Lupus
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Sleep disorders in systemic lupus erythematosus. Does vitamin D play a role? A Gholamrezaei, Z Sayed Bonakdar, L Mirbagher and N Hosseini Lupus 2014 23: 1054 originally published online 14 April 2014 DOI: 10.1177/0961203314532563 The online version of this article can be found at: http://lup.sagepub.com/content/23/10/1054
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Lupus (2014) 23, 1054–1058 http://lup.sagepub.com
CONCISE REPORT
Sleep disorders in systemic lupus erythematosus Does vitamin D play a role? A Gholamrezaei1, Z Sayed Bonakdar2, L Mirbagher3 and N Hosseini3 1
Poursina Hakim Research Institution, Isfahan, Iran; 2Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; and 3Medical Students’ Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
Objectives: Sleep disorders are common among patients with systemic lupus erythematosus (SLE) with unclear underlying mechanisms. We assessed the role of vitamin D in sleep quality of patients with SLE. Methods: A retrospective study was conducted on women with SLE for whom the following data were available at the same time; sleep quality (Pittsburgh Sleep Quality Index (PSQI)), disease activity, cumulative disease damage, psychological state (Hospital Anxiety and Depression Scale (HADS)), and serum vitamin D level. Bivariate and regression analyses were computed to find contributors of sleep quality. Results: In total, 63 women were studied. Serum vitamin D level was correlated with physical activity (r ¼ 0.310, p ¼ 0.015), season of assessment (r ¼ 0.302, p ¼ 0.016), the PSQI global score (r ¼ 0.262, p ¼ 0.043), anxiety score (r ¼ 0.298, p ¼ 0.021), and non-significantly with depression score (r ¼ 0.218, p ¼ 0.094). Including all variables into a linear regression model, vitamin D level was independently associated with the global PSQI score (beta ¼ 0.364, p ¼ 0.042). Association of vitamin D level with psychological state disappeared after controlling for season of assessment (beta ¼ 0.248, p ¼ 0.154). Conclusions: We found a role for vitamin D in sleep quality of SLE patients. Further studies are warranted to confirm these results and to find possible mechanisms of action. Lupus (2014) 23, 1054–1058. Key words: Systemic lupus erythematosus; sleep; sleep disorders; vitamin D deficiency
Introduction Sleep disorders are highly frequent in patients with systemic lupus erythematosus (SLE), but the underlying mechanisms are yet unclear.1 Previous studies have been focused on disease-related factors including disease activity, cumulative damage, and using corticosteroids, as well as psychological factors, mainly depression.1 The results of previous studies have been controversial regarding disease-related factors, albeit most of them confirmed the major role of psychological factors in sleep quality of patients with SLE.1 Vitamin D deficiency is commonly seen in patients with SLE and is associated with disease activity and clinical course.2 In non-SLE populations, vitamin D deficiency has been shown to be associated with sleep disturbances and psychological health, particularly depression.3,4 Although Correspondence to: Ali Gholamrezaei, Poursina Hakim Research Institution, Post Box: 81465-1798, Isfahan, Iran. Email: [email protected] Received 21 December 2013; accepted 28 March 2014
several factors can affect sleep quality in patients with SLE, including demographic and diseaserelated as well as psychological factors, a role for vitamin D deficiency is also plausible. There is no report on the effects of vitamin D on sleep quality in patients with SLE. Through a study on sleep quality of patients with SLE, we had access to simultaneous data on vitamin D levels of a part of our studied population. This study was a retrospective analysis of these data, and evaluated the association of vitamin D level with sleep quality in women with SLE.
Methods Patients and settings This retrospective study was done on data gathered from women with SLE referring to an outpatient clinic of rheumatology in Isfahan City (Iran) between January and July 2013. Inclusion criteria were a) the diagnosis of SLE based on the American College of Rheumatology (ACR) revised
! The Author(s), 2014. Reprints and permissions: http://www.sagepub.co.uk/journalsPermissions.nav
Downloaded from lup.sagepub.com at Iceland Telecom on August 14, 2014
10.1177/0961203314532563
Sleep and Vitamin D in SLE A Gholamrezaei et al.
1055 5
criteria for SLE; b) age between 18 and 65 years; and c) having data on sleep quality, disease activity, cumulative disease damage, psychological state and serum vitamin D level at the same time. The original study was approved by the local university ethics committee and consent had been obtained from the patients for participation. Assessments Data included age, years of education, weight, height, physical activity (never/rarely, sometimes, and regular), disease duration, disease activity, cumulative disease damage, prednisolone use, serum vitamin D level, sleep quality, and anxiety and depression. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D level of
http://lup.sagepub.com/
Sleep disorders in systemic lupus erythematosus. Does vitamin D play a role? A Gholamrezaei, Z Sayed Bonakdar, L Mirbagher and N Hosseini Lupus 2014 23: 1054 originally published online 14 April 2014 DOI: 10.1177/0961203314532563 The online version of this article can be found at: http://lup.sagepub.com/content/23/10/1054
Published by: http://www.sagepublications.com
Additional services and information for Lupus can be found at: Email Alerts: http://lup.sagepub.com/cgi/alerts Subscriptions: http://lup.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav
>> Version of Record - Aug 12, 2014 OnlineFirst Version of Record - Apr 14, 2014 What is This?
