Cigarette smoking in hypertensive patients. Blood pressure and endocrine responses.

The blood pressure and endocrine responses to cigarette smoking were studied in 19 hypertensive patients to determine whether smoking activates the renin-aldosterone axis. Blood pressure rose from 140 +/- 7/99 +/- 3 (mean +/- SEM) to 151 +/- 5/108 +/- 2 mm Hg (p less than 0.01) within 10 minutes after smoking, and pulse rate also increased significantly (69 +/- 2 to 96 +/- 4 beats per minute). Plasma renin activity did not change but rose 15 minutes after ambulation. In contrast, plasma aldosterone and plasma cortisol levels increased significantly after smoking and peaked at 20 minutes: 13.9 +/- 0.9 to 20.2 +/- 2.0 ng/dl (p less than 0.01) and 10.2 +/- 1.0 to 22.0 +/- 2.2 micrograms/dl (p less than 0.01), respectively. These responses were closely correlated (r = 0.6467, p less than 0.01), suggesting a pituitary-adrenal mechanism is activated during smoking. Plasma ACTH levels rose from 58 +/- 6 to 87 +/- 10 pg/ml in 10 minutes (p less than 0.001) and to 90 +/- 14 pg/ml at 20 minutes (p less than 0.01). Total plasma catecholamine levels also rose from 468 +/- 60 to 624 +/- 73 pg/ml 10 minutes after smoking (p less than 0.01) and to 724 +/- 69 pg/ml (p less than 0.01) 15 minutes after ambulation. In hypertensive smokers, cigarette smoking is associated with an increase in blood pressure, pulse rate, and plasma ACTH, cortisol, aldosterone, and plasma catecholamine levels. The long-term significance of these acute hormonal changes in regard to blood pressure homeostasis and vascular disease in cigarette smokers remains to be determined. Smoking should be avoided prior to blood pressure and endocrine determinations.