Dependence of a drop in blood pressure in pulmonary circulation and in the right heart on dosage of isosorbide dinitrate]

An effect of isosorbide dinitrate on blood pressure values in the pulmonary circulation and the right heart has been investigated in 25 patients with a history of the first transmural myocardial infarction. Group I including 12 patients has been given 5 mg isosorbide nitrate in a 60-minute intravenous infusion while group II of 13 patients has been given 10 mg of the drug in the same way. Both groups have been matched in clinical data and blood pressure value in the pulmonary circulation which has been normal. Pulmonary blood pressure has been measured with Swan-Ganz catheter prior to the administration of drug, and 15, 30, 45 and 60 minutes following an infusion. Isosorbide dinitrate in a dose of 5 mg did not decrease blood pressure in the pulmonary circulation statistically significantly. The differences in blood pressure falls did exceed 9%. Filling pressure in the right ventricle did not change either while systolic blood pressure decrease by 16.6%. A double dose of isosorbide dinitrate reduced blood pressure in the pulmonary artery by about 1/3 of the baseline value, and blood pressure in the right ventricle (mean right atrial pressure) by 57.2%. Both systolic and diastolic arterial pressures were reduced. Isosorbide dinitrate reduced blood pressure in the pulmonary circulation in patients who underwent myocardial infarction, and hypotensive effect has been dose-related. A reduction in the right ventricular filling pressure has been a one of important mechanisms decreasing pulmonary pressures.     

Modified heart-lung preparation for the evaluation of systolic and diastolic coronary flow in rats

A modified heart-lung preparation of the rat, which permits measuring systolic and diastolic coronary flow separately and enables coronary compliance to be evaluated, is described. The systemic circulation was substituted by a shunt circuit, and the elastic properties of the arterial tree were mimicked by a rubber balloon. Systolic and diastolic coronary flow was evaluated from the pulmonary and aortic flow signal. Integrated phasic pulmonary flow represented right ventricular stroke volume. Integrated phasic systolic aortic flow represented left ventricular stroke volume minus that volume flowing into the coronary arteries during systole, because the aortic flow probe had to be inserted distal to the origin of the coronary vessels. Because right and left ventricular stroke volume was identical under steady-state conditions, the difference between systolic pulmonary and systolic aortic flow resulted in systolic coronary flow. Diastolic coronary flow was measured by means of the retrograde flow through the aortic flow probe. Coronary compliance was calculated according to Frank's windkessel model from coronary resistance and from central diastolic aortic pressure, which decayed exponentially after switching out the rubber balloon and the shunt circuit. It could be shown that the proportion of systolic to diastolic coronary flow depends on coronary compliance.     

Combined pulmonary stenosis and insufficiency preserves myocardial contractility in the developing heart of growing swine at midterm follow-up.

This study was conducted to determine the effects of chronic combined pulmonary stenosis and pulmonary insufficiency (PSPI) on right (RV) and left ventricular (LV) function in young, growing swine. Six pigs with combined PSPI were studied, and data were compared with previously published data of animals with isolated pulmonary insufficiency and controls. Indexes of systolic function (stroke volume, ejection fraction, and cardiac functional reserve), myocardial contractility (slope of the end-systolic pressure-volume and change in pressure over time-end-diastolic volume relationship), and diastolic compliance were assessed within 2 days of intervention and 3 mo later. Magnetic resonance imaging was used to quantify pulmonary insufficiency and ventricular volumes. The conductance catheter was used to obtain indexes of the cardiac functional reserve, diastolic compliance, and myocardial contractility from pressure-volume relations acquired at rest and under dobutamine infusion. In the PSPI group, the pulmonary regurgitant fraction was 34.3 +/- 5.8%, the pressure gradient across the site of pulmonary stenosis was 20.9 +/- 20 mmHg, and the average RV peak systolic pressure was 70% systemic at 12 wk follow-up. Biventricular resting cardiac outputs and cardiac functional reserves were significantly limited (P < 0.05), LV diastolic compliance significantly decreased (P < 0.05), but RV myocardial contractility significantly enhanced (P < 0.05) compared with control animals at 3-mo follow-up. In the young, developing heart, chronic combined PSPI impairs biventricular systolic pump function and diastolic compliance but preserves RV myocardial contractility.     

