Twincities Research Group - Social environment and health

Gammalt fotografi av svetsare från Norrköping
A welder from Norrköping, 19th century.

An interdisciplinary research group, "the Twincities Research Group", has been initiated at Linköping University. "Twincities" refers to the two equally sized cities Linköping and Norrköping in southeast Sweden. 

These two cities, located within a distance of only 40 km, are part of the same county council and consequently have the same health care structure. However, public health in the twincities is remarkably different. This research design enables us to compare public health in two developing cities into the post-industrial age. The comparison has a design similar to the classical experiment with a control and an experiment group, as the social history and the socio-economic structure of the cities are different.


How could public health in two cities be so different?  – The focus for the Twincities Research Group
Tomas Faresjö, professor

What is Twincities?

In Sweden, the standard of living is high, and there is a well developed welfare sector and health care service. Nevertheless there are marked social and socioeconomic differences in health. Public health also varies between regions, both in terms of life expectancy and the way diseases affect the population.

The cities of Linköping and Norrköping – twins with big differences in public health

The concept ”Twincities” refers to the cities Norrköping and Linköping. These fairly equally sized cities are located within a distance of only 40 km. Linköping is often referred to as »the big small town« and Norrköping as »the small big city«. Despite the extrinsic resemblance between these two cities, there are profound differences. Their social and economic history, not least with regard to public health, are strikingly different. Norrköping could be labelled a ”blue-collar city”, while Linköping could be termed a ”white-collar city”. This design makes it possible to perform a wide array of research in public health and community medicine.

Like a classical experiment

The comparison between these two cities could be compared with a classical experiment, with an experiment group and a control group. Through this design it is possible to keep as many intervening factors as possible under control and uncover the relative importance of the social environment. As the number of different social factors varies between the cities, it is possible to unveil the relative importance of the social environment and its influence on people's health and disease risks. Important factors probably include social history, socioeconomic factors, lifestyle and behavioural factors, but also stress exposures.


"Cardiovascular mortality - the highest rates in Norrköping of all major Swedish cities"

Carina Wennerholm, Björn Grip, AnnaKarin Johansson, Hans Nilsson, Marja-Liisa Honkasalo and Tomas Faresjö, Cardiovascular disease occurrence in two close but different social environments, 2011, INTERNATIONAL JOURNAL OF HEALTH GEOGRAPHICS, (10), 5.

”Even fat people in Norrköping have worse health than fat people in Linköping"

Tomas Faresjö, Mikael Rahmqvist. Educational level is a crucial factor for good perceived health in the local community. Scandinavian Journal of Public Health 2010; 38:605-610.

”Gastrointestinal problems common in the population - but different types of diseases within the Twincities”

Grodzinsky E, Hallert C, Faresjö T, Bergfors E, Faresjö Å. Could gastrointestinal disorders differ in two close but divergent social environments? International Journal of Health Geographics 2012, Febr 6;(1):5.

Ongoing studies


A subsample from the prospective ABIS-study, with around 2.500 children followed from birth and onwards by questionnaires and biological samples. These children are now teenagers and, in principle, all data regarding their health care visits as well as childhood ICDdiagnoses is collected. Half of these children live in Norrköping and half of them in Linköping. This is part of an international collaboration with INRICH and universities in Canada, Holland, the USA and the United Kingdom.


Gastrointestinal problems, particularly Irritable Bowel Syndrome (IBS), is a major public health disease. In this study, data from people with an IBS diagnosis is collected in primary care. These individuals are followed for symptoms, psychosocial factors and also stress measured by cortisol in hair and DNA from saliva. This is part of an international collaboration with Australia.


A sample of around 800 middle-aged women from the Twincities are studied for psychosocial factors, lifestyle, cardiovascular symptoms and self-reported diseases and diagnosis from regional health registers. Comparisons will also be made with similar data from The Scottish Health Survey in collaboration with The University of Edinburgh.


Cardiovascular disease has been intensively studied in the populations of the Twincities. In this study, the historical rise of cardiovascular disease, in the Twincities is studied.

About the Twincities Research Group

Our interdisciplinary research group includes an array of researchers from both social sciences, behavioural sciences, humanistic sciences, and medical and biomedical sciences. We are focusing on socially relevant issues related to people's health and welfare in order to expand our knowledge of the importance of the social environment for health. A basic question is how modern society, where people lead stressful lives affects health. Most major public health diseases such as cardiovascular diseases, mental disorders, cancers and gastrointestinal problems are related to the way we live our lives, and the question is whether this could differ in different social environments.

Are there certain features related to different social environments, such as behaviours, attitudes and values, that are firmly established and affect the population's health not only today but also in the future.

The general design of Twincities makes it possible to unveil the relative importance of the social environment for health.

