University of Oslo, Institute of Health and Society, Department of Community Medicine and Global Health, Oslo, Norway.
Norwegian Institute of Public Health, Department of Health and Inequality, Oslo, Norway.
J Bone Miner Res. 2022 Aug;37(8):1527-1536. doi: 10.1002/jbmr.4628. Epub 2022 Jun 25.
Norway is an elongated country with large variations in climate and duration of winter season. It is also a high-risk country for osteoporotic fractures, in particular hip fractures, which cause high mortality. Although most hip fractures occur indoors, there is a higher incidence of both forearm and hip fractures during wintertime, compared with summertime. In a nationwide longitudinal cohort study, we investigated whether cold ambient (outdoor) temperatures could be an underlying cause of this high incidence and mortality. Hospitalized/outpatient forearm fractures (International Classification of Diseases and Related Health Problems, 10th Revision [ICD-10] code S52) and hospitalized hip fractures (ICD-10 codes S72.0-S72.2) from 2008 to 2018 were retrieved from the Norwegian Patient Registry. Average monthly ambient temperatures (degrees Celsius, °C) from the years 2008 to 2018 were provided by the Norwegian Meteorological Institute and linked to the residential area of each inhabitant. Poisson models were fitted to estimate the association (incidence rate ratios [IRRs], 95% confidence intervals [CIs]) between temperature and monthly incidence of total number of forearm and hip fractures. Flexible parametric survival models (hazard ratios [HR], 95% CI) were used to estimate the association between temperature and post-hip fracture mortality, taking the population mortality into account. Monthly temperature ranged from -20.2°C to 22.0°C, with a median of -2.0°C in winter and 14.4°C in summer. At low temperatures (<0°C) compared to ≥0°C, there was a 53% higher risk of forearm fracture (95% CI, 51%-55%) and 21% higher risk of hip fracture (95% CI, 19%-22%), adjusting for age, gender, calendar year, urbanization, residential region, elevation, and coastal proximity. When taking the population mortality into account, the post-hip fracture mortality in both men (HR 1.08; 95% CI, 1.02-1.13) and women (HR 1.09; 95% CI, 1.04-1.14) was still higher at cold temperatures. There was a higher risk of forearm and hip fractures, and an excess post-hip fracture mortality at cold ambient temperatures. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
挪威是一个狭长的国家，气候差异大，冬季时间长。它也是骨质疏松性骨折（尤其是髋部骨折）高发国家，这些骨折会导致高死亡率。尽管大多数髋部骨折发生在室内，但与夏季相比，冬季前臂和髋部骨折的发生率更高。在一项全国性纵向队列研究中，我们调查了寒冷的环境（室外）温度是否可能是导致这种高发病率和高死亡率的潜在原因。我们从挪威患者登记处检索了 2008 年至 2018 年期间的住院/门诊前臂骨折（国际疾病分类和相关健康问题第十次修订版 [ICD-10] 代码 S52）和住院髋部骨折（ICD-10 代码 S72.0-S72.2）。挪威气象研究所提供了 2008 年至 2018 年的平均每月环境温度（摄氏度，°C），并与每个居民的居住区域相关联。我们使用泊松模型来估计温度与总前臂和髋部骨折每月发生率之间的关联（发病率比 [IRR]，95%置信区间 [CI]）。我们使用灵活参数生存模型（风险比 [HR]，95%CI）来估计温度与髋部骨折后死亡率之间的关联，同时考虑了人口死亡率。每月温度范围从-20.2°C 到 22.0°C，冬季中位数为-2.0°C，夏季中位数为 14.4°C。与≥0°C 相比，低温（<0°C）时前臂骨折的风险增加 53%（95%CI，51%-55%），髋部骨折的风险增加 21%（95%CI，19%-22%），调整了年龄、性别、日历年、城市化程度、居住地区、海拔和沿海距离。考虑到人口死亡率后，男性（HR 1.08；95%CI，1.02-1.13）和女性（HR 1.09；95%CI，1.04-1.14）髋部骨折后死亡率仍较高在寒冷的温度下。在寒冷的环境温度下，前臂和髋部骨折的风险增加，髋部骨折后死亡率增加。