Mineralocorticoid receptor blockade improves diastolic function independent of blood pressure reduction in a transgenic model of RAAS overexpression

There is emerging evidence that aldosterone can promote diastolic dysfunction and cardiac fibrosis independent of blood pressure effects, perhaps through increased oxidative stress and inflammation. Accordingly, this investigation was designed to ascertain if mineralocorticoid receptor blockade improves diastolic dysfunction independently of changes in blood pressure through actions on myocardial oxidative stress and fibrosis. We used young transgenic (mRen2)27 [TG(mRen2)27] rats with increases in both tissue ANG II and circulating aldosterone, which manifests age-related increases in hypertension and cardiac dysfunction. Male TG(mRen2)27 and age-matched Sprague-Dawley rats were treated with either a low dose (～1 mg·kg(-1)·day(-1)) or a vasodilatory, conventional dose (～30 mg·kg(-1)·day(-1)) of spironolactone or placebo for 3 wk. TG(mRen2)27 rats displayed increases in systolic blood pressure and plasma aldosterone levels as well as impairments in left ventricular diastolic relaxation without changes in systolic function on cine MRI. TG(mRen2)27 hearts also displayed hypertrophy (left ventricular weight, cardiomyoctye hypertrophy, and septal wall thickness) as well as fibrosis (interstitial and perivascular). There were increases in oxidative stress in TG(mRen2)27 hearts, as evidenced by increases in NADPH oxidase activity and subunits as well as ROS formation. Low-dose spironolactone had no effect on systolic blood pressure but improved diastolic dysfunction comparable to a conventional dose. Both doses of spironolactone caused comparable reductions in ROS/3-nitrotryosine immunostaining and perivascular and interstitial fibrosis. These data support the notion mineralocorticoid receptor blockade improves diastolic dysfunction through improvements in oxidative stress and fibrosis independent of changes in systolic blood pressure.     

Oscillometric measurement of systolic and diastolic blood pressures validated in a physiologic mathematical model

ABSTRACT: BACKGROUND: The oscillometric method of measuring blood pressure with an automated cuff yields valid estimates of mean pressure but questionable estimates of systolic and diastolic pressures. Existing algorithms are sensitive to differences in pulse pressure and artery stiffness. Some are closely guarded trade secrets. Accurate extraction of systolic and diastolic pressures from the envelope of cuff pressure oscillations remains an open problem in biomedical engineering. METHODS: A new analysis of relevant anatomy, physiology and physics reveals the mechanisms underlying the production of cuff pressure oscillations as well as a way to extract systolic and diastolic pressures from the envelope of oscillations in any individual subject. Stiffness characteristics of the compressed artery segment can be extracted from the envelope shape to create an individualized mathematical model. The model is tested with a matrix of possible systolic and diastolic pressure values, and the minimum least squares difference between observed and predicted envelope functions indicates the best fit choices of systolic and diastolic pressure within the test matrix. RESULTS: The model reproduces realistic cuff pressure oscillations. The regression procedure extracts systolic and diastolic pressures accurately in the face of varying pulse pressure and arterial stiffness. The root mean squared error in extracted systolic and diastolic pressures over a range of challenging test scenarios is 0.3 mmHg. CONCLUSIONS: A new algorithm based on physics and physiology allows accurate extraction of systolic and diastolic pressures from cuff pressure oscillations in a way that can be validated, criticized, and updated in the public domain.     

Enhanced central and conduit pulmonary arterial reservoir function offsets reduced ductal systolic outflow during constriction of the fetal ductus arteriosus

Constriction of the fetal ductus arteriosus (DA) has disparate effects on mean and phasic hemodynamics, as mean DA blood flow is preserved until constriction is severe, but DA systolic and diastolic blood velocities change with only mild constriction. To determine the basis of this disparity and its physiological significance, seven anesthetized late-gestation fetal sheep were instrumented with pulmonary trunk (PT), DA, and left pulmonary artery (PA) micromanometer catheters and transit-time flow probes. Blood flow profile and wave intensity analyses were performed at baseline and during mild, moderate, and severe DA constriction (defined as pulmonary-aortic mean pressure differences of 4, 8, and 14 mmHg, respectively), produced with an adjustable snare. With DA constriction, mean DA flow was initially maintained but decreased with severe constriction (P < 0.05) in conjunction with a reduction (P < 0.05) in PT flow (i.e., right ventricular output). By contrast, DA systolic flow fell progressively during DA constriction (P < 0.001), due to decreased transmission of both early and midsystolic proximal flow-enhancing forward-running compression waves into the DA. However, DA constriction was also accompanied by greater systolic storage of blood in the PT and main PA (P < 0.025), and increased retrograde diastolic flow from compliant major branch PA (P < 0.001). Transductal discharge of these central and conduit PA blood reservoirs in diastole offset systolic DA flow reductions. These data suggest that, during DA constriction in the fetus, enhanced central and conduit PA reservoir function constitutes an important compensatory mechanism that contributes to preservation of mean DA flow via a systolic-to-diastolic redistribution of phasic DA flow.     

Path analysis of familial resemblance in blood pressure in Middle Dalmatia,Croatia

The familial resemblance in blood pressure in Middle Dalmatia, Croatia, has been analyzed using the Path-analytic approach. The sample consisted of 1,126 examinees (526 males and 600 females, aged 17 to 87), inhabitants of the Middle Dalmatia's islands of Brac, Hvar, Korcula and the Peljesac peninsula. The Path analysis was performed with the assumption that each family member (father, mother, offspring 1 and 2) has a latent variable (C) that influences both the blood pressure values (P) and the morphological dimensions significantly correlated with blood pressure (Q). According to the estimates revealed from the most parsimonious models, the diastolic blood pressure has a more pronounced genetic component (h2 = 30-32%) than the systolic blood pressure (h2 = 15%). In contrast to the low intergenerational influences, the members of the same generation showed pronounced effects of shared environment. Common (non-transmitted) offsprings' environment (B) explains 44% of variance of the individual offspring's environment (C) in systolic and 33-35% in diastolic blood pressure. The correlation of father's and mother's environment (u2) was high in the case of diastolic blood pressure (33-44%) but for the systolic blood pressure it was not significantly different from zero. According to the presented results in insular/peninsular population of Middle Dalmatia, family resemblance of systolic and diastolic blood pressure differs. The resemblance is higher in diastolic blood pressure with stronger additive genetic component and stronger environmental and/or genetic component related with morphology. The sources of high heritability of diastolic blood pressure in Middle Dalmatia as well as the sources of high prevalence of hypertension in the same population are the phenomena that might be connected and thus deserve to be further explored in incoming analyses.     

The characteristics of the alpha-adrenergic regulation of the cardiovascular system in middle-aged and elderly subjects]

97 practically healthy young adult, elderly and old people were examined to study the age-associated changes in alpha-adrenergic regulation of the cardiovascular system. The values of central and renal hemodynamics, systolic and diastolic cardiac functions, skin and bulbar microcirculation and arterial blood pressure were determined in dynamics after injection of the alpha-stimulator phenylephrine (0.15 mg/kg of body mass intramuscularly) or alpha-blocker prazosin (0.015 mg/kg of body mass orally). In old age alpha-adrenergic effects on the heart were found to decrease. In elderly and old people the changes of peripheric blood circulation prevail in the structure of hemodynamic shifts arising in stimulation and alpha-adrenergic receptors blockage.     

