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Saudi Journal of Kidney Diseases and Transplantation
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Year : 2017  |  Volume : 28  |  Issue : 5  |  Page : 1112-1118
Insomnia in hemodialysis patients: A multicenter study from morocco

1 Hemodialysis Unit, 5th Military Hospital, Guelmim, Morocco
2 Department of Nephrology, Dialysis and Renal Transplantation, Military Training Hospital Mohammed V, Faculty of Medicine and Pharmacy, University Mohammed V Souissi, Rabat, Morocco
3 Hemodialysis Unit, First Military Medical Center, Agadir, Morocco

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Date of Web Publication21-Sep-2017


Previous studies have shown that insomnia is a common sleep disorder in patients with end-stage renal disease. This study aims to determine the prevalence and risk factors of insomnia in our chronic hemodialysis (HD) patients. This is a cross-sectional study conducted in three HD units in Morocco. To assess the prevalence of insomnia, we used a specific questionnaire. Patients complaining of difficulty in falling asleep and/or nocturnal awakenings occurring seven nights a week during the last month were included in the group “insomnia;” the other patients were used as controls. Clinical, biological, and dialysis data were recorded for each patient. Sleep disorders and their subjective causes were also identified. Eighty-nine percent of questioned patients admitted to having sleep disturbances of different degrees. Insomnia was significantly associated with female gender and time of dialysis. Age, body mass index, inter-dialytic weight gain, and blood pressure were similar between the two groups, as well as dialytic parameters and drug use. There was no significant difference in the values of plasma creatinine, urea, hemoglobin, parathyroid hormone, calcium, phosphorus, C-reactive protein, and albumin between the groups. Disorders most frequently encountered in patients with insomnia were waking up at night (90%), difficulty falling asleep (60%), and daytime sleepiness (60%). The restless legs syndrome was seen in half of these patients. The main reported causes of insomnia were anxiety and/or depression (70%) and bone pain (67%). Insomnia is common in HD patients and is frequently associated with other disorders of sleep. Female sex and duration on dialysis are the two risk factors found in our study. Insomnia does not appear related to any biochemical or dialysis parameters. Increased attention should be given to the management of dialysis patients regarding the diagnosis and management of insomnia and associated sleep disorders.

How to cite this article:
Hamzi MA, Hassani K, Asseraji M, El Kabbaj D. Insomnia in hemodialysis patients: A multicenter study from morocco. Saudi J Kidney Dis Transpl 2017;28:1112-8

How to cite this URL:
Hamzi MA, Hassani K, Asseraji M, El Kabbaj D. Insomnia in hemodialysis patients: A multicenter study from morocco. Saudi J Kidney Dis Transpl [serial online] 2017 [cited 2021 Jan 17];28:1112-8. Available from: https://www.sjkdt.org/text.asp?2017/28/5/1112/215152

   Introduction Top

Insomnia is the most common sleep disorder in different populations including patients on dialysis.[1] It is defined as the subjective sensation of short and/or unsatisfying sleep or trouble falling asleep and/or to nighttime waking.[2] In most cases, the diagnosis of insomnia is based only on the patients’ history. It is commonly accepted that these symptoms must be present at least three to four times for several weeks.[3]

The prevalence of insomnia is variable in the general population, and this variability depends on several factors such as its classification, the characteristics of population under study, and the methodological approach used.[3],[4],[5],[6]

In patients on dialysis, the etiology of insomnia is often multifactorial: biochemical and metabolic changes, lifestyle factors, depression, anxiety, and other underlying sleep disorders can all have an effect on the development and persistence of sleep disruption, leading to chronic insomnia.[1]

Beyond daytime consequences, it has suggested that sleep disturbances, especially insomnia, may influence cardiovascular and infectious death in maintenance hemodialysis (HD) patients.[7] Since 1982, several studies have demonstrated a high percentage of HD patients suffering from sleep disturbances.[8],[9]

The aim of the present study was to evaluate the prevalence of insomnia and other sleep disturbances in our dialysis patients and correlate these disturbances with clinical, biologic, and dialytic data. The secondary aim of this study was to evaluate the impact of recent improvement in dialysis techniques, clinical knowledge, and pharmacological therapies on the prevalence of insomnia.

   Patients and Methods Top

A total of 128 HD patients treated in three HD units in Morocco were enrolled in this study. All patients were surveyed using a simple yes/no questionnaire [Table 1] as described previously by Holley et al and reused more recently by Sabbatini et al.[7],[10]
Table 1: Patient questionnaire used for diagnosis of insomnia.[7]

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The same investigator completed all the questionnaires. Questions were asked in Moroccan Arabic dialect. These questionnaires were reviewed by two specialist physicians to confirm the accuracy and clarity of the Arabic translation. Finally, these questionnaires were pretested on 10 patients and modified for any ambiguity or vagueness.

