Risk Factors for Hypertension (High Blood Pressure)
by Hans R. Larsen, MSc ChE
Hold the licorice
The regular consumption of licorice candies (based on licorice root extract) can result in high blood pressure, sodium and water retention, and excessive loss of potassium. A 70-year old man was admitted to the San Francisco General Hospital because of weakness, mental slowness, and significant weight loss. It was found that he had been eating 25-40 licorice candies a day for four to five years. Some of his symptoms persisted for four months after he stopped eating licorice. Other studies confirm the detrimental effects of continuous licorice consumption.
Farese, Robert V., et al. Licorice-induced hypermineralocorticoidism. The New England Journal of Medicine, Vol. 325, No. 17, October 24, 1991, pp. 1223-27
Low blood pressure linked to depression
GALVESTON, TEXAS. Excessively low blood pressure has long been considered a disorder in continental Europe and has been treated with many remedies and medications ranging from coffee and cold showers to ephedrine and amphetamine. In the United States and the United Kingdom, on the other hand, the prevailing wisdom is that the lower the blood pressure the better.
This assumption may now be about to change following a ground-breaking study carried out by researchers at the University of Texas Medical Branch. The researchers studied 2723 Mexican Americans aged 65 years or older. Participants were interviewed to determine their level of depression and fatigue as well as their self-reported health status and degree of self-esteem. They also had their blood pressure measured at two separate occasions. Seven hundred and seventy-eight (29.7 per cent) of the study participants had a low diastolic pressure (i.e. below 75 mm Hg), 428 (15.9 per cent) had a low systolic pressure (i.e. below 120 mm Hg, and 265 (9.9 per cent) had both diastolic and systolic hypotension.
The researchers found that participants with hypotension were more likely to be depressed, had lower self-esteem and global self-reported health, and were more likely to wake up tired in the morning than were participants with blood pressures in the normal range (systolic pressure between 120 and 139 mm Hg and diastolic pressure between 75 and 84 mm Hg). The low blood pressure correlation with depression, etc. was independent of whether the low blood pressure was inherent or caused by the use of blood pressure lowering medications (antihypertensives). Participants with both low diastolic and low systolic pressures were almost 2.5 times more likely to be significantly depressed than were participants with normal blood pressures.
The researchers conclude that there is a definite association between low blood pressure and depression and warn that over-treatment of high blood pressure (hypertension) could conceivably result in depression.
Stroup-Benham, Christine A., et al. Relationship between low blood pressure and depressive symptomatology in older people. Journal of the American Geriatrics Society, Vol. 48, March 2000, pp. 250-55
Robbins, Michael A., et al. Low blood pressure and depression: comorbidity and competing outcomes. Journal of the American Geriatrics Society, Vol. 48, March 2000, pp. 336-37 (editorial)
Not all sodium salts cause increased blood pressure
SAN FRANCISCO, CALIFORNIA. An experiment was carried out to determine if administration by ingestion of extra sodium chloride (240 mmol of sodium per day) would increase blood pressure in 5 males who suffered from hypertension. The blood pressure of the participants had been kept in the normal range prior to the experiment through restriction of dietary sodium intake to 10 mmol/day (0.23 g of sodium). The average systolic pressure went from 126+-4 mm Hg to 142+-4 mm Hg and the average diastolic pressure went from 76+-2 mm Hg to 84+-4 mm Hg after about 3 days of consuming the extra salt (5.5 g/day) in the form of capsules. Changing the content of the capsules to dextrose (placebo) or sodium citrate (240 mmol of sodium/day) reversed the increase caused by the sodium chloride. Thus it would appear, from this limited experiment, that not all sodium salts cause an increase in blood pressure and that the chloride ion may play an important role. Administration of extra sodium chloride increased plasma volume and calcium excretion whereas extra intake of sodium citrate did not. Both salts induced comparable sodium retention, weight gain, and suppression of plasma renin activity and plasma aldosterone.
Kurtz, Theodore W., et al. "Salt-sensitive" essential hypertension in men. The New England Journal of Medicine, Vol. 317, No. 17, October 29, 1988, pp. 1043-48
Smokeless tobacco (oral snuff or chewing tobacco) can lead to high blood pressure in regular users
SAN FRANCISCO, CALIFORNIA. A study of eight healthy men showed that sodium absorption (measured by urinary excretion) from smokeless tobacco was substantial, averaging 137 and 152 mmol/day for snuff and chewing tobacco respectively as opposed to 107 mmol/day from regular cigarettes. An extra sodium load of this magnitude could increase blood pressure by 5 to 10 mm Hg.
Benowtiz, Neal L. Sodium intake from smokeless tobacco. The New England Journal of Medicine, Vol. 319, No. 13, September 29, 1988, pp. 873-74
Obesity and alcohol may cause hypertension
OAKLAND, CALIFORNIA. A study of 1031 subjects who developed hypertension over a six year period was carried out to determine the possible effects of obesity, weight gain, alcohol usage, and salt consumption on the development of "essential" hypertension. The results from this group were compared with the results from a matched group of 1031 normotensive subjects. Obesity and weight gain were shown to be clear precursors of hypertension. Excessive alcohol consumption also related to the development of hypertension, most significantly on a short-term basis. A family history of hypertension was found to be significant on a mother-daughter basis, but not on a paternal basis. The results concerning the effect of salt intake were inconclusive.
Friedman, Gary D., et al. Precursors of essential hypertension: body weight, alcohol and salt use, and parental history of hypertension. Preventive Medicine, Vol. 17, No. 4, July 1988, pp. 387-400
Anxiety may cause hypertension
BIRMINGHAM, ALABAMA. Many people believe that anxiety and repression of anger can lead to hypertension (high blood pressure). Now medical doctors involved in the Framingham Heart Study have confirmed that a high level of anxiety can indeed cause future hypertension. Their 20-year study involved 497 men and 626 women with normal blood pressure (average 130/78) at the start of the study. The participants were divided according to age, one group being between 45 and 59 and one group between 60 and 77 years of age at the beginning of the study. The men in the 45-59 year age group were found to have twice the risk of developing hypertension (blood pressure >160/95) over the next 20 years if they had a high baseline measure of anxiety compared to men with a low anxiety level. This was independent of their age, initial systolic blood pressure, heart rate, weight, alcohol consumption, glucose tolerance, smoking status, and educational level. Feelings of anger, whether expressed or suppressed, were not significantly correlated with the later development of hypertension. The researchers did not find any correlation between tension level and later hypertension in women or men over 60 years. This is surprising as another recent study did find a relationship between anxiety level and later hypertension in middle-aged women working outside the home.
Markovitz, Jerome H., et al. Psychological predictors of hypertension in the Framingham Study. Journal of the American Medical Association, Vol. 270, No. 20, November 24, 1993, pp. 2439-43
Uric acid implicated in heart disease
NEW ORLEANS, LOUISIANA. Excessive uric acid concentrations in the blood may result in gout and arthritis. Now evidence is mounting that uric acid may also be implicated in hypertension, heart disease, obesity, diabetes, and high cholesterol levels. Uric acid is the end product of purine metabolism and earlier studies have shown that its concentration in the blood is inversely related to blood flow through the kidneys. There is also evidence that uric acid concentration in the blood tends to increase with age and that the accompanying decrease in blood flow through the kidneys is a definite risk factor for coronary heart disease. NOTE: Coffee, tea, meat, and chocolate all contain purine-forming compounds.
Frohlich, Edward D. Uric acid - a risk factor for coronary heart disease. Journal of the American Medical Association, Vol. 270, No. 3, July 21, 1993, pp. 378-79