Early Improvements in Blood Lipid Profile and Vascular Alterations after Gastric Bypass Surgery Prior to Dramatic Weight Loss

Abstract

With 6.6% of adults in the U.S. classified as morbidly obese, excess bodyweight is now the sixth most significant risk factor contributing to the overall burden of disease, emerging as one of the most serious public health concerns in the 21st century. Bariatric surgery has been shown to eliminate comorbid conditions associated with obesity. The aim of this study is to evaluate the effect of weight reduction following laparoscopic Roux‐en Y gastric bypass (RYGB) on remodeling and improvements in arterial function, in addition to immediate reversal of metabolic deviations as weight is lost.Patients that meet protocol inclusion criteria are invited to join the study during their 1 week pre‐operative clinical appointment. At this time patients are consented and instructed to lie supine for 10 minutes of quite relaxation. Patients then begin a sequence of non‐invasive examinations starting with a 12‐lead electrocardiogram, followed by an echocardiogram, carotid artery ultrasound, radial applanation tonometry, and endothelial function analysis using EndoPAT technology. Upon completion of the non‐invasive procedures a fasting blood sample is taken for analysis.Preliminary findings show that RYGB results in significant body weight reduction (pre: 131.8 ±5.6 to post: 125 ±5.2 kg) in morbidly obese subjects, along with reductions in BMI (pre: 45.2 ±2.3 to post: 42.9 ± 2.2) and waist circumference (pre: 122.1 ±5.0 to post: 111.9 ± 3.2 cm) at the 1‐week time point. Decrease in body size and weight was aided by a reduction in low‐density lipoprotein (pre: 127 ±6.2 to post: 113 ±4.5 mg/dL), as well as suggested decreases in glucose levels. Such changes can be associated with an improvement of the lipid and glucose metabolism. However, these results appear before subjects have lost a substantial amount of weight (one week post‐operative), suggesting that noteworthy cardiovascular improvements post‐RYGB are achieved prior to the hypothesized weight‐related change. In addition, a number of improvements to the cardiovascular system were also marked at the 1‐week time point. Estimated left ventricular end systolic pressure and direct measure of left ventricular end systolic volume (pre: 66 ±4 to post: 55 ±3 mmHg) declined post‐GBS with an array of additional markers supporting alterations in central systolic blood pressure and myocardial oxygen demand. The data suggests that vascular changes are happening in the early stages of recovery, prior to dramatic weight loss, thus suggesting vascular modifications are a result of an alternate surgical benefit.