All patients included in the survey were on regular dialysis, three times a week, for at least one year. Three patients were excluded because of psychiatric disorder, recent laparotomy, and multiple bone metastases of prostate cancer in one patient each.

Question 1 of the questionnaire was aimed at informing patient about sleep disorders but was not discriminating. The following questions dealt with insomnia’s symptoms.

Information about the personality and lifestyle of the patient were not included in the study. Bed partners were not surveyed and polysomnography was not performed.

All patients answering “yes” to at least one question were surveyed using a second questionnaire inquiring how many days a week the disturbance was present and the subjective cause of this.

Only patients with difficulty falling asleep and/or nighttime waking occurring at least seven nights a week in the last month were included in the insomnia group. All other patients (those who reported no or only occasional sleep disturbance) were included in the control group.

For each patient, clinical and dialysis data were noted as well as some biological data including predialysis plasma values of creatinine, urea, hemoglobin (Hb), parathormone (PTH), calcium, phosphorus, C-reactive pro-tein (CRP), and albumin.

Dialysis data were represented by the average observed over three successive sessions. The body mass index (BMI) was calculated using postdialysis body weight. Delivered dose was presented by Kt/V index according to the ionic dialysance method (online clearance monitoring in Fresenius 4008S machines and Diascan in Gambro AK-200 machines).

All biological data were analyzed using the same kits. Albumin levels were detected by the bromocresol green albumin method. Plasma PTH samples were analyzed by commercial Elecsys kits (intact PTH, range: 15–65 ng/L).

   Statistical Analysis Top

Data were analyzed using the Statistical Package for the Social Sciences software for Windows (SPSS) version 10.0. (SPSS Inc., Chicago, Illinois). Data are expressed as mean ± standard deviations. P <0.05 was considered statistically significant.

   Results Top

The mean age of our patients (n = 125, 76 males and 49 females) was 54.3 ± 13.2 years and the average duration on dialysis was 52.6 ± 43.8 months. The most common cause of renal failure was diabetes mellitus (41%).

For all patients, dialysis was performed using polysulfone hollow-fiber dialyzers and bicarbonate-buffered dialysate. Blood flow rate was individualized from 240 to 320 mL/min. Dialysate flow rate was 500 mL/min. Dialysate temperature was 37°C.

Only 14 of 125 patients (11.2%) answered “no” to all the questions of the first questionnaire; this means that 89% of questioned patients admitted to having sleep disturbances but of different degrees. According to the proposed classification, 60 patients were considered to have insomnia (insomnia group), and the remaining 65 were included in the control group.

Clinical and dialysis characteristics of the two groups are summarized in [Table 2].
Table 2: Clinical and dialytic characteristics of patients in the two groups being studied

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There was a significantly higher prevalence of insomnia among female patients. Insomnia was also significantly associated with longer duration on dialysis.

Age, causes of uremia, BMI, interdialytic weight gain, mean blood pressure (before and after dialysis), and dialysis schedule did not differ between the two groups. Blood flow rate and delivered dose of dialysis were also comparable between the two groups.

Except for serum albumin level, all other biochemical parameters were similar in the two groups. Erythropoietin, calcitriol, and antihypertensive drugs were equally used by the patients of both groups, and as expected, a significantly higher intake of sleeping pills was observed in patients with insomnia. These data are summarized in [Table 3].
Table 3: Biochemical parameters and use of drugs in the studied groups.

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As shown in [Table 4], multivariate analysis showed a significant independent association between insomnia and female gender and a longer duration on dialysis.
Table 4: Logistic regression analysis between the study groups and clinical and laboratory parameters.

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The characteristics of the sleep disorders experienced by HD patients are listed in [Table 5]. Most of patients (88/125) reported at least two disturbances. Patients with insomnia mostly complained of nocturnal awakenings (90%) and difficulty in falling asleep (60.7%). To a lesser extent, other symptoms including early waking in the morning and restless legs syndrome (RLS) were reported, respectively, in 60% and 50% of patients with insomnia. In this group, daytime sleeping was present in 66% of patients.
Table 5: Reported symptoms of sleep disorders.

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The subjective causes of insomnia are listed in [Table 6]. Some patients reported multiple reasons of insomnia. The causes of sleep disorders in control group are also reported for comparison. A significant difference was found in the proportions of our patients having anxiety (and/or depression) and pruritus.
Table 6: Self-perceived causes of sleep disorders.

