Interindividual variations in resting metabolic rate during weight loss in obese postmenopausal women: A pilot study

The objective of the study was to examine if decreases in resting metabolic rate (RMR) take place early in the weight loss process and if they remain throughout the duration of the weight loss intervention. Twenty obese postmenopausal women (61.8 ± 5.9 years) participated in a 15-week weight loss program. After the fifth week, subjects were characterized as having an increased (>5%) or a decreased (<5%) RMR based on baseline values. Afterward, they were followed for an additional 10 weeks. Outcome measures were as follows: fat mass ([FM] total, trunk), lean body mass (total, trunk), RMR, resting heart rate (RHR), and physical activity level. After 5 weeks, significant decreases were observed for lean body mass, FM, and RHR (P < .05), whereas no overall changes in physical activity level and RMR were observed. However, on an individual basis, large variations in RMR were observed (ranging from −320 to +330 kcal/d). Analyses showed that subjects characterized as either having an increased or a decreased RMR after the fifth week maintained these adaptations at the end of intervention. Finally, subjects displaying a decreased RMR during weight loss had a significantly higher RMR and lower FM accumulations at baseline (total and trunk) compared with those with an increased RMR. Interindividual variations in RMR took place early in the weight loss process and were maintained over the duration of the weight loss program in our cohort of obese postmenopausal women. Baseline RMR, changes in RHR, and FM accumulations (total and trunk) seem to be important factors to consider when studying the effects of weight loss on RMR.     

老老年高血压患者静息心率与动态血压水平相关性研究

目的 研究老老年高血压患者静息心率与动态血压参数之间的相关性.方法 选取2013年2月至2014年2月中国中医科学院广安门医院心内科老老年高血压住院患者147例,均行动态血压监测及心电图检查.根据静息心率的数值将患者分成4组：RHR≥80次/min为1组,70次/min≤RHR≤79次/min为2组,60次/min≤RHR≤69次/min为3组,50次/min≤RHR≤59次/min为4组.比较四组之间的一般临床资料、常规生化指标和动态血压参数.结果 各组比较：总胆固醇3组＞1组,P＜0.05;低密度脂蛋白1组＞其余三组;24h平均DBP 1组（67.11±8.55）mm Hg＞3组（61.47±8.34）mm Hg,1组＞4组（61.79±7.77）mm Hg;白天平均DBP 1组（67.29±8.95）mm Hg＞3组（62.22±8.48）mm Hg,1组＞4组（61.53±8.44）mm Hg;白天SBP负荷1组（40.61±32.57）mm Hg＞2组（33.16±33.36）mm Hg＞3组（23.00±26.26）mm Hg＞4组（20.87±27.22）mm Hg,差异均有统计学意义（P＜0.05）.经多元线性逐步回归分析显示,24h平均DBP、LDL-C为静息心率的影响因素.结论 老老年高血压患者的静息心率与全天平均DBP、LDL-C有着密切的联系,故在诊疗中应予以重视,以期进一步改善生活质量及心脑血管病预后.     

倍他乐克注射液对快室率房颤伴心衰的疗效观察

目的探讨倍他乐克注射液联合西地兰对房颤快速心室率伴心衰的疗效及安全性。方法对房颤伴心衰的患者,先给以西地兰0.2mg稀释后缓慢静注,观测半小时,如心率仍>100次/分、血压≥100/60mmHg以上的患者,予倍他乐克注射液10mg稀释后经微泵静注1小时,当心率≤60次/分、血压<90/60mmHg时停止;微泵静注倍他乐克前、后,观察症状、体征、心率、血压、肺部音、无创血流动力学和BNP、ANP等指标。结果用倍他乐克后心室率平均减少了23.73次/分(P<0.01),收缩压降低5.69mmHg(P<0.05),舒张压降低5.26mmHg(P<0.05),使用倍他乐克前后SI、SV、VI、SVRI、SVR、LVET有明显改变(P<0.05),BNP、ANP无显著变化。结论倍他乐克注射液联合西地兰治疗快室率房颤伴心衰是有效和安全的。     

