Hypertension in the Older Adults
Epidemiological studies show that the prevalence of hypertension in individuals over 60 years old is 49%. Older patients often have multiple comorbidities, and their hypertension is characterized by increased systolic blood pressure (SBP), decreased diastolic blood pressure (DBP), and widened pulse pressure. Blood pressure in this population tends to fluctuate significantly, and conditions such as orthostatic hypotension, supine hypertension, and postprandial hypotension are common. Abnormal circadian blood pressure rhythms, white coat hypertension, and pseudohypertension are also relatively frequent.
For older hypertensive patients, blood pressure should be reduced to below 150/90 mmHg, or to below 140/90 mmHg if tolerated. For very older patients aged 80 years or older, the target blood pressure is <150/90 mmHg. The treatment of hypertension in the older adults should emphasize achieving target SBP levels while avoiding excessive reductions in DBP. Blood pressure should be gradually lowered to target levels to avoid rapid reductions. Antihypertensive drugs such as calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), and diuretics can be considered.
Hypertension in Children and Adolescents
Hypertension in children and adolescents is primarily essential hypertension, characterized by mild to moderate blood pressure elevation, usually without significant clinical symptoms. It is closely associated with obesity, and nearly half of children with hypertension may develop adult hypertension. Left ventricular hypertrophy (LVH) is the most common target organ damage in this population. Significant blood pressure elevations in children and adolescents are often secondary hypertension, with renal hypertension being the leading cause.
Internationally, the 90th and 95th percentiles of blood pressure for age and sex are used as diagnostic thresholds for high-normal blood pressure and hypertension, respectively. Blood pressure ≥120/80 mmHg but below the hypertension threshold is also considered high-normal blood pressure in children and adolescents.
For children and adolescents without target organ damage, blood pressure should be reduced to below the 95th percentile. If renal disease, diabetes, or target organ damage is present, blood pressure should be reduced to below the 90th percentile. Most cases of hypertension in children and adolescents can be managed with non-pharmacological treatments to achieve blood pressure control. However, if lifestyle interventions are ineffective, or if clinical symptoms, target organ damage, diabetes, or secondary hypertension are present, pharmacological treatment should be considered. ACEIs and CCBs are usually the first-line antihypertensive drugs for pediatric patients, while diuretics are generally used as second-line drugs or in combination with other medications. Other drugs, such as alpha-blockers and beta-blockers, are typically used in combination therapy.
Hypertension in Pregnancy
This condition can be seen in Obstetrics and Gynecology.
Resistant Hypertension
Resistant hypertension (RH) refers to hypertension that remains above target levels despite lifestyle modifications and treatment with a tolerable and rational combination of three antihypertensive drugs (including a diuretic) at adequate doses for at least four weeks. It also includes cases where achieving target blood pressure requires at least four antihypertensive drugs. For resistant hypertension, genetic and pharmacogenetic factors may play a role in some patients. However, common causes should also be investigated.
Pseudoresistant hypertension may result from measurement errors, white coat effect, or poor treatment adherence. Common measurement errors include using an improperly sized cuff, placing the cuff over elastic clothing, deflating the cuff too quickly, positioning the stethoscope under the cuff, and applying excessive pressure on the stethoscope. Pseudoresistant hypertension can also occur in older patients with widespread arterial atherosclerosis and calcification. In such cases, higher cuff pressure is required to occlude the hardened artery during brachial artery blood pressure measurement. Pseudoresistant hypertension should be suspected in the following situations:
- Markedly elevated blood pressure without target organ damage
- Significant dizziness, fatigue, or other hypotensive symptoms after antihypertensive treatment, without excessive blood pressure reduction
- Evidence of brachial artery calcification
- Brachial artery blood pressure exceeding lower limb arterial blood pressure
- Severe isolated systolic hypertension
Examples of ineffective lifestyle modifications include inadequate control of body weight, excessive salt intake, excessive alcohol consumption, and failure to quit smoking.
Inappropriate antihypertensive treatment regimens include the use of irrational drug combinations, the use of antihypertensive drugs with significant adverse effects that limit dose escalation and adherence, and the omission of diuretics in multidrug regimens.
Concurrent use of medications that interfere with antihypertensive efficacy is a relatively hidden cause of uncontrolled blood pressure. Nonsteroidal anti-inflammatory drugs (NSAIDs) cause water and sodium retention and enhance vascular responsiveness to vasopressor hormones, counteracting the effects of most antihypertensive drugs except CCBs. Sympathomimetic agents, found in some nasal decongestants and appetite suppressants, activate alpha-adrenergic receptors, and can elevate blood pressure or interfere with antihypertensive drugs. Tricyclic antidepressants block the uptake of antihypertensive drugs like reserpine and clonidine at sympathetic nerve terminals. Cyclosporine stimulates endothelin release, increases renal vascular resistance, and reduces water and sodium excretion. Recombinant human erythropoietin directly increases peripheral vascular resistance. Oral contraceptives and glucocorticoids can antagonize the effects of antihypertensive drugs.
