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Bernard Chamontin

Publications and source records attributed to Bernard Chamontin.

15 recordsLinked to original sources
PubMed2007

Cardiovascular risk factors, atherosclerosis and pulse pressure.

Blood pressure is a complex phenomenon that can be divided into two components: a steady and a pulsatile component. The pulsatile component is estimated by the pulse pressure which is mainly influenced by the large artery stiffness. The purpose of this review was to describe the relation between pulse pressure, cardiovascular risk factors and atherosclerosis. Epidemiological studies have shown positive correlations between pulse pressure and smoking or glucose metabolism impairment. More controversial data have been reported on the relation between blood lipids and large artery stiffness or pulse pressure. In cross-sectional studies, carotid, aortic and coronary plaques were associated with aortic stiffness, particularly echogenic or ulcerative plaques, and in a longitudinal study, the progression of atherosclerosis is accompanied by an increase in pulse pressure. From a pathophysiological point of view, the deleterious influence of most risk factors on endothelial function and the development of atheroma are likely to contribute to these relations. Furthermore, with respect to the connections observed between C-reactive protein, most cardiovascular risk factors, atherosclerotic diseases and pulse pressure, subclinical inflammation might also underlie these relations.

Atherosclerosis↗
PubMed2006

Interleukin 6 is associated with subclinical atherosclerosis: a link with soluble intercellular adhesion molecule 1.

BACKGROUND: Among the markers of inflammation, a cytokine, interleukin (IL)-6, promotes the expression of intercellular adhesion molecule 1 (ICAM-1), C-reactive protein (CRP) synthesis, and leads to a series of procoagulant actions with potential major implications on the progression of atherosclerosis. AIM OF THE STUDY: To analyse in a population-based study, the relationship between IL-6 and atherosclerotic lesions and the role of serum ICAM-1 and CRP on this relationship. POPULATION: Among 1015 individuals randomly recruited between 1995 and 1997 in Haute-Garonne, a French region with a low cardiovascular risk, 953 subjects with complete data for all measurements were analysed. Common carotid intima-media thickness (IMT) and the presence of plaques in the carotid and femoral arteries were assessed by ultrasonography. RESULTS: Quartiles of IL-6, serum ICAM-1 and CRP were positively associated with plaques and IMT. After adjustment for traditional risk factors, IL-6 (P < 0.001) and serum ICAM-1 (P < 0.002) remained positively associated with plaques but not CRP (P = 0.20). Neither IL-6, nor serum ICAM-1, nor CRP were independently associated with IMT. When serum ICAM-1 was entered into the model in addition to traditional risk factors and IL-6, the percentage of variance in the number of plaques explained by the model did not increase significantly. CONCLUSION: IL-6 levels are associated with subclinical atherosclerotic lesions independently of traditional risk factors; the influence of IL-6 on ICAM-1 secretion may play a role in this association. These results argue the interest of IL-6 in the stratification of cardiovascular risk.

Adult↗
PubMed2006

Arteries, inflammation and insulin resistance.

Inflammation plays a role in all stages of atherosclerosis from the formation to the rupture of the plaque. Guided by inflammatory mediators, monocytes bind to an endothelium damaged by cardiovascular risk factors, and then migrate towards the intima where, after incorporating oxidized low-density lipoprotein particles, they are transformed into foam cells. The lipid streak forms and develops as an atherosclerotic plaque, which is susceptible to erosion and rupture. Inflammation fed by excess adipose tissue decreases insulin sensitivity, which is the central feature of the metabolic syndrome. Inflammation therefore appears to be a common factor of atherosclerosis and the metabolic syndrome. The factors triggering this inflammation have yet to be determined. One line of thought would appear to point to diet.

Atherosclerosis↗
PubMed2006

Is exercise testing useful to improve the prediction of coronary events in asymptomatic subjects?

