Burden of knee and lumbar pain in Japanese population clarified
medwireNews: More than one in 10 of the general population in Japan have pain in both lumbar spine and knee, a cohort study has found.
The same dataset also identified risk factors for pain at the two sites, finding that lumbar pain predicted knee pain and vice versa.
The analysis included data on 12,019 participants in the Longitudinal Cohorts of Motor System Organ (LOCOMO) study, a nationwide multi-cohort study funded by the Japanese government.
At the baseline examination, the prevalence of knee pain was 27.9% in men and 35.1% in women (mean 32.7%), and the prevalence of lumbar pain was 34.2% in men and 39.4% in women (mean 37.7%).
For coexistent lumbar and knee pain the prevalence was 10.9% in men and 12.8% in women (mean 12.2%), and the difference between the genders was statistically significant.
“On the basis of the total age and sex distributions derived from the Japanese census in 2010, our results estimate that 18,000,000 people (7,100,000 men and 10,900,000 women) aged ≥40 years would be affected by knee pain and that 27,700,000 people (12,100,000 men and 15,600,000 women) aged ≥40 years would be affected by lumbar pain,” write Noriko Yoshimura (University of Tokyo, Japan) and co-authors in the Journal of Bone and Mineral Metabolism.
The authors used logistic regression analysis to identify baseline factors that predicted the presence of pain at the two sites.
For knee pain, the significant independent predictors were higher age (odds ratio [OR]=1.05 per 1-year increment), female gender (OR=1.60), higher body mass index (BMI; OR=1.14 per 1 kg/m2 increment), living in a rural area (OR=2.42 versus urban area), and the presence of lumbar pain (OR=1.37).
Similarly, age, female gender, high BMI, rural residence, and knee pain were significant independent predictors of lumbar pain, at ORs of 1.02, 1.13, 1.02, 2.02, and 1.38, respectively.
“To our knowledge, this is the first study to report the frequency of the knee pain and lumbar pain and to estimate the total number of prevalent subjects, by using a large-scale population-based cohort study in Japan,” the authors write.
This information will be valuable for rational healthcare planning, they suggest, particularly since the population of Japan is aging rapidly; “a comprehensive and evidence-based prevention strategy for musculoskeletal diseases is urgently needed,” they note.
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By Joanna Lyford, Senior medwireNews Reporter