中老年心血管病患者口腔麻醉前后的血压和心率变化

目的:分析中老年心血管病患者在接受拔牙术时口腔麻醉前后的血压和心率变化情况。方法:收集在北京大学人民医院口腔科进行心电监护拔牙的中老年心血管病患者共1969例。使用心电监护仪测量患者在口腔麻醉前后的血压、心率,记录并统计分析血压、心率的变化情况。结果:所有患者在口腔麻醉后未出现危及生命的严重并发症。术前患者血压、心率的第95百分位数分别为165/95 mmHg(1 mmHg=0.133 kPa)、95次/min。在麻醉前血压≥165/95 mmHg的患者和<165/95 mmHg的患者中,分别9.9%(21/212)和0.4%(7/1757)的患者麻醉后血压≥180/110 mmHg,两者差异有统计学意义(P<0.01)。共28例(1.42%)患者麻醉后血压≥180/110 mmHg,其中17例患者休息后复测血压仍未下降,终止拔牙治疗。与麻醉前比较,麻醉后患者的平均心率显著升高[73(四分位数间距=16)次/min vs 74(四分位数间距=17)次/min,P<0.01]。结论:对于心血管病得到有效治疗且病情稳定的中老年患者,口腔麻醉安全、有效。建议中老年心血管病患者在血压<165/95 mmHg、心率<95次/min的情况下,接受全身情况综合评估后进行口腔麻醉。     

静息心率与老年冠心病关系的研究

目的探讨静息心率对冠心痛发生的预测价值及临床意义。方法选择老年冠心病患者429例为冠心病组,另选同期体检的非冠心病患者60例为非冠心病组。2组患者均测量血压及生化指标检测,并行12导联心电图检查,分析静息心率与冠心病发生是否存在相关性。结果冠心病组的收缩压、TC、TG、LDL-C、静息心率明显高于非冠心痛组(P<0.05,P<0.01)。logistic回归分析显示,校正了舒张压、TC、HDL-C、LDL-C、空腹血糖等因素后,静息心率、收缩压、TG是冠心病的独立危险因素(OR=1.046,95%CI:1.005～1.088,P<0.05)。结论静息心率是冠心病发病的独立危险因素。     

Reproducibility of intra-arterial ambulatory blood pressure: effects of physical activity and posture

OBJECTIVE: To examine the effects of physical activity, body posture and sleep quality on the reproducibility of continuous ambulatory blood pressure monitoring. METHODS: Measurements were performed in 35 subjects (18 hypertensive, 11 male), mean +/- standard deviation age 49 +/- 13 years. Blood pressure (BP) was measured in the brachial artery, and beat-to-beat values of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure and heart rate (HR) were computed. Physical activity and posture were continuously measured with five accelerometers. Subjective quality of sleep was assessed with a questionnaire. Reproducibility was expressed as an intraclass correlation coefficient and as the standard deviation of the within-subject differences. RESULTS: Posture and activity significantly influenced BP and HR. From lying to sitting, the SBP, DBP and HR increased 6 mmHg, 8 mmHg and 8 beats/min, respectively. From sitting to standing these respective increases were 4 mmHg, 2 mmHg and 13 beats/min. A further rise in activity (from standing to moving generally or walking) increased the SBP by 7 mmHg and the HR by 7 beats/min, and decreased the DBP by 8 mmHg. For daytime SBP, DBP and HR, the intraclass correlation coefficient (standard deviation of the within-subject differences) values were 0.93 (7.2 mmHg), 0.94 (3.8 mmHg) and 0.90 (4.1 beats/min). For night-time these respective values were 0.98 (4.4 mmHg), 0.97 (2.5 mmHg) and 0.96 (2.2 beats/min). Correction for physical activity level and posture hardly improved the reproducibility of daytime BP and HR. Reproducibility of night-time BP and HR was not improved by correction for physical activity, supine position or self-reported sleep quality. CONCLUSIONS: Within-subject differences between ambulatory BP recordings cannot be explained by differences in physical activity and body posture.     

