Calcium and Hypertension

Introduction

Hypertension is a condition in which the pressure in the arteries is elevated. Calcium present within the cells plays a significant role in cardiovascular functions. Insufficient intake of calcium affects hypertension. Calcium supplements or increased dietary intake have beneficial effects in lowering hypertension.

What Is Hypertension?

Hypertension refers to a chronic condition in which the pressure in the arteries is elevated. The blood pressure is elevated because the pressure exerted by the blood against the arterial wall is high. It also increases the cardiac load to pump blood. Blood pressure is measured using a sphygmomanometer or a digital machine and expressed in millimeters of mercury (mm Hg).

The following are the causes of hypertension:

• Smoking.

• Obesity.

• Increased salt intake.

• Lack of physical activity.

• Chronic alcoholism.

• Stress.

• Older age.

• Genetics.

• Family history of high blood pressure.

• Chronic kidney disease.

• Adrenal and thyroid disorders.

• Sleep apnea.

Hypertension does not present with any symptoms or warning signs. It can be identified only by measuring it with the ideal device. Severe hypertension may cause symptoms like dizziness, flushing, and blood spots in the eyes.

What Are the Complications of Hypertension?

Hypertension may result in the following complications:

• Heart attack or stroke.

• Aneurysms.

• Heart failure.

• Kidney problems.

• Eye problems.

• Dementia.

What Is Calcium?

Calcium plays an important role in blood clotting, muscle contractions, heart rhythm regulation, and nerve functions. It is also essential for healthy bones and teeth. If the calcium level becomes low, the parathyroid hormone stimulates the bones to release calcium into the blood. This also activates vitamin D to absorb calcium into the intestines and signals the kidneys to excrete the calcium into the urine. Calcitonin hormone stops the release of calcium from the bones and signals the kidneys to release more calcium to counteract the increased calcium levels. So, a good calcium diet is important for maintaining our health.

The recommended dietary allowance (RDA) for calcium for,

• Women of age 19-50 years - 1000mg daily.

• Women more than 51 years -1200mg daily.

• Pregnant and lactating women - 1000mg daily.

• Men of age 19-70 years - 1000mg daily.

• Men more than 71 years - 1200mg daily.

Calcium is highly available in milk, dairy products, fruits, nuts, beans, and leafy greens.

What Is the Role of Calcium in Pulmonary Hypertension?

Intracellular calcium plays a significant role in blood pressure regularization. Parathyroid glands help in calcium homeostasis. Low calcium intake decreases the calcium circulating in the blood. This signals the release of the parathyroid hormone, which stimulates the release of calcium from the bones.

As a result, there are increased calcium ions, and the influx of more calcium ions into the cells causes smooth muscle contraction and vasoconstriction. This leads to increased blood pressure in the blood vessels. Low calcium intake also increases calcitriol synthesis of calcitriol and stimulates the release of renin-angiotensin. This leads to the influx of intracellular calcium ions and increased blood pressure.

How Is Hypertension Diagnosed?

Hypertension is diagnosed based on symptoms, history, and readings from the sphygmomanometer. The systolic pressure is the first number that measures the pressure in the arteries when the heart beats. The diastolic pressure is the second number that measures the pressure in the arteries between heartbeats.

According to the American college of cardiology and the American heart association, blood pressure is divided into four categories.

• Normal Blood Pressure - Blood pressure is normal if it is 120/80 mm hg or lower than that.

• Elevated Blood Pressure - The pressure is elevated if the systolic pressure is between 120-129 mm Hg and the diastolic pressure is 80 mm Hg or less than that.

• Stage I Hypertension - In stage I hypertension, the systolic pressure is between 130-139 mm Hg, and the diastolic pressure is between 80-89 mm Hg.

• Stage II Hypertension - In stage II hypertension, the systolic pressure is 140 mm Hg or higher, and the diastolic pressure is 90 mm Hg or higher.

• Hypertensive Crisis - In a hypertensive crisis, the systolic pressure is higher than 180 mm Hg, and the diastolic pressure is higher than 120 mm Hg.

How Is Hypertension Treated?

Lifestyle changes and diet is essential to control hypertension. The following medications are given for the treatment of hypertension.

• Diuretics release sodium into the urine. The sodium removes water from the blood, decreases the level of fluid flowing through the arteries and veins, and reduces blood pressure.

• Angiotensin-Converting Enzyme Inhibitors relax the blood vessels and block the formation of a substance that blocks the blood vessels.

• Calcium Channel Blockers relax the muscles of the blood vessels and lower blood pressure.

• Other Medications like alpha-blockers, beta-blockers, alpha-beta blockers, vasodilators, renin inhibitors, and aldosterone antagonists are also used in the treatment of hypertension.

What Is the Role of Calcium Channel Blockers?

The entry of calcium ions into the cells is essential for the conduction of the electrical signals that pass from the muscle cells to the muscle cells of the heart and stimulates contraction. It also signals contractions to the heart to pump blood. The entry of calcium constricts the arteries. Calcium channel blockers block the influx of free calcium ions into the cells of the blood vessels. This causes vascular smooth muscle relaxation (dilation), decreased heart rate, reduced myocardial force generation, and decreased conduction velocity within the heart at the atrioventricular node. Dilation of the arteries lowers blood pressure. Dilation and reduced force of contraction reduce the oxygen requirement by the heart. Dilation increases the oxygen-carrying blood to the heart. This reduced demand for oxygen and increased delivery of oxygenated blood prevents heart pain or angina. Calcium channel blockers also reduce the electrical conduction through the heart and regularize abnormal heartbeats. Examples of calcium channel blockers are (Amlodipine, Nifedipine, Diltiazem, Verapamil, Felodipine, Nicardipine, Nimodipine, Nisoldipine, Isradipine, and Felodipine).

Conclusion

Hypertension is a common disorder. Early diagnosis and treatment are crucial in managing the symptoms and complications. Lifestyle changes like quitting smoking and a healthy diet also prevent the progression of hypertension. Low calcium intake is one of the reasons for hypertension. A calcium-rich diet plays a role in decreasing the risk of hypertension.