High post-bariatric weight loss and male sex associated with better chance of hypertension remission

There is an association between high postoperative weight loss and male sex with better chance of hypertension remission, while there is a lower chance of remission depending on disease severity and presence of other metabolic comorbidities, according to researchers from Sweden. The findings were published in the paper, ‘Remission, relapse, and risk of major cardiovascular events after metabolic surgery in persons with hypertension: A Swedish nationwide registry-based cohort study’, published in PLOSOne.

The authors noted that duration of diabetes, glycaemic control, use of insulin, age and postoperative weight loss have all been shown to be associated with the chance of diabetes remission. However, in terms of hypertension, this has been less studied. Several studies have reported that metabolic surgery and pharmacologically treated hypertension is associated with lower risk for major adverse cardiovascular events (MACEs) and all-cause mortality (compared with age- and sex-matched controls with hypertension from the general population) Although the impact of postoperative remission of hypertension is not clear.


Therefore, this study sought to assess which factors are associated with remission and relapse of hypertension after metabolic surgery and compare the risk of MACE and mortality in patients with and without subsequent remission of their hypertension.

The primary outcome was remission of pharmacological treatment of hypertension defined as no prescribed antihypertensive drugs for one entire year, 18 to 30 months after surgery. Secondary outcomes included all-cause mortality and MACEs, defined as the first occurrence of unstable angina, myocardial infarction, acute cerebrovascular event, fatal cardiovascular event or unattended sudden cardiac death


Using data from the Scandinavian Obesity Surgery Registry (SOReg) 52,396 patients were identified and after excluding of patients with heart failure, atrial fibrillation and tachycardia, and patients without hypertension at baseline, 15,984 remained in the study.


Outcomes

Follow-up for 30-day complications was 98.7% (n = 15,778). The follow-up rate for weight loss was 89.7% (n=14,332) at one year and 59.8% (n=9,559) at two years after surgery. All patients were followed for mortality and the use of prescribed drugs until the end of the study. Mean follow-up time was 6.5 ± 2.3 years.


Mean BMI loss one year after surgery was 12.6±4.0 kg/m2, with TWL 29.6±7.8% and EBMIL 76.2± 23.0%. Mean BMI loss two years after surgery was 12.7±4.6 kg/m2, with TWL 29.9±9.1% and EBMIL 76.7 ± 24.8%. The mean BMI loss one year after surgery was 12.8±3.9 kg/m2 versus 9.9±4.2 kg/m2, with TWL 30.0±7.6% versus 24.2±8.7%, and EBMIL 76.8±22.5% versus 67.5±27.1% for gastric bypass and SG, respectively (p<0.001). Mean BMI loss at two years after surgery was 12.9±4.5 kg/m2 vs 9.1±4.7 kg/m2, TWL 30.3±8.9% versus 22.6±10.1%, and EBMIL 77.3 ± 24.3% versus 63.3 ± 30.7%, % for gastric bypass and SG, respectively (p<0.001).


At two years after surgery, 6,286 patients (39.3%) had been taken off their pharmacological treatment for hypertension. The duration of disease, number of antihypertensive drugs, age, BMI, dyslipidaemia, and cardiovascular disease were all associated with a lower remission rate, while higher postoperative weight loss and male sex were associated with a higher chance of reaching remission. The number of antihypertensive medications was reduced from a median of two before surgery to a median of one after surgery (p < 0.001). A reduction of at least 30% of the numbers of antihypertensive drugs was seen in 10,290 patients (64.9%) at two years after surgery.


Of the 6,286 patients who initially reached hypertension remission, relapse occurred in 2,089 patients within ten years (cumulative probability 56.3 ± 2.4%) (Figure 1). The duration of disease, number of antihypertensive drugs, age, and SG were all associated with a higher risk for relapse, while higher postoperative weight loss was associated with a lower risk for relapse, the authors reported.

Figure 1: Relapse-free survival for patients experiencing remission of hypertension at two years after metabolic surgery (unadjusted Kaplan–Meier curve)

At eight years after surgery, MACEs had occurred for 90 patients who initially reached hypertension remission vs 366 patients who did not reach hypertension remission. Ten years after surgery, 115 patients who initially reached hypertension remission had died vs 345 patients who did not reach hypertension remission.


“Metabolic surgery is associated with a significant degree of remission of hypertension with a high postoperative weight loss and male sex being associated with better chance of remission, while age, disease severity, and presence of other metabolic comorbidities being associated with lower chance,” the authors concluded. “Although more than half of the patients relapse within ten years after surgery, the risks for MACE and mortality are markedly reduced compared with those who do not achieve remission at two years. Taken together, this suggests that in patients with severe obesity and hypertension, metabolic surgery should not be delayed.”


Further information

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