Intensive BP management reduces CVD deaths in overweight, obese patients
“[H]ypertension in patients with different body types may be mediated by different mechanisms,” the researchers said. “In patients receiving intensive systolic BP (SBP) management, the relationship between the body mass index (BMI) and cardiovascular outcomes was U-shaped.”
Data from the Systolic Blood Pressure Intervention Trial (SPRINT) was used in this study. The researchers analysed these data using Cox proportional hazards models. Cardiovascular disease (CVD) death was the primary endpoint, while serious adverse events were the safety endpoint.
A total of 9,284 patients were included in the analysis: 37 in the intensive arm and 65 in the standard arm had CVD death. [J Hypertens 2022;40:878-887]
After multivariable adjustment, BMI did not show an association with the incidence of CVD death in the standard arm (hazard ratio [HR], 0.96, 95 percent confidence interval [CI], 0.91‒1.02). The incidence of CVD death in the intensive arm decreased (HR, 0.86, 95 percent CI, 0.78‒0.96) initially before rising (HR, 1.15, 95 percent CI, 1.07‒1.25), with an increase in the BMI (inflection point, 32.33 kg/m2).
“We found that intensive BP management in overweight, class I, and class II obese patients significantly reduced the cardiovascular outcomes without increasing the incidence of serious adverse events,” the researchers said. “However, intensive BP management did not reduce the incidence of cardiovascular outcomes among patients with normal weight or class III obesity.”
Mechanisms of hypertension
Of note, increased plasma volume and cardiac output, instead of dysregulation of vasoconstriction, are the main mechanisms that result in hypertension among obese patients. [Circulation 1985;72:53-60; Am J Med 1983;74:808-812]
In lean patients, however, hypertension appears to be associated with cardiovascular outcomes that are more responsive to routine stimulation by neuroendocrine mechanisms, particularly the sympathetic and renin‒angiotensin systems. [J Am Coll Cardiol 2001;37:169-174]
“Especially, the pathological mechanisms leading to hypertension may be different in patients with different body types, and the relationship between the CVD death risk and the BMI was different in patients of the intensive arms and standard arms,” the researchers said.
In the present study, patients with normal weight and those with class III obesity who received intensive BP management did not have a reduced incidence of cardiovascular outcomes.
In normal-weight patients with hypertension, sympathetic activation was persistent, which was harmful to the body but was not seen in obese hypertensive patients. This could possibly explain why intensive BP management failed to reduce the incidence of cardiovascular events in patients with normal weight. [Hypertension 2018;71:22-33]
Furthermore, extreme obesity could heighten the incidence of cardiovascular outcomes, with patients having an elevated risk of coronary atherosclerotic heart disease and related cardiovascular risk factors. [Eur Heart J 2013;34:345-353; N Engl J Med 2014;370:233-244]
“Therefore, it is still worth considering whether these patients need intensive BP management, or whether a more appropriate BP target is needed for this group of patients,” the researchers said.
“[F]urther clinical evidence is needed to verify the effectiveness of intensive BP management in patients with normal weight and class III obesity,” they noted.