Genetic factors contribute more to hip than knee surgery due to osteoarthritis - a population-based twin registry study of joint arthroplasty
K Magnusson, K Scurrah, E Ystrom, R E Ørstavik, T Nilsen, Ó A Steingrímsdóttir, P Ferreira, A M Fenstad, O Furnes, K B Hagen, K Magnusson, K Scurrah, E Ystrom, R E Ørstavik, T Nilsen, Ó A Steingrímsdóttir, P Ferreira, A M Fenstad, O Furnes, K B Hagen
Abstract
Objective: To explore and quantify the relative strengths of the genetic contribution vs the contribution of modifiable environmental factors to severe osteoarthritis (OA) having progressed to total joint arthroplasty.
Design: Incident data from the Norwegian Arthroplasty Registry were linked with the Norwegian Twin Registry on the National ID-number in 2014 in a population-based prospective cohort study of same-sex twins born 1915-60 (53.4% females). Education level and height/weight were self-reported and Body Mass Index (BMI) calculated. The total follow-up time was 27 years for hip arthroplasty (1987-2014, 424,914 person-years) and 20 years for knee arthroplasty (1994-2014, 306,207 person-years). We estimated concordances and the genetic contribution to arthroplasty due to OA in separate analyses for the hip and knee joint.
Results: The population comprised N = 9058 twin pairs (N = 3803 monozygotic (MZ), N = 5226 dizygotic (DZ)). In total, 73% (95% confidence intervals (CI) = 66-78%) and 45% (95% CI = 30-58%) of the respective variation in hip and knee arthroplasty could be explained by genetic factors. Zygosity (as a proxy for genetic factors) was associated with hip arthroplasty concordance over time when adjusted for sex, age, education and BMI (HR = 2.98, 95% CI = 1.90-4.67 for MZ compared to DZ twins). Knee arthroplasty was to a greater extent dependent on BMI when adjusted for zygosity and the other covariates (HR = 1.15, 95% CI = 1.02-1.29).
Conclusion: Hip arthroplasty was strongly influenced by genetic factors whereas knee arthroplasty to a greater extent depended on a high BMI. The study may imply there is a greater potential for preventing progression of knee OA to arthroplasty in comparison with hip OA.
Keywords: Arthroplasty; Heritability; Osteoarthritis; Twins.
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Source: PubMed