Independent and joint effects of body mass index and metabolic health in mid- and late-life on all-cause mortality: a cohort study from the Swedish Twin Registry with a mean follow-up of 13 YearsShow others and affiliations
2022 (English)In: BMC Public Health, E-ISSN 1471-2458, Vol. 22, no 1, article id 718
Article in journal (Refereed) Published
Abstract [en]
BACKGROUND: There is robust evidence that in midlife, higher body mass index (BMI) and metabolic syndrome (MetS), which often co-exist, are associated with increased mortality risk. However, late-life findings are inconclusive, and few studies have examined how metabolic health status (MHS) affects the BMI-mortality association in different age categories. We, therefore, aimed to investigate how mid- and late-life BMI and MHS interact to affect the risk of mortality. METHODS: This cohort study included 12,467 participants from the Swedish Twin Registry, with height, weight, and MHS measures from 1958-2008 and mortality data linked through 2020. We applied Cox proportional hazard regression with age as a timescale to examine how BMI categories (normal weight, overweight, obesity) and MHS (identification of MetS determined by presence/absence of hypertension, hyperglycemia, low HDL, hypertriglyceridemia), independently and in interaction, are associated with the risk of all-cause mortality. Models were adjusted for sex, education, smoking, and cardiovascular disease. RESULTS: The midlife group included 6,252 participants with a mean age of 59.6 years (range = 44.9-65.0) and 44.1% women. The late-life group included 6,215 participants with mean age 73.1 years (65.1-95.3) and 46.6% women. In independent effect models, metabolically unhealthy status in midlife increased mortality risks by 31% [hazard ratio 1.31; 95% confidence interval 1.12-1.53] and in late-life, by 18% (1.18;1.10-1.26) relative to metabolically healthy individuals. Midlife obesity increased the mortality risks by 30% (1.30;1.06-1.60) and late-life obesity by 15% (1.15; 1.04-1.27) relative to normal weight. In joint models, the BMI estimates were attenuated while those of MHS were less affected. Models including BMI-MHS categories revealed that, compared to metabolically healthy normal weight, the metabolically unhealthy obesity group had increased mortality risks by 53% (1.53;1.19-1.96) in midlife, and across all BMI categories in late-life (normal weight 1.12; 1.01-1.25, overweight 1.10;1.01-1.21, obesity 1.31;1.15-1.49). Mortality risk was decreased by 9% (0.91; 0.83-0.99) among those with metabolically healthy overweight in late-life. CONCLUSIONS: MHS strongly influenced the BMI-mortality association, such that individuals who were metabolically healthy with overweight or obesity in mid- or late-life did not carry excess risks of mortality. Being metabolically unhealthy had a higher risk of mortality independent of their BMI.
Place, publisher, year, edition, pages
BioMed Central, 2022. Vol. 22, no 1, article id 718
Keywords [en]
Body weight, Metabolic syndrome, Metabolically benign obesity, Metabolically healthy obesity, Mortality, Obesity
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Research subject
Wellbeing in long-term health problems (WeLHP)
Identifiers
URN: urn:nbn:se:his:diva-21070DOI: 10.1186/s12889-022-13082-3ISI: 000780938900003PubMedID: 35410261Scopus ID: 2-s2.0-85128008833OAI: oai:DiVA.org:his-21070DiVA, id: diva2:1653237
Funder
Swedish Research Council, 2016–03081Forte, Swedish Research Council for Health, Working Life and Welfare, 2018–01201NIH (National Institute of Health), AG060470Swedish Research Council, 2017–00,641NIH (National Institute of Health), R01 AG10175NIH (National Institute of Health), R01 AG08724NIH (National Institute of Health), R01 AG08861NIH (National Institute of Health), R01 AG028555NIH (National Institute of Health), U01 DK066134Axel and Margaret Ax:son Johnson FoundationVårdal FoundationForte, Swedish Research Council for Health, Working Life and Welfare, 2013–2292
Note
CC BY 4.0
© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
Correspondence: peggy.ler@outlook.com
Springer Nature
Funding
Open access funding provided by Jönköping University. This work was supported by the Swedish Research Council (2016–03081), the Swedish Research Council for Health, Working Life and Welfare (2018–01201), the National Institutes of Health (NIH AG060470), and the Strategic Research Program in Epidemiology (SfoEpi) at the Karolinska Institutet. We acknowledge the Swedish Twin Registry, managed by Karolinska Institutet and receives funding through the Swedish Research Council under the grant no. 2017–00,641.The sub-studies of the Swedish Twin Registry were supported by the National Institutes of Health (grants R01 AG10175, R01 AG08724, R01 AG08861, R01 AG028555, and U01 DK066134), the MacArthur Foundation Research Network on Successful Aging, the Axel and Margaret Ax:son Johnsons Foundation, the Swedish Research Council, the Swedish Foundation for Health Care Sciences and Allergy Research, and the Swedish Council for Working Life and Social Research (2013–2292). The funding bodies played no role in the design of the study, collection, analysis, and interpretation of the data, and in the writing of the manuscript.
Availability of data and materials
The data that support the findings of this study are from the Swedish Twin Registry. Data can be applied for at https://ki.se/en/research/swedish-twin-registry-for-researchers.
2022-04-212022-04-212023-08-28Bibliographically approved