Substantial intentional weight loss and mortality in the severely obese

OBJECTIVE: To compare all-cause mortality in a surgical weight loss cohort with a similarly aged, obese population-based cohort. SUMMARY BACKGROUND DATA: Significant weight loss following bariatric surgery improves the comorbidities associated with obesity. Improved survival as a result of surgical weight loss has yet to be clearly demonstrated using clinical data. METHODS: The surgical weight loss cohort was a series of consecutive patients treated with a laparoscopic adjustable gastric band in Melbourne between June 1994 and April 2005. The Melbourne Collaborative Cohort Study (MCCS) provided a community control cohort, recruited between 1992 and 1994 and followed to June 2005 to determine vital status. Height and weight were recorded at baseline in both studies. Subjects between 37 and 70 years and with a body mass index (BMI) of > or =35 were included. Vital status was determined by follow-up and searching of death registries. Survival time was compared using Kaplan-Meier estimates, and hazard of death was determined using Cox regression, adjusting for sex, age at baseline, and BMI at baseline. RESULTS: Of 966 weight loss patients (mean age 47 years, mean BMI 45 kg/m), the median follow-up time was 4 years. Mean weight loss after 2 years was 22.8% +/- 9% (58% of excess weight). The MCCS cohort included 2119 severely obese members (mean age, 55 years; mean BMI, 38 kg/m; median follow-up time, 12 years). There were 4 deaths in the weight loss cohort and 225 deaths in the MCCS cohort. Weight loss patients had 72% lower hazard of death than the community control cohort (hazard ratio, 0.28; 95% confidence interval, 0.10-0.85). CONCLUSIONS: Substantial surgical weight loss in a morbidly obese population was associated with a significant survival advantage.