Lower Mean Blood Pressure Research Articles

Prevalence and correlates of mitral valve prolapse in a population-based sample of American Indians: the strong heart study

Purpose Mitral valve prolapse is heritable and occurs frequently in the general population despite associations with mitral regurgitation and infective endocarditis, suggesting that selective advantages might be associated with mitral valve prolapse. Subjects and methods Clinical examination and 2-dimensional and color Doppler echocardiography were performed in 3340 American Indian participants in the Strong Heart Study. Results Mitral valve prolapse (clear-cut billowing of one or both mitral leaflets across the mitral anular plane in 2-dimensional parasternal long-axis recordings or >2-mm late systolic posterior displacement of mitral leaflets by M mode) occurred in 37 (1.8%) of 2077 women and 20 (1.6%) of 1263 men ( P = 0.88); 32 (3.5%) of 907 patients with normal glucose tolerance, 11 (2.3%) of 486 patients with impaired glucose tolerance, and 13 (0.7%) of 1735 patients with diabetes ( P <0.0001). Participants with mitral valve prolapse had lower mean (± SD) body mass index (28 ± 5 kg/m 2 vs. 31 ± 6 kg/m 2, P = 0.001) and blood pressure (124/71 ± 19/10 mm Hg vs. 130/75 ± 21/10 mm Hg, P <0.05), as well as lower levels of fasting glucose, triglycerides, serum creatinine, and log urine albumin/creatinine ratio (all P <0.001), than did those without mitral valve prolapse, although all subjects were similar in age (60 ± 8 years). Participants with mitral valve prolapse had lower ventricular septal (0.87 ± 0.08 cm vs. 0.93 ± 0.13 cm) and posterior wall thicknesses (0.82 ± 0.08 cm vs. 0.87 ± 0.10 cm), mass (38 ± 7 g/m 2.7 vs. 42 ± 11 g/m 2.7), and relative wall thickness (0.33 ± 0.04 vs. 0.35 ± 0.05), and increased stress-corrected midwall shortening (all P <0.01). Mitral valve prolapse was associated with a higher prevalence of mild (16 of 57 [28%] vs. 614 of 3283 [19%]) and more severe mitral regurgitation (5 of 57 [9%] vs. 48 of 3283 [1%], P <0.0001). Regression analyses showed prolapse was associated with low ventricular relative wall thickness, high midwall function, and low urine albumin/creatinine ratio, independent of age, sex, body mass index, and diabetes. Conclusions Mitral valve prolapse is fairly common and is strongly associated with mitral regurgitation in the general population. However, it is also associated with lower body weight, blood pressure, and prevalence of diabetes; a more favorable metabolic profile and ventricular geometry; and better myocardial and renal function.

The impact of ischaemic preconditioning on spinal cord blood flow and paraplegia

Purpose: We investigated the effect of ischaemic preconditioning (IP) on ischaemic spinal cord injury in a rabbit model. Methods: Fourteen rabbits were divided into IP and control groups of seven rabbits each. We repeated 3-min clamping of the infrarenal abdominal aorta and 3-min reperfusion twice (preconditioning), followed by 15 min clamping in the IP group. In the control group, the aorta was clamped for 15 min without preconditioning. Lumbar cord blood flow and systemic blood pressure were measured until 3 h of reperfusion. Another 14 rabbits underwent the same procedures with or without IP and neurologic status was assessed on the second postoperative day. Results: The percent change in lumbar cord blood flow after reperfusion was significantly greater ( P=0.013) in the IP group despite lower mean blood pressure. There was no significant difference in overall neurologic status ( P=0.461) but the incidence of spastic paraplegia in the IP group was lower (14%, 1/7) than that of control group (43%, 3/7). Conclusion: IP increased postischaemic lumbar cord blood flow and contributed to lower incidence of spastic paraplegia.

