Fatigue and blood pressure in primary Sjogren's syndrome.
ABSTRACT Primary Sjogren's syndrome (SS) is an autoimmune disease characterized by fatigue. Little is known about the genesis of fatigue. Fatigue is thought to represent a multidimensional concept and it is important to be able to measure it confidently. The aims were to evaluate the reliability and validity of the 20-item Multidimensional Fatigue Inventory (MFI-20) in SS and to search for factors associated with this disabling symptom.
Forty-eight women with primary SS completed the MFI-20 questionnaire. The results were compared with age-matched women with fibromyalgia (FM) and healthy controls. Convergent construct validity was assessed by correlations to a Visual Analogue Scale (VAS) for global fatigue by Spearman's correlation (r(s)). Test-retest reliability was analysed by the intraclass correlation coefficient (ICC) in 28 women. Associations between clinical variables and subscales of the MFI-20 were analysed.
The SS women scored significantly higher in all subscales of the MFI-20 compared to controls but similar to FM. The ICCs were satisfactory, ranging from 0.66 for general fatigue to 0.85 for the total score of MFI-20. All subscales correlated significantly to VAS for global fatigue, general fatigue showing the highest correlation (r(s) = 0.70). The estimated number of hours of sleep/day was significantly associated with many of the fatigue dimensions. All five subscales of the MFI-20 were inversely associated with diastolic blood pressure (BP) and two with systolic BP.
The MFI-20 was found to be a reliable and valid tool for the measurement of fatigue in primary SS. High levels of fatigue were correlated with low BP, suggesting an associated involvement of the autonomic nervous system.
[show abstract] [hide abstract]
ABSTRACT: Fibromyalgia (FM) is a complex syndrome characterized by chronic widespread musculoskeletal pain which is often accompanied by multiple other symptoms, including fatigue, sleep disturbances, decreased physical functioning, and dyscognition. Due to these multiple symptoms, as well as high rates of comorbidity with other related disorders, patients with FM often report a reduced quality of life. Although the pathophysiology of FM is not completely understood, patients with FM experience pain differently from the general population, most likely due to dysfunctional pain processing in the central nervous system leading to both hyperalgesia and allodynia. In many patients with FM, this aberrant pain processing, or central sensitization, appears to involve decreased pain inhibition within the spinal tract, which is mediated by descending pathways that utilize serotonin, norepinephrine, and other neurotransmitters. The reduced serotonin and norepinephrine levels observed in patients with FM suggest that medications which increase the levels of these neurotransmitters, such as serotonin and norepinephrine reuptake inhibitors (SNRIs), may have clinically beneficial effects in FM and other chronic pain conditions. Milnacipran is an SNRI that has been approved for the management of FM. In clinical trials, treatment with milnacipran for up to 1 year has been found to improve the pain and other symptoms of FM. Because FM is characterized by multiple symptoms that all contribute to the decreased quality of life and ability to function, the milnacipran pivotal trials implemented responder analyses. These utilized a single composite endpoint to identify the proportion of patients who reported simultaneous and clinically significant improvements in pain, global disease status, and physical function. Other domains assessed during the milnacipran trials include fatigue, multidimensional functioning, mood, sleep quality, and patient-reported dyscognition. This review article provides information intended to help clinicians make informed decisions about the use of milnacipran in the clinical management of patients with FM. It draws primarily on results from 2 of the pivotal clinical trials that formed the basis of approval of milnacipran in the United States by the Food and Drug Administration.Neuropsychiatric Disease and Treatment 01/2010; 6:197-208. · 1.81 Impact Factor