Clinical effectiveness of stress-reduction techniques in patients with hypertension: systematic review and meta-analysis

Objective: A systematic review and meta-analysis focusing on patient-relevant outcomes and blood pressure was conducted to assess the clinical effectiveness of stress-reduction techniques in adults with essential hypertension. Methods: Systematic reviews and randomized controlled trials (RCTs) were identified as part of a systematic search in six electronic databases ending September 2012. RCTs comparing stress-reduction techniques versus no such techniques with a follow-up of at least 24 weeks and published in English or German were included. Outcomes of interest were death, cardiovascular morbidity/mortality, end-stage renal disease, health-related quality of life, adverse events, changes in blood pressure, and changes in antihypertensive medication. When appropriate, meta-analyses were used to combine data. Results: Seventeen RCTs analyzing different stress-reduction techniques such as biofeedback, relaxation or combined interventions were identified. Data were not reported for most of the patient-relevant outcomes, and meta-analyses could only be used to evaluate effects on blood pressure. The data indicated a blood pressure-lowering effect, but the studies had methodological shortcomings and heterogeneity between them was high. Mean group differences for DBP ranged from -10 to 1mmHg and for SBP from -12 to 10 mmHg. In terms of antihypertensive medication, no favorable effects of stress-reduction techniques could be identified. Conclusions: The available RCTs on stress-reduction techniques used for at least 24 weeks appeared to indicate a blood pressure-lowering effect in patients with essential hypertension, but this should be interpreted with caution because of major methodological limitations. A benefit of specific stress-reduction techniques in hypertensive patients remains unproven.