In resistant hypertension, a 4-month supervised diet and exercise programme resulted in a significant reduction in systolic blood pressure.
According to the American Heart Association, resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of three anti-hypertensive drug classes. The prevalence of RH has been estimated at 10.3% in the general population of anti-hypertensive treated patients, but rises among those with cardiovascular risk factors such as chronic kidney disease (22.9%) and the elderly (12.5%). Management of RH is important, especially given how one study identified how the condition was associated with a 47% increased risk of adverse cardiovascular events compared to controlled patients.
Both exercise and diet appear to play an important role in RH, although the evidence is limited. For example, an aerobic exercise programme in patients with RH reduced both systolic and diastolic pressure but the study included only 50 patients. Similarly, adoption of a low salt diet also reduced overall blood pressure in those with RH, but again, the study included only 12 patients.
This led a team from the Department of Psychiatry and Behavioural Sciences, Duke University, North Carolina, US, to set up the Treating Resistant Hypertension Using Lifestyle Modification to Promote Health (TRIUMPH) trial to examine the effect of diet and exercise on blood pressure control in those with resistant hypertension. The TRIUMPH study randomised patients to one of two arms: a Center-Based Lifestyle intervention (C-LIFE) or Standardised Education and Physician Advice (SEPA) for a 4-month period. The C-LIFE intervention included advice from a nutritionist, weekly group counselling together with behavioural weight management and a three-times weekly exercise session. Participants in the SEPA arm received a 1-hour educational session and blood pressure management diet programme and the same exercise prescription. In other words, both arms were the same except for the higher intensity of the intervention in the C-LIFE arm. Included participants had RH for at least 6 weeks with a clinic systolic blood pressure (SBP) > 130mmHg or diastolic blood pressure (DBP) > 80mmHg, or the need for four or more drugs with a SBP > 120mmHg. The primary outcome measure was the clinic SBP with secondary outcomes including ambulatory SBP and DBP. Other measures included baroreflex sensitivity (which is a measurement to quantify how much control the baroreflex has on the heart rate), high-frequency heart rate variability and flow-mediated dilation.
A total of 140 RH patients with a mean age of 63 years (48% female) were randomised to C-LIFE (90) or SEPA (50). The mean baseline SBP was 139mmHg and the diastolic 79mmHg. C-LIFE participants experienced a lower clinic SBP compared with those assigned to SEPA (126mmHg vs 132.8mmHg, p = 0.005). Similarly, mean DBP levels were significantly lower (73.2mmHg vs 75.6mmHg, p = 0.034). Ambulatory blood pressure measurements were also significantly reduced for C-LIFE but did not change among SEPA patients. In addition, C-LIFE participants had greater improvements in resting baroreflex sensitivity, high-frequency heart rate variability and flow-mediated dilation.
In their conclusion, the authors suggested that the results provided support for the value of an intensive, structured intervention to improve blood pressure in those with treatment resistant hypertension. They added that policymakers should consider RH as a new indication for cardiac rehabilitation that should be covered by government and private insurers.
Blumenthal JA et al. Effects of Lifestyle Modification on Patients With Resistant Hypertension: Results of the TRIUMPH Randomized Clinical Trial. Circulation 2021