Trends in osteoporosis prevalence over a 10-year period in Japan: the ROAD study 2005-2015.

Introduction: This study aimed to clarify the trends in the prevalence of osteoporosis among general inhabitants using population-based cohort data of the baseline and the survey 10 years later.

Materials And Methods: The baseline survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted in 2005-2007; 1690 participants (596 men, 1094 women, mean age 65.2 years) completed all examinations of osteoporosis, including a questionnaire of medical information in the present/past and bone mineral density measurement using dual-energy absorptiometry. The fourth survey was performed in 2015-2016; 1906 individuals (637 men, 1269 women, 65.0 years) completed assessments identical to those at the baseline survey. Osteoporosis was defined using the World Health Organization criteria.

Results: The prevalence of lumbar spine (L2-L4) osteoporosis at the baseline survey was 13.6% (men, 3.4%; women, 19.2%) and that at the fourth survey was 9.7% (men, 1.4%; women, 13.9%), which decreased significantly (p < 0.01), while that of the femoral neck was not significantly different between the baseline and fourth surveys. Regarding the prevalence of osteoporosis of L2-L4 or the femoral neck, the prevalence of osteoporosis in women aged ≥ 70 was 38.8% at the fourth survey and 48.9% at the baseline study; thus, the prevalence at the fourth survey was significantly lower than that at the baseline survey (p < 0.01).

Conclusions: In the population-based survey with a 10-year interval, the prevalence of osteoporosis at lumbar spine tended to decrease significantly. This preferable change in osteoporosis could contribute to the decrease in the occurrence of osteoporotic fracture in the future.