Excessive sodium intake can counteract the effects of antihypertensive drugs. Volume overload is common in patients with obesity, diabetes, or kidney damage. In some patients whose blood pressure remains uncontrolled despite combination therapy, the absence of diuretics or improper use of diuretics is often observed. A short-term trial of intensified diuretic therapy can be used to assess the effect, combining long-acting thiazide diuretics with short-acting loop diuretics.
Insulin resistance is a major cause of resistant hypertension in obese and diabetic patients. Adding insulin sensitizers to antihypertensive therapy can significantly improve blood pressure control. Weight loss in obese patients can also substantially reduce blood pressure or decrease the need for antihypertensive medications.
The management of resistant hypertension should be based on an evaluation of the above potential causes, effective lifestyle interventions, and the formulation of a rational antihypertensive regimen. Secondary hypertension should be ruled out, and patient adherence should be improved. With these measures, blood pressure can be controlled in most patients.
Hypertensive Emergencies and Urgencies
Hypertensive emergencies refer to situations in which patients with primary or secondary hypertension experience a sudden and significant rise in blood pressure (generally exceeding 180/120 mmHg) accompanied by progressive dysfunction of vital target organs, such as the heart, brain, and kidneys. Hypertensive emergencies include hypertensive encephalopathy, intracranial hemorrhage (including cerebral hemorrhage and subarachnoid hemorrhage), ischemic stroke, acute left heart failure, acute coronary syndromes (unstable angina, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction), aortic dissection, eclampsia, rapidly progressive glomerulonephritis, renal crises caused by collagen vascular diseases, pheochromocytoma crises, and severe perioperative hypertension. In rare cases, patients may develop malignant hypertension, characterized by a diastolic blood pressure persistently ≥130 mmHg, accompanied by symptoms such as headache, blurred vision, retinal hemorrhage, exudates, and papilledema. Renal damage is prominent, with persistent proteinuria, hematuria, and casts in the urine. It is important to note that the degree of blood pressure elevation does not always correlate with the severity of acute target organ damage. Intravenous antihypertensive medications are usually required in these cases.
Hypertensive urgencies refer to situations where blood pressure is significantly elevated but without severe clinical symptoms or progressive target organ damage. Patients may experience symptoms caused by elevated blood pressure, such as headache, chest tightness, nosebleeds, and restlessness. The degree of blood pressure elevation is not the criterion for distinguishing hypertensive emergencies from urgencies; the sole distinguishing factor is the presence or absence of recently developed acute progressive target organ damage.
Timely and appropriate management of hypertensive emergencies is crucial to quickly alleviate the condition, prevent progressive or irreversible target organ damage, and reduce mortality. The urgency of blood pressure reduction differs between hypertensive emergencies and urgencies. The former requires rapid blood pressure reduction using intravenous medications and the removal of the underlying cause or trigger, while the latter requires blood pressure reduction within 24-48 hours using fast-acting oral antihypertensive drugs.
For hypertensive emergencies, appropriate and effective antihypertensive medications can be selected and administered via intravenous infusion, and blood pressure should be closely monitored. If possible, oral antihypertensive therapy can be initiated early.
A rapid and significant drop in blood pressure during hypertensive emergencies may lead to a marked reduction in blood flow to vital organs. A gradual and controlled reduction in blood pressure is recommended. Generally, in the initial phase (within the first hour), the target is to lower the mean arterial pressure (MAP) by no more than 25% of the pretreatment level. Over the next 2-6 hours, blood pressure should be reduced to a safer level, typically around 160/100 mmHg. If the patient is stable and can tolerate further reductions, blood pressure can be gradually lowered to normal levels over the next 24-48 hours. If signs of ischemia in vital organs are observed after blood pressure reduction, the extent of the reduction should be smaller. Over the following 1-2 weeks, blood pressure can be gradually reduced to normal levels.
Medications should be chosen based on rapid onset, short duration of action, quick reversibility after discontinuation, and minimal side effects. Additionally, the selected drugs should ideally not significantly affect heart rate, cardiac output, or cerebral blood flow during the blood pressure reduction process.
Some antihypertensive drugs are unsuitable or even harmful for hypertensive emergencies. For example, intramuscular injections of reserpine have a slow onset of action, and repeated injections over a short period can lead to unpredictable cumulative effects, causing severe hypotension and excessive sedation, which may interfere with the assessment of consciousness. Strong diuretics should also not be used at the start of treatment unless there is heart failure or significant fluid volume overload. This is because, in most hypertensive emergencies, the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) are excessively activated, leading to increased peripheral vascular resistance and reduced circulating blood volume, making the use of strong diuretics risky.
