Mills, Paul Joseph
Cardiovascular and adrenergic reactivity and beta-adrenergic receptor sensitivity in practitioners of the Transcendental Meditation program and type A behavior.

Order No. 8718397

Excessive cardiovascular reactivity to stress has been identified as a risk factor for coronary heart disease. To test the hypothesis that meditation may be an effective means to reduce cardiovascular reactivity, and thus reduce risk of heart disease, this study examined the acute and chronic effects of the Transcendental MeditationΠ(TM) program on cardiovascular and adrenergic reactivity to stress, including the determination of lymphocyte beta-adrenergic receptor sensitivity, while controlling for Type A behavior, a marker for cardiovascular reactivity.

Forty two males, mean age 32.5 (aged 20-48, 21 practicing the TM program and 21 non-meditating controls) were rated by the Structured Interview for Type A behavior pattern. The experiment consisted of a 30-minute baseline followed by: 5 minutes of mental arithmetic, 20 minutes of TM or relaxation, 5 minutes of a second mental arithmetic, and a 4-minute isometric hand grip at 30% maximum voluntary contraction. A 20-minute rest period separated each intervention period.

The results indicated that the TM group had both a lower resting blood pressure prior to, and a lower blood pressure level during, all three stressor periods. Following the acute TM period, the TM group had a lower diastolic blood pressure response, and a higher initial heart rate response, to the second mental stress, as well as a lower diastolic blood pressure response to the isometric hand grip task. The TM group had a higher beta-max, a lower percent of receptors in the high affinity state, and a lower mean resting epinephrine level. There were no significant differences between the TM and control groups for any of the Type A behavior or Spielberger anger expression scale components. Regression analysis revealed that the Type A behavior components verbal competition, rapid, and explosive were predictive of diastolic blood pressure reactivity and heart rate reactivity. The Spielberger angerout component was predictive of both resting and response values of heart rate and catecholamines.

These findings support the hypotheses that TM is associated with (1) reduced blood pressure reactivity to stress, and (2) altered beta-adrenergic receptor sensitivity. The results also support previous research showing TM's long-term effects of lowered blood pressure. Source: DAI, 48, no. 06B, (1987): 1612


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