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Complications of hypertensionFrom Wikipedia, the free encyclopedia

Main complications of persistent high blood pressure

Complications of hypertension are clinical outcomes that result from persistentelevation of blood pressure .[1] Hypertension is a risk factor for all clinicalmanifestations of atherosclerosis since it is a risk factor for atherosclerosis itself.[2][3][4][5][6] It is an independent predisposing factor for heart failure ,[7][8] coronaryartery disease ,[9][10] [11] stroke ,[1] renal disease ,[12][13][14] and peripheral arterial

disease .[15][16] It is the most important riskfactor for cardiovascular morbidity and mortality , in industrialized countries .[17]

Contents

[hide ]

• 1 Complications affecting the heart

• 2 Complications affecting the brain

• 3 Complications affecting the eye

• 4 Complications affecting the kidneys• 5 Complications associated to diabetes and hypertension

o 5.1 Treatment for diabetic patients with hypertension

• 6 References

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Complications affecting the heart

Main articles: Left ventricular hypertrophy , Hypertensive cardiomyopathy ,and Myocardial infarction

Left ventricular hypertrophy

Hypertensive heart disease is the result of structural and functionaladaptations [18] leading to left ventricular hypertrophy ,[19][20][21] diastolic dysfunction ,[18][20]CHF , abnormalities of blood flow due to atherosclerotic coronary arterydisease [18] and microvascular disease ,[9][10][19] and cardiac arrhythmias .[19] Individuals with left ventricular hypertrophy are at increased risk for, stroke ,[22] CHF ,[22] and sudden death .[22] Aggressive control of hypertension can regressor reverse left ventricular hypertrophy and reduce the risk of cardiovascular disease .[23] [24][25][26] left ventricular hypertrophy are seen in 25% of thehypertensive patients and can easily be diagnosed by using echocardiography .[27] Underlying mechanisms of hypertensive left ventricular hypertrophy are of 2types: mechanical , mainly leading to myocyte hypertrophy ; neuro-hormonal ,mainly resulting in a fibroblastic proliferation .[27]

Abnormalities of diastolic function, ranging from asymptomatic heart disease [28][29]

[30] to overt heart failure ,[31][32] are common in hypertensive patients. Patients withdiastolic heart failure have a preserved ejection fraction , which is a measure of systolic function. [33][34] Diastolic dysfunction is an early consequence of hypertension-related heart disease and is exacerbated by left ventricular hypertrophy [20][34] and ischemia .

Complications affecting the brain

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Main articles: Hypertensive encephalopathy and Cerebrovascular accident

Hypertension is an important risk factor for brain infarction and hemorrhage. [1][10]

[35][36][37][38][39] [40] Approximately 85% of strokes are due to infarction and theremainder are due to hemorrhage , either intracerebralhemorrhage or subarachnoid hemorrhage .[41] The incidence of stroke risesprogressively with increasing blood pressure levels, particularly systolic bloodpressure in individuals >65 years. Treatment of hypertension convincinglydecreases the incidence of both ischemic and hemorrhagic strokes .[41]

Hypertension is also associated with impaired cognition in an aging population ,[42]

[43][43][44][45] Hypertension-related cognitive impairment and dementia may be aconsequence of a single infarct due to occlusion of a "strategic" larger vessel [46] or multiple lacunar infarcts due to occlusive small vessel diseaseresulting in subcortical white matter ischemia. [43][45][47][47][47] Several clinicaltrials suggest that antihypertensive therapy has a beneficial effect on cognitivefunction , although this remains an active area of investigation. [48][49][50]

Cerebral blood flow remains unchanged over a wide range of arterialpressures (mean arterial pressure of 50–150 mmHg) through a processtermed autoregulation of blood flow .[51] Signs and symptoms o f hypertensiveencephalopathy may include severe headache , nausea and vomiting (often of aprojectile nature), focal neurologic signs, and alterations in mental status .

Untreated, hypertensive encephalopathy may progressto stupor , coma , seizures , and death within hours. [52][53][54][55] It is important todistinguish hypertensive encephalopathy from other neurologic syndromes thatmay be associated with hypertension, e.g., cerebral ischemia , hemorrhagic or thrombotic stroke, seizure disorder , mass lesions, pseudotumor cerebri , deliriumtremens , meningitis , acute intermittent porphyria , traumatic or chemical injury tothe brain, and uremic encephalopathy .[41]

Complications affecting the eye

Main article: Hypertensive retinopathy

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Hypertensive retinopathy with AV nicking and mild vascular tortuosity

Hypertensive retinopathy is a condition characterized by a spectrum of retinalvascular signs in people with elevated blood pressure .[56] It was first described byLiebreich in 1859. [57] The retinal circulation undergoes a series of pathophysiological changes in response to elevated blood pressure. [58] In theinitial, vasoconstrictive stage , there is vasospasm and an increase inretinal arteriolar tone owing to local autoregulatory mechanisms . This stage isseen clinically as a generalized narrowing of the retinal arterioles . Persistentlyelevated blood pressure leads to intimal thickening, hyperplasia of the mediawall , and hyaline degeneration in the subsequent, sclerotic , stage. This stagecorresponds to more severe generalized and focal areas of arteriolar narrowing,changes in the arteriolar and venular junctions, and alterations in the arteriolar light reflex (i.e., widening and accentuation of the central light reflex, or "copper wiring"). [59]

