Long-term mortality after bariatric surgery versus matched controls: a National Health and Nutrition Examination...

While bariatric surgery reduces short-term mortality and improves metabolic outcomes, less is known about the long-term causes of death in patients who undergo these procedures. Understanding these outcomes is critical for long-term care and risk counseling.

To identify any shifts in the long-term causes of death among bariatric surgery patients in the United States and compare these to matched nonsurgical controls, as well as to obese and normal-weight individuals in the general population.

United States; National Health and Nutrition Examination Survey (NHANES) Linked Mortality Files.

We analyzed data from NHANES 2005 to 2018 linked to the National Death Index through 2019. Individuals with self-reported bariatric surgery were matched to controls by age, sex, and body mass index (BMI). We excluded deaths occurring within 1 year of survey participation. Causes of death were classified by International Classification of Diseases Version 10 (ICD-10) categories. Descriptive statistics and survival trends were analyzed.

Among 435 bariatric patients and 1740 controls, there were 87 and 212 long-term deaths, respectively. The leading causes of death in the bariatric group were cardiovascular disease (30%), cancer (21%), and diabetes (9%). Compared to controls, bariatric patients had proportionally higher rates of suicide (6.6%) and liver disease (8.5%). In contrast, diabetes-related deaths occurred in 5.7% of bariatric patients compared to 9.8% in controls. Bariatric patients had a three times higher risk of death from suicide (standardized mortality ratios [SMRs] 3.33; 95% confidence interval (CI), 1.08-7.78) and a higher risk of death from liver disease (SMR 3.00; 95% CI, 1.10-6.53) compared to matched controls. Diabetes-related mortality was also markedly elevated (SMR 2.00; 95% CI, .86-3.94).

Long-term causes of death after bariatric surgery remain primarily cardiovascular and oncologic, but higher rates of suicide and liver-related mortality highlight the need for targeted follow-up and psychosocial care.