The patients underwent an extensive examination with questionnaires, clinical examination and imaging. One of the main aims of this study is to better understand the underlying causes of pain in persons with hand OA. We know today that the degree of OA cannot fully explain the pain that is experienced by patients with hand OA, and the researchers wanted to better understand the underlying mechanisms behind their pain experience. In addition, they wanted to validate different disease biomarkers, including imaging, to evaluate the degree of structural damage and inflammation in hand OA.
Since 2017, the research group behind Nor-Hand has published 13 papers based on results from the data collection in 2016-17, which we find quite impressive. If you are interested in reading more of the results in these papers, they can be found here on the database PubMed and in the journal O&C Open. Two PhD candidates have already defended their thesis based on results from the Nor-Hand study, and an additional two PhD candidates will defend their work in 2023.
What have we learned about pain?
Pernille Steen Pettersen defended her PhD thesis in December 2020. Her work focused on pain sensitization in patients with hand OA. Simply said, some persons are more sensitive to painful or non-painful stimuli due to changes in the peripheral and central nervous system. Pernille nicely showed that patients with increased pain sensitivity based on clinical tests experienced more intense hand pain when compared to those with less or no pain hypersensitivity. Her results suggest that pain sensitization is relevant for patients with hand OA, and that pain sensitization maybe can partly explain the discrepancy that we see between OA severity and pain intensity. Read more about Pernille´s results in her papers here.
The researchers also got a lot of attention around the paper by PhD candidate Marthe Gløersen, showing that body mass index was associated with pain, not only in the knees and hips as expected, but also in the hands. These results tell us that overweight and obesity have systemic unfavorable effects beyond the increased loading of joints in the lower extremities that are relevant in OA. Whether weight reduction can lead to less pain in patients with hand OA has not yet been explored. Read more about the results in Marthe´s papers here.
PhD candidate Elisabeth Mulrooney recently published her first paper in the thesis, describing the strong associations between psychological factors involving emotions and cognition and the severity of pain. Whether pain is the cause of the consequence of these psychological factors could not be studied due to the use of cross-sectional data in this paper. The researchers are looking forward to the analyses of the longitudinal data set, which will hopefully we give us a better understanding of these relationships. Elisabeth´s paper can be read here.
Imaging of hand OA
Øystein Maugesten was the first PhD candidate who used data from the Nor-Hand study in his thesis, and he defended his work in September 2020. His PhD thesis focused on a novel imaging technique involving fluorescence optical imaging to quantify the amount of microcirculation in the hands as a measure of inflammation. Øystein´s first paper was important in order to identify a suitable method to evaluate the images using different scoring methods. In his following work the researchers found an association between fluorescence enhancement in joint areas and pain, while the agreement between fluorescence enhancement and synovitis by more established methods such as ultrasound and MRI was low. Hence, they question the usefulness of fluorescence optical imaging in hand OA. You can read more about Øystein´s results here.
The medical student Caroline Mehl Fjellstad got interested in hand OA research when she was heavily involved in the data collection of the Nor-Hand study. She wrote a paper as part of her study thesis at medical school, and found that synovitis by ultrasound was associated with pain in finger joints and thumb base joints. Her paper can be found here. The results suggest that treating inflammation can be beneficial both in patients with OA in finger joints and in patients with OA in thumb base joints. This will be studied closer in the MERINO study on methotrexate in erosive hand OA and in the PICASSO study on intraarticular steroid injections in thumb base OA.
Treatment of hand OA
Unfortunately, there is currently no disease modifying therapies of hand OA that can stop the development or progression of the disease. Among medical options, the patients are usually advised to use analgesics and anti-inflammatory drugs on demand.
The medial student Marianne Ulrichsen wrote her study thesis at medical school about the use of alternative therapies among patients with hand OA. The research team found that almost 1 of 4 patients in the Nor-Hand study had visited a complementary or alternative medicine (CAM) provider during the last year. These persons had more pain than those who had not visited a CAM provider despite the use of more pharmacological and non-pharmacological therapies. Their results suggest that many patients with OA do not experience satisfactory effects of the recommended interventions and seek help from CAM providers. Read more about the results here.
The way forward
Today our research group consists of one senior researcher, two postdocs, two PhD candidates and one research coordinator. In addition, we have several international collaboration partners and many medical students have been involved in the data collection and in the analyses of the rich data set.
As described in the protocol regarding the follow-up examination in 2019-21 (see here), there are several new and interesting research questions that the Nor-Hand researchers can investigate, and they are excited to begin the analyses of the longitudinal data.