This is followed by an exudative stage, in which there is disruption of the blood–retina barrier , necrosis of the smooth muscles and endothelial cells , exudation

of blood and lipids , and retinal ischemia . These changes are manifested in theretina as microaneurysms , hemorrhages , hard exudates, and cotton-wool spots.Swelling of the optic disk may occur at this time and usually indicates severelyelevated blood pressure (i.e., malignant hypertension ). Because better methodsfor the control of blood pressure are now available in the general population,malignant hypertension is rarely seen. In contrast, other retinal vascular

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complications of hypertension, such as macroaneurysms and branch-veinocclusions , are not uncommon in patients with chronically elevated bloodpressure. These stages of hypertensive retinopathy however, may not besequential. [58][60] For example, signs of retinopathy that reflect the exudative

stage, such as retinal hemorrhage or microaneurysm , may be seen in eyes thatdo not have features of the sclerotic stage, [58] The exudative signs arenonspecific, since they are seen in diabetes and other conditions.

Complications affecting the kidneys

Main article: Hypertensive nephropathy

Hypertension is a risk factor for renal injury and ESRD .[61][62] [63][64][65][66][67] Renal riskappears to be more closely related to systolic than to diastolic blood pressure ,[68]

[69] and black men are at greater risk than white men for developing ESRD atevery level of blood pressure. [70][71] [72][73][74]

The atherosclerotic , hypertension-related vascular lesions in the kidney primarilyaffect the preglomerular arterioles, [68][75] [76] resulting in ischemic changes in theglomeruli and postglomerular structures. [41]Glomerular injury may also be aconsequence of direct damage to the glomerular capillaries due to glomerular hyperperfusion. Glomerular pathology progresses to glomerulosclerosis ,[77][78] andeventually the renal tubules may also become ischemic and gradually atrophic .

The renal lesion associated with malignant hypertension consists of fibrinoidnecrosis of the afferent arterioles ,[79][80][81] [82][83][84][85] sometimes extending intothe glomerulus , and may result in focal necrosis of the glomerular tuft .[81][86][87]

Clinically, macroalbuminuria (a random urine albumin /creatinine ratio >300 mg/g) or microalbuminuria (a random urine albumin /creatinine ratio 30–300 mg/g) are early markers of renal injury. These are also risk factors for renaldisease progression and for cardiovascular disease .[41]

Complications associated to diabetes andhypertension

Diabetes has several complications of which one is hypertension or high bloodpressure. Data indicate that at least 60-80 percent of individuals whom developdiabetes will eventually develop high blood pressure. The high blood pressure isgradual at early stages and may take at least 10–15 years to fully develop.

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Besides diabetes, other factors that may also increase high blood pressureinclude obesity , insulin resistance and high cholesterol levels. In general, fewer than 25 percent of diabetics have good control of their blood pressure. Thepresence of high blood pressure in diabetes is associated with a 4 fold increase

in death chiefly from heart disease and strokes. [88]

The chief reason why people with diabetes develop high blood pressure ishardening of the arteries . Diabetes tends to speed up the process of atherosclerosis. The other fact about diabetes is that it affects both large andsmall blood vessels in the body. Over time, blood vessels become cloggedwith fatty depots , become non-compliant and lose their elasticity. The process of atherosclerosis is a lot faster in diabetic individuals whom do not have goodcontrol of their blood sugars . The high blood pressure eventually leads to heart

failure, strokes, heart attacks, blindness , kidney failure , loss of libido and poor circulation of blood in the legs. When the blood supply to the feet iscompromised, the chances of infections and amputations also increases. Alldiabetics should know that even mild elevations in blood pressure can bedetrimental to health. Studies have shown that diabetics with even a slightelevation in blood pressure have 2-3 times the risk of heart disease compared toindividuals without diabetes. [89]

Blood pressure readings do vary but experts recommend that blood pressure

should not range above 130/80. Secondly, high blood pressure is a silent diseaseand thus it is vital for all diabetics to regularly check their blood pressure or haveit checked at a doctor's office on a regular basis. The American DiabetesAssociation recommends that all diabetics get their blood pressure measured bya health care professional at least 2-5 times a year. [90]

Treatment for diabetic patients with hypertensionOnce blood pressure is found to be high in diabetics, there are ways to treat it:

Medications like the Angiotensin-converting enzyme inhibitors (ACEI) are widelyused to control blood pressure in diabetics. These medications not only controlblood pressure but also delay or prevent the development of kidney disease indiabetes. Many studies have shown that ACEI should be the drugs of first choicein diabetics with high blood pressure. Other medications used to treat high bloodpressure include water pills. Sometimes, a combination of medications is used totreat high blood pressure. All diabetics should quit smoking . The combination of

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diabetes and smoking usually leads to amputations of the toes and feet. Measureyour blood sugars regularly, and make sure that they are well balanced as themajority of complications of diabetes can be prevented by ensuring such bloodsugars stay within normal limits. [91] It is also recommended to eat a healthy diet

and avoid sugary foods and limit the intake of salt. Also, ensure thatyour cholesterol levels are under control. Exercise is a must for all diabetics.Walking twice a day for 30 minutes can be a fair substitute for those not engagedin intense gym activities. Losing weight is also beneficial as this has been shownto improve blood sugar control, increase insulin sensitivity and reduce bloodpressure. [92]