Anxiety moderates cardiovascular responses to painful stimuli during sphygmomanometry.

Sphygmomanometry is the most common technique of blood pressure (BP) determination. We were interested in the role of anxiety as a predictor of BP changes induced by painful stimuli during sphygmomanometry. We studied 141 normotensive healthy subjects who were asked to complete a State-Trait-Anxiety-Inventory (STAI) prior to the experiment. BP was determined continuously and non-invasively using a Finapres device (Penaz-technique) and by arm sphygmomanometry. Five sphygmomanometric measurements took place, during the fourth the arm cuff was inflated to 300 mmHg (unpredictable to the subject), the others were done with a pressure of 175 mmHg. State and trait anxiety (STAI X1 and X2) correlated positively with diastolic BP changes during inflation of the arm cuff (state anxiety: r = 0.26, P < 0.05; trait anxiety: r = 0.20, P < 0.05). Our results suggest that anxiety may have an impact on cardiovascular responses following painful stimuli.     

Tracking-Cuff System for Beat-to-Beat Recording of Blood Pressure

A system is described for the automatic beat-to-beat tracking of blood pressure (BP) based on the detection of Korotkoff sounds. Upon each detection, a discrete adjustment in cuff pressure is made prior to the next cardiac cycle. In comparison with other continuous tracking systems, digital control allows for estimation of systolic BP based on precise knowledge of cuff pressure at each heart beat. Simultaneous recordings of intra-arterial pressure (radial artery) and systolic pressure measured with the tracking system were made in 4 subjects during 1-min trials of resting, paced respiration, and mental arithmetic. Correlations of the paired measures of intra-arterial and cuff pressure for 27 trials varied from .46 to .90 (median = .72). The standard error of estimate of intra-arterial systolic BP varied from 1.8 to 6.3 mmHg (median = 3.6). The system can be used without discomfort to track systolic BP for 60 and 120 sec in experiments involving repeated cuff inflations. Critical features and advantages of the tracking-cuff system for blood pressure measurement and biofeedback are discussed.     

A New Probe for Ankle Systolic Pressure Measurement Using Photoplethysmography (PPG)

An automated method for ankle systolic pressure measurement, less operator dependent than the standard continuous wave (CW) Doppler technique, would imply an advantage both in patient measurements and in epidemiological studies. We present a new photoplethysmographic (PPG) probe that uses near-infrared light (880 nm) to detect pulsatory blood flow underneath the distal end of a standard pneumatic cuff. The probe is adapted to the anatomical conditions at the ankle, permitting recording of pressures in both ankle arteries separately. The validity of the equipment was tested with CW Doppler-derived systolic pressures and invasive blood pressure measurements for reference. In 20 healthy subjects, visual analysis of the PPG curves revealed a mean difference between CW Doppler and PPG measurements of –0.5 mmHg (SD 6.9). Corresponding results for the anterior and posterior tibial arteries separately were –1.8 mmHg (SD 6.2) and 0.9 mmHg (SD 7.3), respectively. A correct probe position was essential for the results. In direct recordings from the dorsalis pedis artery in 10 intensive care patients, PPG underestimated systolic pressure in the anterior tibial artery by 4.5 mmHg (SD 12.1). With further development, the PPG probe, integrated in the pneumatic cuff, may simplify measurements of ankle systolic pressures.     

Blood flow and oxygen consumption with near-infrared spectroscopy and venous occlusion: spatial maps and the effect of time and pressure of inflation

We have measured the local blood flow (BF) and oxygen consumption (OC) in the human calf muscle using near-infrared spectroscopy during venous occlusion. Venous occlusion was achieved by inflating a pneumatic cuff around the thigh of the subject. We have investigated the influence of the inflation time and cuff pressure on the recovered values of BF and OC. We have found that if the cuff pressure is increased from a threshold pressure (approximately 30 mm Hg) to a critical pressure (approximately 45 mm Hg) in less than about 6 s, one measures the same values of BF and OC independent of the total inflation time and final cuff pressure. We also report nine-pixel spatial maps of BF and OC to show that this technique can lead to spatially resolved measurements of blood flow and oxygen consumption in tissues.     

