People living with Sjögren's syndrome, an autoimmune disorder characterized by dry eyes and dry mouth, appear to function at a level comparable to their healthier peers, according to a cross-sectional study published online in advance of print in Clinical Rheumatology. The study by clinicians and researchers at Tufts University reveals that people living with Sjögren's perceive significant decline in cognitive, psychological and physical function. Nonetheless, despite the burdens of the disease, levels of function approach that of healthy controls.
The National Institutes of Health estimates that Sjögren's syndrome affects between one and four million people in the United States, the majority of whom are women over the age of 40. Although Sjögren's primarily causes dry mouth and dry eyes, the authors of the study note that at least 20% of patients report cognitive, psychological, and physical symptoms over time, such as difficulties with attention, concentration, memory, anxiety, depression, fatigue, and sleep disturbance.
Previous studies have estimated how common these symptoms are for people with Sjögren's, although it is unclear the extent to which they can be attributed to the disease itself. The new study compared 37 people living with Sjögren's to 37 people without an autoimmune disorder, matched for age, gender, and level of education. The individuals in these two groups were tested to see how they rated themselves at one point in time, compared to objective measures of cognitive, psychological, and physical health.
The researchers found that people with Sjögren's reported higher levels of cognitive impairments such as attention, dexterity, memory loss; psychological disorders such as depression and anxiety; and physical impairment such as fatigue and sleep disturbance when compared to their healthier counterparts. However, only two of the objective measures showed any statistically significant difference in measurable function between the two groups, relating to cognitive health, specifically attention and memory.
One test, which assessed attention and memory, identified a decrease in free recall, or the ability to recollect and recite members of a list, among people with Sjögren's compared to their peers. Another test assessing attention, perceptual speed, motor speed, visual scanning, and memory revealed decreased motor speed among people with Sjögren's.
"Our results suggest that people living with Sjögren's still are able to maintain a reasonably high level of function, despite their perception of declining function over time. Sjögren's can interfere with daily functioning and the burden of illness is very real. Nonetheless, it is apparent that even with these interferences people can compensate and function reasonably well," said co-principal investigator and first author Lynn C. Epstein, M.D., a psychiatrist and clinical professor of psychiatry at Tufts University School of Medicine.
Epstein, for many years an associate dean at Brown University School of Medicine, is former president of the American Medical Women's Association, and Distinguished Life Fellow of the American Psychiatric Association.
"More in-depth studies are needed in order to fully understand these findings. The next steps would be to study how actual and perceived function change over time," said senior author David J. Greenblatt, M.D., Louis Lasagna Professor of Pharmacology and Experimental Therapeutics at Tufts University School of Medicine. Greenblatt is also a member of the graduate program faculty in Pharmacology and Experimental Therapeutics at the Sackler School of Graduate Biomedical Sciences at Tufts.
"Patients with Sjögren's experience a range of symptoms that call for a multidisciplinary approach to research and care. This study enables us to respond more directly to patients' concerns about their function and reminds patients and researchers alike that there is more room to investigate their experience of the disease," said co-principal investigator Athena Papas, D.M.D, Ph.D., the Erling Johansen Professor of Dental Research at Tufts University School of Dental Medicine. Dr. Papas is a leading researcher and clinician specializing in the oral health care of patients who are elderly, medically compromised, and those who have Sjögren's syndrome. The Dry Mouth Clinic at Tufts' School of Dental Medicine has one of the largest groups of Sjögren's patients in the country.
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Epstein LC, Masse G, Harmatz JS, Scott TM, Papas AS, Greenblatt DJ. "Characterization of cognitive dysfunction in Sjögren's syndrome patients." Clinical Rheumatology. Published online Dec 15,2013, DOI: 10.1007/s10067-013-2453-6