Ongoing research project from 2023:

NOREPOS-Climate project

A continuation of Work Package 3 in the project Novel Aspects of an Old Problem

Several previous studies have identified variations in fracture risk based on geographic and urban-rural factors, indicating a higher incidence in southern Norway compared to the North and urban areas compared to rural. Whether this variation is due to altered bone metabolism, i.e., osteoporosis risk or differences in fall tendency is not fully known. In the NOREPOS-Climate project, we investigate potential associations between the risk of forearm and hip fractures and various weather elements, such as cold ambient temperatures, as well as estimates of air pollution (particulate matter, Nitrogen dioxide, and ground-level ozone). Quality-assured register-based data on fractures in the entire Norwegian population across all age groups have been linked to weather information supplied by the Norwegian Meteorological Institute (MET) and air pollution estimations from the Urban Background Model within the Nordic WelfAir project at Aarhus University, Denmark. The background population with demographic variables, such as age, gender, immigrant status, education level, and urbanization are provided by Statistics Norway. In a sub-study, the data have also been linked to the Cohort of Norway and other health studies for the investigation of the influence of smoking and Body Mass Index (BMI) on these associations. The linkages have been performed in a Geographic Information System (GIS), through the participants’ basic district.

Scientific publications:

• Dahl, C., Madsen, C., Omsland, T. K., Sogaard, A. J., Tell, G. S., Holvik, K., & Meyer, H. E. (2021). Contribution of elevation and residential proximity to the coast in explaining geographic variations in hip fracture incidence. A Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) study. Osteoporos Int, 32(5), 1001-1006. doi:10.1007/s00198-020-05736-y

• Dahl, C., Madsen, C., Omsland, T. K., Sogaard, A. J., Tunheim, K., Stigum, H., . . . Meyer, H. E. (2022). The Association of Cold Ambient Temperature With Fracture Risk and Mortality: National Data From Norway-A Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) Study. J Bone Miner Res, 37(8), 1527-1536. doi:10.1002/jbmr.4628

Contact: Associate Professor Cecilie Dahl. E-mail:

Completed research project 2018-2023, funded by the Research Council of Norway:

Novel aspects of an old problem

The Norwegian Epidemiologic Osteoporosis Studies

Every hour, two forearm fractures and one new hip fracture occur in Norway. Hip fractures are painful, reduce function, shorten life expectancy, and entail large healthcare costs. Although the risk of hip fracture has declined during the past couple of decades, an increase in the number of fractures is expected due to a growing elderly population. There are some well-established risk factors for fracture, but the question why Norway is the world leader remains unresolved. We will use our national database of hip fractures in combination with health studies and registers covering the entire population to study factors considered important to reduce the number of fractures. The project has three main goals: Firstly, a pioneer model for estimating the contribution of changes in risk factors and treatments over two decades will be developed to explain the decline in hip fracture incidence. Secondly, there is an intriguing link between the immune system and bone metabolism, but we do not know whether normal variation in immune function affects fracture risk. In a very large sample from the general population, we will study a measure of immune function in relation to long-term risk of osteoporosis and hip fracture. Thirdly, to explore causes of geographic variations in fracture risk, we will combine data on day-to-day weather conditions, climate changes, topography and air pollution with individual-level sociodemographic and fracture outcome data. This new knowledge may inform targeted preventive measures for fractures across Norway.

Scientific publications from the completed research projects are listed here.

Read more in the Project Databank of the Research Council of Norway

Read more about the project in the spring 2024 issue of EU Research.

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Completed research project, funded by the Research Council of Norway:

Hip fractures: Predictors, incidence and survival

The Norwegian Epidemiologic Osteoporosis Studies


The overall research question posed is why Norway has among the highest incidences of hip fractures in the world. To contribute to the answer we will:
1) assess the incidence of, and mortality after, hip fracture in the Norwegian population 1994-2007 with special focus on geographic differences, seasonal variations, socioeconomic differences and time trends;
2) assess whether drinking water is related to osteoporosis and hip fracture. Specific factors in drinking water include a) calcium, magnesium, water hardness, acidity, and alkalinity; b) aluminium, cadmium, lead, and fluoride; and c) content of E.coli and coli form bacteria (as approximations of inflammation);
3) prospectively investigate the impact of the combination of vitamins D and A status on the risk of hip fracture in a population-based multi-centre cohort of men and women residing in different districts of Norway, with special emphasis on exploring any possible interaction between the two vitamins.


Although Norway has among the highest incidences of hip fractures in the world, the true figures are not known, nor are the causes. Osteoporotic fractures bring about much pain, suffering and reduced quality of life for the patients, and the economic consequences are very high. A linkage will be established with hip fractures, deaths, socioeconomic factors and water quality from the whole Norwegian population 1994-2007. The linkage will also include COhort NORway, with information about risk factors (including stored biologic samples) from >181,000 participants, and >47,000 bone mineral density measures (NOREPOS), some of the largest cohort studies in the world.
Our first and fundamental objective is to describe the incidence and mortality of hip fractures 1994-2007.
Thereafter, we seek to explain some of the variation in hip fracture risk by environmental and lifestyle factors. There are indications that water quality, through its variable content of minerals and bacteria, could affect the risk for hip fracture. The investigation of this novel hypothesis is made possible through data from the Norwegian Registry of Waterworks. Second, there are indications that vitamin A (whose intake in Norway is generally high) affects the relation between vitamin D and skeletal health negatively. A nested case-control study using stored sera will examine whether a high intake of Vitamin A increases the risk of fractures. No previous studies, and no other research groups, have had the opportunity to investigate important and novel public health determinants of hip fractures on such a large scale. The linkages between exposure and outcome data give us an international advantage. Results will give directions for future research and for preventive strategies. The research will be conducted by NOREPOS, a ten-year old unique interdisciplinary research network including all the university medical faculties in the country, in addition to the Norwegian Institute of Public Health.

Scientific publications from the completed research projects are listed here.

Norwegian Epidemiologic Osteoporosis Studies | E-mail: