Association of urinary sodium excretion with blood pressure and risk factors associated with hypertension among Cameroonian pygmies and bantus: a cross-sectional study.

BACKGROUND: High salt intake increases blood pressure (BP) and hypertension risk. This study aimed to examine association of urinary sodium excretion with BP and hypertension correlates among Cameroonian pygmies under hunter-gatherer subsistence mode and Bantus, living in urban area under unhealthy behavioral habits. METHODS: In this cross-sectional cluster sampling study, we randomly enrolled rural pygmies living in Lolodorf and urban Bantus living in Douala. The World Health Organization steps questionnaire was used to collect socio-demographic and lifestyle data. Height, weight, BP and single overnight spot urine samples were obtained in all participants. BP was measured in triplicate. Urinary sodium and potassium excretion was determined by flame photometry. Data were recorded and analyzed using SPSS 16.0. RESULTS: We included 150 Pygmies and 150 Bantus aged 38 ± 12 years and 33 ± 11 years, respectively (p <  0.0001). Compare to Bantus, pygmy's height and weight were respectively: 1.54 ± 0.09 m vs 1.72 ± 0.12 m; and 54.4 ± 9.2 kg vs 77.2 ± 14.8 kg, all p <  0.0001. Age-standardized prevalence of hypertension was 3.3% among Pygmies and 28% among Bantus (p <  0.0001). Age-adjusted systolic and diastolic BP were lower in Pygmies than in Bantus (107 ± 12 vs 119 ± 17 mmHg and 71 ± 11 vs 78 ± 13 mmHg respectively, all P <  0.0001). BP increased with age but to a lesser extent in Pygmies (all p <  0.01). Urinary sodium excretion was lower in Pygmies than in Bantus (46.9 ± 32.4 vs 121.5 ± 61.0 mmol/l, p <  0.0001). Systolic and diastolic BP were positively associated with urinary sodium excretion in Bantus (all p <  0.05). In the two groups, urinary potassium excretion was similar, and was not related to blood pressure. In the total study group and in Bantus taken separately, urinary sodium excretion was higher in hypertensive than in normotensive subjects. Multivariable logistic regression showed that urinary sodium excretion, Bantu status and age emerged as independent determinants of hypertension in the whole study group (OR (95%CI): 1.012 (1.005-1.018); 11.408 (3.599-36.165); 1.095 (1.057-1.135) respectively, p <  0.0001). CONCLUSION: Hunter-gatherer pygmies exhibit low level of urinary sodium excretion related to low rate of hypertension and slower BP increase with age. Salt intake was a major driver of hypertension in our study population. Our findings highlight the need of efforts to implement nationwide prevention programs promoting risk factor screening and healthier lifestyles including reduction of dietary salt intake in Cameroonian.

High prevalence of nocturnal arterial hypertension and non-dipping in lung transplant recipients.

OBJECTIVE: An abnormal circadian blood pressure (BP) profile is associated with adverse cardiovascular and all-cause outcomes. It is highly prevalent after heart, liver and kidney transplantation. We aimed to assess the prevalence of an abnormal ambulatory BP pattern in lung transplant recipients (LTx). METHODS: Ambulatory BP monitoring (ABPM) was performed in 53 LTx and compared to those of 42 control subjects matched for age, gender and daytime BP. In 19 patients in whom at least two recordings were performed, we compared the first and the last one. RESULTS: The non-dipping pattern (a less than 10% reduction in nocturnal BP) was more prevalent in LTx than in control subjects (89 versus 64%, P < 0.01). Nighttime BP was higher in LTx than in control subjects (P < 0.01 and < 0.001 for systolic BP (SBP) and diastolic BP (DBP), respectively). The nocturnal reduction of BP was lower in LTx than in control subjects (3 versus 8% for SBP and 6 versus 13% for DBP, both P < 0.001). These results remained significant after adjustment for the presence of diabetes mellitus and creatinine clearance. In the 19 patients in whom ABPM was performed twice (mean interval between the two recordings was 22 months), ambulatory BP values remained unchanged between the two recordings, although the number of antihypertensive agents was significantly higher. CONCLUSION: An abnormal circadian BP profile is highly prevalent after lung transplantation. It is observed consistently over prolonged periods of time.

[How to formalise the supervision of learning of clinical reasoning]. / Formalisation de la supervision de l'apprentissage du raisonnement clinique.

Since clinical reasoning is central to most decisions made in the clinic, it is essential to teach it with the greatest relevance. Knowing that around 10% of learners encounter major difficulties in clinical reasoning during their course, training supervisors in effective pedagogical interventions is crucial. Here we summarize the methods allowing supervisors to identify errors of clinical reasoning in medical students and interns and we explain remediation techniques adapted to the types of error identified. Access to short illustrative videos of a MOOC (Massive Open On line Course) devoted to the supervision of clinical reasoning constitutes practical help for supervisors who are not expert in the complexity of medical pedagogy at bedside.

Prevalence and determinants of blood pressure variability in pygmies of Southern region Cameroon.

INTRODUCTION: The impact of urbanization and living conditions on the prevalence of hypertension in the Cameroonian population is poorly known. AIM: To evaluate the prevalence and determinants of blood pressure (BP) in adult Pygmies and Bantus living in urban and rural areas of Southern Cameroon. PARTICIPANTS AND METHODS: This was a cross-sectional comparative study of 406 adults (96 urban Bantus, 100 urban Pygmies, 111 rural Bantus and 99 tropical rainforest Pygmies with a traditional Pygmies way of life), recruited in Southern Cameroon (mean age 42 ±â€Š17 years; 56.7% women). Sociodemographic, anthropometric and BP parameters were collected. Hypertension was defined as BP at least 140/90 mmHg and/or use of BP-lowering drug(s). RESULTS: The age-standardized prevalence of hypertension in urban Bantus, rural Bantus, urban Pygmies and traditional Pygmies was 18.0, 13.5, 9.3 and 4.1%, respectively. Mean SBP and DBP differed significantly according to Bantu vs. Pygmy ethnicity, and urban vs. rural residency. After multiple adjustments, mean arterial pressure was significantly associated with age, BMI, Bantu ancestry and urban residency. CONCLUSION: Bantu ethnicity and urban residency are significantly associated with high-BP among people from Southern Cameroon.

Cross-sectional survey evaluating blood pressure control ACHIEVEment in hypertensive patients treated with multiple anti-hypertensive agents in Belgium and Luxembourg.

OBJECTIVE: This study evaluates the actual blood pressure control rate and its estimation by general practitioners, the use of single-pill or free combinations, and the attitude towards single-pill combinations in primary care. METHODS: Cross-sectional observational survey in primary care between January 2015 and September 2016 in Belgium and Luxembourg. The participating general practitioners enrolled hypertensive patients taking at least 2 antihypertensive molecules (as fixed or free associations). RESULTS: 742 general practitioners included a total of 8,006 patients, with a mean age of 66 ± 12 years. Systolic blood pressure and diastolic blood pressure were respectively 141 ± 17 mmHg and 82 ± 10 mmHg (means ± SD). These patients had a blood pressure control rate of 45%, whereas it was estimated by general practitioners to be 60%. General practitioners with 11-25 years' experience performed better than general practitioners with 36-51 years' experience in the evaluation of blood pressure control. Combinations used were free in 39%, single-pill in 34% and mixed in 27% of the patients. Patients receiving single-pill combinations were younger than those treated with free combinations (63 ± 12 vs. 68 ± 12 years, p < 0.001), with fewer comorbidities (39 vs. 55%, p < 0.001). In patients treated solely with free pill associations, 66% of patient cases, general practitioners were willing to switch to a single-pill combination. The main reasons were improved adherence (76%) and better blood pressure control (64%). CONCLUSION: In patients requiring at least two antihypertensive drugs, blood pressure control rate remains low and is overestimated by general practitioners. Free combinations remain largely used although many general practitioners seem willing to shift to single-pill combinations. Treatment simplification could improve adherence and blood pressure control rate, which has been shown to lead to reduced morbidity and mortality.

Arterial stiffness and cardiometabolic phenotype of Cameroonian Pygmies and Bantus.