Is oscillometric ankle pressure reliable in leg vascular disease?

The objective of the study was to evaluate the validity of oscillometric systolic ankle pressure in symptomatic leg arterial occlusive disease. Ankle pressure measurements using oscillometric curves obtained using a standard 12-cm cuff with a specially designed device for signal processing were validated against the continuous wave (CW) Doppler technique. Thirty-four subjects without signs or symptoms of peripheral vascular disease (68 legs) and 47 patients with leg ischaemia (85 legs) varying from moderate claudication to critical ischaemia were examined. The oscillometric curves were analysed using several algorithms reported in the literature, based on the assumption that maximum oscillations are recorded near mean arterial pressure. In normals, reasonable agreement between CW Doppler and oscillometric methods was seen. When an algorithm that determined the lowest cuff pressure at which maximum oscillations occurred, and a characteristic ratio for systolic pressure of 0.52 was used, the mean difference between CW Doppler and oscillometry was 1.7 mmHg [range -19 to +27, limits of agreement (2 SD) 21.1 mmHg]. In ischaemic legs, oscillometry overestimated systolic ankle pressure by a mean of 28.8 mmHg [range -126 to +65, limits of agreement 82.8 mmHg]. The difference was more pronounced among patients with critical ischaemia compared with claudicants, and also more evident among diabetics. The error of oscillometric pressure determination in subjects with leg arterial disease inversely increased with CW Doppler ankle pressure. In 39% of the recordings in legs with a CW Doppler systolic pressure below 100 mmHg, the oscillometric mean arterial pressure was higher than the recorded CW Doppler systolic pressure. In conclusion, the oscillometric method to determine systolic ankle pressure, based on the concept of maximum cuff oscillations occurring near mean arterial pressure, is not reliable in leg arterial disease, usually overestimating ankle pressure.     

Effects of cuff width on arterial occlusion: implications for blood flow restricted exercise

The purpose of this study was to determine the difference in cuff pressure which occludes arterial blood flow for two different types of cuffs which are commonly used in blood flow restriction (BFR) research. Another purpose of the study was to determine what factors (i.e., leg size, blood pressure, and limb composition) should be accounted for when prescribing the restriction cuff pressure for this technique. One hundred and sixteen (53 males, 63 females) subjects visited the laboratory for one session of testing. Mid-thigh muscle (mCSA) and fat (fCSA) cross-sectional area of the right thigh were assessed using peripheral quantitative computed tomography. Following the mid-thigh scan, measurements of leg circumference, ankle brachial index, and brachial blood pressure were obtained. Finally, in a randomized order, arterial occlusion pressure was determined using both narrow and wide restriction cuffs applied to the most proximal portion of each leg. Significant differences were observed between cuff type and arterial occlusion (narrow: 235 (42)?mmHg vs. wide: 144 (17)?mmHg; p?=?0.001, Cohen's D?=?2.52). Thigh circumference or mCSA/fCSA with ankle blood pressure, and diastolic blood pressure, explained the most variance in the cuff pressure required to occlude arterial flow. Wide BFR cuffs restrict arterial blood flow at a lower pressure than narrow BFR cuffs, suggesting that future studies account for the width of the cuff used. In addition, we have outlined models which indicate that restrictive cuff pressures should be largely based on thigh circumference and not on pressures previously used in the literature.     

