Hypertension and Lipid Disorders

Vinod R. Patel

Thomas C. Rosenthal

CLINICAL PEARLS

Hypertension and lipid disorders are among the most common and asymptomatic problems in the elderly population today.
Despite apparent benefits, compliance with statin therapy declines substantially with time in elderly patients. This occurs even when cost is not an issue.
Hypertension is a common problem in elderly subjects, reaching a prevalence of 60% to 80%.
Isolated systolic hypertension accounts for 60% of cases of hypertension in the elderly.
In persons older than 50 years, systolic blood pressure (BP) >140 mm Hg is a much more important cardiovascular disease risk factor than diastolic pressure.
Patient compliance is the factor most associated with successful treatment. Motivation improves when patients have a positive experience with, and trust in the clinician.
The elderly may have sluggish baroreceptors and sympathetic responsiveness, as well as impaired cerebral autoregulation. Therapy should be gentle and gradual, avoiding drugs that are likely to cause postural hypotension.
The elderly may ingest more sodium to compensate for a decrease in taste sensitivity.
The elderly may depend more on processed, prepackaged foods that are high in sodium and fat rather than fresh foods that are low in sodium.
Lower initial doses of medications (often one half that in younger patients) should be used to minimize the risk of side effects.
The reduction in BP should be gradual to minimize the risk of ischemic symptoms, particularly in patients with postural hypotension.
In advancing age, one must consider comorbid treatments of diabetes, renal failure, dementia, arthritis, coronary artery disease, and benign prostatic hyperplasia.
Nonsteroidal anti-inflammatory drugs (NSAIDs) may adversely impact BP control.
Despite their proved benefit, lipid-lowering drugs and antihypertensive medications are markedly underutilized in elderly patients.

HYPERTENSION

Aging is associated with an increased prevalence of hypertension, coronary artery disease, and heart failure and a reduction in exercise capacity.¹ Elevated blood
pressure (BP) and dyslipidemia are the most common and asymptomatic problems in the ambulatory care setting worldwide. The incidence of hypertension is increasing because of increase in awareness, life span, and clarification of the definition of hypertension by the Joint National Committee (JNC) (see Table 24.1). Hypertension will become an epidemic as the baby boomers age.

TABLE 24.1 DEFINITION OF HYPERTENSION (JNC 7)

Classification	Systolic	Diastolic
Normal blood pressure	<120 mm Hg	<80 mm Hg
Prehypertension	120-139 mm Hg	80-89 mm Hg
Stage 1 hypertension	140-159 mm Hg	90-99 mm Hg
Stage 2 hypertension	≥160 mm Hg	≥100 mm Hg
Chobanian AV, Bakris, GL, Black HR, et al. The seventh report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure: The JNC 7 report. JAMA. 2003;289:2560.

Although the diastolic BP peaks at age 50, the systolic BP continues to increase with age. It increases in all races. African Americans tend to develop hypertension more often and at younger ages, Mexican Americans tend to develop hypertension later in life, and white Americans show continuous increase to a prevalence of 60% to 80% by late life.² Only 34% of the individuals with hypertension have adequate control, defined as a level below 140/90 mm Hg.³

Current definitions for hypertension have been established by the seventh report of the JNC.³ They are based on the average of two or more readings at each of two or more visits after an initial screen. Normal BP is defined as systolic BP of 120 mm Hg and diastolic BP of 80 mm Hg. BP between normal and 139 mm Hg systolic, and 89 mm Hg diastolic is considered prehypertension. High normal BP for over 12 years is associated with a 1.6-fold greater risk of cardiovascular disease in men and 2.5-fold greater risk in women compared with subjects with optimal BP at base-line.³, ⁴, ⁵ In the absence of end-organ damage, a patient should not be labeled as having hypertension unless the BP is persistently elevated after three to six visits over a period of several months.

History, Symptomatology, and Initial Evaluation

Hypertension is asymptomatic. Patients may have been told by a health care provider during health screening examinations that they had a high reading. Patients with severe hypertension may present with headache and dizziness. Patients with long-standing hypertension may present with target organ damage, like blindness, loss of visual acuity, floaters in front of the eyes, episodic weakness, chest pain, shortness of breath, and symptoms of peripheral vascular disease like claudication. If the patient presents with muscle weakness, flank pain, thinning of the skin, intermittent tachycardia, sweating, tremors, pedal edema, secondary hypertension should be considered. Some hypertensive patients will report palpitations while taking over-the-counter medication like pseudoephedrine.