BACKGROUND: Pygmies living in the Central African rainforest with a traditional hunter-gatherer lifestyle have a low incidence of cardiovascular diseases. Because of progressive loss of traditional habitat and ancestral lands, some Pygmies have migrated to urban areas and adopt specific Bantu lifestyles such as increased salt consumption and a sedentary way of life. We tested the hypothesis that migrant Pygmies could present with hemodynamic and metabolic characteristics different from those of traditional in-situ Pygmies and possibly closer to those of Bantu farmers. PATIENTS AND METHODS: The study included 148 Pygmies (94 traditional and 54 migrants) and 164 Bantus. Peripheral and central hemodynamics, aortic pulse wave velocity (PWV), and augmentation index corrected for heart rate (AIx) were measured, as well as fasting lipid profile. Urinary sodium and potassium excretion was also measured on a morning spot. RESULTS: Compared to Bantus, Pygmies had lower height (even between men and women, but men were taller than women in the three groups), weight, waist and hip circumference, peripheral and central blood pressure, total, low-density lipoprotein, and high-density lipoprotein cholesterol and apolipoprotein B100 levels, sodium urinary excretion, and lower prevalence of the metabolic syndrome. By contrast, they had a higher waist-to-hip ratio, and higher triglycerides levels, as compared to Bantu farmers. PWV and AIx did not differ between Bantus and Pygmies. Compared to traditional in-situ Pygmies, migrant Pygmies were not taller when adjusted for sex, had lower brachial and central blood pressure, higher PWV (adjusted for mean arterial pressure, BMI, and sex), and higher apolipoprotein B100 levels. In the whole population, multivariable analysis revealed that PWV was independently associated with age, weight, height, mean arterial pressure, total cholesterol, and hip circumference, whereas AIx was independently related to age, sex, height, heart rate, diastolic blood pressure, and group (from Bantu farmers to Pygmies). CONCLUSION: Comparisons between Bantus and Pygmies, and between migrant Pygmies and traditional in-situ Pygmies, showed mixed results, with favorable and deleterious hemodynamic and metabolic characteristics in all groups. This could be due to increased contacts between these populations, which blunt the expected differences and because the beneficial effects of the hunter-gatherer subsistence mode of traditional in-situ Pygmies are counterbalanced by unhealthy behavioral habits.

Prevalence, awareness, treatment, and control of hypertension among rural and urban dwellers of the Far North Region of Cameroon.

OBJECTIVE: To assess the prevalence and determinants of high blood pressure (BP) and awareness, treatment, and control rates in the Far North Region of Cameroon, where these variables have not been explored so far. METHODS: In total, 889 individuals (41.5% women) aged at least 18 years participated in a cross-sectional survey conducted in Maroua (urban area) and Tokombere (rural area) from November 2014 to May 2015, using a multistage cluster sampling frame. Anthropometric variables, BP, and fasting capillary glucose were assessed in all participants. Hypertension was defined as BP at least 140/90 mmHg or antihypertensive therapy and BP control as BP less than 140/90 mmHg. Prevalence estimates were age standardized to the Cameroon population. RESULTS: The prevalence of hypertension was 37.8% (rural: 34%; urban: 41.2%; men: 38.8%; women: 37.9%). Hypertension was associated with urban environment (odds ratio: 1.42; 95%; confidence interval 1.06-1.89), age at least 70 years (4.06; 2.02-6.14), male sex (4.06; 2.02-6.14), abdominal obesity (2.36; 1.54-3.61), and high blood sugar (2.01; 1.31-3.08). Among individuals with hypertension, 18.6% (rural: 17.9%; urban: 19.5%) were aware of having high BP. Among those aware, 29.3% (rural: 17.3%; urban: 36.3%) reported receiving treatment, of whom 16.3% (rural: 22.6%; urban: 4.2%) had BP controlled. Awareness, treatment, and BP control levels were higher in women than men. CONCLUSION: Hypertension is highly prevalent in Far North Cameroon and awareness, treatment, and control rates are low. Efforts to improve detection, treatment, and control of hypertension in Cameroon are needed.

Ethnic differences in arterial stiffness and wave reflections after cigarette smoking.