Ambulatory blood pressure variations relative to sitting or standing position in renal transplant patients

OBJECTIVE: High blood pressure is almost constant in renal transplant patients for whom dysautonomia is frequently described. The main objective of this study was to analyse the variations in blood pressure and heart rate recorded by ambulatory measurement during changes in position in renal transplant patients. METHODS: Thirty-nine non-diabetic renal transplant patients with a renal transplant functioning for more than a year, were selected at random. Blood pressure was measured using the validated monitor Diasys Integra with a position sensor to discriminate between standing and sitting/lying. RESULTS: Systolic blood pressure and heart rate were significantly higher when the patient was standing than when sitting/lying (+2.9 mmHg, P<0.05 and +9 beats/min, P<0.001 respectively) and diastolic blood pressure tends to be higher (+1.7 mmHg, NS) when standing. One minute after standing up, the heart rate rises by about 9 beats/min (P<0.001) while systolic and diastolic blood pressures do not vary significantly. Variations in systolic blood pressure and heart rate on changing position are therefore in the same direction as those recorded in elderly normotensive or hypertensive untreated subjects, but with a lower amplitude. CONCLUSIONS: In most of non-diabetic functional renal transplant patients, there is an absence of an orthostatic decline in blood pressure. Thus, it could be considered that there is no real dysautonomia in this specific population.     

Weight loss and weight maintenance,ambulatory blood pressure and cardiac autonomic tone in obese persons with the metabolic syndrome

BACKGROUND: Cardiac autonomic function may play a role in obesity-associated hypertension. Most studies on the effects of weight loss on blood pressure and autonomic function do not distinguish between acute or continuing weight loss and steady-state weight maintenance after weight loss. OBJECTIVES: We sought to clarify the changes in ambulatory blood pressure, heart rate and heart rate variability as assessed by spectral analysis during rapid weight loss and extended weight maintenance. PARTICIPANTS: Abdominally obese (body mass index 35.2 +/- 2.1 kg/m2, waist 114.3 +/- 9.0 cm) men and women (n = 41) with the metabolic syndrome. METHODS AND RESULTS: The 34 men and women completing the 1-year weight maintenance period lost 14.6 +/- 3.5 kg during the 9-week very-low-calorie diet and maintained a 12.5 +/- 7.5 kg weight loss to the end of the trial. Ambulatory 24-h blood pressure decreased dramatically during the diet (-9.0 +/- 8.0/-4.6 +/- 4.9 mmHg), but had risen to near baseline levels by the end of weight maintenance (-2.2 +/- 8.2 /-1.2 +/- 6.1 mmHg). Night-time heart rate decreased (-5.5 +/- 9.6 beats/min, P = 0.012), and heart rate variability total and low-frequency power measured during 5 min of controlled breathing increased by 46-56% (P = 0.003-0.09) during rapid weight loss. These changes gradually attenuated during weight maintenance, and only the change in night-time heart rate was still of borderline significance after 1 year of weight maintenance (-3.6 +/- 8.6 beats/min, P = 0.063). Heart rate variability high-frequency power tended to increase during weight loss and weight maintenance. CONCLUSION: Despite successful weight maintenance, the decrease in ambulatory blood pressure after rapid weight loss was largely transient. The increase in parasympathetic tone was more sustained, but also gradually attenuated during 1 year of weight maintenance.     

老年性高血压患者的静息心率增加与靶器官损害的相关性研究

目的　探讨老年高血压病患者静息心率 (restingheartrate ,RHR)与靶器官损害的关系。方法　入选老年高血压病患者 2 0 6例 ,按收缩压 (SBP)水平分为三组 :SBP <16 0mmHg(1mmHg =0 133kPa) ,16 0mmHg≤SBP <180mmHg ,SBP≥ 180mmHg。在以上每一组中 ,又按RHR水平分为 :RHR1组 ,<6 5次 /min ;RHR2组 ,6 5次 /min≤RHR <6 9次 /min ;RHR3组 ,70次 /min≤RHR <74次 /min ;RHR4组 :75次 /min≤RHR <79次 /min ;RHR5组 ,RHR≥ 80次 /min。对入选患者做以下检查 :心电图、超声心动图、颈动脉超声、肌酐清除率以及尿微量白蛋白。结果　 (1)RHR5组的尿微量白蛋白定量和左心室质量指数均高于RHR1～RHR4各组 (P <0 0 5或P <0 0 1)。RHR5组或RHR4组的颈动脉内膜厚度和颈动脉内径大于RHR1和RHR2组 ;而左室射血分数和肌酐清除率小于RHR1和RHR2组 (P <0 0 5或P <0 0 1)。(2 )RHR与颈动脉内膜厚度、颈动脉内径、左心室质量指数、尿微量白蛋白定量呈正相关 (r分别为 0 312、0 2 89、0 6 30、0 5 76 P <0 .0 1) ,而与左室射血分数、肌酐清除率呈负相关 (r分别为 - 0 5 6 3、- 0 5 10 ,P <0 .0 1)。结论　RHR的增加是老年高血压病患者靶器官损害的重要危险因素。     

