Physiological response to whole-body vibration in athletes and sedentary subjects.

Whole-body vibration (WBV) is a new exercise method, with good acceptance among sedentary subjects. The metabolic response to WBV has not been well documented. Three groups of male subjects, inactive (SED), endurance (END) and strength trained (SPRINT) underwent a session of side-alternating WBV composed of three 3-min exercises (isometric half-squat, dynamic squat, dynamic squat with added load), and repeated at three frequencies (20, 26 and 32 Hz). VO(2), heart rate and Borg scale were monitored. Twenty-seven healthy young subjects (10 SED, 8 SPRINT and 9 END) were included. When expressed in % of their maximal value recorded in a treadmill test, both the peak oxygen consumption (VO(2)) and heart rate (HR) attained during WBV were greatest in the SED, compared to the other two groups (VO(2): 59.3 % in SED vs 50.8 % in SPRINT and 48.0 % in END, p<0.01; HR 82.7 % in SED vs 80.4 % in SPRINT and 72.4 % in END, p<0.05). In conclusions, the heart rate and metabolic response to WBV differs according to fitness level and type, exercise type and vibration frequency. In SED, WBV can elicit sufficient cardiovascular response to benefit overall fitness and thus be a potentially useful modality for the reduction of cardiovascular risk.

High mobility group box 1 protein (HMGB-1): a pathogenic role in preeclampsia?

We evaluated whether preeclampsia is associated with elevated circulating levels of High mobility group box 1 protein (HMGB-1), a nuclear protein with proinflammatory effects when released extracellularly. We enrolled 48 women, 32 in third trimester pregnancy (16 with, 16 without preeclampsia), and 16 healthy non pregnant. In the peripheral blood of pregnant women, HMGB-1 concentration was assessed serially, before and after delivery. With or without preeclampsia, third trimester pregnancy was associated with elevated levels of HMGB-1. This elevation is exaggerated in preeclampsia. The source of HMGB-1 observed in these conditions is likely to involve tissues other than the placenta itself.

[Hypertension. Effects of antihypertensive therapy on cognitive functions]. / Hypertension. Effets du traitement antihypertenseur sur les fonctions cognitives.

A cause and effect relationship between arterial hypertension and decline of cognitive function has long been suspected. In middle-age subjects indeed, an abnormally high blood pressure is a risk factor for the long-term development of dementia. Presently, it seems crucial to treat hypertensive patients in order to better protect them against cognitive decline. However, in the elderly patients the risk of mental deterioration may also be enhanced when diastolic pressure becomes too low, for example below 70 mmHg. Further studies are required to better define the antihypertensive drug regimen and target blood pressure which would be optimal for the prevention of cerebral small vessel disease.

Are all diuretics equal for the treatment of hypertensive patients?

Thiazide (hydrochlorothiazide, etc.) and thiazide-like (chlortalidone, indapamide,etc.) diuretics are widely used to treat hypertensive patients. There is growing evidence that these diuretics are not interchangeable and that it might be preferable to choose a thiazide-likediuretic whenever the use of a diuretic is considered. This is in order to prevent optimally the development of cardiovascular complications and the occurrence of metabolic side effects, in particular diabetes (AU)

Las tiazidas (hidroclorotiazida, etc.) y los diuréticos de tipo tiazídico (clortalidona,indapamida, etc.) son fármacos ampliamente utilizados para tratar la hipertensión. Existe pruebas crecientes de que estos diuréticos no son intercambiables y sería preferible elegir un diurético de tipo tiazídico siempre que se considere el uso de los mismos. La razón para ello es evitar de manera óptima el desarrollo de complicaciones cardiovasculares y la aparición de efectos secundarios metabólicos, en particular la diabetes (AU)

[Are all diuretics equal for the treatment of hypertensive patients?]. / Tous les diurétiques sont-its égaux pour traiter les matolades hypertendus?

Thiazide (hydrochlorothiazide,...) and thiazide-like (chlortalidone, indapamide,...) diuretics are widely used to treat hypertensive patients. There is growing evidence that these diuretics are not interchangeable and that it might be preferable to choose a thiazide-like diuretic whenever the use of a diuretic is considered. This is in order to prevent optimally the development of cardiovascular complications and the occurrence of metabolic side effects, in particular diabetes.

