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Effects of obesity surgery on overall and disease-specific mortality in a 5-country, population-based study

Research output: Contribution to journalArticle

Kauppila JH, Tao W, Santoni G, von Euler-Chelpin M, Lynge E, Tryggvadóttir L, Ness-Jensen E, Romundstad P, Pukkala E, Jesper Lagergren

Original languageEnglish
Pages (from-to)119-127.e1
Issue number1
Early online date30 Mar 2019
Accepted/In press25 Mar 2019
E-pub ahead of print30 Mar 2019
Published1 Jul 2019


King's Authors


Background & Aims Bariatric surgery might reduce overall mortality from obesity. We investigated whether survival times of patients who have undergone bariatric surgery are similar to those of the general population levels and are longer than in obese individuals who did not receive surgery. Methods We performed a population-based cohort study of persons with a diagnosis of obesity listed in nationwide registries from Nordic countries, from 1980 through 2012. Bariatric surgery was analyzed in relation to all-cause mortality and the obesity-related morbidities cardiovascular disease, diabetes, cancer, and suicide. Poisson models provided standardized mortality ratios (SMRs) with 95% CIs. Multivariable Cox regression provided hazard ratios (HRs) for mortality in operated and non-operated participants. Results Among 505,258 participants, 49,977 underwent bariatric surgery. Overall all-cause SMR was increased after surgery (1.94; 95% CI, 1.83–2.05) and increased with longer follow up, to 2.28 (95% CI, 2.07–2.51) ≥15 years post-surgery. SMRs were increased for cardiovascular disease (2.39; 95% CI, 2.17–2.63), diabetes (3.67; 95% CI, 2.85–4.72), and suicide (2.39; 95% CI, 1.96–2.92), but not for cancer (1.05; 95% CI, 0.95–1.17); SMRs increased with time. In non-operated obese participants, all-cause SMR was 2.15 (95% CI, 2.11–2.20), which remained stable during follow up. Compared to non-operated obese participants, patients who underwent bariatric surgery had decreased overall mortality from all causes (HR, 0.63; 95% CI, 0.60–0.66), cardiovascular disease (HR, 0.57; 95% CI, 0.52–0.63), and diabetes (HR, 0.38; 95% CI, 0.29–0.49), but increased mortality from suicide (HR, 1.68; 95% CI, 1.32–2.14). Cancer mortality was decreased overall (HR, 0.84; 95% CI, 0.76–0.93), but increased ≥15 years of follow up (HR, 1.20; 95% CI, 1.02–1.42). Conclusions In a study of persons with a diagnosis of obesity listed in nationwide registries of Nordic countries, we found that obese patients who undergo bariatric surgery have longer survival times than non-operated obese individuals, but their mortality is higher than that of the general population and increases with time. Obesity-related morbidities could account for these findings.

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