Blood pressure and heart rate of students undergoing a medical licensing examination

AIMS: To assess the effect of a real life mental stress situation on blood pressure (BP) and heart rate (HR) in students undergoing a medical licensing examination. METHOD: Prospective observational study of 121 medical students taking the final licensing exam. BP and HR were taken before and after the exam. Additionally, BP was measured by ambulatory BP monitoring device and HR was recorded continuously by an HR monitor belt in 25 students throughout the examination. MAJOR FINDINGS: Diastolic BP (DBP) increased from 81 +/- 10 mmHg before the exam to 86 +/- 9 mmHg (p = 0.008) during the exam and to 88 +/- 11 mmHg, (p = 0.007) 15 min after the exam. Systolic BP (SBP) did not increase significantly during (from 131 +/- 14 before the exam to 136 +/- 18 mmHg) and after the exam (135 +/- 16 mmHg). HR decreased during (to 100 +/- 18 beats/min, p < 0.001), and after the exam (to 95 +/- 19 beats/min, p < 0.001) compared to values before the exam (114 +/- 19 beats/min). SBP was higher in male students compared to female students before (138 +/- 10 vs 125 +/- 18 mmHg) and after (126 +/- 18 vs 115 +/- 17 mmHg) the exam (p < 0.01). CONCLUSION: Only DBP increased during medical licensing examination, albeit within a small range. SBP did not change significantly and HR decreased during the exam. Male students showed a higher SBP compared to female students.     

高龄高血压患者静息心率与肾脏损害的相关性

目的 探讨高龄高血压患者静息心率（ RHR）与肾脏功能指标的相关性.方法 2006年9月～2011年2月入住本院患者419例为研究对象,男289例,女130例,年龄80～94岁,平均（80.8±6.1）岁.按照RHR分为A组：RHR＜ 70 beats/min,B组：RHR 70～80次/min,C组：RHR＞ 80次/min,同时进行血压、体质量指数（BMI）、糖化血红蛋白、吸烟指数（SI）的检测,用肾小球滤过率（ GFR）、血肌酐（SCr）、肌酐清除率（CCr）,微量白蛋白尿（MAU）评估肾功能,分析静息心率与肾功能参数的相关性.结果 三组平均RHR差异有统计学意义[A,B,C组分别为（63.4±7.2）,（74.1±4.0）,（84.3±8.8）次/min,P＜0.05];三组SI和收缩压（SBP）均存在差异[A,B,C组SI分别为（321±73）,（ 378±99）,（463±79）（支·年）; SBP分别为（140.2±10.1）,（146.3±8.1）,（149.8±9.6） mmHg,P＜0.05].C组BMI和舒张压（DBP）均明显高于另外两组[A,B,C组BMI分别为（23.7±3.0）,（23.1±5.4）,（25.9±5.9） kg/m2;DBP分别为（64.6±9.5）,（65.2±9.1）,（71.3±12.4） mmHg,P＜0.05];三组肾功能参数差异有统计学意义[A,B,C组GFR分别为（84.5±11.0）,（78.2±10.6）,（67.6±10.1） ml/min; SCr分别为（87.3±23.1）,（90.0±22.3）,（ 104.0±19.7） μmol/L,CCr分别为（73.9±16.8）,（68.0±18.3）,（62.5±20.1） ml/min,MAU分别为（51.4±11.3）,（ 56.0±17.3）,（90.9±22.8） mg/L,P＜0.05].RHR分别与SBP（ r=0.264,P=0.002）,GFR（r=-0.330,P=0.011）,CCr（r=-0.436,P＜0.01）和MAU（r=0.208,P=0.029）存在相关性.结论 高龄高血压患者RHR与肾功能损害相关,提示RHR增快可以作为高龄高血压患者肾功能受损的预测因子.     