BACKGROUND: Smoking increases plasma nicotine. Nicotine releases catecholamines and alters arterial distensibility. The nicotine intake per cigarette is greater and serum cotinine levels, the proximate metabolite of nicotine, are higher in Blacks than in Whites. We tested the hypothesis that cigarette smoking increases the pulse wave velocity (PWV), a marker of arterial stiffness, and the augmentation index (AI), a measure of wave reflection, more in Blacks than in Whites. METHODS: We matched Black (n = 30) and White (n = 30) smokers for age, gender, body mass index and height. We determined carotid-femoral PWV (PWVCF) and carotid-radial PWV (PWVCR) (Complior), the AI derived from the aortic pressure waveform (applanation tonometry, Sphygmocor), blood pressure, heart rate (HR) and cotinine levels before and after cigarette smoking. We also performed measurements in 16 participants after sham smoking. RESULTS: Smoking increased the AI, PWVCF and PWVCR in the whole population (all P < 0.05, n = 60). Increases in the AI and PWV were positively related to serum cotinine levels (all P < 0.05). Smoking increased serum cotinine (P = 0.01) and mean blood pressure (P = 0.03) more, but raised the HR to a lesser extent, in Blacks [+8 +/- 4 versus +13 +/- 6 beats/min in Whites (mean +/- SD), P = 0.01]. Blacks disclosed larger increases in AI adjusted for HR (Blacks, +7.2 +/- 8 versus Whites, +4.4 +/- 8%; P = 0.03), PWVCF (Blacks, +1.1 +/- 0.2 versus Whites, +0.6 +/- 0.3 m/s; P < 0.01) and PWVCR (Blacks, +1.4 +/- 0.1 versus Whites, +0.7 +/- 0.4 m/s; P < 0.01) normalized for the mean blood pressure. No changes were observed with sham smoking. CONCLUSIONS: Smoking acutely increases the PWV and AI in Blacks more than in Whites. Differences in nicotine metabolism and beta-adrenergic sensitivity could explain these findings.

Acute Kidney Injury in Elderly Patients With Chronic Kidney Disease: Do Angiotensin-Converting Enzyme Inhibitors Carry a Risk?

In contrast to angiotensin receptor blockers (ARBs), mainly excreted by the liver, the dosage of angiotensin-converting enzyme (ACE) inhibitors, cleared by the kidney, must be adapted to account for renal clearance in patients with chronic kidney disease (CKD) to avoid acute kidney injury (AKI). Community-acquired AKI and the use of ACE inhibitors or ARBs in the emergency department were retrospectively assessed in 324 patients with baseline stage 3 or higher CKD. After stepwise regression analysis, the use of ACE inhibitors (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1-3.1; P=.02) and the presence of dehydration (OR, 30.8; 95% CI, 3.9-239.1) were associated with AKI. A total of 45% of patients using ACE inhibitors experienced overdosing, which causes most of the excess risk of AKI. These results suggest that dosage adjustment of ACE inhibitors to renal function or substitution of ACE inhibitors with ARBs could reduce the incidence of AKI. Moreover, ACE inhibitors and ARBs should be stopped in cases of dehydration.

Prognosis of patients with systemic rheumatic diseases admitted to the intensive care unit.

OBJECTIVE: To determine prognostic factors in patients with systemic rheumatic diseases admitted to the intensive care unit (ICU) and to examine whether the observed mortality rate is predicted using the Acute Physiology And Chronic Health Assessment II (APACHE II) score. DESIGN AND SETTING: Retrospective study with historical controls in a 31-bed medicosurgical ICU at a university hospital. PATIENTS AND PARTICIPANTS: Seventy-one patients admitted to the ICU for an acute illness related to a systemic rheumatic disease and/or its treatment and 353 ICU control patients. RESULTS: Systemic rheumatic diseases were mainly rheumatoid arthritis and vasculitides. In-hospital mortality rate was 28/71 (39%), including 23 patients who died in the ICU. Multivariable logistic regression showed that poor prior health status (Berdit's classification), APACHE II score, and admission for infection were associated with mortality, whereas prior use of immunosuppressive agents was not. APACHE II score at admission was higher in nonsurvivors (22+/-9) than in survivors (17+/-5) (p<0.01). The standard mortality ratio, i.e., the ratio between observed and predicted mortality, was 1.7 in the 71 study patients and 1.0 in the 353 control patients (p<0.0001). CONCLUSIONS: In patients with systemic rheumatic diseases admitted to the ICU for at least 48 h, poor prior chronic health status, APACHE II score, and infection were prognostic factors for in-hospital mortality. SMR was higher than in a control ICU population.

