title: Lifestyle habits and fatigue among people with systemic lupus erythematosus and matched population controls.
abstract: OBJECTIVE
  The objective of this paper is to identify clusters of fatigue in patients with systemic lupus erythematosus (SLE) and matched controls, and to analyze these clusters with respect to lifestyle habits, health-related quality of life (HRQoL), anxiety and depression.
  
  
  METHODS
  Patients with SLE (n = 305) and age- and gender-matched population controls (n = 311) were included. Three measurements of fatigue (Fatigue Severity Scale (FSS), Vitality (VT, from SF-36) and Multidimensional Assessment of Fatigue scale (MAF) and hierarchic cluster analysis were used to define clusters with different degrees of fatigue. Lifestyle habits were investigated through questionnaires. HRQoL was assessed with the SF-36 and anxiety/depression with the Hospital Anxiety and Depression Scale.
  
  
  RESULTS
  Three clusters, denominated "High," "Intermediate" and "Low" fatigue clusters, were identified. The "High" contained 80% patients, and 20% controls (median; VT 25, FSS 5.8, MAF 37.4). These had the most symptoms of depression (51%) and anxiety (34%), lowest HRQoL (p < 0.001) and they exercised least frequently. The "Intermediate" (48% patients and 52% controls) (median; VT 55, FSS 4.1, MAF 23.5) had similarities with the "Low" regarding sleep/rest whereas social status and smoking were closer to the "High." The"Low" contained 22% patients and 78% controls (median; VT 80, FSS 2.3, MAF 10.9). They had the highest perceived HRQoL (p < 0.001), least symptoms of anxiety (10%), no depression, smoked least (13%) and reported the highest percentage (24%) of exercising ≥ 3 times/week.
  
  
  CONCLUSIONS
  Fatigue is common, but not a general feature of SLE. It is associated with depression, anxiety, low HRQoL and less physical exercise. Patients with SLE and population controls with a healthy lifestyle reported lower levels of fatigue. Whether lifestyle changes can reduce fatigue, which is a major problem for a majority of SLE patients, needs to be further explored.
authors.affiliation: Rheumatology Clinic, Karolinska University Hospital, Stockholm, Sweden Division of Nursing, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden susanne.pettersson@karolinska.se.
authors.forename: S
authors.initials: S
authors.lastname: Pettersson
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Boström
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Eriksson
authors.affiliation: Department of Medicine, Unit of Rheumatology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Svenungsson
authors.affiliation: Department of Medicine, Unit of Rheumatology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Gunnarsson
authors.affiliation: Rheumatology Clinic, Karolinska University Hospital, Stockholm, Sweden Division of Nursing, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
authors.forename: E Welin
authors.initials: EW
authors.lastname: Henriksson
mesh_terms: D000328:Adult; D001007:Anxiety / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D016022:Case-Control Studies; D016000:Cluster Analysis; D003863:Depression / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006184:Habits; D006801:Humans; D008019:Life Style; D008180:Lupus Erythematosus, Systemic / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
keywords: Lupus erythematosus; cluster analysis; exercise; fatigue; health-related quality of life; lifestyle habits; systemic