Factors Affecting Blood Pressure Variability: Lessons Learned from Two Systematic Reviews of Randomized Controlled Trials

Systematic reviews can often reveal much more than the original objective of the work. The objectives of this retrospective analysis were to answer three basic questions about blood pressure variability: 1) Does blood pressure entry criterion have an effect on baseline blood pressure variability? 2) Do thiazide diuretics have a significant effect on blood pressure variability? and 3) Does systolic blood pressure vary to the same degree as diastolic blood pressure? This analysis of blood pressure variability is based on resting standardized research setting BP readings from two systematic reviews evaluating blood pressure lowering efficacy of thiazide diuretics from double blind randomized controlled trials in 33,611 patients with primary hypertension. The standard deviation reported in trials was the focus of the research and the unit of analysis. When a threshold systolic or diastolic blood pressure value is used to determine entry into a trial, baseline variability is significantly decreased, systolic from 14.0 to 9.3 mmHg and diastolic from 8.4 to 5.3 mmHg. Thiazides do not change BP variability as the standard deviation and coefficient of variation of systolic blood pressure and diastolic blood pressure did not differ between thiazide and placebo groups at end of treatment. The coefficient of variation of systolic blood pressure was significantly greater than the coefficient of variation of diastolic blood pressure. Entry criterion decreases the baseline blood pressure variability. Treatment with a thiazide diuretic does not affect blood pressure variability. Systolic blood pressure varies to a greater degree than diastolic blood pressure.     

右心导管法测大鼠肺动脉压力的改良

目的:目前常用的测量大鼠肺动脉压力的右心导管法存在一定的缺陷,且很难得到典型的压力曲线图。本实验对大鼠经颈外静脉插管与测压的方法进行改良,同时与已有报道的实验结果进行比较,并提供正常SD大鼠右心房、右心室及肺动脉的压力参考值及典型的压力曲线图,以协助研究人员判断导管位置,及时调整导管的深度和方向,快速测出肺动脉压力。方法:雌雄不分的清洁级SD大鼠共30只,体重180~230 g,6~7周龄。应用自制的末端呈一弧形的PE-10管,采用改良后的右心导管法,经颈外静脉插入大鼠心腔及肺动脉,检测并计算大鼠右心房、右心室和肺动脉的收缩压、舒张压及肺动脉平均压。结果:右心房压力波动较平缓,呈小波浪形;右心室压力曲线波动大,骤升骤降;肺动脉压力曲线有重搏波。正常SD大鼠右心房舒张压为(2.03±2.56)mmHg,收缩压为(2.82±1.85)mmHg;右心室舒张压为(5.72±3.99)mmHg,收缩压为(18.73±4.80)mmHg;肺动脉舒张压为(15.27±2.64)mmHg,收缩压为(18.49±2.53)mmHg,肺动脉平均压为(16.34±2.32)mmHg。右心室收缩压与肺动脉收缩压无明显差异(P0.05)。结论:改良后的方法可准确到达大鼠肺动脉,提供的压力参考值及曲线图有助于研究人员顺利完成测压实验。     

Intersalt revisited: further analyses of 24 hour sodium excretion and blood pressure within and across populations. Intersalt Cooperative Research Group.

OBJECTIVES--To assess further the relation in Intersalt of 24 hour urinary sodium to blood pressure of individuals and populations, and the difference in blood pressure from young adulthood into middle age. DESIGN--Standardised cross sectional study within and across populations. SETTING--52 population samples in 32 countries. SUBJECTS--10,074 men and women aged 20-59. MAIN OUTCOME MEASURES--Association of sodium and blood pressure from within population and cross population multiple linear regression analyses with multivariate correction for regression dilution bias. Relation of sample median daily urinary sodium excretion to difference in blood pressure with age. RESULTS--In within population analyses (n = 10,074), individual 24 hour urinary sodium excretion higher by 100 mmol (for example, 170 v 70 mmol) was associated with systolic/diastolic blood pressure higher on average by 3/0 to 6/3 mm Hg (with and without body mass in analyses). Associations were larger at ages 40-59. In cross population analyses (n = 52), sample median 24 hour sodium excretion higher by 100 mmol was associated with median systolic/diastolic pressure higher on average by 5-7/2-4 mm Hg, and estimated mean difference in systolic/diastolic pressure at age 55 compared with age 25 greater by 10-11/6 mm Hg. CONCLUSIONS--The strong, positive association of urinary sodium with systolic pressure of individuals concurs with Intersalt cross population findings and results of other studies. Higher urinary sodium is also associated with substantially greater differences in blood pressure in middle age compared with young adulthood. These results support recommendations for reduction of high salt intake in populations for prevention and control of adverse blood pressure levels.     