Endothelin antagonists: new bullets against lung injury?

Acute lung injury is a syndrome of inflammation and of increased permeability of the blood-gas barrier. Endothelins are thought to exert proinflammatory effects. Kuklin and colleagues show that the endothelin receptor antagonist tezosentan reduces pulmonary edema in endotoxemic sheep, in parallel with a prevention of protein kinase C-alpha activation. In turn, the level of some cytokines increased after tezosentan treatment. Whether these contrasting effects of endothelin blockade on inflammatory mechanisms have clinical relevance and whether these agents might benefit patients with acute lung injury is unknown.

Survey on treatment of hypertension and implementation of World Health Organization/International Society of Hypertension risk stratification in primary care in Belgium.

OBJECTIVE: To gain insight into the prevalence, treatment and control of hypertension and into the implementation of the 1999 World Health Organization/International Society of Hypertension guidelines for the management of hypertension in general practice in Belgium. DESIGN: A prospective cross-sectional survey. SETTING: Primary care. METHODS: Participating physicians enrolled the first 15 men, at least 55 years old, who visited the surgery, measured their blood pressure with a validated automatic device and recorded data on age, medical history, drug utilization, cardiovascular risk factors and target organ damage. Patients were considered to have hypertension when systolic blood pressure was >or= 140 mmHg, diastolic blood pressure was >or= 90 mmHg or when they were under antihypertensive therapy. RESULTS: Among 3761 evaluable patients, 74% were considered to be hypertensive, 80% of whom were treated with antihypertensive drugs. Blood pressure was under control in 38% of the treated patients and in 31% of all hypertensives. Among the 1316 hypertensive patients in whom risk stratification was possible, 47, 56 and 86% of the patients in, respectively, the medium, high and very high risk groups were treated with antihypertensive drugs. Among the treated patients, 46, 37 and 31%, respectively, had reached goal pressure. Within each risk category, patients were treated more frequently when baseline blood pressure was higher. Logistic regression analysis revealed that hypertension grade and level of risk contributed independently to the odds of being treated. CONCLUSIONS: The results indicate that a large number of older hypertensive men are treated with antihypertensive drugs in primary care, but that the goal blood pressure is not reached in a substantial number of patients due to undertreatment. Furthermore, whereas patients at higher risk are treated more frequently than patients at lower risk, blood pressure itself remains an important factor for the initiation of antihypertensive drug therapy within each risk category.

Effect of beta-adrenergic stimulation on pulse wave velocity in black and white subjects.

BACKGROUND: Reduced beta-adrenergic sensitivity has been reported in black subjects. We hypothesized that beta-adrenergic stimulation by isoproterenol would affect pulse wave velocity (PWV), a marker of arterial stiffness, differently in black and white subjects. METHODS: Healthy normotensive black subjects (n = 21) matched for age, gender, height and body mass index with healthy normotensive white subjects (n = 20), participated in a randomized, double-blind, placebo-controlled cross-over study. The PWV was determined using an automated device at baseline and after 30 min of an equal volume infusion of isoproterenol (8 mug/kg per min) or placebo (dextrose 5%), separated by a washout period of 25 min. RESULTS: At baseline, heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) and PWV were comparable in black and in white subjects. Placebo had no significant effect on haemodynamic variables. Isoproterenol increased HR, SBP and pulse pressure and decreased DBP with a comparable magnitude in both groups. Compared with placebo, isoproterenol decreased carotid-femoral PWV in white (from 5.9 +/- 1.2 to 5.7 +/- 1.1 m/s, means +/- SD, P = 0.05), but not in black subjects (from 6.2 +/- 1.3 to 6.6 +/- 1.7 m/s, P = 0.1). The difference in response between black and white subjects was significant (P = 0.04). Isoproterenol decreased carotid-radial PWV only significantly in white subjects. CONCLUSION: These results are compatible with the hypothesis of an altered beta-adrenergic sensitivity, which is expressed by a blunted effect of isoproterenol on arterial stiffness in black subjects.

