hyertension课件

Hypertension,告報者：劉佩姎 營養師 日期：93/03/25,L. Kathleen Maban and Sylvia Escott-Stump:Food, Nutrition & Diet Therapy, 9th,Hypertension,Hypertension is the most common public health problem in developed countries. Called Silent Killer No cure is available, but prevention and management decrease the incidence of hypertension and disease sequelae.,Classification,Essential or Primary hypertension: 90 95% the cause cant be determined, therefore treatment is nonspecific. Secondary hypertension: caused by another disease, ex: renal or endocrine,SBP (systolic blood pressure) 140 mmHg and/or DBP (diastolic blood pressure) 90 mmHg,Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure,Prevalence,Morbidity and Mortality,Physiology,Blood pressure levels: a function cardiac output mutipied by peripheral resistance (the resistance in blood vessels to the flow of blood) Diameter of blood vessels Sympathetic nerve system ( for short-term control) Kidney (for long-term control),Blood Pressure fail Sympathetic nerve system Norepinephrin Act on small arteries and arterioles peripheral resistance Blood Pressure,Decreased arterial pressure Renin (Kidney) Renin substrate Angiotensin I (Plasma protein),Coverting Enzyme (Lung),Angiotensin II,(Inactived),Regulatory mechanism falter, hypertension develop. Neurohormonal and intrarenal Peripheral resistance left ventricle of heart increase effort in pumping blood left ventricular hypertrophy congestive f=heart failure,Primary prevention,A population strategy: lower the blood pressure in general population A targeted strategy: direct intervention to lower blood pressure at individuals who are at greatest risk of developing hypertension.,Genetic predisposition to H/N interacts Obesity Life-style Dietary components,Diet-related factors influencing development of hypertension,Changing four modifiable factors has documented efficacy in the primary prevention of hypertension. -Overweight -High salt intake -Alcohol consumption -Physical inactivity,Overweight,Two to six times higher in overweight than in normal-weight individuals Higher prevalence rates are seen in Mexican-Americans and non-Hispanic black women Greater fluctuation in weight 5059 yr non-Hispanic white women 3039 yr non-Hispanic black and Mexican-American women 2034 yr weight gaining more than 30 lb in a 10 years,Factor associated,Low educational attainment Low socioeconomic status,Framingham Study,Increase related weight of 10% was predictive of a 7 mmHg rise in blood pressure,Inuslin resistance hyperinsulinemia activation of sympathetic nervous and renin-angiotensin system physical changes in the kidney,BMI,Energy intake plasma insulin increase renal sodium reabsorption blood pressure ,Early identification of children as potential hypertensive,Excess consumption of sodium Chloride,Consuming 100 mEq/day or less or sodium was associated with a 2.2 mmHg fall in SBP The rise in SBP seen with aging over 30 years would be 9 mmHg less and the rise in DBP 4.5 mmHg less if the average sodium intake were lowered by 100 mEq/day,Alcohol Consumption,Three drinks per days (a total of 3 oz of alcohol) is the threshold for raising blood pressure and is associated with a 3 mmHg rise,Not more than 1 oz of ethanol/day, which is equal to 2oz of 100-proof whiskey, or 24 oz of beer,Exercise,Physical activity produces a fall in SBP and DBP of about 6 to 7 mmHg,Moderate physical activity defined as 30 to 45 minutes of brisk walking, three to five times per week,Other Dietary Factors,Potassium Calcium Magnesium Lipids,Potassium,Inversely related higher potassium intakelower blood pressure reduces peripheral vascular resistance by direct arteriolar dilatation, increase loss of water and sodium from the body Sodium: potassium ratio of the diet is related to BP,Clinical trails with potassium supplement yielded mixed results Dietary potassium is an adjunct to weight control and reduced sodium consumption for prevent of H/N Na:K ratio of 1.0 is the goal,Calcium,African-American and women Clinical trials showed minimal hypotensive effects of high dietary calcium intake from foods or supplement . Calcium from dietary sources to meet the RDA is recommended,Magnesium,Mg is a potent inhibitor of vascular smooth muscle contraction and may play a role in blood pressure regulation as a vasodilator. Most clinical studies, Mg supplement has been ineffective in altering blood pressure, possible because of the confounding effects of antihypertensive medications and the short duration of the studies. Adequate data are lacking to recommend routine supplement with magnesium to prevent hypertension,lipids,PUFA Precursors of prostaglandins -affect renal sodium excretion -relax vascular musculature,Large doses of fish oils (50 ml daily with 15g -3 PUFA) have lowered BP in mildly hypertensive men Knapp and Fitzgerald, 1989 Smaller doses (620g fish oil/daily) had no effect on BP in hypertensive or normotensive subjects Lofgren, 1993; Sack, 1994,Small doses are hazardous with respect to their effect on bleeding time, weight gain, glycemic control and LDL-cholesterol,-3 FA is not recommended for preventing hypertension,Combination of risk factors for cardiovascular disease,Medication Management Life-style modification Weight management Salt restriction,Medication,Either raise blood pressure or interfere with the effectiveness of antihypertensive drugs, ex: oral contraceptives, steroid, nonsteroidal, anti-inflammatory agent, nasal decongestants, other cold remedies, appetite suppressants, tricyclic antidepressants.,Management,Goal: to reduce morbidity and mortality from stroke, hypertension-associated heart disease and renal disease. -increase to at least 50% the number of people with hypertension whose BP is less than 140/90.,Life-style modification,Before drug therapy is begun, three to six months of compliant life-style modification should be tried. Life-style modification cant completely correct the BP, but they will help increase the efficacy of pharmacological agents and improve other CVD risk factor.,Life-style modification,Weight management,The effectiveness of weight reduction has been well documented in high in both mild and severe hypertensives. Lower blood p