3.Causes of EH (1)Genetic Predisposition (2)Environmental factors: Increased sodium intake may cause hypertension in some patients who have a high sensitivity to sodium. Emotional stress may play a role in pathogenesis of hypertension 17
17 3. Causes of EH ⑴ Genetic Predisposition ⑵ Environmental factors: ▪ Increased sodium intake may cause hypertension in some patients who have a high sensitivity to sodium. ▪ Emotional stress may play a role in pathogenesis of hypertension
3.Causes of EH (1)Genetic Predisposition (2)Environmentl factors (3)Others: ■ Obesity:Hypertension is more common among obese individuals,especially in those with visceral or upper body obesity. Sleep apnea:Snoring and sleep apnea are clearly associated with hypertension,and this may be induced by increased sympathetic activity in response to hypoxemia during apnea. 18
18 3. Causes of EH ⑴ Genetic Predisposition ⑵ Environmentl factors ⑶ Others: ▪ Obesity: Hypertension is more common among obese individuals, especially in those with visceral or upper body obesity. ▪ Sleep apnea: Snoring and sleep apnea are clearly associated with hypertension, and this may be induced by increased sympathetic activity in response to hypoxemia during apnea
4.Mechanisms of Essential Hypertension Blood pressure(BP)=CO x TPR Any factor which will lead to an increase in cardiac output and TPR could precipitate hypertension. The interplay of various derangements in factors affecting cardiac output and peripheral resistance may precipitate the disease. 19
19 4. Mechanisms of Essential Hypertension ▪ Blood pressure(BP) = CO x TPR ▪ Any factor which will lead to an increase in cardiac output and TPR could precipitate hypertension. ▪ The interplay of various derangements in factors affecting cardiac output and peripheral resistance may precipitate the disease
Sympathetic nervous hyperactivity could raise blood pressure either alone or in concert with stimulation of renin release by catecholamines.However correlation between plasma catecholamines and blood pressure are poor.Insensitivity of the baroreflexes may play a role in the genesis of adrenergic hyperactivity. Renal sodium retention may cause hypertension in some patients who have a high sensitivity to sodium. 20
20 ❖Sympathetic nervous hyperactivity could raise blood pressure either alone or in concert with stimulation of renin release by catecholamines. However correlation between plasma catecholamines and blood pressure are poor. Insensitivity of the baroreflexes may play a role in the genesis of adrenergic hyperactivity. ❖Renal sodium retention may cause hypertension in some patients who have a high sensitivity to sodium
*The renin- stem (RAS) may play i 1 pathogene sion. Hyperinsu h resistance: Associatic ertension and hyper been recognize s.All obese people are nic secondary stance, particularly if the obesity is predominantly visceral,i.e., abdominal or upper body. 21
21 ❖The renin-angiotensin system (RAS) may play important role in pathogenesis of hypertension. ❖Hyperinsulinemia / insulin resistance: Association between hypertension and hyperinsulinemia has been recognized for many years. All obese people are hyperinsulinemic secondary to insulin resistance, particularly if the obesity is predominantly visceral, i.e., abdominal or upper body