Evaluation of blood pressure changes and heart rate in young health men based on results of a 24-hour monitoring of pressure]

Systolic and diastolic blood pressures and heart rate were monitored in a group of 20 young healthy men for 24 hours. Period of time between 8 o'clock a.m. and 10 o'clock p.m. was treated as waking state whereas period of time from 12 p.m. to 6 a.m. as sleep phase. Mean value of systolic blood pressure for waking state was 124.6 +/- 7.6 mm Hg, and for sleep phase 110.4 +/- 11.5 mm Hg. (p < .001). Mean diastolic blood pressures were also significantly different (76.5 +/- 5.9 mm Hg and 63.8 +/- 7.7 mm Hg, respectively), the same concerns heart rate (79.6 +/- 6.4 and 63.0-7.2 min-1, respectively). In both cases p < .001. To evaluate dependence of heart rate on systolic blood pressure in waking state the following calculation was made: HR = 0.230 x systolic blood pressure +51.4 (r = 0.24; p < .001) whereas for sleep phase r did not reach a level of statistical significance (HR = 0.074 x systolic blood pressure + 53.9; r = 0.094). Single or even multiple measurements of the arterial blood pressure are not sufficient to evaluate circadian changes.     

Segregation analysis of systolic and diastolic blood pressure in Middle Dalmatia Island population

A complex segregation analysis of systolic and diastolic blood pressure has been performed on pedigree data from rural populations inhabiting Middle Dalmatian islands of Brac, Hvar and Korcula and the Peljesac peninsula. The purpose of the performed analysis was to possibly elucidate a signal of a large-effect gene responsible for high prevalence of hypertension present in this population (the age-adjusted prevalence of developed hypertension being 31.82% in males and 28.23% in females). The analysis was performed on a sample of 389 two- and three-generation families consisting of 2 to 19 observed individuals (1126 examinees in total, 526 males and 600 females, aged 17 to 83). Since the examinees were randomly selected from census data encompassing 22.6% of the total population--the family relations having been established afterwards--the selected sample can be considered representative for the examined populations. By applying the usual transmission probability tests, the major gene model has been accepted for systolic as well as for diastolic blood pressure. The most parsimonious models showed that: (a) inheritance of blood pressure in the Middle Dalmatia population can be attributed to the effect of a major gene responsible for 34% (systolic) and 36% (diastolic) blood pressure variation; (b) alleles of that major gene act in co-dominant fashion; (c) allele frequency for high blood pressure (A2) is 18% (systolic) and 15% (diastolic blood pressure); and (d) the residual (non-major gene) familial correlation is negligible and can be constrained to zero. Since the results are also indicating heterogeneity within the sample in the genetic determination of the systolic blood pressure, the obtained results thus justify further search for the most promising subpopulation for incoming genetic epidemiological investigations of hypertension.     

同步间歇指令通气和适应性支持通气对COPD合并呼吸衰竭患者周围循环和血气的影响

目的:研究同步间歇指令通气(SIMV)与适应性支持通气(ASV)对慢性阻塞性肺部疾病(COPD)合并呼衰患者机体外周血循环、血气指标的影响。方法:选取2006年3月至2013年12月在我院接受治疗的COPD合并呼吸衰竭患者86例,对其分别先后采用ASV、SIMV呼吸模式,记录呼吸机参数、外周血循环参数及血气指标。结果:ASV组呼吸频率(RR)、潮气量(TV)、吸气峰值压(PIP)均显著低于SIMV组(均P0.01);ASV组外周血心率(HR)、收缩压(SBP)、舒张压(DBP)、中心静脉压(CVP)均显著低于SIMV组(均P0.01);ASV组动脉血氧分压(PaO_2)、pH、血氧饱和度(Sa O2)均较SIMV组显著升高(均P0.05)。结论:ASV模式下治疗COPD合并呼吸衰竭患者的呼吸参数、外周血循环参数、血气改善效果优于SIMV模式。     

