Prevalence of the Hypertension Disease - Essay Example

?Hypertension Introduction Hypertension, or high blood pressure (BP), has been variously defined over the years with advances in the understanding ofthe etiology and pathophysiology of the condition. Blood pressure specifically refers to arterial blood pressure levels, with optimal levels being those that lead to minimal vascular damage. Normal levels of BP defined by Joint National Committee 7 (JNC 7) state values of 120 mm of Hg and 80 mm of Hg for systolic and diastolic respectively (Chobanian et al. 2003). The American Heart Association (AHA) defines hypertension as systolic and diastolic BP higher than 140 and 90 mm of Hg respectively (Carretero & Oparil 2000). BP related health conditions and comorbid conditions have been the major criteria guiding the definition of hypertension. Introduction of sphygmomanometer brought about the revelation that many of the renal, vascular and cardiac diseases are linked to elevated BP. BP is dependent on race and age, among many other factors. BP levels to be considered as elevated in comparison to normal, and the levels to be considered pathologic still remain arbitrary (Kotchen & Kotchen 2007). Prevalence of the disease To establish the prevalence of a condition, specific and precise definition of the condition is an essential prerequisite. Due to non-fulfillment of this criterion in cases of hypertension, an accurate value of prevalence is difficult to obtain. On the basis of a literature review of studies based on data from National Health and Nutrition Examination Surveys (NHANES), Crim and associates (2012) attempted to determine the prevalence of hypertension. The results indicated age-standardized prevalence rates of 28.9% to 32.1% for hypertension during the years 2003 and 2004. The prevalence rate for the same in United States during the years 2007-8 was found to be 29.8%. International data indicate a comparable or higher prevalence rates in countries other than U. S., with age dependent prevalence too being higher in European countries (Lloyd-Jones & Levy 2007). Causes or Risk factors for the disease Multiple variables including genetic, environmental, demographic and socioeconomic factors present a risk factor for hypertension (Lloyd-Jones & Levy 2007). The major risk factors are briefly described below: Age Prevalence of hypertension exhibits a steep rise with age; the rates are increasing from 9.3% in men of age group 18-34 years to 68.1% in men of age group 75 and above. Corresponding prevalence rates for women are 2.1% and 84.0% respectively. Studies have indicated age to be the most significant risk factor for hypertension and cardiovascular diseases with more than 9 out of 10 elderly people developing hypertension during their remaining life (Fields et al. 2004). 1.1 Weight The second major risk factor for hypertension is weight with prevalence rates being 42.5%, 27.8% and 15.3 % for individuals with Body Mass Index (BMI) of 30 kg/m2, 25.0-29.9 kg/m2 and >25.0 kg/m2 respectively (Fields et al. 2004). Similar results have also been obtained from long-term follow-up studies such as Framingham heart study. Recent researches have, however, reported that maintaining stable BMI for long period has a positive impact on BP (Lloyd-Jones & Levy 2007). 1.2 Other Risk Factors Other risk factors noted for hypertension include gender with more men in the age below 60 vulnerable to hypertension, but trends reverse in post 60 age group. Race and diet also affect prevalence of hypertension. African-Americans are more at risk. Individuals who have high dietary intake of sodium chloride are more vulnerable than those who take higher levels of magnesium, potassium and calcium salts. Omnivores are more at risk than vegetarians. Insulin resistance, high alcohol intake, sedentary life styles are also major risk factors (Carretero & Oparil 2000). Studies have also indicated a genetic predisposition affecting vulnerability to hypertension, but further studies are required to understand this aspect of the disease (Lloyd-Jones & Levy 2007). Symptoms The only consistent symptom of hypertension is elevated BP exclusively. Renal and cardiovascular problems associated with hypertension develop while the individual is ignorant of being hypertensive. Certain symptoms associated with extreme rise in BP include severe headache along with or without nausea or vomiting, confusion, vision alterations, and/or nosebleeds. Pathophysiology of the disease The major factors contributing to the pathophysiology of hypertension include enhanced activity sympathetic nervous system, psychological stress, elevated levels of hormones or vasoconstrictors that retain the sodium ion, or increased uptake leading to higher levels of the same, along with low levels of