Does short-term alcohol or high salt intake alter 24-hour blood pressure and heart rate in men with essential hypertension?
Short-term high salt intake raises 24-hour blood pressure throughout the day, whereas alcohol intake causes diurnal blood pressure fluctuations without changing the 24-hour average in hypertensive men.
To compare the influences of alcohol and salt intake on 24-h blood pressure (BP), we studied short-term effects of repeated alcohol ingestion and dietary salt intake in hypertensive patients. Thirty-two Japanese men with mild to moderate essential hypertension (54 +/- 1 years old, mean +/- SE) were examined. Sixteen patients were given alcohol (1 ml/kg) with dinner for 7 d after a 7-d control period with an isocaloric beverage. Another group consisting of 16 age- and weight-matched patients consumed a low-sodium diet (25 mmol/d) for 7 d, followed by a high-sodium diet (250 mmol/d) for 7 d. Twenty-four-hour BP was measured at the end of each period. Average 24-h BP in the alcohol period (137 +/- 4/83 +/- 2 mmHg) was similar to that in the control period (138 +/- 4/84 +/- 2 mmHg). However, BP in the alcohol period was significantly lower in the evening, but significantly higher in the morning than that in the control period. Heart rate increased for several hours after alcohol ingestion, resulting in a significant increase in 24-h heart rate (67 +/- 2 vs. 64 +/- 2 beats/min). Average 24-h BP was higher in the high salt period (144 +/- 4/89 +/- 4 mmHg) than in the low salt period (135 +/- 3/85 +/- 3 mmHg, p < 0.05). The pressor effect of high salt intake was sustained throughout the day and was associated with a decrease in 24-h heart rate (60 +/- 2 vs. 66 +/- 2 beats/min). In conclusion, short-term repeated intake of alcohol may have little effect on average 24-h BP while it causes an evening fall and a morning rise in BP, and high salt intake raises BP throughout the day. Alcohol consumption increases and salt loading decreases 24-h heart rate.
Kawano et al. (Mon,) studied this question.