Allometric scaling of mammalian blood pressure: A comment on White and Seymour (2014)

White and Seymour examined the scaling of central arterial blood pressure against body mass in mammals ranging in size from a 30 g mouse to a 4080 kg elephant. Exponents in power functions fitted to each of three datasets (systolic, diastolic, and mean arterial pressure) were reported to be significantly greater than zero and indistinguishable from 0.33. The first of these outcomes would indicate that blood pressure increases with body size, whereas the second is consistent with the heart working against gravity to move blood to the head. Taken together, these results seemingly refute the notion that the cephalic circulation functions as an energy‐neutral siphon. However, the main findings by White and Seymour were presented in the form of graphs that distorted the relationships between the variables of interest. I use simple graphics to show that the data were unsuited from the outset for use in allometric analyses and that conclusions of the investigation are not well supported.     

The role of genetic and environmental factors in phenotypic variability of arterial pressure and body weight and their interconnection (a family study)

Contribution of genetic and environmental factors into phenotypic variability of blood pressure and body mass as well as into phenotypic correlation between these traits was defined. It was shown that additive genetic determinant is responsible for considerable level of blood pressure and body mass variability. Those common environmental factors are of importance which operate within the limits of one generation. Maternal effect of systolic and diastolic blood pressure variability is negligible. The correlation between systolic and diastolic blood pressure is determined both by environmental and genetic factors, whereas that between blood pressure and body mass is mediated by only environmental factors. The contribution of environmental factors into correlation between blood pressure and body mass lessens with age. The results obtained may be applied in development of population and individual programmes for preventing cardiovascular diseases.     

The effects of propranolol, phentolamine, and atropine on canine coronary vascular gradients

The objective of this study was to measure pressure gradients in the coronary circulation following the administration of three receptor-blocking drugs, propranolol, phentolamine, and atropine when administered singly and in sequence. As well, we examined the responses of these gradients to eight interventions: left stellate ganglion or left vagosympathetic trunk stimulation, administration of isoproterenol, acetylcholine, noradrenaline, adenosine, phenylephrine, or adrenaline. Using a multiple linear regression model we examined the actions and interactions of the receptor-blocking agents on hemodynamic variables and vascular gradients. Propranolol reduced heart rate as expected and blocked the responses to isoproterenol administration. As well, it abolished the epicardial coronary artery diastolic gradient. The gradient was restored when propranolol was the second receptor blocker administered but was abolished when it was the third. Phentolamine induced vasodilation with a decrease in coronary small vessel gradients. This effect persisted without regard to the sequence of administration. When it was the second or third agent it decreased the microcirculation and small vein gradients, an action it did not manifest when given singly. Atropine singly did not alter pressures or gradients; but as the second agent it altered the transmural, outflow tract, epicardial diastolic, and microcirculation and small vein diastolic gradients; and as the third agent the changes were in the transmural, epicardial systolic and diastolic, and small artery systolic and diastolic gradients. The pattern of responses was not predictable and that indicates that unique changes occur in the responses of the coronary circulation when multiple receptor-blocking agents are employed. Adrenergic control tends to dominate in the coronary arterial circulation, and muscarinic control in the coronary microcirculation and veins with considerable overlap.     

Central Pressure Appraisal: Clinical Validation of a Subject-Specific Mathematical Model

