Dr. Benjamin Lebwohl answers questions about recent study findings linking celiac disease to neuropathy.
Recently, we posted about new study results about celiac disease and neuropathy on NFCA’s Facebook. This study, “Risk of Neuropathy Among 28,232 Patients With Biopsy-Verified Celiac Disease,” was of great interest, as many of members of our community reported that they experience symptoms of neuropathy. Because we wanted to go a little deeper into the results of this study so that you could learn more about them, we turned to one of the study’s investigators, Dr. Benjamin Lebwohl.
Dr. Lebwohl is a part of the faculty of the Celiac Disease Center at Columbia University. He is also an associated scholar at the Karolinska Institute in Stockholm, Sweden, where he performs population-based research in celiac disease in the Department of Medical Epidemiology and Biostatistics.
Q. In basic terms, can you explain the background and major findings of your study?
A. We have known since the 1960's that some patients with celiac disease have neuropathy, damage to nerves that can cause pain, weakness, and loss of sensation. In some patients, this is the only, or main, clinical feature of celiac disease, whereas others may have neuropathy as one of many symptoms. The severity can also vary widely. It can be as mild as a tingling that is only mentioned to the doctor in passing, or it can be so severe as to be incapacitating.
What we don't know is what the risk for this condition is in patients with celiac disease. Previous estimates have been based on studies of in-patients with celiac disease (in-patients at hospitals), or attendees at referral centers or support groups. Those studies were important but the populations might not be reflective of the general population of patients with celiac disease.
The present study is an analysis of a large, population-based database created by Professor Jonas Ludvigsson. This study found that patients diagnosed with celiac disease are about 2.5 times as likely to develop neuropathy compared to the general population.
This is the largest study to date to investigate the link between celiac disease and neuropathy. Professor Ludvigsson's database has been the source of studies of celiac disease that have greatly increased our understanding of the relationship between celiac disease and other conditions and outcomes. There are several major advantages of using this database: It is large, with more than 29,000 patients with celiac disease, allowing us to detect even small signals; it encompasses the entire population of Sweden, so that its findings are reflective of the average celiac patient; and it is validated, by which I mean that Professor Ludvigsson has shown that the patients in this database truly have celiac disease, based on medical record review of a substantial subset of patients.
Q. What should our readers take away from the findings of this study, and what does this mean for patients with celiac disease?
A. This study found that neuropathy is more likely to develop in patients with celiac disease than in the general population, and that this increased risk was present both before and after the diagnosis of celiac disease. The highest risk was found in the first year after the celiac diagnosis, and that is likely due in part to the fact that a diagnosis of celiac disease is a time of a general spike in visits to the doctor and receiving additional diagnoses. But even 5 years after the diagnosis of celiac disease an increased risk was detectable.
That said, it is a relief to find that despite this increased relative risk compared to the general population, there was not a lot of neuropathy found in either group. In fact, over the course of an average of 10 years of follow-up time, only 0.7% of the celiac disease patients were found to have neuropathy. So more than 99% did not.
Q. What suggestions do you have for the direction of future research in this area?
A. We need to better understand why neuropathy develops at various stages. It is quite possible that this condition is due to a number of causes related to celiac disease. Before the celiac diagnosis, perhaps dietary gluten is stimulating an immune response that targets the nerves. Or perhaps a nutritional deficiency (such as vitamin B12 or copper, or an as-yet-unidentified deficiency) is happening due to a poorly functioning intestine. After the celiac diagnosis, perhaps the neuropathy has another set of causes, such as another vitamin deficiency or even toxicity related to the gluten-free diet. Or perhaps it occurs as an immune hyperactivity that persists despite the elimination of gluten. We also need to study whether there's a connection between these causes of neuropathy and "brain fog" that our patients frequently describe. So, there is much more to learn.
Visit archneur.jamanetwork.com to learn more about the study.
Check out the Beyond Celiac International Celiac Disease Symposium (ICDS) 2013 poster about celiac disease and brain fog.