Hypertension

Blood Flow www.sdm.scot.nhs.uk/images/pfo.jpg

Blood Pressure Measure of pressure exerted on the wall of the blood vessels Measure of the pressure exerted when heart contracts Normal: Contraction = systole = 105-139mmHg Relaxation = disystole = 70-90 mmHg Hypertension greater than 140/90 mmHg Symptoms --- often none

How controlled Controlled by mechanism in kidney Blood flow through kidney Cells sense the decreased volume, pressure and sodium Produce a enzyme call “renin” Renin breaks down protein to form angiotensin I Angiotension I converted to Angiotensin II by another enzyme called “Angiotension Converting Enzyme” or ACE Angiotension II increase BP and bring water and sodium into blood

Types of Hypertension Essential Systolic Secondary No identifiable cause Both systolic reading and disystolic readings are high Systolic Fewer cases/ more often in elderly Systolic reading elevated Secondary Kidney disease Cushings disease Diabetes Pre-eclampsia

Prevalence Less in more physically active group When controlled for activity, income, smoking, smoking, weight, Black had odds ratio of 1.77 compared to whites (0.73) (Bassett et.al, 2002) Higher percentage of hypertension in the Southeast- (Hall et.al, 1997) (Glover et.al, 2002) Black men 35%; Black women 37.7% (40.5%) White men 36.5%; White women 21.5% (27.4%) Why? Obesity– 25% Diet high in sodium and fat Lack of education Access and utilization of health care

Complications Earlier onset Stroke- 80% higher stroke mortality Heart Disease– 50% higher heart disease mortality Kidney Failure—320% greater End Stage Kidney Disease

Treatment Diet Exercise Drugs Diuretics– AKA “water pills” Beta Blockers—block receptors on heart to reduce the contractions ACE inhibitors Ca channel blockers Angiotension II inhibitors

Why more prevalent in African Americans? Decreased renin Stress Genetics Adaptation Food Lack of exercise

Race/ Gender 1960-1962 1971-1974 1976-1980 1989-1994 1997-2002 White/male 39.3 41.7 43.5 24.3 36.5 Black/male 48.1 51.8 48.7 34.9 35.5 White/ female 31.7 32.4 32.3 19.3 21.5 Black/ female 50.8 50.3 47.5 33.8 37.7 Centers for Disease Control

References Hall, et. al. (1997) Hypertension-related morbidity and mortality in the southeatern United States Glover et al. (2005) Racial/ethnic disparities in prevalence, treatment, and control of hypertension, MMWR weekly, January 14, 54, 7-9 National Institutes of Health, Joint National Committee on Prevention , Detection, Evaluation and Treatment of High Blood Pressure (1999), http:// www.ncbi.nlm.nih.gov.