What is the link between obesity and sudden death?

Increased body mass index has been associated with increased risk of sudden cardiac death. For every five unit increase in BMI there is an associated 16% increased risk of SCD. Though the highest risk is among those with high BMI, higher risk has also been noted in those with low BMI, suggesting a J-curve phenomenon. Those with normal BMI have the lowest risk of SCD [1]. Seattle Proportional Risk Model evaluated 9885 patients with heart failure without implantable defibrillators, of whom 2552 died during an average follow-up of 2.3 years. They found that higher body mass index was independently associated with a greater proportional risk of sudden death [2].

Visceral obesity has a stronger risk for SCD than elevated BMI. A 0.1 unit increase in waist hip ratio was associated with 82% increased risk of sudden cardiac death. Increased risk of SCD with visceral obesity is noted in both males and females [3]. Nurses Health Study documented that abdominal obesity was strongly associated with all cause and cardiovascular mortality in addition to increased cancer mortality [4]. Obesity is an important risk factor for SCD independent of conventional cardiovascular risk factors. A study of over ten thousand middle aged subjects found that body mass index of 30 or more was associated with 79% increase in risk of SCD after adjustment for age, gender, smoking, blood pressure, diabetes, cholesterol, baseline cardiac disease and ECG abnormalities [5,6].

References

1. Aune D, Schlesinger S, Norat T, Riboli E. Body mass index, abdominal fatness, and the risk of sudden cardiac death: a systematic review and dose-response meta-analysis of prospective studies. Eur J Epidemiol. 2018 Aug;33(8):711-722. doi: 10.1007/s10654-017-0353-9. Epub 2018 Feb 7. PMID: 29417316; PMCID: PMC6061127.
2. Shadman R, Poole JE, Dardas TF, Mozaffarian D, Cleland JG, Swedberg K, Maggioni AP, Anand IS, Carson PE, Miller AB, Levy WC. A novel method to predict the proportional risk of sudden cardiac death in heart failure: Derivation of the Seattle Proportional Risk Model. Heart Rhythm. 2015 Oct;12(10):2069-77. doi: 10.1016/j.hrthm.2015.06.039. Epub 2015 Jun 30. PMID: 26142301.
3. Aune D, Schlesinger S, Norat T, Riboli E. Body mass index, abdominal fatness, and the risk of sudden cardiac death: a systematic review and dose-response meta-analysis of prospective studies. Eur J Epidemiol. 2018 Aug;33(8):711-722. doi: 10.1007/s10654-017-0353-9. Epub 2018 Feb 7. PMID: 29417316; PMCID: PMC6061127.
4. Zhang C, Rexrode KM, van Dam RM, Li TY, Hu FB. Abdominal obesity and the risk of all-cause, cardiovascular, and cancer mortality: sixteen years of follow-up in US women. Circulation. 2008 Apr 1;117(13):1658-67. doi: 10.1161/CIRCULATIONAHA.107.739714. Epub 2008 Mar 24. PMID: 18362231.
5. Holmstrom L, Junttila J, Chugh SS. Sudden Death in Obesity: Mechanisms and Management. J Am Coll Cardiol. 2024 Dec 3;84(23):2308-2324. doi: 10.1016/j.jacc.2024.09.016. Epub 2024 Nov 6. PMID: 39503654.
6. Eranti A, Aro AL, Kerola T, Tikkanen JT, Rissanen HA, Anttonen O, Junttila MJ, Knekt P, Huikuri HV. Body Mass Index as a Predictor of Sudden Cardiac Death and Usefulness of the Electrocardiogram for Risk Stratification. Am J Cardiol. 2016 Feb 1;117(3):388-93. doi: 10.1016/j.amjcard.2015.10.057. Epub 2015 Nov 18. PMID: 26723105.