Comparative effects of aging in men and women on the properties of the arterial tree

OBJECTIVESWe measured the properties of the arterial tree, seeking differences between men and women as they aged.BACKGROUNDThere are many differences between men and women, besides menopause, which might account for such disparities. These include body height, heart rate, stroke volume and smaller arterial diameters. Any gender differences in arterial stiffness could influence pulse pressure (PP), now recognized as a cardiovascular risk factor.METHODSA total of 530 patients (347 men and 183 women) were classified by age into quartiles: ≤40, 41–47, 48–54 and ≥55 years. The middle groups represented the menopausal years. Studies included brachial artery blood pressure (BP), aortic pulse wave velocity (PWV), B-mode ultrasonography and wave form analysis of the common carotid artery (CCA), with its conversion to the aortic wave form. Standard echocardiography provided left ventricular dimensions and flows. Calculated values included CCA compliance and distensibility, systemic compliance, stroke volume and peripheral resistance.RESULTSAt all ages, women had higher heart rates but lower BP than men. Pulse pressure, however, was lower in young women and higher in older women. Measurements influenced by body size, such as CCA diameter, compliance and systemic compliance, were lower in women. Those related to arterial wall properties, such as CCA and aortic distensibility, were the same. Although aortic PWV rose similarly with aging, PWV had more of an influence on PP in women than did mean BP. The reverse was true in men.CONCLUSIONSDespite lower mean BP and similar arterial distensibility, women develop a higher degree of pulsatility with aging, as compared with men. This is mainly due to their smaller physical characteristics, independent of the role of menopause and its related hormonal changes.

Relationship between ocular perfusion pressure and retrobulbar blood flow in patients with glaucoma with progressive damage

PURPOSE: To evaluate the relationship between ocular perfusion pressure and color Doppler measurements in patients with glaucoma. MATERIALS AND METHODS: Twenty patients with primary open-angle glaucoma with visual field deterioration in spite of an intraocular pressure lowered below 21 mm Hg, 20 age-matched patients with glaucoma with stable visual fields, and 20 age-matched healthy controls were recruited. After a 20-minute rest in a supine position, intraocular pressure and color Doppler measurements parameters of the ophthalmic artery and the central retinal artery were obtained. Correlations between mean ocular perfusion pressure and color Doppler measurements parameters were determined. RESULTS: Patients with glaucoma showed a higher intraocular pressure ( P < .0008) and a lower mean ocular perfusion pressure ( P < .0045) compared with healthy subjects. Patients with deteriorating glaucoma showed a lower mean blood pressure ( P = .033) and a lower end diastolic velocity in the central retinal artery ( P = .0093) compared with normals. Mean ocular perfusion pressure correlated positively with end diastolic velocity in the ophthalmic artery (R = 0.66, P = .002) and central retinal artery (R = 0.74, P < .0001) and negatively with resistivity index in the ophthalmic artery (R = −0.70, P = .001) and central retinal artery (R = −0.62, P = .003) in patients with deteriorating glaucoma. Such correlations did not occur in patients with glaucoma with stable visual fields or in normal subjects. The correlations were statistically significantly different between the study groups (parallelism of regression lines in an analysis of covariance model) for end diastolic velocity ( P = .001) and resistivity index ( P = .0001) in the ophthalmic artery, as well as for end diastolic velocity ( P = .0009) and resistivity index ( P = .001) in the central retinal artery. CONCLUSIONS: The present findings suggest that alterations in ocular blood flow regulation may contribute to the progression in glaucomatous damage.

Acculturation and blood pressure in a community-based sample of Chaldean-American women.

With the steady increase of non-European, non-English speaking immigrants to the United States, the relationship between acculturation and risk for cardiovascular disease (CVD) is an issue of growing importance to researchers interested in the health of new immigrant populations. The influence of acculturation processes on adverse changes in blood pressure (BP), a major risk factor for CVD, has been examined in Hispanic-Americans and Asian-Americans. Published studies on this relationship in Arab-Americans are lacking, however, despite their growing numbers. With a specific focus on Chaldean-Americans, a major subgroup of the large Arab-American population located in metropolitan Detroit, Michigan, the current study investigates the influence of level of acculturation on BP in a community probability sample of 130 Chaldean-American women. Study participants were interviewed in their homes (92% response rate). Physical measurements included BP, body mass index (BMI), and waist-hip ratio. Demographic and acculturation data were obtained through a standardized questionnaire. The crude hypertension prevalence in the sample was 16%. Three dimensions of acculturation were identified through content and factor analysis: English language preference, parental school involvement, and ethnic identity. In unadjusted analyses, both English language preference and Chaldean-American ethnic identity were associated (p < 0.01) with lower mean BP, but these differences became nonsignificant when age, BMI, and waist-hip ratio were statistically controlled. Parental school involvement was not associated with BP in any analyses. In this study, the strongest predictors of BP were BMI and waist-hip ratio, both of which were inversely correlated with age, education, English language preference, employment outside the home, and parental school involvement. Future studies of acculturation and BP in Chaldean-Americans (and other Arab-American populations) should use improved measures of acculturation, broader assessments of behavioral and socioeconomic status, and larger samples that includes both genders.