Risk factors for developing hypertension are high sodium intake, excess alcohol and saturated fat intake, physical inactivity, smoking, diabetes, dyslipidemias, hormonal medications (estrogens, androgens), and psychological factors including stress, family circumstances, and type A personality.

In essential hypertension there is usually a family history of hypertension. Other family history may include premature cardiovascular death, diabetes, and familial diseases such as pheochromocytoma.

Physical examinations should include accurate measurement of BP, general examinations for distribution of body fat, skin lesions, examination of carotids, cardiac and respiratory auscultation, detection of carotid or abdominal bruits, peripheral edema, and muscle strength.

Types of Hypertension

Essential Hypertension

Essential hypertension is the most common type of hypertension, especially in patients with a family history.⁶ Essential hypertension is seen primarily in societies in which salt intake is above 100 mEq per day (2.3 g sodium).⁷ Essential hypertension is particularly common in obese patients and is often associated with metabolic syndrome and diabetes mellitus.⁸ It is more common and more severe in black populations.

Secondary hypertension is less common and potentially correctable. Renal disease usually presents with pedal edema, abnormal urinalysis, and hypertension. Pheochromocytoma may present with paroxysm of hypertension associated with tachycardia and may have family history. Patients using steroids may have cushingoid faces and central obesity. Other rare causes of hypertension are hyperthyroidism and hyperparathyroidism. Physical findings associated with secondary hypertension are listed in Table 24.2.

Isolated Systolic Hypertension

JNC 7 defines isolated systolic hypertension as a systolic level of 140 mm Hg regardless of age.³ Isolated systolic hypertension accounts for 65% to 75% of cases of hypertension in the elderly.⁹ Isolated systolic hypertension is associated with a two- to fourfold increase in the risk of myocardial infarction, left ventricular hypertrophy, renal dysfunction, stroke, and cardiovascular mortality.¹⁰,¹¹ As the systolic pressure rises and the diastolic pressure falls after age 60 in both normotensive and untreated hypertensive subjects,¹² the pulse pressure becomes widened. The widened pulse pressure has been considered a risk factor
for cardiovascular disease as it may interfere with tissue perfusion. Caution is advised when treating elderly patients with isolated systolic hypertension, who start with lower diastolic pressures. The diastolic BP should not be reduced to <60 mm Hg to attain the target systolic pressure.

TABLE 24.2 PHYSICAL FINDINGS IN SECONDARY HYPERTENSION

Causes	Findings
Renal disease like glomerulonephritis or secondary renal disease	Hypertension along with other glomerulonephritis symptoms
Pheochromocytoma	Paroxysmal tachycardia and hypertension
Primary hyperaldosteronism	Hypertension, hypokalemia, and metabolic alkalosis
Coarctation of aorta	Bruit in back, decreased/lagging pulsations
Cushing syndrome	Cushingoid features on physical examination

Complications

Risk increases as a continuum as the BP rises above 110/75 mm Hg.¹³ In older patients, systolic pressure and pulse pressure are more powerful determinants of risk than diastolic pressure.¹⁴,¹⁵ Hypertension increases the workload of the cardiac muscle, causing left ventricular hypertrophy,¹⁶ which is associated with heart failure, ventricular arrhythmias, myocardial infarction, and sudden cardiac death.¹⁷ Hypertension is the most important risk factor for stroke and intracerebral hemorrhage, and the incidence of both are markedly reduced by effective antihypertensive therapy.¹⁸ BP reduction as low as a 2 mm Hg fall in mean systolic BP would be associated with 7% lower risk of ischemic heart disease death and a 10% lower risk of stroke death.¹⁹ When compared to diabetes, cigarette smoking, and dyslipidemia, hypertension is the most powerful risk factor for heart disease and stroke death.²⁰

Hypertension is also associated with nephrosclerosis secondary to chronic renal injuries and can accelerate the progression of underlying renal diseases, causing chronic renal insufficiency and end-stage renal disease.²¹

Malignant hypertension is an acute, severe elevation of BP that can be a life-threatening emergency.²² It is associated with papilledema, encephalopathy, subarachnoid hemorrhage, and intracerebral hemorrhage.