Carotid sinus reflexes during postural changes, naturally elicited fighting behaviour, and phases of sleep in the cat

Reflex responses of mean blood pressure and of heart rate to either bilateral common carotid occlusion (CO) or unilateral carotid sinus dilatation (CSD) during rest and different behaviours have been compared in conscious cats. Unloading and loading the carotid sinus receptors elicited equal reflex responses both of mean blood pressure and of heart rate during control immobile behaviour (CO: +34 +/- 6 mmHg and +35 +/- 6 beats . min-1; CSD: -37 +/- 4 mmHg and -52 +/- 11 beats . min-1), standing on the hindlimbs (CO: +36 +/- 5 mmHg and +29 +/- 5 5 beats . min-1; CSD: -40 +/- 6 mmHg and -61 +/- 10 beats . min-1), fighting against an attacking animal (CO: +34 +/- 5 mmHg and +31 +/- 5 beats . min-1; CSD: -37 +/- 5 mmHg and -56 +/- 10 beats . min-1), quiet wakefulness (CO: +37 +/- 5 mmHg and +38 +/- 4 beats . min-1; CSD: -34 +/- 4 mmHg and -53 +/- 8 beats . min-1) and synchronised sleep (CO: +36 +/- 5 mmHg and +37 +/- 4 beats . min-1; CSD: -36 +/- 4 mmHg and -52 +/- 6 beats . min-1). Desynchronised sleep was associated with an identical response to CSD (-30 +/- 4 mmHg and -51 +/- 7 beats . min-1) but with a reduced (p less than 0.01) reflex response to CO (+18 +/- 3 mmHg These data indicate that carotid sinus baroreflexes largely maintain their ability to modulate pressure upwards and downwards when blood pressure has been reset at somewhat higher levels by standing and fighting and at somewhat lower levels by synchronised sleep. The selective depression of carotid occlusion responses during desynchronised sleep suggests a central or peripheral shift of the baroreflex stimulus-response curve or a selective central inhibition of the reflex response to baroreceptor unloading.     

Herbal ephedra/caffeine for weight loss: a 6-month randomized safety and efficacy trial

OBJECTIVE: To examine long-term safety and efficacy for weight loss of an herbal Ma Huang and Kola nut supplement (90/192 mg/day ephedrine alkaloids/caffeine). DESIGN: Six-month randomized, double-blind placebo controlled trial. SUBJECTS: A total of 167 subjects (body mass index (BMI) 31.8+/-4.1 kg/m(2)) randomized to placebo (n=84) or herbal treatment (n=83) at two outpatient weight control research units. MEASUREMENTS: Primary outcome measurements were changes in blood pressure, heart function and body weight. Secondary variables included body composition and metabolic changes. RESULTS: By last observation carried forward analysis, herbal vs placebo treatment decreased body weight (-5.3+/-5.0 vs. -2.6+/-3.2 kg, P<0.001), body fat (-4.3+/-3.3 vs. -2.7+/-2.8 kg, P=0.020) and LDL-cholesterol (-8+/-20 vs. 0+/-17 mg/dl, P=0.013), and increased HDL-cholesterol (+2.7+/-5.7 vs. -0.3+/-6.7 mg/dl, P=0.004). Herbal treatment produced small changes in blood pressure variables (+3 to -5 mm Hg, P< or =0.05), and increased heart rate (4+/-9 vs. -3+/-9 bpm, P<0.001), but cardiac arrhythmias were not increased (P>0.05). By self-report, dry mouth (P<0.01), heartburn (P<0.05), and insomnia (P<0.01) were increased and diarrhea decreased (P<0.05). Irritability, nausea, chest pain and palpitations did not differ, nor did numbers of subjects who withdrew. CONCLUSIONS: In this 6-month placebo-controlled trial, herbal ephedra/caffeine (90/192 mg/day) promoted body weight and body fat reduction and improved blood lipids without significant adverse events.     

Obesity markers and blood pressure in a sample of Portuguese children and adolescents.