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   Discussion Top

Our study shows that insomnia is still frequent in HD patients since half of our patients complained of this sleep disorders. There are some methodologic differences in the present study as compared with most of the previous studies. The attention has been focused on insomnia alone, assessed by the persistence of its symptoms. This allowed us to obtain two distinct groups sharing the same dialysis technique. Many previous studies had included patients with only sporadic sleep disturbances or have made comparison between heterogeneous groups (patients with sleep disturbances compared to normal participants or patients affected by other chronic illnesses).[11],[12] Our results suggest that female sex and long duration on dialysis are associated with a higher risk of insomnia whereas biochemical parameters and dialytic data do not seem to play a crucial role in determining it.

A higher prevalence of sleep disorders has been associated with female gender in HD patients in other studies.[12],[13]

Our study demonstrates a significantly higher risk of insomnia in patients with longer duration on dialysis. Sabbatini et al demonstrated a similar result.[7] In their large multicenter study, the authors explained this finding by the progressive appearance of symptoms and concurrent diseases commonly associated with dialysis treatment such as cardiovascular and neurological diseases or secondary hyperpara-thyroidism. Indeed, in this study, higher levels of PTH were founded in patients with insomnia. Furthermore, it was reported that patients requiring parathyroidectomy slept fewer hours, had a higher prevalence of sleep disorders, and were more often insomniac.[14] In our study, PTH levels were paradoxically slightly lower in the “insomnia group.” As other indicators of bone mineral disease, serum calcium and phosphate levels did not differ between the two groups. Hypercalcemia has been described as a risk factor for insomnia in HD patients.[15]

Serum albumin was lower in patients with insomnia; this parameter was reported as a major risk factor for insomnia in a recent study.[16]

No significant difference was detected in Hb levels or the need for erythropoietin in patients with insomnia. Delano has reported an improvement in insomnia in HD patients when Hb was corrected by erythropoietin.[17] This finding was confirmed by Benz et al. in their study, with the increase in hematocrit levels inducing a significant reduction in the incidence of periodic limb movements.[18] The large use of erythropoietin and calcitriol in our patients maintained Hb and PTH at acceptable levels.

The retention of middle molecules is another cause of sleep disorders, as suggested by many authors.[8] In our patients, delivered dose of dialysis represented by Kt/V was similar in the two groups, so this potential factor can be reasonably excluded from the study.

The incidence of RLS was low in our patients with insomnia compared with the percentage reported by Holley et al. and more recently by Walker et al.[9],[10] In this last study, RLS was related to plasma values of creatinine and urea; hence, it is suggested that the improvement in dialysis efficacy in recent years has contributed to reduction of incidence of RLS.

Dialysis shift did not influence the incidence of insomnia in our study. In a recent study and irrespective of dialysis shift, sleep disturbances were not different among patients.[19] In contrast with our finding, an decreased risk of insomnia was reported in patients dialyzed in the morning shift.[7] Insomnia was significantly more frequent in patients with the afternoon dialysis shift in another study.[13] The authors of these studies have not offered any clear explanation for this association.

The reported causes of sleep disturbances suggested that the psychological status of patients greatly influences the onset of insom-nia.[20] In our study, the high frequency of psychological causes of insomnia contrasted with the low use of sleeping pills compared to other studies.[8],[10] The same finding was reported by Sabbatini et al.[7] It can be explained by the low compliance of patients with the prescription of the attending nephrologist (cost of therapy, side effects, etc.) or by the little attention devoted by physicians to the problem of sleep disorders as reported by some authors.[21]

We do understand that there are some limitations to the present study. It has evaluated sleep disturbances in homogeneous but not large patient samples. Information about style and quality of life were not included in the study. Behavioral factors as cause of insomnia and the consequence on the quality of life were not analyzed. Another limitation is using translated questionnaires that are not validated for our population.

   Conclusions/Recommendations Top

Our study clearly demonstrates that the prevalence of clinically significant insomnia in HD patients is still high (49%) despite all the new technical and therapeutic advances of the last decade. The most reported cases were associated with other sleeping disorders, such as RLS and daytime sleepiness. Insomnia seems to be associated with long duration on dialysis in female gender and seems not linked to the most important clinical or dialysis data.

Identifying and treating other underlying sleeping disorders may improve insomnia and therefore patients’ quality of life and also decrease the prevalence of complications related to poor sleep quality.

Conflict of interest: None declared.