Parental Hypertension and Cardiovascular Response to Cognitive and Isometric Challenge

The purposes of this investigation were to contrast the cardiovascular responses of sons of hypertensive and normotensive parents to tasks involving cognitive and isometric challenge, and lo examine the relationship of individual differences in heart rate (HR) reactivity to baseline blood pressure (BP) measurements. Thirty-six male, undergraduate volunteers (18 with and 18 without a parental history of hypertension) were scheduled for two, 1-hr experimental sessions (Days I and II). On Day 1, HR and BP measurements were obtained while subjects performed each of three laboratory tasks: a difficult test in concept formation, serial subtraction, and a sustained handgrip at 30% of maximum voluntary contraction. Each task lasted 3 min and was preceded by a 3-min baseline interval. On Day II, subjects were instructed to relax quietly while baseline measures of HR and BP were recorded. Relative to sons of normotensive parents, offspring of hypertensives exhibited higher mean Systolic BPs during all task periods; no corresponding group differences were observed on either Day I or Day II baseline recordings. Unlike SBP, Diastolic BP measurements did not vary reliably by parental hypertensive/normotensive status. Although the mean HRs of sons of hypertensives were significantly higher than in offspring of normotensives, these differences obtained uniformly across both the baseline and task intervals. Among subjects identified as High HR reactors during the two cognitive tasks, sons of hypertensive parents exhibited Day II baseline SBPs about 9 mmHg higher than did subjects without a parental history of hypertension. Among subjects identified as Low HR reactors, baseline SBPs did not differ reliably between sons of hypertensive and normotensive parents.     

Continuous blood pressure measurement by using the pulse transit time: comparison to a cuff-based method

Pulse transit time (PTT) and pulse wave velocity (PWV), respectively, were shown to have a correlation with systolic blood pressure (SBP) and have been reported to be suitable for indirect BP measurements. The aim of this study was to create a function between SBP and PWV, and to test its reliability for the determination of absolute SBP using a non-linear algorithm and a one-point calibration. 63 volunteers performed exercise to induce rises in BP. Arterial PTT was measured between the R-spike of the ECG and the plethysmographic curve of finger pulse-oximetry. The reference BP was measured using a cuff-based sphygmomanometric aneroid device. Data from 13 of the 63 volunteers served for the detection of the PWV–BP relationship. The created non-linear function was used to calculate BP values after individual correction for the BP offset in a group of 50 volunteers. Individual correlation coefficients for SBP measured by PTT (SBP_PTT) and by cuff (SBP_CUFF) varied between r = 0.69 and r = 0.99. Taking all data together, we found r = 0.83 (276 measurements in 50 volunteers). In the Bland–Altman plot, the limits of agreement were \textmean_{\textSBP\textPTT , \textSBP\textCUFF} {\text{mean}}_{{{\text{SBP}}_{\text{PTT}} , {\text{SBP}}_{\text{CUFF}} }} ± 19.8 mmHg. In conclusion, comparing SBP values using the PTT-based method and those measured by cuff resulted in a significant correlation. However, the Bland–Altman plot shows relevant differences between both methods, which are partly due to greater variability of the SBP_PTT measurement during intensified exercise. Results suggest that PTT can be used for measuring absolute SBP when performing an individual correction for the offset of the BP–PWV relation.     

Bayesian fusion algorithm for improved oscillometric blood pressure estimation

A variety of oscillometric algorithms have been recently proposed in the literature for estimation of blood pressure (BP). However, these algorithms possess specific strengths and weaknesses that should be taken into account before selecting the most appropriate one. In this paper, we propose a fusion method to exploit the advantages of the oscillometric algorithms and circumvent their limitations. The proposed fusion method is based on the computation of the weighted arithmetic mean of the oscillometric algorithms estimates, and the weights are obtained using a Bayesian approach by minimizing the mean square error. The proposed approach is used to fuse four different oscillometric blood pressure estimation algorithms. The performance of the proposed method is evaluated on a pilot dataset of 150 oscillometric recordings from 10 subjects. It is found that the mean error and standard deviation of error are reduced relative to the individual estimation algorithms by up to 7 mmHg and 3 mmHg in estimation of systolic pressure, respectively, and by up to 2 mmHg and 3 mmHg in estimation of diastolic pressure, respectively.     