History of the cities

Fasad på Arbetets museum i Norrköping  The city of Norrköping was one of the first industrialized cities in Sweden. It was once called ”The Swedish Manchester”. In the late 1900s,  the city went through several economical crises, resulting in factory closures. The city could be labelled a ”blue-collar city”. However, for the past ten years, one of the Linköping University campuses has been situated in the city, and it has become more prosperous. Today there are 135.000 inhabitants in the city.

The city of Linköping is an old, small medieval city, with bishop and regional administration, surrounded by farming landscapes. The city has seen rapid growth in the last 60 years due to high technology industries and the establishment of the university. The city could be labelled a ”white-collar city”. Today the city is home to 150.000 inhabitants

Linköpings domkyrka


Faresjö T, Söderquist J, Ludvigsson J, Grodzinsky E, Nilsson H. Tvillingstäder med stora sociala skillnader i folkhälsa. Ett samhällsmedicinskt "experiment" inleds i Norrköping och Linköping. Läkartidningen 2007;104:1788-90.

Tomas Faresjö, Mikael Rahmqvist. Educational level is a crucial factor for good perceived health in the local community. Scandinavian Journal of Public Health 2010; 38:605-610.

Carina Wennerholm, Björn Grip, Annakarin Johansson, Hans Nilsson, Marja-Liisa Honkasalo, Tomas Faresjö. Cardiovascular diseases in two social environments – the Twincities. International Journal of Health Geographics 2011, 10:5.

Karlén J, Ludvigsson J, Frostell A, Theodorsson E, Faresjö T.
Cortisol in hair measured in young adults - a biomarker of major life stressors? BMC Clin Pathol. 2011 Oct 25;11:12.

Grodzinsky E, Hallert C, Faresjö T, Bergfors E, Faresjö Å. Could gastrointestinal disorders differ in two close but divergent social environments? International Journal of Health Geographics 2012, Febr 6;(1):5.

Karlén J, Faresjö T, Ludvigsson J. Could the social environment trigger for the induction of diabetes-related autoantibodies in young children? Scandinavian Journal of Public Health, 2012, Mar;40(2):177-82.

Karlén J, Frostell A, Theodorsson E, Faresjö T, Ludvigsson J. Maternal influence on child HPA axis: a prospective study of cortisol levels in hair. Pediatrics. 2013 Nov;132(5):e1333-40.

Falk M, Faresjö A, Faresjö T. Sun exposure habits and health risk-related behaviours among individuals with previous history of skin cancer. Anticancer Res. 2013 Feb;33(2):631-8.

Faresjö Å, Theodorsson E, Chatziarzenis M, Sapouna V, Claesson HP, Koppner J, Faresjö T. Higher perceived stress but lower cortisol levels found among young Greek adults living in a stressful social environment in comparison with Swedish young adults. PLoS One. 2013 Sep 16;8(9):e73828.

Faresjö Å, Grodzinsky E, Hallert C, Timpka T. Patients with irritable bowel syndrome are more burdened by co-morbidity and worry about serious diseases than healthy controls--eight years follow-up of IBS patients in primary care. BMC Public Health. 2013 Sep 11;13:832.

Pembrey M, Saffery R, Bygren LO; Network in Epigenetic Epidemiology; Network in Epigenetic Epidemiology. Human transgenerational responses to early-life experience: potential impact on development, health and biomedical research. J Med Genet. 2014 Sep;51(9):563-72.

Rajmil L, Fernandez de Sanmamed MJ, Choonara I, Faresjö T, Hjern A, Kozyrskyj AL, Lucas PJ, Raat H, Séguin L, Spencer N, Taylor-Robinson D; International Network for Research in Inequalities in Child Health (INRICH). Impact of the 2008 economic and financial crisis on child health: a systematic review. Int J Environ Res Public Health. 2014 Jun;11(6):6528-46. Review.

Wennerholm C, Jern M, Honkasalo M-L, Faresjö T. Life before myocardial infarction – a qualitative study of middle-aged women. Health. 2014, 6, 2765-2774.

Karlén J, Ludvigsson J, Hedmark M, Faresjö Å, Theodorsson E, Faresjö T. Early psychosocial exposures, hair cortisol levels, and disease risk. Pediatrics. 2015 Jun;135(6):e1450-7.

Grodzinsky E, Walter S, Viktorsson L, Carlsson AK, Jones MP, Faresjö Å.
More negative self-esteem and inferior coping strategies among patients diagnosed with IBS compared with patients without IBS - a case-control study in primary care. BMC Fam Pract. 2015 Jan 28;16:6.

Nätt D, Johansson I, Faresjö T, Ludvigsson J, Thorsell A. High cortisol in 5-year-old children causes loss of DNA methylation in SINE retrotransposons: a possible role for ZNF263 in stress-related diseases. Clinical Epigenetics 2015, 7:91.

Research Group