Postprandial Hypotension: Clinical Investigation In The Elderly Hypertensive Patients

Objective: Postprandial hypotension usually is defined as a fall in systolic blood pressure of at least 20mmHg that occurs within 2 hours of the start of meal ingestion or the systolic blood pressure decreases to less than 90 mmHg if the preingestion systolic blood pressure was greater than 100 mmHg. Symptomatic postprandial hypotension may arise from the systolic blood pressure falling which decreases less than 20 mmHg. In this situation, the autoregulation of cerebral blood flow may be unable to compensate the relative modest reduction in systemic blood pressure that is induceed by eating a meal. It is reported that the prevalence of postprandial hypotension varies from 2.6% of random selected community dwellers to 36% residents of the elder nursing home. PPH is an important clinical problem that may produce to a syncope, fall, angina pectoris, and cerebrovascular events. The clinical presentation is characterized by symptoms of lightheadedness with an onset within 30 minutes after meal. PPH has been reported in healthy elderly persons, elderly patients with hypertension, elderly residents of nursing homes, patients with Parkinson disease, and patients with diabetes mellitus. The pathogenesis of PPH is likely multifactories. These include inadequate sympathetic nervous system compensation for increased splanchnic blood postprandially; impaired baroreflex function; inadequate postprandial cardiac output; impaired peripheral vasoconstriction; and release of vasodilatory gastrointestinal peptides. Elderly patients with hypertension may be more susceptible to cerebral underperfusion because of the reduction in cerebral blood flow associated with both hypertension and ageing. Hypertension predisposes to a postprandial fall in blood pressure and simultaneously shifts the cerebral autoregulatory curve to the right so that the brain can tolerate a chronic highly perfusion pressure. Elderly hypertensive patients therefore, may develop symptoms with a smaller relative reduction in blood pressure than younger patients. When PPH occurs, it so easy causes cardio-cerebral ischemic symptoms to them. Ambulatory blood pressure monitoring (ABMP) is considered a valuable and useful test for the management of patients with hypertension. Because ABMP can produce considerable information about BP variations, it has been suggested that ABMP may be a useful test to detect the abrupt changes in BP in elderly persons, especially after a meal or with changes in posture. This trial studies the incidence of PPH, clinical features and the influence factors by doing 24-hour ambulatory blood pressure monitoring in elderly patients with hypertension, and explores the situation of PPH in the elderly patients with hypertension in the domestic.Methods: Select elderly patients with essential hypertension hospitalized of our hospital from 2010-10-12 to 2011-3-12 , whose condition is relatively steady, and give them 24-hour ambulatory blood pressure monitoring. The total selected subjects are 69 cases. They were divided into three groups: Group A was 30 cases from 60 to 69 years old, including 19 male and 11female, average age was (64.5±2.6). Group B was 25 cases from 70 to 79 years old, including 15 male and 10female, average age was (74.6±2.7). Group C was 14 cases from 80 to 94 years old, including 8 male and 6 female, average age was (83.8±5.4). All 69 patients have been performed 24-hour ABPM. Before doing ABPM the subjects were asked to fast at least 12 hours, and the cuff was applied to the left arm of the patients. The monitor was programmed to take readings every 15 minutes during the day(7:00AM to 10:00PM), and every 30 minutes at night (10:00PM to 7:00AM). Over 80% blood pressure measurement have been recorded in 24 hours that was effective ABPM. Less than 80% of recorded was considered an invalid measurement result and needed to be measured again. The circadian BP was considered as reversed when mean SBP during the day period was lower than mean SBP during the night period. Postprandial SBP declined (△SBP) was defined by the following equation:△SBP = preprandial SBP– postprandial SBP where preprandial SBP was average value of measuring SBP 2 times during preceding the meal, and postprandial SBP= minimum SBP during the 2 hours following the meal.△SBP》20mmHg was defined as PPH. Meanwhile we recorded the postprandial discomfort of patients, activities of patients during diurnal time, as well as the time patients went to sleep and slept quality.Results: (1) Postprandial blood pressure trend of 69 elderly patients with essential hypertension is declined. Among three meals this trend is similar.△SBP in breakfast (1.45 + 10.1) is more than lunch (7.8 + 12.2) and dinner (7.1 + 9.0), P<0.001. Group A has 8 patients of PPH (26.67 %) , and Group B has 7 (24.13 %), and Group C has 4 (28.57%). Distinction of△SBP among different age groups has no significant (P>0.05). (2) The incidence of PPH of 69 elderly patients is 27.54 %. The incidence of PPH after breakfast is higher (23.19 %) than lunch (10.15 %) and dinner (7.24 %), P<0.05. There is no distinction between lunch and dinner (P>0.05). The incidence of PPH among difference age groups has no statistical distinction (P>0.05). (3) These factors, including age, gender, BMI, activity during diurnal time, stroke, Cardiac disease, orthostatic hypotension and application of the drug have no obvious influence to PPH. Diabetes and diurnal variation of SBP could influence the incidence of PPH. (4) PPH can cause dizziness, fatigue, and angina pectoris as well as cardio-cerebral ischemic symptoms.Conclusion: Postprandial blood pressure trend of elderly patients with essential hypertension is declined.△SBP after breakfast is more than that after lunch and dinner.△SBP among different age groups was similar. The incidence of PPH of 69 elderly patients with essential hypertension is 27.54 %. The incidence of PPH after breakfast is higher. Diabetes and diurnal variation of SBP could influence the incidence of PPH. ABPM can provide abundant information about BP variation and rhythms, which is a very good means to diagnose PPH. PPH can cause cardio-cerebral ischemic symptoms, and should be strengthened recognition and intervention.