Quantitative Comparison of Korotkoff Sound Waveform Characteristics: Effects of Static Cuff Pressures and Stethoscope Positions

The underlying principles of Korotkoff sound (KorS) during blood pressure measurement and its waveform characteristic changes with cuff pressure and stethoscope position have not been fully understood. This study aimed to quantify the effects of cuff pressure and stethoscope position on the measured KorS waveform characteristics. Thirty healthy subjects were recruited in this study. Four stethoscopes were placed on the circumferential direction around the arm (m1, m2, m3 and m4; m1 was above the artery, and equal distance between each other), and then sequentially at three different longitudinal positions (‘upper’, ‘middle’ and ‘low’ part under the cuff). At each longitudinal position, three levels of static cuff pressure (high: SBP?+?10 mmHg, low: DBP-10 mmHg, and medium: DBP?+?(SBP-DBP)/3) were applied during the recording of KorS waveform. The averaged KorS waveform was firstly computed by using an interpolation method, separately for measurements from different stethoscope locations and cuff pressures. Two quantitative indices were derived to characterize the recorded KorS waveform: intensity amplitude and high-level duration of KorS waveform. Post-hoc pairwise comparisons after analysis of variance were used to compare the waveform characteristic differences between different stethoscope locations and between cuff pressures. Variance analysis demonstrated that the effects of stethoscope circumferential and longitudinal positions and cuff pressure on the two KorS waveform indices were significant (all p?<?0.001). In detail, KorS waveform recorded at cuff pressure P_MEDIUM had larger intensity amplitude and shorter high-level duration than those recorded at cuff pressure P_HIGH or P_LOW. In most conditions, the stethoscope above the artery (m1) produced the largest RMS intensity amplitude and shortest high-level duration, while the stethoscope at the opposite location of m1 generated the smallest RMS intensity amplitude and longest high-level duration. In terms of the effect of longitudinal position, the stethoscopes below the middle of the cuff always produced KorS recordings with larger intensity amplitude and shorter high-level duration. This study has quantified and provided scientific evidence that cuff pressure, stethoscope longitudinal and circumferential positions are important factors influencing KorS waveform characteristics.     

高血压微循环与体循环动力学临床研究系列——Ⅱ.高血压病人皮肤微循环血流阻力的临床研究

高血压病人30例,正常血压对照30例,采用Laser Doppler血流计测定手指皮肤血流量,间接测定甲襞毛细血管压,并计算皮肤血流阻力,以袖带法测量肱动脉、桡动脉和指动脉血压,计算出平均血压和毛细血管前压降。结果显示:高血压组皮肤微循环中的血流阻力和毛细血管压升高(26.77±14.53对17.74±9.28mmHg/V,P<0.01;68.68±19.42对43.11±10.30mmHg,P<0.01),而皮肤血流改变无显著性差异(2.56±1.01对2.43±0.92,P>0.05);高血压组毛细血管压升高与其上游压降呈负相关关系(r=-0.78,P<0.01),提示皮肤毛细血管压和血流阻力是受其上游“阻力血管”所控制。用血管扩张剂治疗后的病人,血压明显下降而皮肤血流阻力仍处于升高状态。从而提示皮肤血流阻力的“结构成份”增加并借此作为评价“结构阻力”可逆性的客观指标。     

Cardiovascular responses to human calf muscle stretch during varying levels of muscle metaboreflex activation

The purpose of the present study was to investigate the cardiovascular responses to muscle metaboreflex- and concurrent muscle stretch-induced mechanoreflex activation. Eight subjects (7 males, 1 female) performed 90 s of isometric calf plantarflexion at 0, 30, 50 and 70% of maximum voluntary contraction. During exercise and for 3.5 min postexercise, circulatory occlusion (PECO) was ensured by inflation of a thigh cuff. After 90 s of PECO the calf muscle was stretched for 60 s (Stretch). Heart rate (HR; assessed from ECG), blood pressure (BP; Finapres) and phase of respiratory cycle were recorded. Exercise increased diastolic BP (DBP) from rest by 1+/-0.8, 14+/-2.5, 29+/-3.9 and 35+/-3.6 mmHg, during the 0, 30, 50 and 70% conditions, respectively (ANOVA rest versus exercise, P<0.05). During PECO DBP remained elevated, by 2+/-0.4, 8+/-0.3, 12+/-0.3 and 13+/-0.9 mmHg, respectively. Stretch produced a further increase in DBP that was not different between conditions (3+/-1.4, 2+/-0.8, 3+/-1.0 and 3+/-0.9 mmHg, for the 0, 30, 50 and 70%, respectively). HR increased during exercise but returned to baseline during PECO. HR increased at Stretch onset in all conditions. No EMG was detected from the gastrocnemius and soleus during Stretch. Our data show that the cardiovascular responses to human calf Stretch are independent of the level of concurrent muscle metaboreflex activation.     