OBJECTIVE: The value of exercise testing (ET) in asymptomatic subjects remains controversial and is unknown in countries with a low coronary heart disease (CHD) incidence. The aim of this study was to investigate the ability of ET to improve the prediction of a first coronary event in such a population. METHODS: Using a prospective cohort study, 1051 consecutive healthy asymptomatic adults were enrolled in a cardiovascular screening program including ET. The pre-test risk of CHD was evaluated by the 10-year Framingham risk function. Positive ET was defined as a horizontal or downsloping ST-segment depression >/=1.0 mm. The primary outcome was total coronary events (CE) occurrence, including cardiac deaths, acute myocardial infarction and stable or unstable angina. The mean follow-up period was 6 years. RESULTS: Subjects were aged 18-79 years and 36% were women. A total of 89 subjects (8.5%) had a positive ET. Positive exercise testing was associated with CE occurrence in a univariate analysis only in subjects with higher pre-test risk, defined by a 10-year Framingham risk >10.4% [hazards ratio (HR)=2.61; 95% confidence interval (CI) (1.07-6.40)]. In this risk category, ET was able to provide incremental information over the major risk factors in both men and women [risk factor-adjusted HR for positive ET=2.86; 95% CI (1.14-7.20)]. This risk excess in subjects with positive ET persisted even when a coronary revascularization was performed. Subjects with intermediate pre-test probability (10-15%) and positive ET had a post-test probability of CE largely equivalent to the probability in subjects with known CHD. CONCLUSION: Additional information provided by ET in subjects with a pre-test risk at 10-years >10% should lead to a more efficient use of risk-reducing therapies than it would be the case in this risk category with the analysis of traditional risk factors only.

Adolescent↗
PubMed2005

Genetic testing in pheochromocytoma or functional paraganglioma.

PURPOSE: To assess the yield and the clinical value of systematic screening of susceptibility genes for patients with pheochromocytoma (pheo) or functional paraganglioma (pgl). PATIENTS AND METHODS: We studied 314 patients with a pheo or a functional pgl, including 56 patients having a family history and/or a syndromic presentation and 258 patients having an apparently sporadic presentation. Clinical data and blood samples were collected, and all five major pheo-pgl susceptibility genes (RET, VHL, SDHB, SDHD, and SDHC) were screened. Neurofibromatosis type 1 was diagnosed from phenotypic criteria. RESULTS: We have identified 86 patients (27.4%) with a hereditary tumor. Among the 56 patients with a family/syndromic presentation, 13 have had neurofibromatosis type 1, and germline mutations on the VHL, RET, SDHD, and SDHB genes were present in 16, 15, nine, and three patients, respectively. Among the 258 patients with an apparently sporadic presentation, 30 (11.6%) had a germline mutation (18 patients on SDHB, nine patients on VHL, two patients on SDHD, and one patient on RET). Mutation carriers were younger and more frequently had bilateral or extra-adrenal tumors. In patients with an SDHB mutation, the tumors were larger, more frequently extra-adrenal, and malignant. CONCLUSION: Genetic testing oriented by family/sporadic presentation should be proposed to all patients with pheo or functional pgl. We suggest an algorithm that would allow the confirmation of suspected inherited disease as well as the diagnosis of unexpected inherited disease.

Adolescent↗
PubMed2005

C-reactive protein elevation predicts pulse pressure reduction in hypertensive subjects.

Cross-sectional studies have shown a positive association between increased pulse pressure (PP) and an increased likelihood of a C-reactive protein (CRP) level >3 mg/L. In a retrospective subgroup analysis of the hypertensive subjects of the multicenter double-blind study, REASON (PREterax in Regression of Arterial Stiffness in a ContrOlled Double-BliNd), in which fixed first-line antihypertensive combination therapy with an angiotensin converting enzyme (ACE) inhibitor, perindopril (2 mg), and a diuretic, indapamide (0.625 mg), proved significantly more effective than atenolol in normalizing PP, we sought to determine whether perindopril plus indapamide was also more effective than atenolol in lowering CRP levels and, if so, whether this effect correlated with a preferential reduction in PP. At the final visit (12 months) in the 269 patients studied, the decrease in PP was greater, and the proportion of patients with CRP >3 mg/L lower (17.9% versus 28. 9%, P=0.03; adjusted odds ratio, 1.02 to 4.08, P=0.01), in the perindopril plus indapamide group than in the atenolol group. After adjustment for confounders, patients with a baseline CRP >3 mg/L displaying the greatest decrease in PP were more likely (P=0.04) to have a CRP < or =3 mg/L at 12 months. No such relationship was found with systolic or diastolic blood pressure. Perindopril-indapamide combination therapy is more effective than beta-blockade in lowering elevated CRP in hypertensive subjects. This effect is significantly associated with a more effective PP reduction in patients with baseline CRP >3 mg/L.