potassium and calcium ions due to inadequate intake (Figure 1). BP results as a consequence of heart contraction against blood vessel resistance. Thus Usually hypertension, or elevated BP, results due to a rise in systemic vascular resistance rather than a rise in cardiac output. Several factors contribute to a rise in the former, such as vasoconstrictors including angiostenin II, norepinephrine, throboxane, endothelin etc and vasodilators including prostaglandins, bradykinin etc. Besides these, Na+ levels are also significant contributors (Franco et al. 2007). Figure 1: Pathophysiology of hypertension: Renin-angiostensin system (Gilbert) Diagnosis of the disease The four steps to diagnosis of hypertension are initial evaluation, BP measurement, study of medical history and physical evaluation followed by laboratory tests and other confirmatory diagnostic procedures. Initial evaluation involves an assessment of baseline BP and extent of damage due to associated cardiovascular diseases. It enables a prognosis. Cuff technique is next used to measure BP of the patient using certified equipment such as a sphygmomanometer. An exhaustive physical examination of the patient along with study of complete medical history is done. This procedure includes gathering of information regarding the duration, type and symptoms of hypertension, history of cardiovascular diseases, family history, history of medications and lifestyle details. Physical examinations are conducted to obtain BP, verification in contralateral arm, body measurements, signs of organ damage, and funduscopic examination for hypertensive retinopathy. Finally laboratory tests such as urinalysis, complete blood count, blood chemistry and ECG are done (Carretero & Oparil 2000). Treatment of the disease Aim of treatment strategy for hypertension is either reducing cardiac output or lowering peripheral vascular resistance, or both. Thus, drug therapy includes administration of thiazide diuretics, ACE inhibitors, angiotensin II receptors antagonists, calcium channel blockers, ?-adrenoreceptor blockers and/or ?-blockers, vasodilators etc. Disease management strategy also focuses on lifestyle changes to lower sodium and alcohol intake through dietary modification, weight loss, and exercises. This is, in fact, the first line of management, drugs used only when this fails or the disease has already progressed to dangerous stage (Foex & Sear 2004). Conclusion Hypertension, or rise in blood pressure, is a condition affecting a large proportion of population worldwide. Irrespective of race and ethnicity, the current lifestyle patterns have further contributed to rise in prevalence of the condition. Besides multiple risk factors of its own, the condition is a major risk factor for several cardiovascular and renal diseases. It is, however, a modifiable risk factor. Though the condition is asymptomatic, regular checkups and identification of vulnerable populations can enable early identification of the condition. An early identification followed by disease management, though lifestyle changes, can lower the BP and prevent development of associated cardiovascular and renal diseases as well as organ damage. Thus, effective management of disease and awareness can lower global burden of this highly prevalent condition. References Carretero, OA, & Oparil, S 2000, 'Essential hypertension: part I: definition and etiology.' Circulation, pp. 329-35. Chobanian, AV, Bakris, GL, Black, HR, et al. 2003, Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; National Heart, Lung, and Blood Institute; National High Blood Pressure Education Program Coordinating Committee, Joint National Committee . Crim, MT, Yoon, SS, Oritz, E, Wall, HK, Schober, S, Gillespie, C, et al. 2012, 'National surveillance definitions for hypertension prevalence and control among adults, Circulation. Fields, LE, Burt, VL, Cutler, JA, et al. 2004, 'The burden of adult hypertension in the United States 1999 to 2000: a rising tide,' Hypertension, pp. 398-404. Foex, P, & Sear, JW 2004, 'Hypertension: pathophysiology and treatment,' Continuing Education in Anaesthesia, Critical Care and Pain, pp. 71-5. Franco, V, Calhoun, DA, & Oparil, S 2007, 'Pathophysiology of hypertension,' in HR Black & WJ Elliott, Hypertension: a companion to Braunwald's heart disease (pp. 25-48), Elseviers, Philadelphia. Gilbert, S 2007, Renin-Angiotesin system, viewed 2012, Tuftsopencourseware: Kotchen, TA, & Kotchen, JM 2007. 'Defining hypertension,' in HR Black & WJ Elliott, Hypertension: a companion to Braunwald's heart disease (pp. 49-57), Elseviers, Philadelphia, PA. Lloyd-Jones, DM, & Levy, D 2007. 'Epidemiology of hypertension,' In HR Black & WJ Elliot, Hypertension: a companion to Braunwald's heart disease (pp. 3-14), Elseviers, Philadelphia. Read More