Arm position and blood pressure: a risk factor for hypertension?

The objective of this study was to re-evaluate the effect of arm position on blood pressure (BP) measurement with auscultatory and oscillometric methods including ambulatory blood pressure monitoring (ABPM). The setting was the hospital outpatient department and the subjects chosen were normotensive and hypertensive. The effect of lowering the arm from heart level on indirect systolic BP (SBP) and diastolic BP (DBP) measurement as well as the importance of supporting the horizontal arm were measured. In the sitting position, lowering the supported horizontal arm to the dependent position increased BP measured by a mercury device from 103+/-10/60+/-7 to 111+/-14/67+/-10 mmHg in normotensive subjects, a mean increase of 8/7 mmHg (P<0.01). In hypertensive subjects, a similar manoeuvre increased BP from 143+/-21/78+/-17 to 166+/-29/88+/-20 mmHg, an increase of 23/10 mmHg (P<0.01). Combined results from normotensive and hypertensive subjects demonstrate a direct and proportional association between BP (SBP and DBP) and the increase produced by arm dependency. Similar changes and associations were noted with oscillometric devices in the clinic situation. However, supporting the horizontal arm did not alter BP. Of particular interest, analysis of 13 hypertensive subjects who underwent ABPM on two occasions, once with the arm in the 'usual' position and once with the arm held horizontally for BP measurement during waking hours, demonstrated changes comparable to the other devices. The mean 12-hour BP was 154+/-19/82+/-10 mmHg during the former period and significantly decreased to 141+/-18/74+/-9 mmHg during the latter period (P<0.01). Regression analysis of the change in SBP and DBP with arm position change again demonstrated a close correlation (r(2)=0.8113 and 0.7273; P<0.001) with the artefact being larger with higher systolic and diastolic pressures. In conclusion, arm movements lead to significant artefacts in BP measurement, which are greater, the higher the systolic or diastolic pressure. These systematic errors occur when using both auscultatory and oscillometric (clinic and ABPM) devices and might lead to an erroneous diagnosis of hypertension and unnecessary medication, particularly in individuals with high normal BP levels. Since clinical interpretations of heart level vary, the horizontal arm position should be the unambiguous standard for all sitting and standing BP auscultatory and oscillometric measurements.     

Chikungunya: a risk for Mediterranean countries?

The Italian outbreak of the 2007 summer and the active spreading of the Asian tiger mosquito Aedes albopictus in southern Europe, raise the possibility of local transmission of chikungunya (CHIK) in Mediterranean countries. Established in at least 12 countries in southern Europe since the end of the 1970s and in southern France since 2004, Ae. albopictus, is invading the French Mediterranean coast from East to West. To determine the possibility of an outbreak of CHIK in southern France, we provide an assessment of vector competence towards CHIK virus of different mosquito species, including Ae. albopictus, collected in 2006 in Camargue and the "C?te d'Azur" (Alpes Maritimes). In the laboratory, Ae. albopictus showed a high susceptibility to CHIK infection (77.1%) comparable to that observed for specimens collected in March 2006 in La Reunion Island. Hence, Ae. albopictus from southern France has the potential to serve as a vector based on its susceptibility to CHIK infection. Its presence in a tourist area such as the "C?te d'Azur" should be considered as a potential threat for the introduction of CHIK virus as in Italy where the initial case was probably a traveller coming back from an endemic zone.     

Older blood pressure medications-do they still have a place?

Hypertension is a major risk factor for cardiovascular disease, but control of hypertension remains inadequate, often because of poor patient adherence to prescribed medical regimens that are viewed as poorly tolerated and expensive. Physicians have largely stopped using some older blood pressure medications in favor of newer agents, mostly because of a presumed more favorable side effect profile. The investigators reviewed the pharmacologic properties and the evidence supporting the effectiveness and tolerability of several older blood pressure drugs: sympatholytic agents such as reserpine, methyldopa, and clonidine; diuretics such as chlorthalidone, ethacrynic acid and spironolactone; the vasodilators hydralazine and minoxidil; and others. In conclusion, some of these drugs are well studied and represent alternatives for patients who cannot afford or tolerate newer medications.     

Homocysteine as a risk factor for cardiovascular disease: should we (still) worry about?

