Early RA Patients Lose Grip Over 5 Years
Assessment and rehab could help prevent grip force loss
Judy George,July 22, 2017 - published in MedPage Today
Early rheumatoid arthritis (RA) patients have significantly impaired grip strength 5 years after diagnosis, which might be helped by assessing hand function and prescribing rehabilitation in clinical settings, according to researchers in Sweden.
In a study of 225 patients with early RA, grip force significantly improved in the first 12 months of the study, but was lower than expected after 5 years -- 139 newtons (N) versus 244 N, reported Carl Turesson, MD, PhD, of Skane University Hospital in Malmo, Sweden, and colleagues.
"Grip strength improved in early RA, in particular during the first year. It was still significantly impaired 5 years after diagnosis, even among those with limited self-reported disability and those in clinical remission," they wrote in Arthritis Care & Research. "This suggests that further efforts to improve hand function are important in early RA."
Grip strength and pinch measurements are closely related to hand disability and articular damage, they noted. Previous studies have shown that many patients have self-reported activity limitation in their hands, with a high prevalence of hand and wrist disability leading to severe deformities within 10 years.
The Turesson group studied a group of 225 patients with early RA (defined as symptoms for 12 months or less), recruited in 1995-2005 from the rheumatology outpatient clinic in Malmo. Patients were managed with usual care, with no pre-specified pharmacotherapy or rehabilitation protocol. In a structured follow-up program, all patients were examined by the same rheumatologist over time, with visits scheduled at 6, 12, and 24 months, then at 5 and 10 years.
The researchers assessed disability using the Health Assessment Questionnaire Disability Index (HAQ-DI), and obtained information about current treatment with disease modifying anti-rheumatic drugs (DMARDs) and corticosteroids through a structured interview at each visit. The baseline median HAQ-DI score was 0.75 and the mean Disease Activity Score in 28 Joints (DAS28) score was 4.6±1.4. HAQ-DI.
The researchers used the electronic instrument Grippit (AB Detektor, Gothenburg, Sweden) to measure grip force. Patients sat comfortably in a chair without armrests and followed standardized instructions. The Grippit device measured the grip force every 0.5 second during a 10-second, uninterrupted grip, recording the peak (maximum) value and the average value of the grip.
Because a sustained grip is considered more important in daily activity than peak grip, the researchers used average grip force as the main outcome and peak grip force as the secondary outcome. They measured grip force in the dominant and non-dominant hand 3 times, and used the average of the 3 measurement values from each hand.
Most patients used methotrexate, and 17% were treated with a biologic DMARD sometime during the first 5 years.
To compare the results of the study group, the researchers used a reference sample recruited from a variety of settings near Oslo. The 566 participants in the reference sample were representative of a Norwegian background population in terms of height, weight, work status, and exercise habits.
The researchers found that:
At baseline, the mean baseline average grip force was 105±78 N, which was significantly lower than the expected value of 266 ± 91 N; P<0.001
The average improved significantly from the start of the study to the 12-month visit (age-corrected mean change: 34 N; 95% CI 26-43)
At 5 years, the average grip force was still lower than expected (mean 139 N versus 244 N; P<0.001), and also among those with HAQ-DI less than or equal to 0.5 and those in clinical remission
The proportion of patients with peak grip force below the threshold for performing most activities of daily living (89 N, or 20 pounds) also decreased with time. At baseline, 43% of the patients had peak grip force values less than 89 N. Five years later, 27% of the patients -- 34% of women and 8% of men -- had such a low grip force.
"With a grip strength below this level, patients have difficulties lifting lighter objects, and need two hands, for example, to lift a cup of coffee," the authors explained.
"The results of this study, taken together with the evidence for a beneficial effect of hand exercise in patients with RA, suggest that there is still a need in clinical settings to assess hand function and offer rehabilitative interventions," they added.
Strengths of this study include its structured design over 5 years with all patients being examined by the same rheumatologist, leading the authors to conclude that results could be generalized to RA patients seen in clinical practice. On the other hand, they noted, the results may not apply to other ethnic or geographic settings, or to patients who used completely different strategies for pharmacological treatment and rehabilitation.
This study was supported by the Swedish Research Council, the Swedish Rheumatism Association and Lund University. The authors reported no conflicts of interest.
Reviewed by F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner