Potassium blood pressure elevation

Elevated blood pressure is usually caused by a combination of several abnormalities (multifactorial). Epidemiologic evidence points to genetic inheritance, psychological stress, and environmental and dietary factors (increased salt and decreased potassium or calcium intake) as perhaps contributing to the development of hypertension. Increase in blood pressure with aging does not occur in populations with low daily sodium intake. Patients with labile hypertension appear more likely than normal controls to have blood pressure elevations after salt loading. 

Estimated safe and adequate intakes of potassium are given in the section on MINERAL(S), Table M-25, Mineral Table. The levels of potassium suggested in this table were calculated from the sodium intakes in order to achieve equivalent amounts of potassium on a molar basis. Older individuals need relatively less potassium than the rapidly growing infant, but an equivalent intake of potassium appears to be somewhat protective against the blood pressure elevating effects of a given level of sodium. 

ACE inhibitors lower the elevated blood pressure in humans with a concomitant decrease in total peripheral resistance. Cardiac output is increased or unchanged heart rate is unchanged urinary sodium excretion is unchanged and potassium excretion is decreased. ACE inhibitors promote reduction of left ventricular hypertrophy. 

A 55-year-old female with a blood pressure of 170/105 mmHg has pitting edema of the lower extremities and an elevated serum creatinine associated with a normal serum potassium. Which of the following agents is contraindicated in this patient ... 

Fluid and electrolyte balance Average and large doses of hydrocortisone or cortisone can cause elevation of blood pressure, salt and water retention, and increased excretion of potassium. These effects are less likely to occur with the synthetic derivatives except when used in large doses. 

The thiazide diuretics are primarily used for most patients with mild or moderate hypertension. Used alone they can lower blood pressure by 10-15 mmHg. In more severe hypertension diuretics are used in combination with other agents. Adverse effects include hypokalemia (lowered serum potassium), impotence, impaired glucose tolerance, hyperlipidemia, and hyperuricemia (elevated uric acid in the blood). 

Mineralocorticoids help control the body s water volume and concentration of electrolytes, especially sodium and potassium. Aldosterone acts on kidney tubule cells, causing a reabsorption of sodium, bicarbonate, and water. Conversely, aldosterone decreases reabsorption of potassium, which is then lost in the urine. [Note Elevated aldosterone levels may cause alkalosis and hypokalemia, whereas retention of sodium and water leads to an increase in blood volume and blood pressure (see p. 180). Hyperaldosteronism is treated with spironolactone (see p. 232).]... 

In 1991, University of Pennsylvania researchers found that just ten days of potassium restriction resulted in rises in blood pressure, whether one had normal or elevated blood pressure to begin with. A twelve-year study of California adults suggested that high potassium intake protects against stroke, the worst result of hypertension. For men in that study, those with low potassium intake had 2.6 times more stroke risk than did men with high consumption of potassium-rich foods. For women, low intake multiplied the risk by nearly five times. 

The hypervolemiaresultingfrom a shift of water elevates the ventricular filling pressure and increases the cardiac output from increased ventricular stroke work. The potassium ions released from shrinking and crenating red blood cells contribute to the lowering of systemic vascular resistance and blood pressure (499). 

A sixty-seven-year-old man suffering from progressive muscular weakness went to a Taipei hospital. Until then, aside from somewhat elevated blood pressure and an enlarged prostate, he d been in good health. The only abnormality doctors could find was a very low level of potassium in his blood. The man revealed that he had been taking a Chinese herbal remedy for his prostate. What natural product did this remedy contain that could cause the muscle weakness ... 

A 50-year-old male patient with cirrhosis and a history of alcohol abuse since age 12 is admitted to the emergency room with seizures. He is dehydrated, and the physician has ordered an intravenous infusion of magnesium sulfate to reduce the seizure activity. In addition, the patient has hypertension treated with diuretics. When reviewing the laboratory work, the nurse notices that the serum blood urea nitrogen (BUN) and creatinine are elevated. The nurse also notices that the serum sodium concentration is elevated and the potassium level is low. The patient is in no apparent distress, with vital signs of blood pressure (BP) 110/62 mm Hg, pulse (P) 60 beats/minute, respiration (R) 12 breaths/minute, and pulse oximetry showing 88 percent oxygen saturation. 

Humans evolved on a diet that was rich in potassium and bicarbonate precursors and low in salt. However, contemporary Western-style diets have the opposite pattern—that is, relatively low content of potassium and high content of salt. Based on intake data from the Third National Health and Nutrition Examination Survey (NHANES-III,1988-1994), the percentage of men and women who consumed equal to or more than 4.7g/day (120mmol/day) was less than 10 and 1%, respectively. Median intake of potassium in the United States ranged from 2.8 to 3.3 g/day (72 to 84 mmol/day) for adult men and 2.2 to 2.4 g/day (56 to 61 mmol/day) for adult women. The median potassium intake of non-African Americans exceeded that of African Americans. Because African Americans have a relatively low intake of potassium and a high prevalence of elevated blood pressure and salt sensitivity, this subgroup would especially benefit from an increased potassium intake. 

Potassium is an essential nutrient that is required for normal cellular function. Although humans evolved on diets rich in potassium, contemporary diets are quite low in potassium. An increased intake of potassium from foods should prevent many of the adverse effects of inadequate potassium intake, which are higher blood pressure levels, greater salt sensitivity, increased risk of kidney stones, and possibly increased bone loss. An inadequate potassium level may also increase the risk of stroke. In view of the high prevalence of elevated blood pressiue, stroke, and conditions related to bone demineralization (i.e., osteoporosis and kidney stones) in the general population, individuals should strive to increase their consumption of potassium-rich foods, particularly fruits and vegetables. 

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