Self-measured versus ambulatory blood pressure in the diagnosis of hypertension.

OBJECTIVE: We examined to what extent self-measurement of blood pressure at home (HBP) can be an alternative to ambulatory monitoring (ABP) to diagnose white-coat hypertension. METHODS: In 247 untreated patients, we compared the white-coat effects obtained by HBP and ABP. The thresholds to diagnose hypertension were > or = 140/> or = 90 mmHg for conventional blood pressure (CBP) and > or = 135/> or = 85 mmHg for daytime ABP and HBP. RESULTS: Mean systolic/diastolic CBP, HBP and ABP were 155.4/100.0, 143.1/91.5 and 148.1/95.0 mmHg, respectively. The white-coat effect was 5.0/3.5 mmHg larger on HBP compared with ABP (12.3/8.6 versus 7.2/5.0 mmHg; P < 0.001). The correlation coefficients between the white-coat effects based on HBP and ABP were 0.74 systolic and 0.60 diastolic (P < 0.001). With ABP as a reference, the specificity of HBP to detect white-coat hypertension was 88.6%, and the sensitivity was 68.4%. CONCLUSION: Our findings are in line with the recommendations of the ASH Ad Hoc Panel that recommends HBP for screening while ABP has a better prognostic accuracy.

Validity of pulse pressure and augmentation index as surrogate measures of arterial stiffness during beta-adrenergic stimulation.

OBJECTIVE: Increased arterial stiffness is a determinant of cardiovascular mortality. Pulse wave velocity (PWV) is a direct measure of arterial stiffness. Aortic augmentation index (AI) and pulse pressure (PP) are surrogate measures of arterial stiffness. Both PWV, AI and PP increase with cardiovascular risk factors. The aim of this study was to test the validity of AI and PP as surrogate measures of arterial stiffness compared with PWV, during beta-adrenergic stimulation with Isoprenaline (Iso). DESIGN AND METHODS: A total of 41 healthy volunteers entered a randomized, double-blind, placebo-controlled, cross-over study. In random order, subjects were given intravenous infusion in equal volume of Iso 8 microg/kg per min (dissolved in glucose 5%) and placebo (glucose 5%). A wash-out period of 25 min was observed between the infusions. Measurements included blood pressure (BP), heart rate (HR), PWV, and AI. PWV were determined using complior (Complior, Artech-Medical, Paris, France). AI and aortic PP were obtained from pulse wave analysis of radial applanation tonometry, using transfer function (SphygmoCor Windows software). RESULTS: Baseline AI increased (P < 0.05) with aging, a lower height and a larger diastolic BP (DBP). Iso increased (P < 0.0001) HR, brachial SBP, brachial and aortic PP as compared with placebo. In contrast, Iso decreased (P < 0.05) AI, brachial DBP, peripheral PWV, but not aortic PWV. Decrease of AI induced by Iso was not related to PWV. In stepwise multiple regression changes in HR, brachial SBP and DBP were independent determinants of AI response to Iso (r = 0.78, P < 0.0001). CONCLUSIONS: Our findings show that AI and PP fail as surrogate measures of arterial stiffness during beta-adrenergic stimulation.

Endothelin receptor blockade in canine oleic acid-induced lung injury.

OBJECTIVE: To investigate the effects of endogenous endothelins on pulmonary haemodynamics and gas exchange in oleic acid lung injury. DESIGN: Prospective experimental study in dogs. SETTING: Animal research laboratory in a university teaching hospital. SUBJECTS. Seventeen anaesthetised and ventilated mongrel dogs. INTERVENTIONS: Nine pretreated dogs received an infusion of the endothelin A and B receptor antagonist bosentan (10 mg/kg) started before oleic acid. Eight treated dogs received bosentan started 90 min after oleic acid. Cardiac index (CI) was manipulated by inflating an inferior vena caval balloon or by opening a femoral arterio-venous bypass. MEASUREMENTS AND RESULTS: Pulmonary vascular resistance was defined by measuring the gradient between mean pulmonary artery pressure (MPAP) and occluded PAP (PAOP) at five levels of CI. Intrapulmonary shunt was measured using the inert gas SF(6). Pretreatment with bosentan prevented the oleic acid-induced shift of (MPAP-PAOP)/CI plots to higher pressures, but did not affect the increase in intrapulmonary shunt. Treatment of established oleic acid lung injury with bosentan had no effect. CONCLUSIONS: Pretreatment, but not treatment, with bosentan, in the dose used, blunted the oleic acid-induced increase in pulmonary vascular resistance, suggesting that endothelins contribute to the increase in pulmonary vascular tone in the early stages of oleic acid lung injury.