Noninvasive blood pressure measurement on the temporal artery using the auscultatory method

Blood pressures in the temporal artery of five normotensive subjects were recorded using a modified auscultatory setup. The setup comprised a pediatric cuff to occlude the artery and a piezoelectric contact microphone to record the Korotkoff sounds. Both the cuff and microphone were held in their respective positions with an adjustable head band. The recordings were taken under four different conditions: the subject lying supine, the subject sitting at rest, the subject sitting immediately after exercise and the subject moving the head gently. These recordings were compared with readings from the brachial artery, obtained with a commercially available automatic blood pressure measuring device. Korotkoff sounds were analyzed in the time and frequency domain. Results indicate that Korotkoff sounds in the temporal artery are much smaller in amplitude, and do not exhibit the same distinctive phases as those of the brachial artery. Despite these differences, these sounds can be used to detect blood pressures at head level. The accuracy of the readings was within ±10%. Successful readings were also obtained with gentle head motions, demonstrating that this setup has the potential to be developed into an ambulatory blood pressure monitoring system.     

Relationship between tourniquet pressure and a cross-section area of superficial vein of forearm

This study investigated the appropriate tourniquet pressure (TP) and duration of tourniquet application for venipuncture by calculating the venous cross-section (VCS) area on ultrasonography. Twenty healthy volunteers without cardiovascular risk factors were enrolled in this study. A target vein (either a cephalic or median cubital vein) was selected on ultrasonography. The pneumatic tourniquet was inflated using a rapid cuff inflator system at setting pressure for 120 sec. TP strength was varied from 20 mmHg to 100 mmHg, in 20 mmHg increments. The order of TP was randomized. Comparisons among more than 3 groups were performed by one-way repeated-measures ANOVA and the Bonferroni method. The VCS area increased rapidly until 10 sec after tourniquet inflation. The VCS area then increased gradually until 30 sec after tourniquet inflation. After that, the VCS area did not increase remarkably. The VCS area increased with TP strength up to 80 mmHg, but the VCS area at TP 100 mmHg decreased to less than that at TP 40 mmHg. Based on these results, we recommend a tourniquet pressure of 60 mmHg, and duration of tourniquet application is 30 to 60 sec for venipuncture.     

Suspicion of aortic coarctation in an outpatient clinic: how should blood pressure measurements be performed?

We conducted a study on blood pressure (BP) measurements in 40 healthy children (aged 11.0 +/- 0.4 years), in 20 healthy students (18.8 +/- 0.9 years), and in 19 children with a history of coarctation (9.3 +/- 4.0 years). Both a standard sphygmomanometer and an oscillometric device (Dinamap, Critikon Inc, Tampa, FL, USA) were used. BP measurements in the arms, thighs and ankles were performed according to a fixed protocol. Although the site of measuring was switched each time successive measurements in the same limb resulted in lower systolic values than the first measurement. In patients with coarctation all gradient estimates correlated well with each other and with the gradient estimates obtained by Doppler-echocardiography. In healthy children, the systolic BP measured by Dinamap was 2 mmHg lower in the right arm than in the thighs, and 12 mmHg lower than in the ankles. In young adults, the differences were 12 and 16 mmHg, respectively. The BP difference between the right arm and the thighs by sphygmomanometer was +4 mmHg in children and -4 mmHg in adults. The cut point value to warrant further examinations was similar with both methods: 5-10 mmHg higher readings in the arm than in the leg. The first BP measurement should be ignored. After that, repetitive measurements in the arm with the higher systolic BP and the legs should be performed.     