[Obstructive sleep apnea and drugs as causes of treatment-resistant hypertension]. / Hypertension artérielle réfractaire au traitement due au syndrome d'apnées du sommeil et à la prise de médicaments.

Treatment-resistant hypertension is still common despite the availability of several types of antihypertensive agents acting by different mechanisms. The existence of refractory hypertension should lead to rule out "white-coat hypertension", poor adherence to prescribed drugs as well as classical causes of secondary hypertension such as renal artery stenosis, primary aldosteronism, pheochromocytoma and renal disease. It is also important to consider the possible existence of obstructive sleep apnea or the regular intake of vasopressive drugs or substances.

PP125. High mobility group box 1 protein (HMGB1): A pathogenic role in preeclampsia?

INTRODUCTION: A central pathogenic mechanism of preeclampsia is believed to be the production by the hypoxic placenta of various mediators which promote inflammation and oxidative stress when released into the maternal circulation. The high mobility group box 1 protein (HMGB1) is a ubiquitous nuclear protein. In conditions of hypoxic cellular stress or necrosis, HMGB1 is released into the extracellular milieu. Extracellular HMGB1 has proinflammatory effects, due to the engagement of various cell membrane receptors, notably the receptor for advanced glycation products (RAGE). OBJECTIVES: In preeclampsia, there is evidence for activation of RAGE, and enhanced amounts of HMGB1 have also been demonstrated in the placenta and amniotic fluid, but not, so far, in maternal blood. We hypothesize therefore that, in preeclampsia, the concentration of HMGB1 is abnormally high in maternal blood. METHODS: We enrolled 16 women in third trimester pregnancy and suffering from preeclampsia (blood pressure > 140/90mmHg with significant proteinuria), 16 women with normal pregnancies who were matched pairwise with the former for BMI and gestation week, and 16 non pregnant healthy women, matched for age with the other two groups. HMGB1 was assessed in peripheral blood with a commercial ELISA kit. The variance between the three groups was appreciated using an ANOVA analysis. Significance was considered for a probability value of < 0.5. RESULTS: The median [interquartile range] HMGB1 concentrations (in ng/mL) were 2.1 [1.1-3.2] in preeclamptic pregnancies, 1.1 [1.0-1.2] in normal pregnancies (p<0.05 vs preeclamptic group), and 0.6 [0.5-0.8] in non pregnant women (p<0.01 vs both other groups). CONCLUSION: In third trimester pregnancy, the presence of preeclampsia is associated with an approximately two-fold increase of HMGB1 concentration in maternal peripheral blood. Considering its known proinflammatory effects, HMGB1 could be one mediator responsible for the maternal manifestations of preeclampsia.

[Usefulness of BNP measurement for stratifying cardiovascular risk in hypertensive patients]. / Une place pour le BNP dans ta stratification du risque cardiovas- culaire chez le malade hypertendu?

The production of brain natriuretic peptide (BNP) by ventricular cardiomyocytes is increased in patients with left ventricular hypertrophy (LVH). Increased plasma levels of BNP or of the inactive fragment NP-proBNP are associated with an increased cardiovascular risk. The measurement of plasma concentrations of these peptides may be useful for stratifying the cardiovascular risk of hypertensive patients, particularly if there is no electrocardiographic evidence for LVH.

Enhanced diastolic reflections on arterial pressure pulse during exercise recovery.

During recovery from a maximal or submaximal aerobic exercise, augmentation of central (aortic) systolic pressure by reflected pressure waves is blunted in healthy humans. However, the extent to which reflected pressure waves modify the central pulse in diastole in these conditions remains unknown. We evaluated systolic and diastolic central reflected waves in 11 endurance-trained athletes on recovery from a maximal running test on a treadmill (treadmill-max) and a 4000 m run in field conditions. On both occasions in each subject, the radial pulse was recorded with applanation tonometry in the resting preexercise state and then 5, 15, 25, 35, and 45 min after exercise termination. From the central waveform, as reconstructed by application of a generalized transfer function, we computed a systolic (AIx) and a diastolic index (AId) of pressure augmentation by reflections. At 5 min, both indices were below preexercise. At further time-points, AIx remained low, while AId progressively increased, to overshoot above preexercise at 45 min. The same behavior was observed with both exercise types. Beyond the first few minutes of recovery following either maximal or submaximal aerobic exercise, reflected waves selectively augment the central pressure pulse in diastole, at least in endurance-trained athletes.

