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.
Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
Akihiro
A
Sudo
Noriki
N
Miyamoto
Kazuhiro
K
Horikawa
Masao
M
Urawa
Toru
T
Yamakawa
Tomomi
T
Yamada
Atsumasa
A
Uchida
D000368:Aged; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D011859:Radiography; D012307:Risk Factors