The Short-Term Effects of Roux-en-Y Gastric Bypass on Renal Excretion of Sodium and Its Association with Blood Pressure

Effect of Bariatric Surgery on Flow-Mediated Vasodilation as a Measure of Endothelial Function: A Systematic Review and Meta-Analysis

Objectives. Flow mediated vasodilation (FMD) is a marker of endothelial function and its decline is related to increased cardiovascular risk. This systematic review and meta-analysis evaluated the impact of bariatric surgery on FMD. Materials and methods. A systematic literature search in PubMed, Scopus, Embase, and Web of Science was performed to 1 May 2021. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. All types of bariatric surgery were considered, with the inclusion that FMD had to have been tested before and after the surgical procedure. Meta-analysis was carried out using a random-effects model and the generic inverse variance approach. The leave-one-out approach was used for sensitivity analysis. To assess metabolic parameter confounders, a weighted random-effects meta-regression was used. Results. A meta-analysis and a systematic review of 23 studies (n = 891 individuals) demonstrated improvement in FMD following bariatric surgery (weighted mean difference (WMD): 5.867, 95% CI: 4.481, 7.252, p < 0.001; I2: 96.70). Iteratively removing each item in the meta-analysis did not result in a significant alteration in the pooled estimate of effect size. There was an improvement in FMD for up to 6 months following bariatric surgery in a meta-analysis from 7 trials that included 356 subjects (WMD: 5.248, 95% CI: 2.361, 8.135, p < 0.001; I2: 98.18). The meta-analysis from 9 trials (n = 414 subjects) showed an improvement in FMD 6 to 12 months after bariatric surgery (WMD: 5.451, 95% CI: 3.316, 7.587, p < 0.001; I2: 94.18). The meta-analysis from 10 trials (n = 414 subjects) demonstrated an improvement in FMD 12 months after bariatric surgery (WMD: 2.401, 95% CI: 0.944, 3.859, p = 0.001; I2: 88.35). Random-effects meta-regression did not show any association between the alteration in FMD and percent body mass index (BMI) change (slope: 0.0258; 95% CI: −0.323, 0.375; p = 0.884), or changes in blood pressure; however, there was an association between the changes in FMD and the duration of follow-up (slope: −0.106; 95% CI: −0.205, −0.008; p = 0.033) with greater changes in FMD after 12 months. Conclusions. Bariatric surgery significantly improved FMD that increased with time, and the resultant improvement in endothelial function was independent of weight loss or a reduction in blood pressure.

Changes in Antihypertensive Medication Following Bariatric Surgery

Obesity is a leading cause of hypertension (i.e., high blood pressure [BP]). While hypertension can be managed with antihypertensive medication, substantial weight loss can also lower BP, reducing the need for antihypertensive medication. Articles in this review (n = 60) presented data on antihypertensive medication use among adults pre- and postoperatively. Roux-en-Y gastric bypass was the most studied surgical approach followed by Laparoscopic Sleeve Gastrectomy. Antihypertensive medication was discontinued in a large proportion of patients after surgery, and the mean number of antihypertensive medications decreased by approximately one. In almost a third of the studies, over 75% of participants experienced hypertension remission. All articles aside from two reported a decrease in systolic BP, with about 40% reporting a decrease of ≥ 10 mm Hg.

The Impact of Bariatric Surgery Versus Non-Surgical Treatment on Blood Pressure: Systematic Review and Meta-Analysis

The purpose of this study was to compare bariatric surgery versus non-surgical treatment on blood pressure for patients with obesity. Nineteen RCTs (1353 total patients) were included. In the pooled analyses, bariatric surgery reduces more systolic blood pressure (WMD: - 3.937 mmHg, CI95%: - 6.000 to - 1.875, p < 0.001, I² = 0%), diastolic blood pressure (WMD: - 2.690 mmHg, CI95%: - 3.994 to - 1.385, P < 0.001, I² = 0%) and more antihypertensives. In subgroup analyses, patients after Roux-en-Y gastric bypass, with poor control of hypertension (BP > 130/80 mmHg) and diabetes mellitus (HbA1C > 7.0%, FPG > 7.0 mmol/L), elder patients (> 45 years), non-severe obesity (BMI < 40 kg/cm², body weight < 120 kg), less waist circumference (< 115 cm) tend to decrease more blood pressure. Besides, patients after surgery also lost more weight (p < 0.001), decreased more waist circumference (p < 0.001), fasting plasma glucose (p < 0.001), glycosylated hemoglobin (p < 0.001), triglycerides (p < 0.001), hsCRP (p = 0.001), increased more high-density lipoprotein cholesterol (p < 0.001), and had better remission of metabolic syndrome (p < 0.001). Changes in total cholesterol, low-density lipoprotein cholesterol, renal function, resting heart rate, and 6-min walking test were not significantly different. Therefore, bariatric surgery is more effective than non-surgical treatment in controlling patients' blood pressure.

Characteristics and resolution of hypertension in obese African American bariatric cohort

Weight reduction continues to be first-line therapy in the treatment of hypertension (HTN). However, the long-term effect of bariatric malabsorptive surgical techniques such as Roux-en-Y Gastric Bypass (RYGB) surgery in the management of hypertension (HTN) is less clear. African Americans (AA) are disproportionately affected by obesity and hypertension and have inconsistent outcomes after bariatric surgery (BS). Despite a plethora of bariatric literature, data about characteristics of a predominantly AA bariatric hypertensive cohort including hypertension in obese (HIO) are scarce and underreported. The aims of this study were, (1) to describe the preoperative clinical characteristics of HIO with respect to HTN status and age, and (2) to identify predictors of HTN resolution one year after RYGB surgery in an AA bariatric cohort enrolled at the Howard University Center for Wellness and Weight Loss Surgery (HUCWWS). In the review of 169 AA bariatric patients, the average BMI was 48.50 kg/m2 and the average age was 43.86 years. Obese hypertensive patients were older (46 years vs. 37.89 years; p < .0001); had higher prevalence of diabetes mellitus (DM, 43.09% vs. 10.87%; p < .0001) and dyslipidemia (38.2% vs. 13.04%; p 0.002). Hypertensive AA who were taking ≥ 2 antihypertensive medications prior to RYGB were 18 times less likely to experience HTN resolution compared to hypertensive AA taking 0-1 medications, who showed full or partial response. Also, HIO was less likely to resolve after RYGB surgery in patients who needed ≥ 2 antihypertensive medications prior to surgical intervention.