Is the physical burden of Sjogren's Syndrome underestimated?

Image source Shorpy. 

Last Wednesday I put up a post about a recent Tufts study in which a principal researcher summarized the study results in this quote from the Tufts press release:

“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.

In my post, I expressed a few concerns regarding the study's treatment and examination of Sjogren's related fatigue:

Since fatigue is one of my most disabling symptoms of Sjs and I'm a bit touchy about labeling fatigue as an all in your head symptom, I found it interesting that elsewhere in the discussion section of this study, fatigue is included under the description of "neuropsychiatric problems". Continue reading here. 

 My post prompted several comments and responses which were very interesting, especially this from Dr. Sarah Schafer in which she references two important studies that seem to contradict the Tufts study conclusion: 

I’m sure some Sjogren’s patients live quite productive lives.  Some lupus patients do too. The variability in AI symptoms within a population is to be expected.  However, the conclusion by Epstein et al  that “ levels of function approach that of healthy controls” is disturbing and goes against much evidence and plain common sense.  This reinforces the old and incorrect bias that Sjogren’s patients are just not that sick.  A study like this can perpetuate the current lack of clinical concern/ obliviousness of medical professionals.   It can also reduce incentives to research this disease which has sent many strong willed,  previously highly functioning people out of the workforce.  

Dr. Schafer addresses functional disability caused by Sjogren's in this study:

 Primary Sjogren’s Syndrome: health experiences and predictors of health quality among patients in the United States -by Segal et al (Open Access article), 2009    Link:  www.hqlo.com/content/7/1/46 

She highlights these findings in the study:

p. 2  (second paragraph in article): “the degree of functional disability was as great in patients with primary SS as those with SLE” 

p. 5 under the  heading,  Predictors of Health-Related Quality of Life: “sicca severity and disease duration were not significant contributors to impaired quality of life in any of the full models (with age and disease duration taken into account). Somatic fatigue was the only unique predictor of general health… ” 

p. 6, under Discussion: “Our data demonstrates that the reduction in health-related quality of life in PSS is similar to that experienced by patients with RA and SLE…” etc (read on). 

The noted functional impairment in that article,  as well as the finding that 70 % of primary Sjogren’s have disabling fatigue (1), suggests to me that the physical burden of this illness is often simply overlooked.  Fatigue and pain are invisible, and therefore easy to disregard or minimize.   RA patients have fatigue and pain,  but they also have visible, measurable joint damage.  Lupus patients may develop end organ damage – sometimes fatal - that is not usually seen in Sjogren’s.  However, we have our own end organ issues, not just lacrimal and salivary glands. Neuropathies are common (not so easy to diagnose and measure). Vasculitis of skin is a problem for many but often overlooked.   Lymphoma, a real and potentially fatal Sjogren’s complication, could be considered a type of end organ damage, but this is fact is also often downplayed. 

The fatigue article:  

1. Ng, Wan-Fai. Primary Sjögren’s syndrome: Too dry and too tired. Rheumatology. 2010;49:844-853.

This is excellent information. 

In addition to Dr. Schafer's comments, I'd like to mention that the first study that Dr. Schafer quoted, Primary Sjögren's Syndrome: health experiences and predictors of health quality among patients in the United States found here, had a much larger sample size (277 primary Sjogren's syndrome patients were compared to 606 controls) than the Tufts study (37 primary Sjogren's syndrome patient participants and 37 control subjects). 

If you felt frustrated by reading the Tufts article, I strongly recommend that you take the time to read these two other studies.