Comparative analgesic and cardiopulmonary effects of bupivacaine and ropivacaine in the epidural space of the conscious dog

To compare the cardiopulmonary effects and sensory blockade of epidural bupivacaine and ropivacaine. Prospective randomized study. Six young adult medium-sized crossbred dogs weighing 25.7 ± 7.1 kg. Dogs were chronically implanted with a lumbosacral epidural catheter. Acepromazine sedated dogs received all treatments: 0.5% bupivacaine at 0.14 mL kg-1 (LB5) or 0.22 mL kg-1 (HB5); 0.5% ropivacaine at 0.14 mL kg-1 (LR5) or 0.22 mL kg-1 (HR5); 0.75% bupivacaine at 0.22 mL kg-1 (HB7.5) or 0.75% ropivacaine at 0.22 mL kg-1 (HR7.5). Loss of sensation was tested at the level of the perineum, hind toe webs, flank, and caudodorsal rib areas before injection, and post-injection (PI) up to 150 minutes PI. Systemic arterial blood pressure and heart rate were recorded before injection, and every 10 minutes PI until 150 minutes PI. Arterial blood gas analyses were performed prior to injection, and at 30, 60 and 150 minutes PI. No statistical differences existed between groups for the cardiopulmonary data or time to onset of block. Group HR7.5 had lower systolic (10-70 minutes PI) and diastolic (10-70 minutes PI) blood pressures and group HR5 had lower mean (10-90 minutes PI) and diastolic (10-90 minutes PI) blood pressures compared to baseline. Heart rate was lower compared to baseline in groups LR5 and HB7.5. A significant, but mild metabolic acidosis developed in groups LR5 and HB7.5 (150 minutes PI). No differences were present for the duration of block between groups, but duration of block in the dorsocaudal rib area was shorter in group HR5 compared to HR7.5. Epidural ropivacaine and bupivacaine at the doses used have mild effects on the cardiopulmonary system, and extent of block are similar. The 0.75% concentration of bupivacaine and ropivacaine at 0.22 mL kg-1 appeared to contribute to greater success of block (>80%) at dermatomes L5-L7.

Intra-arterial blood pressure reference ranges, death and morbidity in very low birthweight infants during the first seven days of life.

We aimed to: (1) assess the association of average, low, high and variable mean blood pressure (mbp) on death and the common morbidities of very low birthweight infants, and in doing so, (2) to derive representative reference ranges for mbp in very low birthweight infants. This five year retrospective study assessed 1 min computer recordings of intra-arterial mbp in 232 very low birthweight infants over the first 7 days of life in a tertiary NICU. Four measures of mbp were assessed: average, variability, maximum (per time period), and percentage of time with a mean blood pressure less than the infant's gestation. Correlation was made with death and the development of intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL) and retinopathy of prematurity (ROP). The mbp increased with increasing birthweight and postnatal age (though with a slight decrease on days 6 and 7). Birthweight, gestation and colloid support (adjusted for birthweight and gestation) were the only factors significantly associated with mbp. IVH was predominantly associated with a low and variable mbp on the day IVH was noted or the day before. PVL and ROP were not associated with blood pressure. These reference ranges include more infants and data than previously published and relate mbp in this cohort to morbidity and mortality. They could assist clinicians in judging appropriate mbp for birthweight.

Perioperative care in left ventricular volume reduction.

While the operative technique of left ventricular volume reduction (LVVR) is rapidly becoming standardized, the optimal perioperative management strategy is yet to be determined. We present our experience with the care of patients undergoing LVVR. LVVR was performed in 21 patients (mean age = 65.5 years) with congestive heart failure. Our management strategy was initially based on afterload reduction with sodium nitroprusside, but was later modified to include routine preoperative intra-aortic balloon support, normothermic cardiopulmonary bypass, antegrade intermittent warm blood cardioplegia, and postoperative support with phosphodiesterase-III inhibitors. Hemodynamic manipulations are aimed to attain systemic vascular resistance between 600 and 800 dyne/sec per cm(-5) and the lowest mean blood pressure that is able to maintain satisfactory systemic perfusion. Postoperatively, aggressive antifailure medical therapy with a high dose of angiotensin converting enzyme inhibitors, nitrates, and diuretics was initiated early and maintained indefinitely. Using this approach, postoperative progress was characterized by hemodynamic stability. IABP support was used for 59.6+/-9 hours following surgery, and inotropic support for 103+/-12 hours. In our series there were four (19%) in-hospital deaths, two of which were related to heart failure. The described approach is associated with an acceptable early outcome. However, further advances in myocardial protection methods and pharmacological and mechanical support techniques are necessary for a wider adoption of this procedure.

