Bariatric surgery in obese subjects with hypertension results in improved BP outcomes
Effects of Bariatric Surgery Versus Medical Therapy on the 24-Hour Ambulatory Blood Pressure and the Prevalence of Resistant Hypertension The GATEWAY Randomized Clinical Trial
Introduction and methods
Observational studies have suggested that bariatric surgery results in CV benefit by reducing blood pressure (BP) [1-3]. However, there are gaps in the literature on this subject as most cohorts and intervention studies focused on diabetes and metabolic variables as primary outcomes. In addition, data is limited to office BP measurements in patients with grade 3 obesity. Recently, the Gastric Bypass to Treat Obese Patients With Steady Hypertension (GATEWAY) trial showed that Roux-en-Y gastric bypass (RYGB) combined with medical therapy (MT) resulted in greater reduction of total number of antihypertensive medications as well as higher number of patients with hypertension remission at 12 months, compared to the MT alone .
The GATEWAY trial is a randomized, nonblinded, single-center, clinical trial that enrolled 100 patients aged 18 to 65 years, body mass index ranging from 30.0 to 39.9 kg/m², with established hypertension treated with ≥2 antihypertensive drugs at maximum doses or >2 drugs at moderate doses. Subjects were randomized to either RYGB combined with MT (50 patients) or MT alone (50 patients).
In this substudy of the GATEWAY trial, a more detailed analysis was performed with assessment of 24-hour ambulatory BP monitoring (ABPM), including nondipping status and BP variability, and prevalence of resistant hypertension (RH) at 12 months follow-up was analyzed. Variability of office systolic and diastolic BP were calculated with 3 collected measurements using the SD. For ABPM variability, average real variability (ARV) was calculated. ARV is a useful predictor of outcomes, with higher values of ARV associated with worse outcomes .
- 24-hour ABPM profile was similar after 12 months in both groups, but the RYGB group required less antihypertensive classes as compared to the MT (0 [0–1] vs 3 [2.5–4] classes; P<0.001).
- After 12 months, no significant differences in the SD office BP were observed between the 2 groups, but the RYGB group had a lower ARV of the systolic nighttime BP compared with the MT (between-group difference −1.63; 95%CI: −2.91 to −0.36; P=0.01).
- Rate of nondipping BP did not change significantly during the follow-up, despite less need of antihypertensive treatment.
- Prevalence of RH decreased from 10 to 0% after 12 months in the RYGB group and number of patients with RH remained stable in the MT group (16 vs 14.9%).
RYGB resulted in similar 24-hour ABPM profile and rate of nondipping compared to MT alone, but the RYGB group required less antihypertensive classes. In addition, RYGB improved BP variability and resulted in a reduction of patients with resistant hypertension. This study suggests that bariatric surgery is a promising additive treatment to improve BP control in obese patients with hypertension.