   References Top

Novak M, Shapiro CM, Mendelssohn D, Mucsi I. Diagnosis and management of insomnia in dialysis patients. Semin Dial 2006;19:25-31.  Back to cited text no. 1
Meyer TJ. Evaluation and management of insomnia. Hosp Pract (1995) 1998;33:75-8, 83-6.  Back to cited text no. 2
Leger D, Guilleminault C, Dreyfus JP, Delahaye C, Paillard M. Prevalence of insomnia in a survey of 12,778 adults in France. J Sleep Res 2000;9:35-42.  Back to cited text no. 3
Chesson A Jr., Hartse K, Anderson WM, et al. Practice parameters for the evaluation of chronic insomnia. An American Academy of sleep medicine report. Standards of Practice Committee of the American Academy of sleep medicine. Sleep 2000;23:237-41.  Back to cited text no. 4
Chevalier H, Los F, Boichut D, Bianchi M, Nutt DJ, Hajak G, et al. Evaluation of severe insomnia in the general population: Results of a European multinational survey. J Psycho-pharmacol 1999;13:S21-4.  Back to cited text no. 5
Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research. Psychiatry Res 1989;28:193-213.  Back to cited text no. 6
Sabbatini M, Minale B, Crispo A, et al. Insomnia in maintenance haemodialysis patients. Nephrol Dial Transplant 2002;17: 852-6.  Back to cited text no. 7
Strub B, Schneider-Helmert D, Gnirss F, Blumberg A. Sleep disorders in patients with chronic renal insufficiency in long-term hemodialysis treatment. Schweiz Med Wochenschr 1982;112:824-8.  Back to cited text no. 8
Walker S, Fine A, Kryger MH. Sleep complaints are common in a dialysis unit. Am J Kidney Dis 1995;26:751-6.  Back to cited text no. 9
Holley JL, Nespor S, Rault R. A comparison of reported sleep disorders in patients on chronic hemodialysis and continuous peritoneal dialysis. Am J Kidney Dis 1992;19:156-61.  Back to cited text no. 10
Winkelman JW, Chertow GM, Lazarus JM. Restless legs syndrome in end-stage renal disease. Am J Kidney Dis 1996;28:372-8.  Back to cited text no. 11
Sloand JA, Shelly MA, Feigin A, Bernstein P, Monk RD. A double-blind, placebo-controlled trial of intravenous iron dextran therapy in patients with ESRD and restless legs syndrome. Am J Kidney Dis 2004;43:663-70.  Back to cited text no. 12
Al-Jahdali HH, Khogeer HA, Al-Qadhi WA, et al. Insomnia in chronic renal patients on dialysis in Saudi Arabia. J Circadian Rhythms 2010;8:7.  Back to cited text no. 13
De Santo RM, Esposito MG, Cesare CM, et al. High prevalence of sleep disorders in hemodialyzed patients requiring parathyroi-dectomy. J Ren Nutr 2008;18:52-5.  Back to cited text no. 14
Virga G, Stanic L, Mastrosimone S, et al. Hypercalcemia and insomnia in hemodialysis patients. Nephron 2000;85:94-5.  Back to cited text no. 15
Han SY, Yoon JW, Jo SK, et al. Insomnia in diabetic hemodialysis patients. Prevalence and risk factors by a multicenter study. Nephron 2002;92:127-32.  Back to cited text no. 16
Delano BG. Improvements in quality of life following treatment with r-HuEPO in anemic hemodialysis patients. Am J Kidney Dis 1989;14:14-8.  Back to cited text no. 17
Benz RL, Pressman MR, Hovick ET, Peterson DD. Potential novel predictors of mortality in end-stage renal disease patients with sleep disorders. Am J Kidney Dis 2000;35:1052-60.  Back to cited text no. 18
Bastos JP, Sousa RB, Nepomuceno LA, et al. Sleep disturbances in patients on maintenance hemodialysis: Role of dialysis shift. Rev Assoc Med Bras (1992) 2007;53:492-6.  Back to cited text no. 19
Tanaka K, Morimoto N, Tashiro N, et al. The features of psychological problems and their significance in patients on hemodialysis – With reference to social and somatic factors. Clin Nephrol 1999;51:161-76.  Back to cited text no. 20
Meissner HH, Riemer A, Santiago SM, et al. Failure of physician documentation of sleep complaints in hospitalized patients. West J Med 1998;169:146-9.  Back to cited text no. 21

Correspondence Address:
Mohamed Amine Hamzi
Hemodialysis Unit, 5th Military Hospital, Guelmim
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PMID: 28937071

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  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]


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