Endothelin antagonists: discovery of EMD 122946, a highly potent and orally active ETA selective antagonist.

The discovery, in vitro and in vivo studies of the highly potent ETA antagonist EMD 122946 are presented. This compound displayed high binding affinity and functional antagonism [IC50 = 3.2 x 10(-11) M, pA2 = 9.5 (ETA)] and inhibited the ET-1 induced pressor response in pithed rats with an ED50 of 0.3 mg/kg. In conscious spontaneously hypertensive rats and in DOCA-salt hypertensive rats the compound lowered mean blood pressure with an ED50 of 0.06 mg/kg. EMD 122946 exhibited high bioavailability in rats and monkeys.

Low-intensity exercise training decreases cardiac output and hypertension in spontaneously hypertensive rats.

The decrease in cardiac sympathetic tone and heart rate after low-intensity exercise training may have hemodynamic consequences in spontaneously hypertensive rats (SHR). The effects of exercise training of low and high intensity on resting blood pressure, cardiac output, and total peripheral resistance were studied in sedentary (n = 17), low- (n = 17), and high-intensity exercise-trained (n = 17) SHR. Exercise training was performed on a treadmill for 60 min, 5 times per week for 18 weeks, at 55% or 85% maximum oxygen uptake. Blood pressure was evaluated by a cannula inserted into the carotid artery, and cardiac output was evaluated by a microprobe placed around the ascending aorta. Low-intensity exercise-trained rats had a significantly lower mean blood pressure than sedentary and high-intensity exercise-trained rats (160 +/- 4 vs. 175 +/- 3 and 173 +/- 2 mmHg, respectively). Cardiac index (20 +/- 1 vs. 24 +/- 1 and 24 +/- 1 ml.min-1 x 100 g-1, respectively) and heart rate (332 +/- 6 vs. 372 +/- 14 and 345 +/- 9 beats/min, respectively) were significantly lower in low-intensity exercise-trained rats than in sedentary and high-intensity exercise-trained rats. No significant difference was observed in stroke volume index and total peripheral resistance index in all groups studied. In conclusion, low-intensity, but not high-intensity, exercise training decreases heart rate and cardiac output and, consequently, attenuates hypertension in SHR.

Effects of hydralazine on renal sympathetic nerve activity in normal and congestive heart failure rats.

We investigated the effects of hydralazine on renal sympathetic nerve activity in anaesthetized heart failure rats. Sham-operated rats (group 1) received 0.5 mg kg-1 of hydralazine as bolus and were then infused with 0.3-0.5 mg kg-1 h-1 for 3 h intravenously. Heart failure rats received either the same regime (group 2) as group 1, or the same volume of vehicle (group 3). Heart failure rats exhibited lower mean blood pressure (P < 0.05) and elevated renal sympathetic nerve activity (P < 0.01) in the basal state. In group 2, the mean blood pressure decreased 26% after 30 min of hydralazine administration and remained lower for 3 h, with unchanged renal sympathetic nerve activity. In group 1, the mean blood pressure decreased 36%, and the heart rate and renal sympathetic nerve activity were significantly inhibited. Bilateral vagotomy did not alter renal sympathetic nerve response to hydralazine, but resulted in tachycardia. The results indicate that hydralazine, despite its profound hypotensive effect, did not activate renal sympathetic nerve activity in heart failure rats and inhibited renal sympathetic nerve activity in sham-operated rats. This inhibition was not mediated through the vagal nerve.

Can hypotension episodes cause cochlear damage in young subjects?

In the absence of a satisfactory interpretation, sudden sensorineural hearing loss is often attributed either to infective phenomena or to organic-type circulatory defects. This latter pathogenesis inevitably comes to mind in elderly patients or in the presence of signs of circulatory dysfunction. Nevertheless, the not-infrequent observation of sudden hearing loss in young persons lacking factors predictive of short-term vascular impairment makes us suppose the existence of etiopathogenetic mechanisms of a functional nature. A survey of our cases, matched with a control group, revealed the presence of lower mean blood pressure levels in the group of young patients with 'idiopathic' sudden hearing loss. This finding supports the hypothesis that a condition of haemodynamic imbalance linked to hypotension plays a role in the genesis of cochlear damage in young subjects. Such a mechanism would bear important therapeutic implications: should it be responsible for the damage in at least some cases, vasoactive drugs with a vasodilatative action could have adverse effects on the possibility of recovery.

