Long-Term Weight Loss and Metabolic Syndrome Remission after Bariatric Surgery: The Effect of Sex, Age, Metabolic Parameters and Surgical Technique - A 4-Year Follow-Up Study.

Introduction: Bariatric surgery is an effective treatment for morbid obesity and its metabolic related comorbidities. However, the literature reports inconsistent results regarding weight loss (WL) and the resolution of comorbidities associated with obesity.

Objective: We aim to evaluate long-term differences in WL between different surgical techniques and the impact of each surgical technique on metabolic parameters (type 2 diabetes mellitus [T2DM], dyslipidemia,hypertension, and metabolic syndrome). We also aim to evaluate the effect of baseline clinical characteristics in WL and in the evolution of metabolic syndrome (MetS) components. Our hypothesis is that different types of surgery have different effects on WL and the prevalence of comorbidities over time.

Methods: We retrospectively evaluated WL and metabolic parameter remission (T2DM, dyslipidemia, hypertension, and MetS) during 4 years in 1,837 morbidly obese patients (females, 85%; age, 42.5 ± 10.6 years; BMI, 44.0 ± 5.8) who underwent bariatric surgery (Roux-en-Y gastric bypass [RYGB], laparoscopic sleeve gastrectomy [LSG], and laparoscopic adjustable gastric band [LAGB]).

Results: The mean percentage of WL for RYGB, LSG, and LAGB was, respectively, 32.9 ± 8.7, 29.8 ± 9.8, and 16.2 ± 9.6 at 12 months and 30.6 ± 9.1, 22.7 ± 10.0, and 15.8 ± 10.8 at 48 months (p < 0.001), even after adjustment for baseline weight, BMI, age, and sex (p < 0.001). Women had more WL during the first 36 months (p = 0.013 and 0.007 at 12 and 36 months, respectively) and older patients had less WL compared to younger ones (p <0.001), except at 48 months. Patients with T2DM had less WL than those without diabetes after adjustment (sex, age, and surgical technique) during the same period. Patients with hypertension had less WL at 12 months (p = 0.009) and MetS at 24 months (p = 0.020) compared to those without these comorbidities. There was no significant difference regarding the presence of dyslipidemia in WL. The RYGB group showed better results for MetS resolution.

Conclusion: During the 4-year follow-up, RYGB was the surgical procedure that caused the highest WL and MetS resolution.