Criteria in the choice of an occluding cuff for the indirect measurement of blood pressure

For a sphygmomanometric method of indirect blood-pressure measurement to be accurate, the cuff must operate so that the intrabladder pressure is always the same as the pressure applied by the tissues of the arm to the artery wall. To determine under what conditions this occurs, analyses are presented assuming the arm to be a rotationally symmetric, incompressible solid cylinder acted upon by various cuff pressure fields. The results indicate that the pressure applied to the artery wall is markedly influenced by longitudinal motion of the arm tissue, which must be constrained to have an accurate pressure transmission. It is shown that a wide cuff does effectively accomplish this under its central region. The analyses agree with experiments in which indirect and direct blood-pressure measurements were made and most of the clinical observations of others. However, the claim that ‘if the cuff is too wide, the reading will be erroneously low’ is not indicated in the analytical solution and has not been observed in the authors' experiments. These analytical and experimental results were used to establish criteria for the design of appropriate occluding cuffs. Based upon these criteria, cuffs for clinical use have been produced from a plastic film in a variety of lengths and widths.     

Perceived Changes in the Intensity oi Arterial Pulsations as a Function oi Applied Cufi Pressure

A psychophysical scaling procedure was employed to investigate subjects' ability to discriminate pulsatile arterial sensations produced by applying an occluding cuff about the upper arm. Subjects (n = 8) were exposed to 5 presentations of 7 occluding cuff pressure levels ranging from above systolic to below diastolic arterial pressure. During each cuff inflation, subjects were instructed to attend to the pulsating sensations in the arm. When the cuff deflated, subjects adjusted the volume ofa tone to a level that matched their subjective estimate of pulsation intensity. Consistent with previous reports, subjects perceived maximum intensity pulsations when cuff pressure approximated calculated mean arterial pressure (MAP), 1/3 (systolic -diastolic) + diastolic. The perceived intensity ofthe sensations decreased monotonically as cuff pressure was varied in either the systolic or diastolic direction producing a highly symmetrical function on both sides of MAP. The gradient of arterial pulsations produced by the occluding cuff pressure, the accuracy of the judgments ofthe intensity of perceived pulsations, and the possibility that these pulsations may he more physiologically related to the hemodynamics of blood flow, suggest that these sensations may be employed as a more effective discriminative stimulus in a blood pressure biofeedback procedure.     

Evaluation of the harmonized alert sensing technology device for hemodynamic monitoring in chronic hemodialysis patients

The Harmonized Alert Sensing Technology (HASTE) device was developed to overcome the primary shortcomings of interval based noninvasive blood pressure (BP) monitoring. This study was conducted to assess the reliability of the HASTE system compared with standard cuff BP values in patients on hemodialysis. A total of 1,370 HASTE measurements were compared with oscillometric standard cuff systolic BP values in 42 sessions of 15 patients on hemodialysis. The average discrepancy between the HASTE and cuff systolic BP was 1.41 +/- 16.90 mm Hg. Compared with cuff measurements, 31% of systolic BP fell within a range of 5 mm Hg difference, 57% of systolic BP fell within 10 mm Hg, and 73% of systolic BP fell within a 15 mm Hg band. According to British Hypertension Society standards or Association for the Advancement of Medical Instrumentation criteria, the current HASTE method did not perform well. Technology to provide noninvasive hemodynamic monitoring is, however, in its developmental stage. The effort at continuous systolic pressure monitoring using existing, readily available, and frequently used techniques is exciting. Although the HASTE system as currently configured and calibrated did not adequately perform, variations in site analysis and conversion factors may increase pressure sensitivity and tracking over the course of a standard dialysis treatment.     

