The Characteristic Of Morning Surge Circadian And Mechanism Of Target Organ Damage In Essential Hypertension In Elderly

Backgroud:Effective antihypertensive management has decreased cardiovascular and cerebral vessel disease incidence in population,but the morbidity and mortality of cardiovascular and cerebral vessel disease are being highly in elderly with hypertension.Recently more and more attention are paid to clinic study on how to prevente hypertension and complications,what is more the 24 hour ambulatory monitoring development has had characteristic of chronobiology and blood pressure circadian rhythm understood deeply.In the early morning , blood pressure keep rising suddenly,SBP and DBP rise on the speed of 3 mm Hg/h and 2 mm Hg/h velocity repectively,even get to the peak of 80 mm Hg.It is morning surge that we explain the phenomenon when blood pressure being rising sharply. There has been the coincidence in time between moring surge and cardiac sudden death,myocardial infarction,unstable angina, stroke, however it is independent on 24 hour blood pressure level.So morning surge high reactive is a considerable risk factor.On the whole , hypertension patient in elderly should be paid moreimportant attension to decrease the cardiopathy morbidity and mortality,improve prognosis,develop health protection.Study on blood pressure circadian in elderly with essential hypertension has great medical practice significance.Based on lowering morning surge,we will try to keep or recover relative normal blood pressure circadian in elderly ,to maximum extent decreasing target organ damage. Objective :1 To compare 24hABPM with OBPM in monitoring morning surge of essential hypertension in elderly and making clinic assessment.2 To investigate the characteristic of morning surge blood pressure variability and circadian blood pressure mode of essential hypertension in elderly by the way of 24 hour ambulary blood pressure monitoring.3 To approach the relation among the morning surge and insulin resistance, rennin - angio tensin-aldersterone and hypothalamus-appendix-adrenal.4 To raise hypothesis: dawn phenomenon and morning surge show that hyperglycaemia in early morning has some relation to morning surge on the basis of insulin resistance.5 To investigate the potential damage morning surge has done to key target organs. Method:1 114 cases were divided into morning surge group of 54 cases and non-mornig of 60 cases choosed from total essential hypertension patients who agreed with withdrawing drug for 2 weeks, 32 cases of health control were collected respectively.Morning surge amplitude was calculated with two methods: (1) sleep-to-wake=2 hour average systolic blood pressure after waking- 2 hour average systolic blood pressure before waking; (2)sleep-trough=2 hour average systolic blood pressure after waking-minimum systolic blood pressure during nighttime.Morning surge was divided into two subgroups,persisitent group 37 and wave group 17.According the decreasing amplitude at nightdipper (10%～20%); over-dipper (≥20%) ;non-dipper (0%～10%) ;inverted dipper (≤0%) .2 To test cholesterone,fasting blood glucose, insulin, fibrinogen, body mass index, insulin resistance. Using the method of radioimmunity testing PRA, AngII, ALD, GH, COR, microalbuminuria and having linear correlation analysis.3 To detect LVMI, CCA-IMT, ICA-IMT and arteria brachialis endothelium diastolic function with ultrasound and QTcd in ECG.Result:1 OBPM readings have no significance between morning surge group and non-morning surge group.But systolic blood pressure is keeping rising the whole day and decreasing less at night in morning surge group of essential hypertension in elderly.2 24h, daytime, nocturnal and morning blood pressure are higher significantly than other groups(P<0.05),diastolic blood pressure has no significance. Systolic blood pressure and diastolic blood. pressure of sleep-trough indicated statistic significance. Over-dipper circadian show mainly is in wave morning surge group.3 FBG,Ang II ,ALD in morning group are more increaser than other groups (P<0.05 ),so GH and COR did (P<0.01) .4 Sleep-Troup morning surge has positive correlation to Ang II (r =0.42, P<0.01 ), ALD (r =0.28,P<0.05 ), GH(r=0.45,P<0.001),COR(r=0.32, P<0.01) , IR(r =0.39, P<0.01).5 LVMI, CCA-IMT, ICA-IMT, QTcd and microalbuminuria have significance than non-morning surge group (P<0.01) . ADD and NID are down regualted (P<0.05,P<0.01) in morning surge group. Especially the incidence of impaired glucose tolerance,left ventricular hypertrophy and stroke are highly significantly (P<0.05,P<0.05,P<0.01).Conclusion:1 24h ambulatory blood pressure monitoring profiles can provide more superiority than office blood pressure readings for antihypertensive in elderly.2 Sleep-trough morning surge is a better way to reflect morning surge variability.Morning surge circadian show multiple modes,the lower blood pressure decreas,the higher morning surge is.3 Morning surge suddenly keep latent stress state repeatedly, GH,COR disorder make glucose and insulin resistance more serious in morning ,so it is possible that dawn phenomenon has relation to moring surge phenomenon. Hyperglycemia decreasing should be paid attension when antihypertensive in elderly.4 Renin-angiotensin-alderstone and hypothalamus-pituitary-adrenal adjust interactly morning surge circadian regulation through ALD and COR.5 Morning surge hypertension in elderly is not a negligible risk factor,because it has had blood pressure rising ,blood pressure burden intensive,more target organ damage,myocardium remodeling serious,electric activity stability disappearing ,blood vessel endothelium remodeling, endothelium diastolic and systolic function disorder, nerve - endocrin system imbalance.