Adrenergic beta-Antagonists↗
PubMed2005

A polymorphism in the endothelin-A receptor gene is linked to baroreflex sensitivity.

BACKGROUND: The baroreflex plays an essential role in regulating the cardiovascular system. However, very few studies have focused on the links between genetic polymorphisms and baroreflex sensitivity (BRS). METHODS: A total of 146 hypertensive individuals who had never been treated, and 105 healthy individuals (controls) were included in the study. The genotypes of 17 polymorphisms of 11 genes involved in the regulation of the cardiovascular system were studied. BRS was measured using a sequence method: BRS was evaluated as the slope of spontaneous increases [systolic blood pressure (SBP)+/reflex response (RR)+] or decreases (SBP-/RR-) in SBP and pulse interval by recording blood pressure (BP) continuously for 20 min. RESULTS: Following univariate analysis, the genetic polymorphism of endothelin receptor A EDNRA/C+1222T was found to be significantly correlated with the BRS (SBP-/RR-) level in both populations. In normotensive subjects, mean BRS values (SBP-/RR-) were 11.93 +/- 3.69 ms/mmHg in EDNRA CC homozygotes, 9.94 +/- 2.97 ms/mmHg in CT heterozygotes and 9.51 +/- 3.16 ms/mmHg in TT homozygotes (P = 0.01). In hypertensive subjects, mean BRS values (SBP-/RR-) were 9.26 +/- 3.59 ms/mmHg in EDNRA CC homozygotes, 9.03 +/- 4.14 ms/mmHg in CT heterozygotes and 6.60 +/- 2.42 ms/mmHg in TT homozygotes (P = 0.01). After adjustment for age, sex, SBP and diastolic blood pressure and body mass index, the EDNRA/C+1222T polymorphism remained significantly correlated with BRS in both normotensive (P = 0.01) and hypertensive (P = 0.01) subjects. CONCLUSIONS: These results suggest that the endothelin system may be involved in the regulation of BRS in humans. In particular, the T allele of the EDNRA/C+1222T polymorphism is associated with a reduction in BRS in both healthy and hypertensive subjects.

Adult↗
PubMed2004

Twenty-four-hour ambulatory blood pressure monitoring efficacy of perindopril/indapamide first-line combination in hypertensive patients: the REASON study.

BACKGROUND: Circadian blood pressure (BP) measurements provide more information on hypertensive complications than office BP measurements. The purpose of this study was to analyze the efficacy of the first-line combination of perindopril 2 mg plus indapamide 0.625 mg versus atenolol 50 mg on BP parameters and variability over 24 h in patients with hypertension. METHODS: A double-blind, randomized, controlled, 12-month study comparing perindopril/indapamide and atenolol was performed in 201 patients (age 55.0 years) with uncomplicated sustained essential hypertension. Ambulatory BP measurements (ABPM) were done every 15 min over 24 h. RESULTS: After 1 year of treatment, the decrease in systolic BP was significantly greater for perindopril/indapamide than for atenolol during the entire 24-h period (-13.8 v -9.2 mm Hg), the daytime and the nighttime periods (P <.01). Diastolic blood pressure (DBP) variations were comparable for the two groups (-7.2 v -8.3 mm Hg, NS). Pulse pressure (PP) reduction was also significantly greater for perindopril/indapamide than for atenolol (for the whole 24 h, -6.6 v -0.9 mm Hg, P <.001). The through to peak (T/P) BP ratio and the smoothness index were comparable in the two groups for DBP. For systolic blood pressure (SBP), higher values of the T/P ratio (0.80 v 0.59) and the smoothness index (1.45 v 0.98; P <.02) were achieved for the perindopril/indapamide combination than for atenolol. CONCLUSIONS: The perindopril/indapamide first-line combination decreased SBP and PP more effectively than atenolol. Moreover, the BP control effect was smooth and consistent throughout the 24-h dosing interval and BP reduction variability was lower than the one induced by atenolol.

