Gastric Bypass vs Diet and Cardiovascular Risk Factors: A Nonrandomized Controlled Trial

Area of Science:

• Cardiovascular disease
• Metabolic disorders
• Bariatric surgery

Background:

• Roux-en-Y gastric bypass (RYGB) is linked to reduced cardiovascular (CV) risk, but whether this is due to the surgery itself or associated weight loss is debated.
• Understanding the independent effects of RYGB on CV risk factors is crucial for patient management.

Purpose of the Study:

• To compare the 6-week effects of RYGB versus a very low-energy diet (VLED) on cardiovascular risk factors in patients with severe obesity.
• To determine if RYGB confers CV benefits independent of weight loss.

Main Methods:

• A nonrandomized controlled study involving 78 individuals with severe obesity.
• Participants were assigned to either RYGB or a VLED intervention, both preceded by a 3-week low-energy diet (LED).
• Cardiovascular risk factors were assessed at baseline and after 6 weeks of intervention.

Main Results:

• RYGB led to significant reductions in major atherogenic blood lipids (LDL cholesterol, non-HDL cholesterol, apolipoprotein B, lipoprotein[a]) compared to VLED, despite similar fat mass loss.
• Changes in glycemic control and blood pressure were comparable between the RYGB and VLED groups.
• The study included 78 participants (65% women) with a mean age of 47.5 years and high baseline BMI.

Conclusions:

• RYGB demonstrates a significant, independent effect on reducing atherogenic lipids, suggesting a mechanism beyond weight loss for cardiovascular risk reduction.
• These findings highlight potential direct benefits of RYGB on cardiovascular health.