large sample of kidney transplant recipients compared with wait-listed dialysis patients and also a matched group obtained from a nationally representative sample of the Hungarian population. RESULTS: The prevalence of insomnia was 15% in wait-listed patients, whereas it was only 8% in transplant recipients (P < 0.001), which, in turn, was not different from the prevalence of this sleep problem in the sample of the general population (8%). Prevalences of insomnia in the transplant group were 5%, 7%, and 14% for the groups with glomerular filtration rates (GFRs) greater than 60 mL/min (> 1.00 mL/s), 30 to 60 mL/min (0.50 to 1.00 mL/s), and less than 30 mL/min (< 0.5 mL/s), respectively (P < 0.01). However, estimated GFR was no longer associated significantly with insomnia in the transplant population after statistical adjustment for several covariates. In a multivariate model, insomnia was significantly and independently associated with treatment modality (transplantation versus wait listing), as well as the presence of depression, restless legs syndrome, and high risk for obstructive sleep apnea syndrome, and with self-reported comorbidity. CONCLUSION: The prevalence of insomnia was substantially less in the transplant group than in wait-listed dialysis patients and similar to that observed in the general population. Because this condition potentially is treatable, attention should be directed to the appropriate diagnosis and management of insomnia in the kidney transplant recipient population.

Validation of the Kidney Disease Quality of Life-Short Form questionnaire in kidney transplant patients.

OBJECTIVE: The aim of this study was to determine the basic psychometric properties, reliability, and validity of the Kidney Disease Quality of Life-Short Form (KDQOL-SF) questionnaire in kidney transplant patients. METHODS: The reliability and validity of the instrument were determined in 418 kidney transplant patients followed in a single outpatient transplant centre. RESULTS: Internal consistency of all the Medical Outcome Study Short Form 36 (SF-36) domains was very good, and the Cronbach's alpha value was above .70 for all but three of the disease-specific subscales. We found significant, moderate to strong negative correlations between most of the KDQOL-SF domains and the Center for Epidemiologic Studies-Depression (CES-D) scores. Finally, substantial differences in KDQOL-SF scores were seen between groups of transplanted patients who were expected to be clinically different, supporting the discriminant validity of the KDQOL-SF instrument. CONCLUSION: We propose that the KDQOL-SF is a reliable and valid tool and most of its subscales can be used to assess health-related quality of life (HRQOL) in kidney transplant patients and to compare HRQOL between different end stage renal disease (ESRD) patient populations.

Factor structure and reliability of the Hungarian version of the Illness Intrusiveness Scale: invariance across North American and Hungarian dialysis patients.

OBJECTIVES: The objectives of this study were to compare the factor structure and to assess the reliability of the Hungarian version of the Illness Intrusiveness Rating Scale (IIRS), testing internal validity and employing simultaneous confirmatory factor analysis (SCFA) in two large samples of North American versus Hungarian patients with end-stage renal disease (ESRD). METHODS: Translation was conducted according to current recommendations. Following pilot testing, 365 maintenance haemodialysis patients completed the scale. Hungarian data were compared with IIRS data from North American ESRD patients undergoing maintenance hemodialysis to evaluate item bias (Group x Item ANOVA). RESULTS: Confirmatory factor analyses indicated a good fit between the previously hypothesized three-factor model ("relationships and personal development", "intimacy", and "instrumental" life domains) of the original English version and the Hungarian translation. Although statistically significant (P<.05), the effect size for the Groups x Items interaction was not substantial. Internal consistency was very good (Cronbach's alpha=.80) for the total score, and, although somewhat lower than ideal, it was still in the acceptable range for the subscales (.64-.67). These numbers are similar to values reported for the original English version. Test-retest reliability was also acceptable. CONCLUSION: The Hungarian translation of the IIRS has the same three-dimensional factor structure as the original English-language version does. Furthermore, it is sufficiently reliable for research applications. These features satisfy important requirements of cultural equivalence.

Anemia in kidney transplanted patients.

BACKGROUND: Although a known cardiovascular risk factor, anemia in the renal transplant recipients has only recently been receiving an increasing attention. METHODS: In a cross-sectional study, data was obtained from 959 patients followed at a single outpatient transplant clinic. Based on the guideline of the American Society of Transplantation, anemia was defined as hemoglobin (Hb) < or =130 g/L in males and < or =120 g/L in females. RESULTS: About one-third (34%) of the patients were anemic. The prevalence of anemia was comparable in males and females. Serum Hb concentration was significantly correlated with the estimated glomerular filtration rate (eGFR) (abbreviated modification of diet in renal disease formula) (r = 0.266, p < 0.001), serum transferrin (r = 0.268, p < 0.001) and serum albumin (r = 0.196, p < 0.001). None of the immunosuppressive medications or the use of angiotensin converting enzyme inhibitors was associated with a higher likelihood of anemia. In multivariate analysis the eGFR, serum albumin and serum transferrin, potential markers of nutritional status and/or chronic inflammation, and also iron deficiency were independently and significantly associated with anemia. Erythropoietin was administered only to 63 (19%) anemic patients. CONCLUSIONS: Post-transplant anemia is a prevalent and under-treated condition. Based on our results we suggest that, besides other factors, protein/energy malnutrition and/or chronic inflammation may be independently associated with anemia. Further studies are needed to determine whether the presence of anemia and its treatment will have an impact on long-term outcomes of this population.

Sleep disorders and illness intrusiveness in patients on chronic dialysis.

BACKGROUND: The prevalence of sleep problems (insomnia, restless legs syndrome, periodic limb movements in sleep and sleep apnoea) has been shown to be high in patients with end-stage renal disease (ESRD) and might contribute to impaired quality of life in this population. METHODS: In a cross-sectional study using self-administered questionnaires, we examined the prevalence of sleep disorders and assessed their effect on different aspects of health-related quality of life in a sample of Hungarian patients on maintenance dialysis. RESULTS: Our data confirm that sleep problems are frequent in patients with ESRD; 65% of the patients reported symptoms of at least one specific sleep disorder; insomnia was the most common sleep complaint with 49%, the prevalence of sleep apnoea was 32% and the prevalence of restless legs syndrome was 15%. Co-morbidity, assessed by the End-Stage Renal Disease Severity Index, was shown to be an independent predictor of sleep disorders. Patients with sleep disorders reported higher illness intrusiveness and worse self-perceived health than those without sleep problems. The presence of sleep disorders was an independent predictor of illness intrusiveness, an important determinant of health-related quality of life. CONCLUSION: Sleep disorders are important determinants of illness intrusiveness and health-related quality of life in patients with ESRD. Sleep problems may be treated successfully; therefore, more attention should be paid to assessing these problems in this patient population.