Sodium Nitroprusside
Sodium nitroprusside directly dilates both veins and arteries, reducing both preload and afterload. It is administered via intravenous infusion starting at a rate of 0.3-0.5 μg/(kg·min), with the dose gradually increased to achieve the desired antihypertensive effect. The commonly used maximum dose in clinical practice is 10 μg/(kg·min). Blood pressure must be closely monitored during the use of sodium nitroprusside, and the infusion rate should be carefully adjusted based on blood pressure levels. The effect lasts only 2-10 minutes after stopping the infusion. Sodium nitroprusside can be used for various hypertensive emergencies. At typical doses, adverse effects are mild and may include nausea, emesis, and muscle tremors. Sodium nitroprusside is metabolized in red blood cells to produce cyanide. Prolonged or high-dose use may lead to thiocyanate toxicity, especially in patients with renal impairment, who are at greater risk.
Nitroglycerin
Nitroglycerin dilates veins and selectively dilates coronary arteries and large arteries. Its ability to lower arterial pressure is less potent than sodium nitroprusside. It is initially administered via intravenous infusion at a rate of 5-10 μg/min. The antihypertensive effect is rapid, and the effect disappears within a few minutes after discontinuation. The dose can be increased to 100-200 μg/min. Nitroglycerin is mainly used for hypertensive emergencies accompanied by acute heart failure or acute coronary syndromes. Adverse effects include tachycardia, facial flushing, headache, and emesis.
Nicardipine
Nicardipine is a dihydropyridine calcium channel blocker with rapid action and a short duration of effect. It lowers blood pressure while improving cerebral blood flow. It is administered via intravenous infusion starting at 0.5 μg/(kg·min), with the dose gradually increased up to 10 μg/(kg·min). Nicardipine is primarily used in hypertensive emergencies associated with acute cerebrovascular disease or other hypertensive emergencies. Adverse effects include tachycardia and facial flushing.
Labetalol
Labetalol is a beta-blocker with alpha-receptor blocking activity. It has a relatively rapid onset of action (5-10 minutes) and a longer duration of effect (3-6 hours). It is initially administered via slow intravenous injection at a dose of 20-80 mg or via intravenous infusion at a rate of 0.5-2 mg/min. Labetalol is mainly used for hypertensive emergencies in patients with pregnancy or renal dysfunction. Adverse effects include dizziness, orthostatic hypotension, and cardiac conduction block.
Hypertension Concurrent with Other Clinical Conditions
Hypertension can coexist with cerebrovascular disease, coronary artery disease, heart failure, chronic kidney disease, and diabetes.
The management of blood pressure in acute stroke remains controversial. For patients with acute ischemic stroke who are candidates for thrombolysis, blood pressure should be controlled to <180/110 mmHg.
For patients with systolic blood pressure >220 mmHg, intravenous antihypertensive medications should be actively used to lower blood pressure. For patients with systolic blood pressure >180 mmHg, intravenous antihypertensive medications can be used to control blood pressure, with 160/90 mmHg as a reference target. In the stable phase, the goal of antihypertensive treatment is to reduce the risk of recurrent stroke. For older patients, those with severe bilateral or intracranial arterial stenosis, or those with severe orthostatic hypotension, blood pressure should be lowered cautiously. The process should be slow and steady, with the aim of avoiding a reduction in cerebral blood flow.
In patients with hypertension combined with myocardial infarction or heart failure, ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and beta-blockers should be prioritized.
The primary goal of antihypertensive treatment in patients with chronic kidney disease (CKD) is to slow the progression of kidney function deterioration and prevent cardiovascular and cerebrovascular events. ACEIs or ARBs can delay kidney function decline in the early and middle stages of hypertension, but caution is needed as they may worsen kidney function in cases of low blood volume or advanced disease.
In type 1 diabetes, blood pressure is typically normal before the onset of proteinuria or kidney dysfunction. Hypertension is often a manifestation of nephropathy.
In type 2 diabetes, hypertension often coexists with diabetes at an early stage. Most patients with diabetes and hypertension also have obesity, dyslipidemia, and significant target organ damage. Therefore, aggressive antihypertensive treatment is necessary. Achieving target blood pressure levels often requires a combination of two or more antihypertensive drugs. ACEIs or ARBs are effective in reducing and delaying the progression of diabetic kidney disease.
Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and novel non-steroidal mineralocorticoid receptor antagonists have some antihypertensive effects. Current evidence supports the use of these drugs to improve cardiovascular and renal outcomes in patients with diabetic kidney disease.