Adrenergic beta-Antagonists↗
PubMed2004

Relationship between C reactive protein and pulse pressure is not mediated by atherosclerosis or aortic stiffness.

BACKGROUND: Pulse pressure (PP), C reactive protein (CRP) and soluble intercellular adhesion molecule-1 (sICAM-1) levels have been associated with cardiovascular prognosis. Interestingly, previous reports have shown that PP was associated both with CRP and sICAM-1. The mechanisms underlying these associations remain unknown. On the one hand, it has been shown that PP influences, via endothelial function, the expression of various molecules, which in turn may generate inflammation. On the other hand, inflammation-induced changes in the arterial wall, modifying the PP, may be the confounding factor of these relationships. The aim of the present study was to investigate the role played by the arterial structure and the aortic stiffness on these relationships. METHODS: In a cross-sectional population sample of 891 healthy subjects, carotid-femoral pulse wave velocity and blood pressure were measured in the supine position. The common carotid intima-media thickness and the presence of plaques were assessed by ultrasonography. CRP and sICAM-1 levels were measured by an immunonephelemetric method and an immunoenzymatic method, respectively. RESULTS: A positive relationship was found between PP and CRP (P < 0.001). This relationship remained after adjustment for classical cardiovascular risk factors, and successively for mean blood pressure, intima-media thickness, presence of plaques and pulse wave velocity (P < 0.05). No significant association was observed between PP and sICAM-1. CONCLUSIONS: The results of this study demonstrate that changes in arterial structure and in arterial stiffness are not confounding factors in the relationship between PP and CRP.

Adult↗
PubMed2004

CD14 C(-260)T gene polymorphism, circulating soluble CD14 levels and arteriosclerosis.

BACKGROUND: CD14 pathway is at the crossroads between infection and inflammation. In human pathology, divergent results have been reported on the relationship between a polymorphism in the promoter of receptor CD14 (C260T), expression of soluble CD14 (sCD14) receptor and atherosclerosis. The aim of the study was to investigate in a cross-sectional population-based sample the relationships between C260T polymorphism in CD14 gene, sCD14 blood levels and arterial wall. METHODS: Among 1015 subjects, randomly recruited by the Toulouse MONICA center between 1995 and 1997, 899 subjects with complete data for all the measurements, were analyzed. sCD14 was measured using an immuno-enzymatic method. Common carotid intima-media thickness (IMT) and the presence of plaques in the carotid and femoral arteries were assessed by ultrasonography. A genotypic examination for the CD14 C260T polymorphism was performed. RESULTS: An increase in sCD14 expression was observed in subjects carrying t allele (P < 0.01). No significant difference in intima-media thickness, number of plaques and pulse wave velocity was noticed according to C260T polymorphism. An interaction (P < 0.05) was observed between C260T polymorphism and current smoking in sCD14 expression: among smokers, no significant change in sCD14 was observed in individuals carrying t allele. CONCLUSION: Although (C260T) polymorphism in CD14 gene in this study is associated with expression of sCD14, no significant association was found between this polymorphism and early markers of atherosclerosis. This polymorphism affects plasma levels of sCD14 in relation to current smoking status. Further studies are needed to determine whether this interaction influences the deleterious effect of smoking on vascular events.

Adult↗
PubMed2003

Why is hypertension so frequently uncontrolled in secondary prevention?