BACKGROUND: Little information exists regarding the effect of several obesity markers on blood pressure (BP) levels in youth. DESIGN: Transverse study including 2494 boys and 2589 girls. METHODS: Height, weight and waist were measured according to the international criteria and body fat (BF) by bioimpedance. BP was measured by an automated device. Hypertension was defined using sex-specific, age-specific and height-specific observation-points. RESULTS: Body mass index (BMI) and waist were positively related with systolic blood pressure (SBP) and diastolic blood pressure (DBP) and heart rate in both sexes, whereas the relationships with BF were less consistent. Stepwise linear regression analysis showed that BMI was positively related with SBP and DBP in both sexes, whereas BF was negatively related with SBP in both sexes and with heart rate in boys only; finally, waist was positively related with SBP in boys and heart rate in girls. Age and heart rate-adjusted values of SBP and DBP increased with BMI: for SBP, 117+/-1, 123+/-1 and 124+/-1 mmHg in normal, overweight and obese boys, respectively; corresponding values for girls were 111+/-1, 114+/-1 and 116+/-2 mmHg (mean+/-SE, P<0.001). Overweight and obese boys had an odds ratio for being hypertensive of 2.26 (95% confidence interval: 1.79-2.86) and 3.36 (2.32-4.87), respectively; corresponding values for girls were 1.58 (confidence interval 1.25-1.99) and 2.31 (1.53-3.50). CONCLUSION: BMI, not BF or waist, is consistently and independently related to BP levels in children; overweight and obesity considerably increase the risk of hypertension.     

Effect of sildenafil citrate on blood pressure and heart rate in men with erectile dysfunction taking concomitant antihypertensive medication. Sildenafil Study Group

OBJECTIVES: To assess the acute effect of sildenafil citrate on blood pressure and heart rate in men with erectile dysfunction taking concomitant antihypertensive medication. DESIGN: Post-hoc subanalysis of five, 12- or 24-week, prospective, randomized, double-blind, placebo-controlled studies. SETTING: Private-practice and academic urology clinics. PATIENTS: A total of 1685 men with erectile dysfunction of > or = 6 months duration, of whom 667 (sildenafil n = 406, placebo n = 261) were taking antihypertensive medication (diuretic, beta-blocker, alpha-blocker, angiotensin converting enzyme inhibitor, and/or calcium antagonist). Of the patients taking antihypertensive medication, 608 (91%) completed the studies (374 of 406 receiving sildenafil, 234 of 261 receiving placebo). INTERVENTIONS: The last dose of oral sildenafil (25-200 mg) or placebo was taken at home on the morning of the final clinic visit. Patients taking antihypertensive medication maintained usual dosing schedules. MAIN OUTCOME MEASUREMENTS: Sitting systolic (SBP)/diastolic blood pressure (DBP) and heart rate at baseline and after dosing with sildenafil or placebo (end-of-treatment visit). RESULTS: Mean changes from baseline in SBP/DBP for men taking antihypertensive medication were -3.6/-1.9 mmHg for those receiving sildenafil and -0.8/-0.1 mmHg for those receiving placebo compared with -2.2/-2.0 mmHg and -0.1/0.4 mmHg, respectively, for men not taking antihypertensive medication. Mean changes from baseline in heart rate for men taking antihypertensive medication were -0.6 beats/min after sildenafil and 0.9 beats/min after placebo compared with 0.4 beats/min and -0.6 beats/min, respectively, for patients not taking antihypertensive medication. Differences in SBP, DBP, and heart rate between the patients taking and those not taking antihypertensive medication were small. CONCLUSIONS: The acute, short-term effects of oral sildenafil on blood pressure and heart rate in men with erectile dysfunction were small and not likely to be clinically significant in those taking concomitant antihypertensive medication.     

Comparison of noninvasive oscillometric and intra-arterial blood pressure measurements in hyperacute stroke