Effects of the Level of PaCO2 on Recovery of Energy Metabolism: Is Normocarbia or Hypocarbia Better for Ischemia-Reperfused Cat Brain?

Background : The effect of arterial carbon dioxide tension(PaCO2) during ischemia and reperfusion has been a controversial issue. In this study, the effect of PaCO2 during ischemia and reperfusion was evaluated by 31P magnetic resonance spectroscopy(MRS). Methods : Incomplete global cerebral ischemia was induced by ligation of carotid artery under lowered mean blood pressure(mean blood pressure= 40 mmHg) for 30 minutes followed by 2 hours of reperfusion. Eighteen cats were divided into 3 groups: For group 1(n=6)(control group), animals were subjected to normocarbia(PaCO2=28∼33 mmHg) during ischemia and reperfusion, for group 2(n=6), animals were subjected to hypocarbia(PaCO2=18∼23 mmHg) during ischemia and reperfusion, and for group 3(n=6), animals were subjected to normocarbia during ischemia and hypocarbia during reperfusion. Results : For group 1, the energy metabolism measured by [PCr/Pi] was recovered about 74.7 6.4%. For group 2, the energy metabolism failed to be completely recovered by 120 minutes of reperfusion(69.3 7.3%), whereas for group 3, the energy matabolism was completely recovered by 120 minutes of reperfusion(97.6 2.4%). There were statistically significant differences between group 1 and group 3(p ＜0.05). The changes in pH were not significantly different among the groups Conclusion: In this study, a condition of hypocarbia during reperfusion seems better for the energy metabolism after incomplete global ischemia of cats. (Korean J Anesthesiol 1997; 33: 610∼616)

Clinical Investigation: Effect of Angiotensin Converting Enzyme Inhibition [Cilazapril] on Blood Pressure Recording in Hypertensive Obstructive Sleep Apneic Patients

Grote L, Heitmann J, Köhler U, Ploch T, Penzel T, Peter J. H. Effect of angiotensin converting enzyme inhibition [Cilazapril] on blood pressure recording in hypertensive obstructive sleep apneic patients.We investigated the efficacy of an Angiotensin Converting Enzyme [ACE] inhibitor on daytime and night-time blood pressure in 55 male hypertensive patients with moderately severe to severe obstructive sleep apnea. We resolved to determine if treatment oriented towards the reduction of hypertension would be successful, despite persistent repetitive hypoxemia and sleep-disordered breathing. The study was a randomized, double-blind, single daily dose, placebo-controlled protocol, with 8 days drug intake (placebo or 2.5 mg Cilazapril) and monitoring on the final day of drug administration. Subjects underwent continuous 24-h arterial blood pressure monitoring during baseline and treatment conditions. Polysomnography was performed at night during the 24-h arterial monitoring period. Cilazapril (2.5 mg) lowered systolic, diastolic and mean blood pressure, despite persistence of repetitive obstructive apneas during sleep and the associated repetitive hypoxemia. The lowering of blood pressure occurred without a significant change in heart rate, and was noted during nocturnal sleep, performance testing and graded exercise.

Dietary Calcium Supplementation and Blood Pressure-Reply

In Reply. —Dr Cappuccio's aggressive attack on our work is particularly unfortunate because he has either not read or not understood our article. Cappuccio seems to think we suggested our findings have public health implications. In fact, we stated that [i]t is unlikely that there are important underlying effects of calcium supplementation in reducing blood pressure in those with adequate calcium intake. Cappuccio criticizes our handling of the question of underlying hypertension. We pointed out in our article that the issue is not what investigators arbitrarily decide is high blood pressure, but the degree of overlap of blood pressure in putatively and patients. Mean blood pressure in populations labeled vs those labeled demonstrated a huge overlap, with many hypertensive populations showing lower mean blood pressures than many of the normotensive populations. The informal regression analysis we reported showed no relationship between mean blood pressure and the magnitude of