OBJECTIVE: To analyze blood pressure (BP) control in secondary prevention. DESIGN: Individual data of two cross-sectional studies on preventive cardiology (PRATIK and ESPOIR studies conducted, respectively, in general practice and with private cardiologists) were analyzed. SETTING: Primary care. PARTICIPANTS: Patients both with treated hypertension and coronary disease. MAIN OUTCOME MEASURES: Risk factors, treatments, cardiovascular history and BP were recorded. Each population was divided in three groups: group I, no other risk factor; group II, one or two risk factors; group III, three or more risk factors or diabetes. RESULTS: A total of 1423 and 2596 patients, respectively, recruited in general practice and by cardiologists were analyzed. Of these, 473 (33.24%) and 1060 (40.83%) patients, respectively, had controlled hypertension. Among uncontrolled hypertensives, more than 50% had borderline isolated systolic hypertension. Associated risk factors negatively affect hypertension control, which had been achieved in a lower percentage of patients in group III than in group I (general practice, 26.28 versus 42.20%; cardiological practice, 32.42 versus 56.13%). In general practice, the percentage of patients receiving beta-blockers was significantly lower in group III. Among individuals with uncontrolled hypertension, only 17.58 and 26.69% received at least three-drug treatment including diuretics in general and in cardiological practice, respectively. CONCLUSION: The negative influence of associated risk factors and the under-use of combination therapy contribute to poor BP control. In addition the high frequency of borderline isolated systolic hypertension suggests that the prerequisite to improve hypertension control should be to convince practitioners of the beneficial effect of tight systolic BP control (below 140 mmHg) in secondary prevention.

Aged↗
PubMed2003

Soluble CD14 and aortic stiffness in a population-based study.

OBJECTIVE: Soluble CD14 (sCD14), an effective mediator for the activation of monocytes by bacterial endotoxin is involved in the release of substances able to modify the characteristics of the arterial wall. The aim of this study was to investigate, in humans, the relationship of sCD14 with aortic stiffness and to analyse the influence of arterial structure and endothelial function on this relationship. DESIGN: Cross-sectional population-based study. PARTICIPANTS: One thousand and fifteen subjects randomly selected from the polling lists, were recruited by the Toulouse MONICA centre between 1995 and 1997. METHODS: Carotid-femoral pulse wave velocity (PWV) and blood pressure (BP) were measured in the supine position. Common carotid intima-media thickness (IMT) and the presence of plaques were assessed by ultrasonography. sCD14 was measured using an immunoenzymatic method. RESULTS: The results concern the 891 subjects with complete data for all the variables. In the bivariate analyses, PWV (P < 0.001), systolic BP (P < 0.05), pulse pressure (PP) (P < 0.01), IMT (P < 0.001), the number of plaques (P < 0.05) and von Willebrand factor activity (vWFa) (P < 0.001) were positively associated with sCD14, whereas no significant relationship was observed between sCD14 and diastolic BP. After adjustment for age and sex, no significant relationship remained between IMT, the number of plaques, SBP, PP and sCD14. A significant and positive relationship was observed between sCD14 and PWV (trend P < 0.05) after adjustment for numerous confounders. CONCLUSION: This population-based study yields first evidence that sCD14 is associated with aortic stiffness independently of age, BP and atherosclerosis in humans.

Adult↗
PubMed2002

Hypertension in high-risk patients: beware of the underuse of effective combination therapy (results of the PRATIK study).

OBJECTIVE: To determine whether blood pressure control in a general practice setting is influenced by the presence of additional risk factors, and to analyse the role of antihypertensive therapy in this relationship. DESIGN: A cross-sectional study was conducted with a sample of 3153 general practitioners. SETTING: Primary care. PARTICIPANTS: The first five hypertensive patients presenting at the practitioner's office were included. MAIN OUTCOME MEASURES: Cardiovascular risk factors, antihypertensive drugs and cardiovascular history were reported. Blood pressure was measured. The analysis was conducted in treated patients who were divided in three groups: no other risk factors (group I); 1-2 risk factors (group II); 3 or more risk factors or target-organ damage or diabetes or associated cardiovascular disease (group III). RESULTS: Data were available for all variables in the 14 066 treated hypertensive individuals who form the basis of this report. Blood pressure control had been achieved in a lower percentage of individuals in group III (27%) than in group I (42.9%). To control hypertension, combination therapies were more frequently required in group III (55.8%) than in group II (43.5%) or group I (34.2%). Among individuals with uncontrolled hypertension, about 39% of patients in group III were receiving monotherapy and the percentage receiving two-drug treatments identified as effective in the 1999 WHO guidelines was significantly lower in group III. CONCLUSION: The study shows that, in general practice, control of blood pressure decreases as the number of risk factors present increases. An underuse of combination therapy, especially effective two-drug treatment in patients with several risk factors, may account for this finding.

Aged↗