Case-control study of risk factors for fractures of the distal radius and proximal humerus among the Japanese population.

We conducted a case-control study to identify risk factors for fractures of the distal radius and proximal humerus. Subjects were selected from women aged 45 and over with distal radius and proximal humerus fractures, resulting from minor trauma. Two age- and gender-matched controls for each case were selected from patients who subsequently visited the same clinic for treatment of conditions other than fractures. Questionnaires including anthropometric data, past and current physical activity, and lifestyle were sent by mail to both subjects and controls. A total of 140 women with distal radius fractures (mean age 67.4 years) and 242 controls were analyzed. Falls during the previous year were a significant risk factor, while futon use (instead of bed use) before fracture was a protective factor for distal radius fractures. A total of 37 women with proximal humerus fractures (mean age 76.3 years) and 67 controls were analyzed. Weight loss was a significant risk factor, while greater frequency of going outside significantly decreased the risk of proximal humerus fracture. There was no significant correlation with eating habits, milk and alcohol consumption, or smoking to the risk of either fracture.