OBJECTIVES: This study aims to compare automatic oscillometric blood pressure recordings with simultaneous direct intra-arterial blood pressure measurements in hyperacute stroke patients to test the accuracy of oscillometric readings. METHODS: A total of 51 first-ever stroke patients underwent simultaneous noninvasive automatic oscillometric and intra-arterial blood pressure monitoring within 3 h of ictus. Casual blood pressure was measured in both arms using a standard mercury sphygmomanometer on hospital admission. Patients who received antihypertensive medication during the blood pressure monitoring were excluded. RESULTS: The estimation of systolic blood pressure (SBP) using oscillometric recordings underestimated direct radial artery SBP by 9.7 mmHg (95% confidence interval: 6.5-13.0, P<0.001). In contrast, an upward bias of 5.6 mmHg (95% confidence interval: 3.5-7.7, P<0.001) was documented when noninvasive diastolic blood pressure (DBP) recordings were compared with intra-arterial DBP recordings. For SBP and DBP, the Pearson correlation coefficients between noninvasive and intra-arterial recordings were 0.854 and 0.832, respectively. When the study population was stratified according to SBP bands (group A: SBP160 mmHg and SBP180 mmHg), higher mean DeltaSBP (intra-arterial SBP-oscillometric SBP) levels were documented in group C (+19.8 mmHg, 95% confidence intervals: 12.2-27.4) when compared with groups B (+8.5 mmHg, 95% confidence intervals: 2.7-14.5; P=0.025) and A (+5.9 mmHg, 95% confidence intervals: 1.8-9.9; P=0.002). CONCLUSION: Noninvasive automatic oscillometric BP measurements underestimate direct SBP recordings and overestimate direct DBP readings in acute stroke. The magnitude of the discrepancy between intra-arterial and oscillometric SBP recordings is even more prominent in patients with critically elevated SBP levels.     

慢性盐负荷及补钾对健康成人血压变异性的影响

目的:探讨慢性盐负荷及补钾对健康成人血压和血压变异性的影响。方法:选取100例年龄在28～60岁的血压正常者参与为期3周的慢性盐负荷及补钾试验,包括基线调查3 d,低盐饮食、高盐饮食和高盐补钾饮食各7 d的研究。在基线调查和各干预阶段的第5,6,7天采用英国产随机零点血压计连续测量3 d血压。测量血压前受试者静坐休息5 min,测量3次,求平均值,并计算3 d血压测量值的标准差和变异系数,作为长时血压变异性指标。结果:受试者血压在低盐期较基线期显著下降［SBP:(112±11)mmHg vs.(117±14)mmHg;DBP:(74±8)mmHg vs.(76±10)mmHg,P<0.01］;高盐期较低盐期明显升高［SBP:(119±14)mmHg vs.(112±11)mmHg;DBP:(77±9)mmHg vs.(74±8)mmHg,P<0.01］;补钾期较高盐期显著降低［SBP:(114±12)mmHg vs.(119±14)mmHg;DBP:(75±8)mmHg vs.(77±9)mmHg,P<0.01］。限盐后收缩压标准差、舒张压标准差均降低［SDSBP:(3.9±1.5)mmHg vs.(4.3±1.0)mmHg;SDDBP:(3.2±1.4)mmHg vs.(3.6±1.6)mmHg,P<0.01］;高盐期较低盐期升高［SDSBP:(4.4±1.6) vs.(3.9±1.5)mmHg;SDDBP:(3.7±1.2) vs.(3.2±1.4)mmHg,P<0.01］。结论:钠、钾摄入量与血压变化密切相关,其中低盐饮食后血压下降,高盐饮食后血压升高,而在高盐负荷基础上给予大剂量补钾使血压下降。高盐饮食可增大血压变异性,限盐可降低血压变异性。     

老年代谢综合征患者静息心率增加与靶器官损害的相关性

目的 探讨老年代谢综合征患者静息心率(RHR)与靶器官损害的关系. 方法 入选老年代谢综合征患者264例,按RHR水平分为4组:RHRl组;RHR<65次/min 46例;RHR2组:65次/min≤RHR<75次/min 77例;RHR3组:75次/min≤RHR<85次/min 89例;RHR4组:RHR≥85次/min 52例.对入选患者检查心电图、超声心动图、颈动脉超声、肌酐清除率(Ccr)及尿微量白蛋白. 结果 (1)RHR4组的颈动脉内膜厚度、颈动脉内径、左心室重量指数及尿微量白蛋白定量均高于RHR1、RHR2和RHR3组(P<0.05或P<0.01),左心室射血分数、Ccr均小于RHR1、RHR2和RHR3组(均为P<0.01);(2)RHR与颈动脉内膜厚度、颈动脉内径、左心事重量指数及尿微量白蛋白定量呈正相关(r分别为0.33、0.23、0.61、0.58,均为P<0.01),与左心室射血分数、Ccr呈负相关(r分别为-0.59、-0.51,均为P<0.01);(3)非条件Logistic回归分析结果 显示,RHR和脉压对心肌肥厚、冠心病、心力衰竭、脑卒中和肾功能损害都有不同程度的影响(P<0.05或P<0.01),其中除心力衰竭外,脉压较RHR的作用更大. 结论 RHR可能是老年代谢综合征患者靶器官损害的独立危险因素,控制RHR对于老年代谢综合征的发生、发展具有重要意义.     

