Summary

The association between obesity and fracture was skeletal site-specific with no gender difference. Obesity was associated with a higher risk of proximal humerus fractures but not for wrist or clinical vertebral fractures.

Purpose

The association between body mass index (BMI) and the risk of clinical fractures at different sites is unclear. This study aimed to examine associations between BMI and fractures at different sites in Korean men and women.

Methods

This study analyzed 285,643 Korean adults (aged 50–80 years) who participated in health examinations from 2002 to 2003 and were followed up until 2015. The incidences of osteoporotic fractures were assessed using the International Classification of Diseases (10th revision; ICD-10) and procedure or radiographic codes. After adjusting for confounders, hazard ratios (HRs) were calculated using Cox proportional hazard models for fracture risk.

Results

Site-specific associations between BMI and fractures were found without gender difference. Specifically, an L-shaped association was found for clinical vertebral fractures, wherein the adjusted HRs per 5 kg/m² increase were 0.80 (95% confidence interval [CI] = 0.76–0.83) in BMI groups < 25 kg/m² and 0.97 (95% CI = 0.92–1.03) in BMI ≥ 25 kg/m². A linear inverse correlation for wrist fractures was observed, wherein the HRs were 0.83 (95% CI = 0.81–0.86) per 5 kg/m² increase. For proximal humerus fractures, a non-linear U-shape association was found, wherein the adjusted HRs per 5 kg/m² increase were 0.66 (95% CI = 0.50–0.88) in BMI groups < 23 kg/m² and 1.25 (95% CI = 1.08–1.45) in BMI ≥ 23 kg/m².

Conclusion

Low BMI was a risk factor for all tested fractures. Obesity was a risk factor for proximal humerus fracture, but it is a protective factor for wrist fracture.

中文翻译：

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不同骨骼部位体重指数与骨折风险的关系：一项全国性队列研究

概括

肥胖和骨折之间的关联是骨骼部位特异性的，没有性别差异。肥胖与较高的肱骨近端骨折风险相关，但与腕部或临床椎骨骨折无关。

目的

体重指数（BMI）与不同部位临床骨折风险之间的关系尚不清楚。本研究旨在研究 BMI 与韩国男性和女性不同部位骨折之间的关联。

方法

本研究分析了 2002 年至 2003 年参加健康检查并随访至 2015 年的 285,643 名韩国成年人（50-80 岁）。使用国际疾病分类（第 10 版；ICD-10）评估骨质疏松性骨折的发生率和程序或射线照相代码。在调整混杂因素后，使用 Cox 比例风险模型计算骨折风险的风险比 (HR)。

结果

发现 BMI 和骨折之间的特定部位关联没有性别差异。具体而言，发现临床脊椎骨折存在 L 型关联，其中BMI < 25 kg/ ^{m 2}和BMI ≥ 25 kg/m ²时为 0.97 (95% CI = 0.92–1.03) 。观察到腕部骨折的线性负相关，其中每增加 5 kg/m ²的 HR 为 0.83 (95% CI = 0.81-0.86) 。对于肱骨近端骨折，发现了非线性 U 形关联，其中在 BMI < 23 kg/m ^{2的组中，每增加 5 kg/m 2}的调整后 HR为 0.66 (95% CI = 0.50-0.88)BMI ≥ 23 kg/m ²时为 1.25 (95% CI = 1.08–1.45) 。

结论

低 BMI 是所有测试骨折的危险因素。肥胖是肱骨近端骨折的危险因素，但它是腕部骨折的保护因素。