Blood pressure and atherogenic lipoprotein profiles of fish-diet and vegetarian villagers in Tanzania: the Lugalawa study

There is evidence that populations with a high intake of fish, and specifically fish oils, are at reduced risk of cardiovascular disease. To explore the effect of fish intake, we compared two groups of Bantu villagers in Tanzania; one group live on the shores of Lake Nyasa and their diet includes large amounts of freshwater fish; the other group live in the nearby hills and have a vegetarian diet. We carried out a cross-sectional study of 622 fish-consuming villagers and 686 vegetarian villagers. 618 (99.4%) and 645 (94.0%), respectively, agreed to take part. Anthropometric and self-reported medical history data were collected by one local physician and a medical assistant, who also measured blood pressure and took blood samples for measurement of plasma lipids. A dietary questionnaire was administered to 25 families (about 15% of the study population) in each village. After adjustment for age, sex, and alcohol intake the fish-consuming group had lower mean blood pressure than the vegetarian group (123/72 vs 133/76 mm Hg, p < 0.001). The frequencies of definite and borderline hypertension (by WHO criteria) were lower in the fish-consuming than in the vegetarian group (2.8 vs 16.4%; 9.7 vs 22.3%, respectively). Plasma concentrations of total cholesterol (mean 3.53 [SD 1.04] vs 4.10 [1.04] mmol/L), triglycerides (0.92 [0.64] vs 1.31 [0.64] mmol/L), and lipoprotein(a) (201 [213] vs 321 [212] mg/L), were all lower (p < 0.0001) in the fish-consuming group than in the vegetarian group. The proportions of n-3 polyunsaturated fatty acids in plasma lipids were higher (p < 0.0001) in the fish-consuming group than in the vegetarian group (eicosapentaenoic acid 2.3 [1.3] vs 0.7 [0.2]%; docosapentaenoic acid 1.1 [0.4] vs 0.6 [0.3]%; docosahexaenoic acid 5.7 [1.6] vs 1.5 [1.1]%). In these villagers, consumption of freshwater fish (300-600 g daily) was associated with raised plasma concentrations of n-3 polyunsaturated fatty acids, lower blood pressure, and lower plasma lipid concentrations.

Cardiac Hypertrophy in Copper-Deficient Rats Is Not Attenuated by Angiotensin II Receptor Antagonist L-158,809

We tested the hypothesis that cardiac hypertrophy which accompanies copper (Cu) deficiency was mediated by angiotensin II (Ang II). Thirty 17-day-old male Holtzman rats were offered a semipurified low-Cu diet (0.45 mg Cu/kg) for 39 days. Fifteen controls (Cu adequate) were given supplemental Cu (20 microgram/ml) in their drinking water, the other 15 (Cu deficient) were given deionized water. Five from each dietary treatment group were chronically infused by using osmotic pumps for 4 weeks with the Ang II receptor antagonist L-158,809, and five from each group were infused with propylene glycol vehicle. Five from each group were not implanted. Blood pressure (BP) changes to injection of Ang II, phenylephrine, and acetylcholine were monitored in cannulated rats. Cu-deficient rats had higher heart weight, left ventricular (LV)/body weight (BW), right ventricular (RV)/BW, lower mean BP, and coronary vascular resistance (CVR) than Cu-adequate rats. L-158-809 did not alter Cu levels or RV/BW in either dietary group, but did lower LV/BW, CVR, and mean BP in both dietary groups. Since Ang II blockage lowered HW/BW and LV/BW in both groups, the stimulus for cardiac hypertrophy in Cu-deficient rats remains unknown.

24-hour blood pressure monitoring in patients with anterior ischemic optic neuropathy.

To define parameters of ambulatory diurnal blood pressure in patients who had experienced anterior ischemic optic neuropathy (AION) in a case-controlled study. Twenty-four patients with AION and 24 control subjects who were matched for age, gender, medical diagnoses, and medications underwent ambulatory automated blood pressure monitoring for 24 hours. The overall diurnal pattern of blood pressure appeared to be normal in all subjects, showing lower blood pressures at night than during the day, an overnight nadir, and an ascending blood pressure curve in the morning to reach daytime levels. Also, patients with AION did not differ from control subjects with respect to the nighttime diastolic nadir or daytime peak systolic blood pressure. However, during the daytime, patients with AION had lower mean systolic and diastolic blood pressures than did matched control subjects. The widest difference between their blood pressure curves occurred after awakening in the morning, when patients with AION had a less steep and more irregular rise of blood pressure. Patients who had signs of vertebrobasilar insufficiency in addition to AION had lower mean diastolic blood pressure during both daytime and nighttime and a lower minimum daytime diastolic blood pressure. On ambulatory measurements of diurnal blood pressure, patients with AION consistently had a lower mean blood pressure than did control subjects and a lag in the usual rise in blood pressure in the morning to meet increasing daytime demands for perfusion. Chronic hypoperfusion of small end-arterial vessels that supply the optic nerve head may predispose to AION, and may be caused by relative hypotension owing to overtreated hypertension or to abnormal vascular autoregulation. Internists should be asked to monitor blood pressure carefully when treating hypertensive patients who are at risk for AION, to avoid hypotension, especially on awakening in the morning.