Endogenous angiotensin II in the regulation of hypoxic pulmonary vasoconstriction in anaesthetized dogs.

INTRODUCTION: The role played by several vasoactive mediators that are synthesized and released by the pulmonary vascular endothelium in the regulation of hypoxic pulmonary vasoconstriction (HPV) remains unclear. As a potent vasoconstrictor, angiotensin II could be involved. We tested the hypothesis that angiotensin-converting enzyme inhibition by enalaprilat and type 1 angiotensin II receptor blockade by candesartan would inhibit HPV. METHODS: HPV was evaluated in anaesthetized dogs, with an intact pulmonary circulation, by examining the increase in the Ppa-Ppao gradient (mean pulmonary artery pressure minus occluded pulmonary artery pressure) that occurred in response to hypoxia (inspiratory oxygen fraction of 0.1) at constant pulmonary blood flow. Plasma renin activity and angiotensin II immunoreactivity were measured to determine whether activation or inhibition of the renin-angiotensin system was present. RESULTS: Administration of enalaprilat and candesartan did not affect the Ppa-Ppao gradient at baseline or during hypoxia. Plasma renin activity and angiotensin II immunoreactivity increased during hypoxia, and subsequent measurements were consistent with effective angiotensin-converting enzyme inhibition after administration of enalaprilat, and with angiotensin receptor blockade after administration of candesartan. CONCLUSION: These results suggest that, although the renin-angiotensin system was activated in hypoxia, angiotensin II is not normally involved in mediating acute HPV.

Infective endocarditis presenting as an isolated aneurysm of the posterior mitral leaflet.

We describe the case of a 64-year-old woman in whom an aneurysm located on the posterior mitral leaflet was detected. Blood cultures grew methicillin-sensitive Staphylococcus epidermidis, and histologic examination of the operative specimen showed polymorphonuclear neutrophilic infiltration of the valve wall associated with fibrin and necrosis, consistent with a diagnosis of endocarditis. The posterior mitral location of the aneurysm and the absence of vegetation are exceptionally rare in this setting. This case demonstrates that a mitral aneurysm may be the sole cardiac presentation of infective endocarditis.

Effects of antiretroviral therapy on arterial stiffness in Cameroonian HIV-infected patients.

BACKGROUND: HIV infection increases cardiovascular risk and highly active antiretroviral therapy may further augment it. We hypothesized that an increase in large artery stiffness may be a mechanism of enhanced cardiovascular risk in treated HIV-infected (HIV-T) patients. MATERIALS AND METHODS: Pulse wave velocity (PWV) and augmentation index (AI) were measured in 108 Cameroonian untreated HIV-infected (HIV-UT) patients and in 130 HIV-T patients. RESULTS: Brachial and aortic systolic blood pressure (BP), diastolic BP, and pulse pressure were higher in HIV-T patients than in HIV-UT patients (all, P < 0.01). PWV was comparable in HIV-T and HIV-UT patients (7.2 ± 1.5 vs. 7.46 ± 2.2 m/s, respectively, P = 0.3), whereas AI was higher in HIV-T patients than in HIV-UT patients (7.9 ± 5 vs. 5.76 ± 4%, respectively, P = 0.003). AI was associated independently with age, brachial systolic BP, brachial diastolic BP, and height in HIV patients (R = 0.75, P < 0.01). CONCLUSION: This study shows that pulse pressure and AI were increased in HIV-T patients, compared with matched HIV-UT patients, suggesting that highly active antiretroviral therapy could increase cardiovascular risk. However, PWV was not accelerated in HIV-T patients.