Science News
from research organizations

Overweight causes heart failure: Large study with new method clarifies the association

Date:
June 25, 2013
Source:
Uppsala Universitet
Summary:
Scientists have used a new method to investigate obesity and overweight as a cause of cardiovascular disease. Strong association have been found previously, but it has not been clear whether it was overweight as such that was the cause, or if the overweight was just a marker of another underlying cause, as clinical trials with long-term follow-ups are difficult to implement.
Share:
FULL STORY

An international research team led by Swedish scientists has used a new method to investigate obesity and overweight as a cause of cardiovascular disease. Strong association have been found previously, but it has not been clear whether it was overweight as such that was the cause, or if the overweight was just a marker of another underlying cause, as clinical trials with long-term follow-ups are difficult to implement.

A total of nearly 200,000 subjects were included in the researchers' study of the causality between obesity/overweight and diseases related to cardiovascular conditions and metabolism, which is being published for the first time in PLOS Medicine. The goal was to determine whether obesity as such is the actual cause of these diseases or whether obesity is simply a marker of something else in the subject's lifestyle that causes the disease.

"We knew already that obesity and cardiovascular disease often occur together. However, it has been hard to determine whether increased BMI as such is dangerous. In this study we found that individuals with gene variants that lead to increased body-mass index (BMI) also had an increased risk of heart failure and diabetes. The risk of developing diabetes was greater than was previously thought," says Tove Fall, a researcher at the Department of Medical Sciences and the Science for Life Laboratory, Uppsala University, who coordinated the study together with researchers from the Karolinska Institutet and Oxford University.

These scientists studied whether a gene variant in the FTO gene, which regulates the appetite and thereby increases the individual's BMI, is also linked to a series of cardiovascular diseases and metabolism. The risk variant is common in the population, and each copy of the risk variant increases BMI by an average of 0.3-0.4 units. Since an individual's genome is not affected by lifestyle and social factors, but rather is established at conception, when the embryo randomly receives half of each parent's genome, the method is thus called "Mendelian randomization." To achieve reliable results a large study material was needed, and nearly 200,000 individuals from Europe and Australia participated.

"Epidemiological studies look for associations in large populations, but it is usually difficult to reliably determine cause and effect -- what we call causality. By using this new genetic method, Mendelian randomization, in our research, we can now confirm what many people have long believed, that increased BMI contributes to the development of heart failure. We also found that overweight causes increases in liver enzymes . This knowledge is important, as it strengthens the evidence that forceful societal measures need to be taken to counteract the epidemic of obesity and its consequences," says Erik Ingelsson, professor at the Department of Medical Sciences and the Science for Life Laboratory, Uppsala University.

The results show that an increase of one unit of BMI increases the risk of developing heart failure by an average of 20 per cent. Further, the study also confirms that obesity leads to higher insulin values, higher blood pressure, worse cholesterol values, increased inflammation markers, and increased risk of diabetes.

The present study was carried out within the framework of the major research consortium ENGAGE, which brings together more than 35 studies and more than 130 co-authors. The study was coordinated by Erik Ingelsson's research group in collaboration with the Karolinska Institutet and Oxford University.

The study was funded by, among others, the European Union's Seventh Framework Programme (ENGAGE), the Swedish Research Council, the Swedish Foundation for Strategic Research, and the Swedish Heart-Lung Foundation.


Story Source:

Materials provided by Uppsala Universitet. Note: Content may be edited for style and length.


Journal Reference:

  1. Tove Fall, Sara Hägg, Reedik Mägi, Alexander Ploner, Krista Fischer, Momoko Horikoshi, Antti-Pekka Sarin, Gudmar Thorleifsson, Claes Ladenvall, Mart Kals, Maris Kuningas, Harmen H. M. Draisma, Janina S. Ried, Natalie R. van Zuydam, Ville Huikari, Massimo Mangino, Emily Sonestedt, Beben Benyamin, Christopher P. Nelson, Natalia V. Rivera, Kati Kristiansson, Huei-yi Shen, Aki S. Havulinna, Abbas Dehghan, Louise A. Donnelly, Marika Kaakinen, Marja-Liisa Nuotio, Neil Robertson, Renée F. A. G. de Bruijn, M. Arfan Ikram, Najaf Amin, Anthony J. Balmforth, Peter S. Braund, Alexander S. F. Doney, Angela Döring, Paul Elliott, Tõnu Esko, Oscar H. Franco, Solveig Gretarsdottir, Anna-Liisa Hartikainen, Kauko Heikkilä, Karl-Heinz Herzig, Hilma Holm, Jouke Jan Hottenga, Elina Hyppönen, Thomas Illig, Aaron Isaacs, Bo Isomaa, Lennart C. Karssen, Johannes Kettunen, Wolfgang Koenig, Kari Kuulasmaa, Tiina Laatikainen, Jaana Laitinen, Cecilia Lindgren, Valeriya Lyssenko, Esa Läärä, Nigel W. Rayner, Satu Männistö, Anneli Pouta, Wolfgang Rathmann, Fernando Rivadeneira, Aimo Ruokonen, Markku J. Savolainen, Eric J. G. Sijbrands, Kerrin S. Small, Jan H. Smit, Valgerdur Steinthorsdottir, Ann-Christine Syvänen, Anja Taanila, Martin D. Tobin, Andre G. Uitterlinden, Sara M. Willems, Gonneke Willemsen, Jacqueline Witteman, Markus Perola, Alun Evans, Jean Ferrières, Jarmo Virtamo, Frank Kee, David-Alexandre Tregouet, Dominique Arveiler, Philippe Amouyel, Marco M. Ferrario, Paolo Brambilla, Alistair S. Hall, Andrew C. Heath, Pamela A. F. Madden, Nicholas G. Martin, Grant W. Montgomery, John B. Whitfield, Antti Jula, Paul Knekt, Ben Oostra, Cornelia M. van Duijn, Brenda W. J. H. Penninx, George Davey Smith, Jaakko Kaprio, Nilesh J. Samani, Christian Gieger, Annette Peters, H.-Erich Wichmann, Dorret I. Boomsma, Eco J. C. de Geus, TiinaMaija Tuomi, Chris Power, Christopher J. Hammond, Tim D. Spector, Lars Lind, Marju Orho-Melander, Colin Neil Alexander Palmer, Andrew D. Morris, Leif Groop, Marjo-Riitta Järvelin, Veikko Salomaa, Erkki Vartiainen, Albert Hofman, Samuli Ripatti, Andres Metspalu, Unnur Thorsteinsdottir, Kari Stefansson, Nancy L. Pedersen, Mark I. McCarthy, Erik Ingelsson, Inga Prokopenko. The Role of Adiposity in Cardiometabolic Traits: A Mendelian Randomization Analysis. PLoS Medicine, 2013; 10 (6): e1001474 DOI: 10.1371/journal.pmed.1001474

Cite This Page:

Uppsala Universitet. "Overweight causes heart failure: Large study with new method clarifies the association." ScienceDaily. ScienceDaily, 25 June 2013. <www.sciencedaily.com/releases/2013/06/130625172248.htm>.
Uppsala Universitet. (2013, June 25). Overweight causes heart failure: Large study with new method clarifies the association. ScienceDaily. Retrieved March 24, 2017 from www.sciencedaily.com/releases/2013/06/130625172248.htm
Uppsala Universitet. "Overweight causes heart failure: Large study with new method clarifies the association." ScienceDaily. www.sciencedaily.com/releases/2013/06/130625172248.htm (accessed March 24, 2017).