Effect of antihypertensive treatment with alacepril on insulin resistance in diabetic spontaneously hypertensive rats

Recent clinical reports have described the close relationship between insulin resistance and hypertension. Previous reports from our laboratory documented that spontaneously hypertensive rats (SHR) have mild insulin resistance, and that this insulin resistance is more intense in SHR with diabetes induced by streptozotocin (STZ). The aim of this study was to elucidate the effects of antihypertensive treatment with alacepril on insulin resistance in these diabetic SHR. Animals were divided into four groups as follows: group A, nondiabetic SHR; group B, diabetic SHR group C, diabetic SHR treated with 0.05% alacepril; and group, D diabetic SHR treated with 0.1% alacepril. Diabetes was induced by intravenous (IV) injection of STZ (35 mg/kg bodyweight [BW]). Alacepril was given orally by mixing in laboratory chow. Mean (+/- SD) blood pressure was lowered in the alacepril-treated groups (A 212 +/- 7mm Hg and B 213 +/- 8 v C 184 +/- 6 and D 167 +/- 9; P < .01). Total integrated plasma glucose levels were different among all the groups by oral glucose tolerance test (OGTT) (B 53.6 +/- 3.3 mmol/L > C47.2 +/- 4.5 > D 42.3 +/- 1.4 > A 34.2 +/- 1.2; P < .01). Steady-state plasma glucose (SSPG during the insulin suppression test was higher in group B than in group A (15.7 +/- 1.5 mmol/L v 10.4 +/- 0.8; P < .001). The SSPG level (12.9 +/- 0.7) was significantly (P < .001) lower in group D than in untreated group B. In the diabetic groups, blood pressure was positively correlated with integrated plasma glucose (PG) (r = .79, P < .001), SSPG (r = .53, P < .02), and plasma triglyceride (r = .70, P < .001), and negatively with high-density lipoprotein (HDL)-cholesterol (r = -.74, P < .001). Alacepril treatment not only dose-relatedly lowered mean blood pressure, but also dose-relatedly improved abnormalities in carbohydrate and lipid metabolism in STZ-induced diabetic SHR. These results suggest that an angiotensin-converting enzyme inhibitor, alacepril, has an antihypertensive effect, but also improves insulin resistance in hypertension with diabetes mellitus.

Beneficial Effects of Beraprost Sodium, a Stable Prostacyclin Analogue, in Diabetic Cardiomyopathy

We examined whether beraprost sodium (beraprost), a stable prostacyclin analogue, prevented cardiomyopathy in diabetic rats in vivo. Diabetes was induced by a bolus injection of streptozotocin in rat-tail vein. Four weeks after the induction of diabetes, the animals were treated with beraprost (30 micrograms/kg/day, p.o.) for 4 weeks until they were used for the measurement of hemodynamics, electrocardiogram (ECG), and plasma creatine phosphokinase (CK) activity. Nontreated diabetic rats have lower mean blood pressure, heart rate, left ventricular systolic pressure, and peak positive dP/dt at basal levels compared to age-matched normal rats. All of these changes were not improved in beraprost-treated rats. The left ventricular end-diastolic pressure and ST/R ratio in the ECG were significantly increased in diabetic rats. These parameters were significantly improved by beraprost compared with nontreated diabetic rats. Additionally, beraprost significantly suppressed the elevation of plasma CK activity as compared with that in non-treated diabetic rats. Changes in peak positive dP/dt in response to isoproterenol were attenuated in nontreated diabetic rats as compared with age-matched normal rats and beraprost-treated diabetic rats. These results suggest that beraprost is capable of preventing diabetic cardiomyopathy without affecting hyperglycemic condition.