应用GAMLSS技术构建基于性别、年龄和身高的新疆7～17岁儿童青少年血压参考标准

目的结合性别、年龄和不同身高百分位数,应用GAMLSS技术探索性构建新疆7～17岁儿童青少年血压百分位数参考标准。方法分析数据来自一项共包含5200名维吾尔族、汉族和哈萨克族中小学生的心血管危险因素的横断面调查,其中男性2531名,女性2669名。血压测量采用美国心脏病联合会（AHA）规范的国际标准血压测量法,精确至2mmHg。身高测量依照《国家学生体质健康标准》方法进行,精确至1cm。应用GAMLSS技术,结合性别、年龄及身高百分位数预测得到血压P50、P90、P95和P99值。以D（μ,σ,υ,τ）的特定分布形式,同时考虑资料的偏度和峰度,利用3次光滑样条函数（cs（.））进行方程拟合,身高百分位数采用LMS法（μ-σ-λ）计算。结果观察拟合的SBP和DBP各年龄别的百分位数曲线,可见：①SBP在儿童青少年期随年龄的增长其发展规律男性与女性不同,男性SBP曲线呈现逐渐升高趋势,女性SBP曲线至12岁时达高峰后停止增长;男、女性DBP随年龄的发展趋势与SBP相近。至17岁时,身高P50所对应的SBPP95和DBPP95男女间差值分别为9和4mmHg,男性血压高于女性。②身高百分位数越大,其对应的血压值越高,观察7～17岁身高P95和身高P5相对应血压P90的差值,每单位身高增加引起的血压变化随年龄增大逐渐减小。③与美国第4版《儿童青少年高血压诊断、评价和治疗指南》相比较,男、女性SBPP90切点值出现时间与美国标准接近,分别为12和13岁;DBP从7岁起即高于美国标准相应的切点值约10mmHg,之后呈增长缓慢,11～12岁后呈下降趋势,至17岁时与美国标准相应的切点值接近。身高P50所对应的DBPP90切点值至9岁时已达80mmHg,远早于美国的16岁。结论在中国范围内首次尝试性应用GAMLSS技术构建新疆儿童青少年分性别、年龄和身高百分位数的血压参考值。描述了血压拟合曲线在不同性别下的发展规律与相互间的特征差异,补充了不同身高百分位数下的血压参考值,可使中国不同地区的儿童青少年群体血压参考值范围更趋精准,尤其可为身高处于极端水平（身高过高或过矮）的儿童青少年人群血压水平的合理诊断提供依据。     

Isolated office hypertension: association with target organ damage and cardiovascular risk indices

BACKGROUND: Isolated office hypertension (IOH) has been accepted as a benign condition by some researchers, whereas others believe that it is associated with cardiovascular abnormalities and increased cardiovascular risk. The aim of this present study was to evaluate the effects of IOH on target organ damage and cardiovascular risk indices. METHODS: Arterial blood pressure (BP) measured in the office and by 24-hour ambulatory blood pressure measurement (ABMP), carotid intima-media thickness (CIMT), left ventricular mass index (LVMI), cardiothoracic index (CTI), duration of QTc, 24-hour microalbuminuria, fibrinogen, C-reactive protein (CRP), total cholesterol, low-density-lipoprotein (LDL) cholesterol, high-density-lipoprotein (HDL) cholesterol and triglyceride levels were evaluated. Thirty-three subjects with IOH (office BP > or = 140/90 mmHg and daytime ambulatory BP <135/85 mmHg), 17 patients with sustained hypertension (office BP > or = 140/90 mmHg and daytime ambulatory BP > or = 135/85 mmHg), and 17 normotensive control subjects were recruited in the study. The three groups were matched for age, sex and body mass index. RESULTS: CIMT was greater in patients with IOH than in normotensive subjects, and it was significantly lower than that of sustained hypertension patients. Significantly higher LVMI was determined in subjects with IOH compared to normotensive subjects. CTI, QTc, microalbuminuria, fibrinogen, CRP, total cholesterol, LDL cholesterol, HDL cholesterol and triglyceride levels did not differ significantly among the three groups. CONCLUSIONS: IOH causes significant target organ damage and should not be regarded as a benign condition.