Exercise prescription based upon cardiac vagal activity for middle-aged obese women

OBJECTIVE: The purposes of this study were to examine a new method to determine exercise intensity for obese people based on the cardiac vagal activity and to determine the effect of this approach on myocardial stress. SUBJECTS: Forty-three middle aged obese female volunteers (age 43.7+/-6.5 y; height 1.56+/-0.05 m; body mass 66.5+/-9.3 kg; body mass index 27.3+/-2.8 kg m(2); percentage body fat 40.7+/-5.9%). MEASUREMENT: In the first experiment, 43 subjects performed a ramp exercise test on a bicycle ergometer with measurement of ECG and gas exchange parameters. In the second experiment, 11 subjects performed 45 min of constant walking exercise on a treadmill at a level corresponding to exercise intensity determined by vagal activity obtained from a ramp bicycle test. Blood pressure, endothelin 1 (ET-1), catecholamine, atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) were measured before and after exercise. RESULTS: The heart rate variability power decreased with increasing work rate, and changed little after reaching individual-specific work rate. We presumed that vagal activity disappeared at this point and that the heart rate at this exercise intensity was determined as the vagal activity threshold (T(VA)). The results showed a significant positive correlation (r=0.742, P<0.0001) between T(VA) and ventilatory threshold (VT) heart rates, although the mean heart rate of T(VA) (114.3+/-8.5 beats/min) was significantly lower (P<0.001) than that at VT (119.0+/-11.7), suggesting the cardiac vagal withdrawal occurred prior to the onset of lactate acidosis (lactic acid accumulation). Furthermore, exercise intervention experiment at T(VA) indicated that ET-1, catecholamine and BNP levels were not significantly different before and after exercise. However, ANP levels increased significantly after exercise (pre-exercise 18.6+/-5.38 vs post-exercise 44.0+/-24.87 pg/ml, P<0.001), which in turn brought about a significant post-exercise reduction in the blood pressure (SBP 117.6+/-13.7 vs 110.5+/-7.4 mmHg, P<0.05; DBP 78.6+/-6.7 vs 73.5+/-6.6 mmHg, P<0.01). CONCLUSION: Our data suggest that it is possible to determine the exercise intensity (T(VA)) on the basis of cardiac vagal response. These results also suggest that exercise at T(VA) level is a safe exercise intensity in the light of cardiac stress, and that T(VA) may be recommended for obese people who might possess lower cardiac sympatho-vagal activity.     

Relationship quality: effects on ambulatory blood pressure and negative affect in a biracial sample of men and women

BACKGROUND: Prospective studies link marriage to better cardiovascular health, but marital dissatisfaction and discord predict increased rates of hypertension, higher blood pressure (BP), greater reactivity to stress, and left ventricular mass. OBJECTIVE: To determine and compare effects of partner status and relationship quality on 24-h BP, urinary norepinephrine and cortisol, and self-reported stress and negative affect. METHODS: Ambulatory BP (ABP) and 24-h urine collections were obtained during a typical work day in 325 adults, including 139 African Americans (AAs). Participants cohabiting with a spouse or partner were classified into high, intermediate and low relationship quality (RQ) groups and compared to those without partners (Alone). RESULTS: Mean ABP was nearly identical in participants with versus without partners (125.7/76.9 versus 125.9/76.7 mmHg). High RQ subjects had lower mean waking ABP than intermediate/low RQ and Alone groups [systolic blood pressure (SBP), F=3.45; diastolic blood pressure (DBP), F=3.38, P-values <0.05]. High RQ was related to lower SBP and DBP in African Americans, and to lower SBP in Whites. High RQ was also linked to lower SBP and DBP in men, and to lower SBP in women. High RQ subjects reported less negative affect and stress than all other groups (P<0.05). Norepinephrine was lower in partnered versus Alone women regardless of RQ status. CONCLUSIONS: Relationship quality is a better predictor of daily BP, affect and stress than partner status. High RQ is linked to lower ABP across race and gender. This reduced ABP may be due, in part, to the stress buffering effects of better RQ and/or the stress enhancing effects of poor RQ.