[Evaluation using a logbook of mastering of clinical skills by medical students]. / Evaluation à l'aide d'un livre de bord compétences clinques acquises par des stagiaires en médecine.

The mastering of the clinical skills is of utmost importance for the physician. The teaching of the skills is nowadays made easier with the <> which lists all the skills and their respective level of expected mastering at graduation. In order to do a survey on how good the students are at those skills, a logbook based on this document has been setup at the Faculty of biology and medicine of the University of Lausanne. This has shown that students went through a clear progression of the mastering of the skills during their elective year in internal medicine, surgery/orthopaedics, paediatric, obstetric and gynaecology as well as psychiatry. Such an instrument should in the future help to better guide the learning process of the clinical skills and to do a better follow-up of their progress.

[Practice guidelines of the European Society of Hypertension for home blood pressure measurement]. / Directives pratiques de la Société européenne d'hypertension sur la mesure de la pression artérielle à domicile.

Self-measurement of blood pressure at home is increasingly used in the diagnostic and therapeutic approach of hypertension. This technique allows multiple measurements of blood pressure away from the clinical setting, making it possible to improve the evaluation of cardiovascular risk. Recently new guidelines on the use of self-measured blood pressure have been made available by the European Society of Hypertension, as summarized in the present paper.

[Hypertension in pregnancy]. / Hypertension et grossesse.

Hypertension in pregnancy Hypertension in pregnancy, whether chronic or recently diagnosed, is always a matter of concern for the general practitioner or the obstetrician. Even if this situation often evolves favorably, and although a "wait and see" attitude may be preferred to an aggressive one in such cases, one should also be aware of how dramatic the outcome may also be. As a matter of fact, what is considered as one of the most frequent complications of pregnancy can run out of control, a possibility which shouldn't be dismissed. In this article, we shall discuss the various strategies for managing this disorder.

[Arterial hypertension: macrocirculation and microcirculation]. / Hypertension artérielle: macrocirculation et microcirculation.

The aim of the present report is to outline, in concise from, the changes in vascular structure which accompany hypertension. Consideration will be given to their potential contribution to hypertensive end organ damage. In so doing, it is important to consider both the macrovascular and microvascular levels, because interactions between them are presently believed to be critically important. The links between hypertension and the pathogenesis of arteriosclerosis fall outside the scope of this short review.

[Muscle enzyme activity and exercise]. / Enzymes musculaires et exercice physique.

Exercise is classically associated with muscular soreness, presenting one to two days later, delayed onset muscular soreness. Blood muscle enzymes and protein elevations are characteristic, and may cause renal failure. Creatin phosphokinase peak appears on the fourth day and depends on exercise type and individual parameters. This effect is attenuated with repeated bouts, by habituation. Metabolic complications are rare. The knowledge of this reaction, even with common exercises, allows to postpone investigations for a complex metabolic disorder, or to avoid stopping a medication for fear of a side effect, as with statins. Indeed, it is necessary to wait for seven days without any exercise before interpreting an elevated CK result.

[ADVANCE: a morbidity mortality study of diabetes and hypertension]. / Hypertension et diabète. ADVANCE: une étude de morbidité-mortalité.

The ADVANCE study is a morbidity-mortality double-blind trial carried out in normotensive or hypertensive patients with type 2 diabetes. The patients were randomly assigned to receive containing a fixed-combination tablet of an ACE inhibitor (perindopril) with a diuretic (indapamide) (4 mg/l,250 mg, n=5569), or placebo (n=5571), administered if needed on top of other blood pressure lowering agents. Significant reductions in the relative risk of death from cardiovascular disease (18%), total coronary events (14%), and total renal events (21%) were observed. Thus, in patients with type 2 diabetes, a drug regimen based on a fixed-dose combination of perindopril/ indapamide affords major protection against both the macro and microvascular complications.

A comparative study of reactive hyperemia in human forearm skin and muscle.

