Short-term effects of gastric bypass versus sleeve gastrectomy on high LDL cholesterol: The BASALTO randomized clinical trial

Abstract

Background: There has been a substantial increase in the use of laparoscopic sleeve gastrectomy (SG) to treat morbid obesity despite observational evidence demonstrating the superiority of Roux-en-Y gastric bypass (RYGB) for reducing low-density lipoprotein (LDL) cholesterol. The main aim was to ascertain whether high LDL cholesterol levels should be considered when selecting the most appropriate surgical procedure for each patient (RYGB or SG).

Methods: In this single-center, randomized clinical trial using intention-to-treat analysis, 38 patients with severe obesity and elevated levels of LDL cholesterol were randomly assigned to undergo RYGB or SG. The primary outcome was LDL cholesterol remission at 12 months, defined as LDL cholesterol < 3.36 nmol/l without lipid-lowering medications. Secondary outcomes included changes in weight, other comorbidities, qualitative lipoprotein traits, cholesterol esters, glycoproteins, cholesterol absorption and synthesis metabolites and complications.

Results: Intention-to-treat analysis revealed that LDL cholesterol remission occurred in 66.6% of RYGB patients compared to 27.8% of SG patients (p = 0.019). Among patients completing follow-up, RYGB demonstrated superior remission (80.0% vs. 29.4%, p = 0.005). Exclusive benefits of RYGB included a reduction in large, medium, and small LDL particles. Cholesterol absorption markers showed differential behavior after both techniques: campesterol (Δ -15.2 µg/mg, 95% CI -30.2 to -0.1) decreased after RYGB, and sitosterol (Δ 21.1 µg/mg, 95% CI 0.9 to 41.2), cholestanol (Δ 30.6 µg/mg, 95% CI 14.8 to 57.9) and campesterol (Δ 18.4 µg/mg, 95% CI 4.4 to 32.3) increased after SG. No differences in weight loss, cholesterol esters, glycoproteins, cholesterol synthesis metabolites or postoperative complications were observed between techniques.

Conclusion: In conclusion, RYGB is superior to SG in terms of short-term of high LDL cholesterol remission. Furthermore, RYGB also led to a greater improvement in lipoprotein parameters that confer an atherogenic profile. Therefore, the presence of elevated levels of LDL cholesterol should be considered when determining the optimal bariatric surgery procedure for each patient.

Trial registration: Clinicaltrials.gov number, NCT03975478).

Keywords: Bariatric surgery; Cholesterol esters; Hypercholesterolemia; LDL cholesterol; Lipoprotein; Roux-en-Y gastric bypass; Sleeve gastrectomy.

Fig. 1

Study flow chart

Fig. 2

Primary endpoint (LDL cholesterol remission) and secondary outcomes related to LDL cholesterol. The differences in high LDL cholesterol remission (Fig. 2A) were determined using a chi-square test. Figure 2B and D show changes observed during follow-up. Negative values indicate a reduction, whereas positive values indicate an increase.  Data are expressed as the means with 95% confidence intervals. The p value refers to the comparison between groups at each time interval. The changes in these parameters were analyzed using repeated-measures ANOVA ( p  < 0.05) adjusted for baseline triglycerides.  LDL, low-density lipoprotein

Fig. 3

Changes in the percentage of excess weight loss (A) and percentage total weight loss (B). Data are expressed as the means ± standard deviations. Significance at p < 0.05 was determined using repeated-measures ANOVA

Fig. 4

Changes in cholesterol absorption and synthesis markers with RYGB and SG