Cardiovascular disease (CVD) is the leading cause of death worldwide. CVD is causally related to "classical" risk factors such as elevated blood pressure, cholesterol, or glucose level and smoking. A causal role in the development of CVD is also suggested for numerous other factors, including an elevated plasma homocysteine concentration. Variation of homocysteinaemia is mainly due to genetic mutations and/or vitamin deficiency. The homocysteine concentration can be lowered with folate. Vitamin supplementation has thus been proposed in individuals with hyperhomocysteinaemia in order to reduce their CVD risk. On the other hand, population-based studies show little or no association between moderate hyperhomocysteinaemia and CVD risk. Nor has any randomised clinical trial clearly proven the efficacy of lowering the homocysteine concentration as a means of lowering the incidence of CVD. Hence at present it is inappropriate to recommend screening and treatment of hyperhomocysteinaemia in asymptomatic persons with or without other CVD risk. Until new evidence is available, clinicians should focus on better control of the "classical" risk factors for CVD.     

Is ABO blood group truly a risk factor for thrombosis and adverse outcomes?

ABO blood type is one of the most readily available laboratory test, and serves as a vital determinant in blood transfusion and organ transplantation. The ABO antigens are expressed not only on red blood cell membranes, determining the compatibility of transfusion, but also on the surface of other human cells, including epithelium, platelet and vascular endothelium, therefore extending the research into other involvements of cardiovascular disease and postoperative outcomes. ABO blood group has been recognized as a risk factor of venous thrombosis embolism since the 1960's, effects now understood to be related to ABO dependent variations are procoagulant factor Ⅷ(FⅧ) and von Willebrand factor(vWF) levels. Levels of vWF, mostly genetically determined, are strongly associated with venous thromboembolism(VTE). It mediates platelet adhesion aggregation and stabilizes FⅧ in plasma. Moreover, many studies have tried to identify the relationship between ABO blood types and ischemic heart disease. Unlike the clear and convincing associations between VTE and ABO blood type, the link between ABO blood type and ischemic heart disease is less consistent and may be confusing. Other than genetic factors, ischemic heart disease is strongly related to diet, race, lipid metabolism and economic status. In this review, we'll summarize the data relating race and genetics, including ABO blood type, to VTE, ischemic heart disease and postoperative bleeding after cardiac surgery.     

Autotransfusion of shed mediastinal blood: a risk factor for mediastinitis after cardiac surgery? Results of a cluster investigation

RATIONALE: After the introduction of autotransfusion of shed mediastinal blood following cardiac surgery, the incidence of mediastinitis increased. The role of autotransfusion in the increased occurrence of this serious complication was examined. METHODS: Using a case-control design, the preoperative, intraoperative, and postoperative characteristics of 11 patients with mediastinitis were compared to those of 33 randomly selected patients undergoing cardiac surgery between September 1, 2000, and April 15, 2001 (control subjects). RESULTS: Patients with mediastinitis were significantly more likely to have a body mass index > 30 (unadjusted odds ratio [OR], 9.9; 95% confidence interval [CI], 2.3 to 42.5), to have received antibiotic therapy during the 2 weeks prior to cardiac surgery (OR, 12.0; 95% CI, 1.1 to 131), or to have required re-exploration within 24 h of the original operation (OR, 8.3; 95% CI, 1.8 to 39). Patients with mediastinitis had 3.4 known risk factors for mediastinitis, compared to only 1.4 risk factors per control subject (p = 0.0001), and longer duration of autotransfusion. After adjustment for other risk factors, autotransfusion for > 6 h was significantly associated with the development of mediastinitis (adjusted OR, 11.9; 95% CI, 1.4 to 97.2). CONCLUSION: Retransfusion of shed mediastinal blood for > 6 h after cardiac surgery was an independent risk factor for mediastinitis.     

Fluoride: a risk factor for inflammatory bowel disease?

Although the association between inflammatory bowel disease (IBD) and oral hygiene has been noticed before, there has been little research on prolonged fluoride exposure as a possible risk factor. In the presented cases, exposure to fluoride seems indirectly associated with higher incidence of IBD. Fluoride toxicology and epidemiology documents frequent unspecific chronic gastrointestinal symptoms and intestinal inflammation. Efflux genes that confer resistance to environmental fluoride may select for IBD associated gut microbiota and therefore be involved in the pathogenesis. Together these multidisciplinary results argue for further investigation on the hypothesis of fluoride as a risk factor for IBD.