IntroductionCurrent evidence suggests that aortic blood pressure has a superior prognostic value with respect to brachial pressure for cardiovascular events, but direct measurement is not feasible in daily clinical practice.AimThe aim of the present study is the clinical validation of a multiscale mathematical model for non-invasive appraisal of central blood pressure from subject-specific characteristics.MethodsA total of 51 young male were selected for the present study. Aortic systolic and diastolic pressure were estimated with a mathematical model and were compared to the most-used non-invasive validated technique (SphygmoCor device, AtCor Medical, Australia). SphygmoCor was calibrated through diastolic and systolic brachial pressure obtained with a sphygmomanometer, while model inputs consist of brachial pressure, height, weight, age, left-ventricular end-systolic and end-diastolic volumes, and data from a pulse wave velocity study.ResultsModel-estimated systolic and diastolic central blood pressures resulted to be significantly related to SphygmoCor-assessed central systolic (r = 0.65 p <0.0001) and diastolic (r = 0.84 p<0.0001) blood pressures. The model showed a significant overestimation of systolic pressure (+7.8 (-2.2;14) mmHg, p = 0.0003) and a significant underestimation of diastolic values (-3.2(-7.5;1.6), p = 0.004), which imply a significant overestimation of central pulse pressure. Interestingly, model prediction errors mirror the mean errors reported in large meta-analysis characterizing the use of the SphygmoCor when non-invasive calibration is performed.ConclusionIn conclusion, multi-scale mathematical model predictions result to be significantly related to SphygmoCor ones. Model-predicted systolic and diastolic aortic pressure resulted in difference of less than 10 mmHg in the 51% and 84% of the subjects, respectively, when compared with SphygmoCor-obtained pressures.     

Inverse correlation between serum free IGF-I and IGFBP-3 levels and blood pressure in patients affected with type 1 diabetes

BACKGROUND: Even though the gene encoding for IGF-I is considered of most importance amongst blood pressure-regulating genes in mouse models, little and discordant data are available in literature for what concerns a possible relationship between blood pressure and serum free IGF-I values in humans. In addition, no information is available on type 1 diabetes patients. AIM: Our aim is to analyze the relationship between systolic and diastolic blood pressure and serum free IGF-I and IGFBP-3 levels in subjects suffering from type 1 diabetes. RESULTS: A highly significant inverse correlation was observed between serum free IGF-I levels and both systolic and diastolic blood pressure in subjects affected with type 1 diabetes. Similar but less significant relationships were observed for IGFBP-3, whose levels were also significantly and directly correlated with those of free IGF-I. The correlation between systolic and diastolic blood pressures with free IGF-I and between systolic blood pressure and IGFBP-3 levels were confirmed after adjusting for age, gender, age at diagnosis, disease duration, familial history, HBA1c, and amount of insulin administered by multivariate logistic regression analysis. A decrease in free IGF-I and IGFBP-3 levels, along with increases in blood pressure, significantly influenced the presence of diabetic complications, confirming how these molecules may be considered as severity markers for patients with type 1 diabetes as well as risk factors for altered pressure control linked diseases.     

Effects of chiral fragrances on human autonomic nervous system parameters and self-evaluation

The effects of chiral fragrances (enantiomers of limonene and carvone) on the human autonomic nervous system (ANS) and on self-evaluation were studied in 20 healthy volunteers. Each fragrance was administered to each subject by inhalation using an A-A-B design. Individuals were tested in four separate sessions; in one session one fragrance was administered. ANS parameters recorded were skin temperature, skin conductance, breathing rate, pulse rate, blood oxygen saturation and systolic as well as diastolic blood pressure. Subjective experience was assessed in terms of mood, calmness and alertness on visual analog scales. In addition, fragrances were rated in terms of pleasantness, intensity and stimulating property. Inhalation of (+)-limonene led to increased systolic blood pressure, subjective alertness and restlessness. Inhalation of (-)-limonene caused an increase in systolic blood pressure but had no effects on psychological parameters. Inhalation of (-)-carvone caused increases in pulse rate, diastolic blood pressure and subjective restlessness. After inhalation of (+)-carvone increased levels of systolic as well as diastolic blood pressure were observed. Correlational analyses revealed that changes in both ANS parameters and self-evaluation were in part related to subjective evaluation of the odor and suggest that both pharmacological and psychological mechanisms are involved in the observed effects. In conclusion, the present study indicates that: (i) prolonged inhalation of fragrances influences ANS parameters as well as mental and emotional conditions; (ii) effects of fragrances are in part based on subjective evaluation of odor; (iii) chirality of odor molecules seems to be a central factor with respect to the biological activity of fragrances.