Underweight Young Women Without Later Weight Gain Are at High Risk for Osteopenia After Midlife: The KOBE Study

BACKGROUND: Although underweight young women are targets for interventions to prevent low bone mineral density (BMD), the relationship between change in body mass index (BMI) from youth to older age and BMD has not been widely investigated in community dwellers. METHODS: both at 20 and at present. RESULTS: at 20 and at present (OR 3.94; 95% confidence interval CI, 1.97-7.89). Those underweight only at present also had significantly increased OR of developing osteopenia (OR 2.95; 95% CI, 1.67-5.24). The OR of those underweight only at 20 was 0.87 (95% CI, 0.51-1.48). CONCLUSIONS: Current underweight was associated with increased risk for osteopenia among Japanese women, especially in those who were underweight both at 20 and at present. To prevent low BMD in the future, maintaining appropriate body weight might be effective for young underweight women.