Reactive hyperemia (RH) in forearm muscle or skin microcirculation has been considered as a surrogate endpoint in clinical studies of cardiovascular disease. We evaluated two potential confounders that might limit such use of RH, namely laterality of measurement and intake of non-steroidal anti-inflammatory drugs (NSAIDS). Twenty-three young non-smoking healthy adults were enrolled. In Experiment 1 (n=16), the RH elicited by 3 min of ischemia was recorded in the muscle (strain gauge plethysmography, hand excluded) and skin (laser Doppler imaging) of both forearms. In Experiment 2 (n=7), RH was determined in the dominant forearm only, one hour following oral acetylsalicylic acid (1 g) or placebo. In Experiment 1, peak RH was identical in both forearms, and so were the corresponding durations of responses. RH lasted significantly less in muscle than in skin (p=0.003), a hitherto unrecognized fact. In the skin, acetylsalicylate reduced duration (43 vs. 57.4 s for placebo, p=0.03), without affecting the peak response. In muscle, duration tended to decrease with acetylsalicylate (21.4 vs. 26.0 s with placebo, p=0.06) and the peak increase in blood flow was blunted (27.2 vs. 32.4 ml/min/100 ml tissue with placebo, p=0.003). We conclude that, when using RH as a surrogate endpoint in studies of cardiovascular disease, a confounding by laterality of measurement need not be feared, but NSAIDS may have an influence, although perhaps not on the peak response in the skin.

[Non-invasive central blood pressure measurement: how and why?]. / Mesure non-invasive de la pression artérielle centrale: comment et pourquoi?

Until today, the usual way to measure arterial blood pressure has been cuff sphygmomanometry, at the level of the brachial artery. Yet, for some years, a non invasive tool has been available, that enables an estimation of the aortic pressure. This is done by using an aplanation tonometry technique to record the pulse wave within the radial artery, with subsequent convertion to a central pressure wave by means of a mathematical method (transfer function). This measurement informs us about the pressure near the target organs: this pressure is influenced by the reflected waves, which are responsible for an augmentation of systolic blood pressures when arterial compliance is abnormally low. Recent clinical trials have shown that for the same value of peripheral blood pressure, different antihypertensive treatments may not impact identically on central blood pressure.

[Sudden death in young athletes]. / Mort subite chez les jeunes athlètes.

Sudden cardiac death in a young athlete is a tragic and marking event, even though the media attention it gets is more important than its incidence (1-2/100000 per year). The main etiology is hypertrophic cardiomyopathy, followed by coronary artery anomalies. Sometimes signs of myocarditis are found at autopsy. The pre-participation examination recommandations ask for oriented history and physical examination, routine EKG being controversial. A systematic screening program in Italy has reduced the occurrence of such deaths, which statistics are non-existant in Switzerland. It would be appropriate to implement a standardized pre-participation examination, as well as to make sure that the trainers, teachers and athletes themselves are able to recognize the frequent warning symptoms.

[Arterial hypertension. Factors favoring long-term compliance with therapy]. / Hypertension artérielle. Facteurs favorisant l'adhérence thérapeutique à long terme.

Achieving blood pressure control in every hypertensive patients remains a difficult task despite the availability of a several types of agents lowering blood pressure by different mechanisms. The choice of initial therapy is important. Starting therapy using a blocker of the renin-angiotensin system increases the probability that the patients remain on the same drug during long-term treatment. Fixed-dose combinations, by improving blood pressure control without impairing tolerability, also facilitate persistence with therapy. Furthermore, stability of treatment has a positive impact on drug-associated costs.

[Clinical implications of central blood pressure]. / Implications cliniques de la pression centrale.

The diagnosis and the treatment of hypertension are based on blood pressure readings traditionally taken at the level of the brachial artery. It is currently possible to determine central blood pressure using the aplanation tonometry technique and applying a transfer function to calculate the impact of reflecting waves on pressure prevailing in thoracic aorta. The reflected waves which reach the thoracic aorta in systole are more marked when the stiffness of the arterial wall is increased, leading to augmentation of central systolic blood pressure. Recent clinical trials have shown that, for the same decrease in peripheral blood pressure, different therapeutic strategies do not necessarily impact identically on central blood pressure. This fact might influence their ability to prevent cardiovascular complications.