Prevalence and risk factors for knee osteoarthritis in elderly Japanese men and women.

BACKGROUND: The aims of the present study were to examine the prevalence and risk factors for knee osteoarthritis in elderly Japanese men and women. METHODS: We examined 598 of the 1513 inhabitants of Miyagawa village aged > or = 65 years (393 women, 205 men). Baseline data, obtained with standard questionnaires, included information on age, past history, sports activity, working, knee pain, smoking, and intakes of alcohol and milk. Bone mineral density of the forearm was measured using dual energy X-ray absorptiometry. Anteroposterior radiographs of both knees were graded for osteoarthritis using the Kellgren-Lawrence grading system. Definite osteoarthritis was defined as a grade of 2 or higher. We used logistic regression analysis by the stepwise method to determine the risk factors for radiographic knee osteoarthritis. RESULTS: The prevalence of definite radiographic knee osteoarthritis was 30.0% overall: 17.7% in men and 36.5% in women. The prevalence of symptomatic knee osteoarthritis was 21.2% overall: 10.7% in men and 26.7% in women. There were significant differences in the risk of radiographic knee osteoarthritis with body mass index (BMI), sex, age, and bone mineral density (BMD). CONCLUSIONS: The prevalence of definite radiographic knee osteoarthritis was 30.0% and that of symptomatic knee osteoarthritis was 21.2%. We found that higher BMI, female sex, older age, and higher BMD were significantly associated with an increased risk for radiographic knee osteoarthritis.

Acrodysostosis with unusual iridal color changing with age.

Acrodysostosis is a rare congenital anomaly syndrome characterized by peculiar facial appearance with a small nose and an open mouth, short stature, short metacarpotarsal, and phalangeal bones with cone-shaped epiphyses, advanced bone-age, and variable degrees of mental retardation. It is most likely that the disease is inherited in an autosomal dominant mode, its pathogenesis has remained unknown. We report a 4-year-old Japanese girl who suffered from acrodysostosis with unusual iridal color. The color of patient's irides was gray-bluish in her infancy but became light-brownish by age 4 years. Of eight Japanese patients reported, four had abnormal eye color: a 7-month-old boy with blue irides and his 2-year-old elder sister with light-blue eyes a 6-year-old girl with gray-brownish irides, and a 4-year-old girl (present case) with blue-brownish irides. The degree of iris pigmentation in acrodysostosis patients may change with age. It is likely that the putative gene for acrodysostosis might play a role not only in remodeling of bones but also in iris pigmentation.