Downloaded from lup.sagepub.com at Iceland Telecom on August 14, 2014
Lupus (2014) 23, 1054–1058 http://lup.sagepub.com
CONCISE REPORT
Sleep disorders in systemic lupus erythematosus Does vitamin D play a role? A Gholamrezaei1, Z Sayed Bonakdar2, L Mirbagher3 and N Hosseini3 1
Poursina Hakim Research Institution, Isfahan, Iran; 2Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; and 3Medical Students’ Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
Objectives: Sleep disorders are common among patients with systemic lupus erythematosus (SLE) with unclear underlying mechanisms. We assessed the role of vitamin D in sleep quality of patients with SLE. Methods: A retrospective study was conducted on women with SLE for whom the following data were available at the same time; sleep quality (Pittsburgh Sleep Quality Index (PSQI)), disease activity, cumulative disease damage, psychological state (Hospital Anxiety and Depression Scale (HADS)), and serum vitamin D level. Bivariate and regression analyses were computed to find contributors of sleep quality. Results: In total, 63 women were studied. Serum vitamin D level was correlated with physical activity (r ¼ 0.310, p ¼ 0.015), season of assessment (r ¼ 0.302, p ¼ 0.016), the PSQI global score (r ¼ 0.262, p ¼ 0.043), anxiety score (r ¼ 0.298, p ¼ 0.021), and non-significantly with depression score (r ¼ 0.218, p ¼ 0.094). Including all variables into a linear regression model, vitamin D level was independently associated with the global PSQI score (beta ¼ 0.364, p ¼ 0.042). Association of vitamin D level with psychological state disappeared after controlling for season of assessment (beta ¼ 0.248, p ¼ 0.154). Conclusions: We found a role for vitamin D in sleep quality of SLE patients. Further studies are warranted to confirm these results and to find possible mechanisms of action. Lupus (2014) 23, 1054–1058. Key words: Systemic lupus erythematosus; sleep; sleep disorders; vitamin D deficiency
Introduction Sleep disorders are highly frequent in patients with systemic lupus erythematosus (SLE), but the underlying mechanisms are yet unclear.1 Previous studies have been focused on disease-related factors including disease activity, cumulative damage, and using corticosteroids, as well as psychological factors, mainly depression.1 The results of previous studies have been controversial regarding disease-related factors, albeit most of them confirmed the major role of psychological factors in sleep quality of patients with SLE.1 Vitamin D deficiency is commonly seen in patients with SLE and is associated with disease activity and clinical course.2 In non-SLE populations, vitamin D deficiency has been shown to be associated with sleep disturbances and psychological health, particularly depression.3,4 Although Correspondence to: Ali Gholamrezaei, Poursina Hakim Research Institution, Post Box: 81465-1798, Isfahan, Iran. Email: [email protected] Received 21 December 2013; accepted 28 March 2014
several factors can affect sleep quality in patients with SLE, including demographic and diseaserelated as well as psychological factors, a role for vitamin D deficiency is also plausible. There is no report on the effects of vitamin D on sleep quality in patients with SLE. Through a study on sleep quality of patients with SLE, we had access to simultaneous data on vitamin D levels of a part of our studied population. This study was a retrospective analysis of these data, and evaluated the association of vitamin D level with sleep quality in women with SLE.
Methods Patients and settings This retrospective study was done on data gathered from women with SLE referring to an outpatient clinic of rheumatology in Isfahan City (Iran) between January and July 2013. Inclusion criteria were a) the diagnosis of SLE based on the American College of Rheumatology (ACR) revised
! The Author(s), 2014. Reprints and permissions: http://www.sagepub.co.uk/journalsPermissions.nav
Downloaded from lup.sagepub.com at Iceland Telecom on August 14, 2014
10.1177/0961203314532563
Sleep and Vitamin D in SLE A Gholamrezaei et al.
1055 5
criteria for SLE; b) age between 18 and 65 years; and c) having data on sleep quality, disease activity, cumulative disease damage, psychological state and serum vitamin D level at the same time. The original study was approved by the local university ethics committee and consent had been obtained from the patients for participation. Assessments Data included age, years of education, weight, height, physical activity (never/rarely, sometimes, and regular), disease duration, disease activity, cumulative disease damage, prednisolone use, serum vitamin D level, sleep quality, and anxiety and depression. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D level of