TABLE 24.3 DIFFERENTIAL DIAGNOSIS

Structural (ICD-9)	Metabolic (ICD-9)	Drug Induced (ICD-9)
Aortic dissection (441.0)	Atherosclerosis (440.9)	Cardiomyopathy, cocaine induced (425.4)
Aortic coarctation (747.1)	Malignant hypertension (401.0)	Cardiomyopathy, cocaine induced (425.4)
Sleep apnea (780.57)	Hyperthyroidism (242.9)
Renal artery stenosis (447.1)	Pheochromocytoma (194.0, 255.6)
Adrenal adenoma (227.0)	Primary hyperaldosteronism (255.1)
Essential hypertension (401.1)

Workup/Keys to Diagnosis

There are two goals to working up a patient with hypertension: (i) Establish whether the patient has essential hypertension, white coat hypertension or secondary hypertension, and (ii) determine end-organ damage (see Table 24.3). Once a patient has met the JNC 7 criteria for high BP, they should be examined for curable secondary causes of hypertension. In absence of signs of secondary hypertension, patients need to undergo a relatively limited workup.

Patients with elevated BP in the office and normal pressure at home may have white coat hypertension. In the absence of end-organ damage, a patient with “white coat hypertension” might require 24-hour ambulatory monitoring to establish their mean BP and determine whether treatment is necessary.

Laboratory testing should include complete blood count, urinalysis, urine microalbumin, complete metabolic profile, fasting lipid profile, and thyroid-stimulating hormone. Electrocardiogram (ECG), radiograph of the chest, and echocardiography may be indicated to determine myocardial hypertrophy. If renal artery stenosis is suspected, angiography is indicated. Measurement of plasma renin activity is usually performed only in patients with possible low-renin forms of hypertension, such as primary hyperaldosteronism.

Management

Medication sensitivity, atherosclerosis, renal dysfunction, and aging physiology conspire to potentiate adverse reactions to antihypertensive medication. Cognitive decline and the expense of medications may further challenge treatment. Therefore, all patients should be counseled about salt restriction, weight loss, and exercise (Evidence Level A).

When needed, antihypertensive therapy has been associated with 35% to 40% mean reductions in stroke incidence; 20% to 25% in myocardial infarction; and >50% in heart failure.²³ Controlling hypertension to below 130/80 mm Hg could prevent 37% of coronary artery diseases in men and 56% in women.²⁴

Equal if not greater benefits have been shown with the treatment of elderly hypertensive patients (older than 65), most of whom have isolated systolic hypertension. Because the elderly start at such higher overall cardiovascular risk, short-term reductions in their hypertension provide apparently greater benefits than that observed in younger patients.

Lifestyle Modification

Salt and alcohol restriction, weight reduction, calcium and magnesium supplementation, ingestion of a vegetarian diet or fish oil supplements, and possibly increasing potassium intake (40 to 80 mEq per day) have demonstrated benefits in the treatment of hypertension.³,²⁵ All of these maneuvers tend to induce a small and unpredictable reduction in BP in most patients.²⁶, ²⁷, ²⁸ Dietary modifications may also lower low-density lipoprotein-cholesterol (LDL-C) while raising high-density lipoprotein-cholesterol (HDL-C). The JNC 7 report recommends moderate sodium restriction (100 mEq per day). The easiest way to do this is by lowering intake of processed foods. Elderly patients, particularly those living alone, may depend on processed, prepackaged foods that are high in sodium rather than fresh foods. The elderly may ingest more sodium to compensate for a decrease in taste sensitivity, leading to volume expansion and a rise in BP.

Behavioral modification such as cessation of smoking, regular aerobic exercise and limited alcohol intake are as important as diet. Consumption of one to two drinks per day appears to reduce cardiovascular risk in hypertensive as well as normotensive patients but patients who consume more than two drinks per day have a twofold increase in the incidence of hypertension compared to nondrinkers.²⁹ Hostile attitudes and impatience should also be discouraged.³⁰

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