Gender and Risk Subgroup Analysis

Reference

Alexander, C.N., Schneider, R.H., Clayborne, M., Sheppard, W., Staggers, F., Rainforth, M., Salerno, J., Kondwani, K., Smith., Walton, K.G. and Egan, B.A trial of stress reduction for hypertension in older African Americans (Part II): Gender and risk subgroup analysis. Hypertension 28(2), pp. 228-237, 1996.

Summary

Objective: To test for the short-term efficacy and feasibility of two stress reduction approaches for the treatment of hypertension in older African Americans of: 1) different genders and 2) high and low risk for five hypertension risk factors including psychological stress, obesity, alcohol use, low exercise level and high sodium/potassium ratio.

Design: Follow-up subgroup analysis of a randomized controlled, single-blind trial of three months duration.

Setting: Primary care, inner city health center.

Participants: Of 213 African American men and women screened, 127 individuals, aged 55-85 years with initial diastolic blood pressure of 90-109 mm Hg and systolic blood pressure of ¾189 mm Hg and final baseline blood pressure of ¾179/104 mm Hg were selected. Of these, 16 did not complete follow-up blood pressure measurements.

Interventions: Mental and physical stress reduction approaches —Transcendental Meditation^® (TM) and progressive muscle relaxation (PMR), respectively — were compared to a lifestyle modification education control and to each other.

Main Outcome Measures: Changes in systolic (SBP) and diastolic (DBP) blood pressure (SBP) from baseline to follow-up for 1) both genders and 2) for high and low risk level (defined by median split) on the following factors&emdash;weight, alcohol consumption, physical inactivity, dietary sodium/potassium intake, psychosocial stress, and a multiple risk factor variable.

Results: Compared to controls, women practicing the TM technique had adjusted reductions in SBP of 10.4 mm Hg (P<.01) and DBP of 5.9 mm Hg (P<.01) whereas PMR women did not show a significant decrease. Compared to controls, TM men reduced SBP by 12.7 mm Hg (p<.01) and DBP by 8.1 mm Hg (p<.01), whereas PMR men significantly reduced DBP only (p<.01). For both high and low risk subgroups on psychosocial stress, the TM program reduced SBP (high, p=.0003; low, p=.06) and DBP (high, p=.001; low, p=.008) compared to controls whereas, for PMR, only the high risk subgroup had significantly reduced SBP (p=.03) . Also, for both high and low risk subgroups on the 5 other risk variables, subjects practicing the TM program showed significantly reduced SBP and DBP compared to controls, whereas PMR subjects showed significant reductions for approximately half of the risk factor subgroup comparisons.

Conclusions: The effects of stress reduction, especially with the TM program, were found to generalize to both genders and a range of diverse risk factor subgroups suggesting a wide range of clinical applications. These results warrant further evaluation.

This work was supported by grants from the Retirement Research Foundation, Chicago, Ill, and the Lancaster Foundation, Bethesda, Md. Preparation of this publication was supported in part by the National Institutes of Health.