HYPERTENSION A Worldwide Epidemic

Hypertension is a major public health problem in the US and worldwide. More than a quarter of world’s adults population totalling one billion, have it. National Health and Nutrition Examination Survey (NHANES) predicted that 63.3 million Americans (20 % of population) are hypertensive (Systolic BP more than 140 and Diastolic BP more than 90). It…

Written by

DR. ANIS ANSARI

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Hypertension is a major public health problem in the US and worldwide. More than a quarter of world’s adults population totalling one billion, have it. National Health and Nutrition Examination Survey (NHANES) predicted that 63.3 million Americans (20 % of population) are hypertensive (Systolic BP more than 140 and Diastolic BP more than 90). It is the second most prevalent chronic disease and account for $33 billion in direct cost and $280 billion in lost production every year.

World health Organisation (WHO) cites a “second wave” epidemic of cardiovascular disease (CVD) related to hypertension and other factors in developing countries and projects that CVD will likely be number one cause of death in the world by 2020. It is a condition that tends to be under diagnosed and inadequately treated even when known. The majority of treated hypertensive patients are not at a goal. Hypertension is the second most common cause of renal failure in dialysis patients.  It is a major risk factor for cardiovascular diseases for example heart attack, stroke and congestive heart failure. Risk of cardiovascular disease increases progressively as blood presser rises.

 

CAUSE

It is true that for 90% of hypertension, cause is unknown. Only in 10% of the cases the cause maybe evident. Some of the reasons known so far are related to renal artery narrowing, pheochromocytoma, and hyperaldosteronism (related with adrenal glands) etc. Sleep Apnea is also known to cause hypertension.

 

 STAGES

Accordingly to Joint National Committee (JNC7) on prevention, detection, evaluation and treatment of high blood pressure has defined stages as following:

 

Normal BP                          Systolic BP <120                Diastolic BP <80

Pre-Hypertension              120-139                                 80-89

Stage 1                                  140-159                                90-99

Stage 2                                  =or>160                                =or >100l

 

Most organisations recommend goals of blood pressure to be less than 130/80 in diabetic and chronic kidney disease patients.

 

PREVALENCE

The prevalence of hypertension increases with age in both men and women.  Until age 55, men are slightly greater risk but after 55, older women in particular, are at considerably greater risk for hypertension. Rising prevalence of hypertension and associated risk with high cholesterol level and obesity represents a “pandemic” newly identified in the past 50 years.  More than 85% of hypertension occurs in overweight or obese persons.  Highest prevalence of hypertension was found in African-Americans. For individuals older than 50 years, life time risk of developing hypertension approaches 90%.

 

SYSTOLIC VS. DIASTOLIC

The coronary artery disease risk correlates with more closely with systolic blood pressure than to diastolic blood pressure for individuals who are older than 55 years whereas risk is more strongly predicted by diastolic blood pressure for individuals who are younger than 55 years. Isolated systolic hypertension (SBP>140, DBP< 90) attributed mainly to increased vascular stiffness from aging. Isolated diastolic hypertension (SBP<140, DBP >90) is more common in men, smoker, and obese younger individuals.

 

METHOD OF BP MEASUREMENT

Office and/or “white coat” effects significantly, mis-classifying as hypertensive 10 – 20% of patients who have lower BP at home or during ambulatory blood pressure monitoring (ABPM). ABPM offers more precise prediction of target injury related to BP as reflected by left ventricular enlargement, protein in the urine or stroke. Studies from Dublin, Ireland showed ABPM to be more correlated with a hazard ratio than clinic BP and were independently an additional risk factor of cardiovascular mortality.

 

DIPPERS VS. NON-DIPPER

Patients whose blood pressure drops while asleep (Dipper) are better off than those whose blood pressure does not drop (Non–Dipper).  The lack of nocturnal fall in BP increased thrombotic stroke risk while blood pressure surges in the morning increased risk of intra cerebral hemorrhage risk.  Non-Dipper BP was also associated with renal failure, an impaired ejection fraction of heart and high mortality.

 

DIET

Researches have identified dietary modification well known to lower blood pressure including reduced salt intake, weight loss, moderation of an alcohol intake among drinkers and adherent to dietary approach to stop hypertension (DASH diet). DASH diet emphasises fruits, vegetables and low fat dairy product. Diet also includes whole grains, poultry, fish and restrict fat, red meats, sugar and sugar containing beverages.

 

TREATMENT

Evidence-based approach to Treatment of hypertension is still evolving. Most patients are salt and volume-sensitive and would be expected to respond to salt a restriction, water pill or both. Due to that some studies have emphasised that initial treatment of hypertension should be a water pill. While in stage 2, combinations of two anti-hypertensive medications should be started. Class of medication also depends on the other co-morbid conditions. Patients with diabetes, congestive heart failure, or coronary artery disease must be maintained on Angiotensin Converting Enzyme Inhibitor (ACEI) or Angiotensin Receptor Blocker (ARB) or Direct Renin Inhibitor while patients with recent heart attack need to be on beta blocker. Efforts are underway to develop Angiotensin-Targeting Vaccines as treatment for hypertension. Patients with sleep Apnea should be placed on Continuous positive airway pressure (CPAP) breathing machines.

 

CONCLUSION

Hypertension is a very complex entity that should be taken very seriously.  It can affect every system in the body and can cause stroke, blindness, heart attack, kidney failure, and blockages in the legs. Having good blood pressure control can alleviate the exacerbation of these problems.  Close follow-up is required.  More awareness efforts are still needed to tackle this complex and worldwide medical epidemic.

[Dr. Anis Ansari is Board Certified Nephrologist, Medical Associate, Clinton, Iowa]