Hypertension in the elderly

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Chapter 13 Hypertension in the elderly


Sonia Sehgal, MD, Neetu Bhola, MD, and Jung Hee Han, DO




Introduction


The number of older adults is growing, and the majority of this population has hypertension. Essential hypertension is the leading diagnosis in outpatient visits in the United States in the geriatric population.[1] It is brought on in part due to the physiologic changes of aging, but for some it occurs earlier due to lifestyle or other risk factors. Hypertension increases the risk for multiple medical conditions which can lead to decreased health status, functional ability and survival. Adequately treating hypertension in the elderly is beneficial and can reduce the risk of stroke, heart failure, and death due to cardiovascular disease. Owing to the unique characteristics of this special population, treatment recommendations require special consideration. This chapter will review both the evaluation and management of hypertension in elderly persons.



Epidemiology


Hypertension remains a chronic and prominent health condition affecting the morbidity and mortality of a great proportion of the elderly population. According to the National Health and Nutrition Examination Survey (NHANES) 2007 to 2010, age-adjusted prevalence of hypertension among people 18 years of age and older was 29.6%. The prevalence sharply increases to 71.6% in those 65 years of age and over.[2] In the Framingham Heart Study, 90% of those 55 years of age and older who were not diagnosed with hypertension went on to develop the condition.[3] Although increasing awareness has improved control rates among all age groups, the rates are unacceptably high in older adults with only 48.6% of this population having controlled hypertension, with highest rates in certain minority populations. Despite improved control, hypertension remains an important risk factor for cardiovascular disease, congestive heart failure and stroke.



Pathophysiology


Age related changes in arterial structure and function predispose older individuals to hypertension. Large vessels stiffen due to impaired function of elastin protein, increased collagen and loss of smooth muscle cells. Also contributing to this vascular dysfunction is atherosclerosis and calcium deposition within the vessel wall. This increased arterial stiffness leads to increased peripheral vascular resistance and decreased vascular compliance. Increased afterload and left ventricular hypertrophy follow.


Progressive renal dysfunction with a decrease in glomerular filtration rate and changes in the kidneys’ ability to manage sodium regulation result in heightened sensitivity to dietary sodium intake and elevated blood pressures. Two-thirds of older adults have salt-sensitive hypertension.


Age associated changes in the sympathetic nervous system also contributes to impaired blood pressure regulation. Decreased baroreflex sensitivity leads to increased blood pressure variability – most noticeably a delayed response in heart rate to decreased blood pressure.


Additional factors contributing to blood pressure dysfunction in the elderly include increased risk of orthostatic and postprandial hypotension – often complicating management strategies. Also, circadian variability in blood pressure leads to relatively higher nighttime and early morning blood pressures increasing an older adult’s risk of myocardial infarction and stroke.


Lifestyle, tobacco, alcohol, caffeine, and certain medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, antidepressants, decongestants, and migraine medications also negatively impact blood pressure control in the elderly patient.



Diagnosis and evaluation


Blood pressure levels as defined by the JNC7 (the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) are noted in Table 13.1. Although the most recent evaluation of available literature conducted by the Eighth Joint National Committee (JNC8) did not redefine blood pressure levels, it did recommend treating hypertensive patients older than 60 years of age to a blood pressure goal of less than 150/90 mmHg.[4]



Table 13.1 Classification of blood pressure levels






































Category Systolic (mmHg) Diastolic (mmHg)
Normal <120 and <80
Prehypertension 120–139 or 80–89
Hypertension:
Stage 1 140–159 or 90–99
Stage 2 >160 or >100

To diagnose hypertension in the elderly, at least three separate blood pressure measurements obtained on two different office visits are needed. Additional measurements as well as orthostatic readings may be required due to increased variability in blood pressure in older adults. Particular attention should be given to using the appropriate cuff size, placing the arm at the level of the heart, and obtaining the readings in a relaxed setting – preferably with the patient seated comfortably for five minutes.


Ambulatory (home) blood pressure monitoring is useful for the evaluation of “white coat” hypertension or patients with a great deal of variability between readings. Increased rigidity of the peripheral arteries due to calcification and atherosclerosis in the rare patient can lead to pseudohypertension. Due to the incomplete compression of the brachial artery when the blood pressure cuff is inflated, falsely elevated systolic readings are obtained. Pseudohypertension should be suspected in patients with refractory hypertension without expected end organ damage or when hypotension results unexpectedly after starting antihypertensive medications. When measuring blood pressures the auscultatory gap (an indication of arterial stiffness) can lead to artificially low readings. To avoid such inaccuracies, inflate the blood pressure cuff 40 mmHg higher than the pressure needed to occlude the brachial pulse.


Initial history should include a review of personal cardiac risk factors, family history as it relates to cardiac disease, evaluation of medications (including prescribed and over-the-counter), herbal remedies, and other supplements. In addition, discussing lifestyle choices (tobacco, alcohol and substance, exercise history, and dietary preferences) is useful. Compliance with sodium restriction and antihypertensive medications may be useful for those patients diagnosed with hypertension who have poor control. High-risk comorbid conditions such as diabetes mellitus, congestive heart failure, stroke, and hyperlipidemia should also be assessed.


Physical exam maneuvers should focus on the cardiovascular system and potential sites of end organ damage from uncontrolled blood pressure. Funduscopic examination to identify papilledema or retinopathy, carotid examination to evaluate bruits, heart examination with particular focus on murmurs, cardiac rhythm, and heart size as well as peripheral pulses and abdominal bruits are cardinal elements of the physical exam needed to evaluate a patient with hypertension. Laboratory and investigative studies should include an electrocardiogram, basic metabolic panel to examine electrolytes, kidney function and glucose, a fasting lipid panel, and urinalysis.


As in younger patients, secondary causes of hypertension such as renal artery stenosis, renal failure, hyperaldosteronism, Cushing’s syndrome, pheochromocytoma, obstructive sleep apnea, and hyperthyroidism should be evaluated in those with refractory hypertension.

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Feb 26, 2017 | Posted by in GERIATRICS | Comments Off on Hypertension in the elderly
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