Is there any difference in lipid profile between patients on a diet vs patients on the same diet after RYGB surgery? Turns out there is a difference!!
The interesting “COCKTAIL” study compared the effects of Roux-en-Y gastric bypass (RYGB) surgery plus diet versus a very low-energy diet (VLED) alone on cardiovascular risk factors in severely obese patients.
Here’s a summary:
Objective: The study aimed to determine if improvements in cardiovascular risk factors after RYGB are due to the surgery or just weight loss.
Design and Participants: The study was conducted at a Norwegian obesity center and included individuals preparing for RYGB or VLED. Both groups initially underwent a 3-week low-energy diet (LED) phase, followed by either RYGB or continuing VLED for 6 weeks.
Interventions: RYGB group: Received RYGB followed by 6 weeks of VLED. VLED group: Received VLED alone for 6 weeks. Main Findings: Both groups showed similar reductions in fat mass, though RYGB resulted in slightly more significant initial weight loss. RYGB significantly reduced major atherogenic blood lipids (LDL, non-HDL, apolipoprotein B, lipoprotein[a]) compared to VLED despite similar fat mass loss. Glycemic control and blood pressure improvements were identical in both groups, suggesting weight loss as the primary driver. RYGB led to specific changes in lipid metabolism and bile acid circulation, potentially contributing to reduced cardiovascular risk beyond weight loss alone.
Conclusions: The study suggests that RYGB may offer cardiovascular benefits beyond weight loss, as evidenced by significant reductions in atherogenic blood lipids. RYGB reduced major atherogenic blood lipids at 6 weeks, while VLED did not show the same decrease despite similar fat mass loss. While the calorie amount was the same, pt in the bariatric group showed significantly better lowering of the LDL lipids. Both groups improved in HbA1c, with no differences in changes between groups in HbA1c, insulin sensitivity (HOMA2%S), and blood pressure. Significant metabolic improvements were seen in both groups during the initial 3-week LED period.
Study link: https://jamanetwork.com/journals/jamasurgery/fullarticle/2820786