Hypertension: Bell C

Padwal RS, Hemmelgarn BR, Khan NA, Grover S, McKay DW, Wilson T, Penner B, Burgess E, McAlister FA, Bolli P, Hill MD, Mahon J, Myers MG, Abbott C, Schiffrin EL, Honos G, Mann K, Tremblay G, Milot A, Cloutier L, Chockalingam A, Rabkin SW, Dawes M, Touyz RM, Bell C, Burns KD, Ruzicka M, Campbell NR, Vallée M, Prasad R, Lebel M, Tobe SW, Anonymous00149. · Division of General Internal Medicine, University of Alberta, Edmonton, Canada. · Can J Cardiol. · Pubmed #19417858 No free full text.

Abstract: OBJECTIVE: To provide updated, evidence-based recommendations for the diagnosis and assessment of adults with hypertension. OPTIONS AND OUTCOMES: The diagnosis of hypertension is dependent on appropriate blood pressure measurement, the timely assessment of serially elevated readings, the degree of blood pressure elevation, the method of measurement (office, ambulatory, home) and associated comorbidities. The presence of cardiovascular risk factors and target organ damage should be ascertained to assess global cardiovascular risk and determine the urgency, intensity and type of treatment required. EVIDENCE: MEDLINE searches were conducted from November 2007 to October 2008 with the aid of a medical librarian. Reference lists were scanned, experts were contacted, and the personal files of authors and subgroup members were used to identify additional studies. Content and methodological experts assessed studies using prespecified, standardized evidence-based algorithms. Recommendations were based on evidence from peer-reviewed full-text articles only. RECOMMENDATIONS: Recommendations for blood pressure measurement, criteria for hypertension diagnosis and follow-up, assessment of global cardiovascular risk, diagnostic testing, diagnosis of renovascular and endocrine causes of hypertension, home and ambulatory monitoring, and the use of echocardiography in hypertensive individuals are outlined. Key messages include continued emphasis on the expedited, accurate diagnosis of hypertension, the importance of global risk assessment and the need for ongoing monitoring of hypertensive patients to identify incident type 2 diabetes. VALIDATION: All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations were required to be supported by at least 70% of task force members. These guidelines will continue to be updated annually.

Padwal RJ, Hemmelgarn BR, Khan NA, Grover S, McAlister FA, McKay DW, Wilson T, Penner B, Burgess E, Bolli P, Hill MD, Mahon J, Myers MG, Abbott C, Schiffrin EL, Honos G, Mann K, Tremblay G, Milot A, Cloutier L, Chockalingam A, Rabkin SW, Dawes MD, Touyz RM, Bell C, Burns KD, Ruzicka M, Campbell NR, Lebel M, Tobe SW, Anonymous00045. · Division of General Internal Medicine, University of Alberta, Edmonton, Canada. · Can J Cardiol. · Pubmed #18548142 links to  free full text

Abstract: OBJECTIVE: To provide updated, evidence-based recommendations for the diagnosis and assessment of adults with hypertension. OPTIONS AND OUTCOMES: The diagnosis of hypertension is dependent on appropriate blood pressure measurement, the timely assessment of serially elevated readings, degree of blood pressure elevation, method of measurement (office, ambulatory, home) and associated comorbidities. The presence of cardiovascular risk factors and target organ damage should be ascertained to assess global cardiovascular risk and determine the urgency, intensity and type of treatment required. EVIDENCE: MEDLINE searches were conducted from November 2006 to October 2007 with the aid of a medical librarian. Reference lists were scanned, experts were contacted, and the personal files of authors and subgroup members were used to identify additional studies. Content and methodological experts assessed studies using prespecified, standardized evidence-based algorithms. Recommendations were based on evidence from peer-reviewed, full-text articles only. RECOMMENDATIONS: Recommendations for blood pressure measurement, criteria for hypertension diagnosis and follow-up, assessment of global cardiovascular risk, diagnostic testing, diagnosis of renovascular and endocrine causes of hypertension, home and ambulatory monitoring, and the use of echocardiography in hypertensive individuals are outlined. Key messages in 2008 include continued emphasis on the expedited, accurate diagnosis of hypertension, the importance of global risk assessment and the need for ongoing monitoring of hypertensive patients to identify incident type 2 diabetes. VALIDATION: All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here received at least 70% consensus. These guidelines will continue to be updated annually.

McNiece KL, Gupta-Malhotra M, Samuels J, Bell C, Garcia K, Poffenbarger T, Sorof JM, Portman RJ, Anonymous00130. · Department of Pediatrics, Division of Pediatric Nephrology and Hypertension, School of Medicine, University of Texas, Houston, TX 77057, USA. · Hypertension. · Pubmed #17592068 links to  free full text

Abstract: The National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents recently recommended staging hypertension (HTN) in children and adolescents based on blood pressure severity. The use of blood pressure staging and its corresponding therapeutic approach was examined in this pooled analysis assessing the risk for end-organ damage, specifically left ventricular hypertrophy among hypertensive adolescents stratified by working group criteria. Newly diagnosed hypertensive adolescents and normotensive control subjects similar in age, race/ethnicity, gender, and body mass index completed casual and 24-hour ambulatory blood pressure measurements, M-mode echocardiography, and fasting serum laboratories. Hypertensive subjects had higher insulin and cholesterol but similar glucose levels as compared with control subjects. Among subjects with stage 1 HTN by casual blood pressure, 34% had white-coat HTN as opposed to 15% of stage 2 hypertensive subjects. Of the subjects with normal casual measurements, 20% had HTN by ambulatory monitoring. Subjects with stage 2 HTN by casual measurement alone (odds ratio: 4.13; 95% CI: 1.04 to 16.48) and after 24-hour ambulatory confirmation (odds ratio: 7.23; 95% CI: 1.28 to 40.68) had increased odds for left ventricular hypertrophy. In addition, the risk for left ventricular hypertrophy was similar for subjects with masked and confirmed stage 1 HTN, whereas subjects with white-coat HTN had a risk comparable to normotensive subjects. Thus, recommendations that adolescents with stage 2 HTN by casual measurements alone receive medication initially along with therapeutic lifestyle counseling are reasonable, though ambulatory blood pressure monitoring remains a valuable tool for evaluating children with stage 2 HTN, because >10% have white-coat HTN.

Scragg R, Sowers M, Bell C. · School of Population Health, University of Auckland, Auckland, New Zealand. · Am J Hypertens. · Pubmed #17586404 No free full text.

Abstract: BACKGROUND: Populations with low vitamin D status, such as blacks living in the US or UK, have increased blood pressure (BP) compared with whites. We analyzed the association between serum 25-hydroxyvitamin D (25OHD) and BP to determine whether low 25OHD explains any of the increased BP in blacks. METHODS: The Third US National Health and Nutrition Examination Survey (NHANES III) is a cross-sectional survey representative of the US civilian population during 1988 to 1994. Analyses were restricted to 12,644 people aged > or =20 years with measurements of BP and 25OHD, after excluding those on hypertensive medication. RESULTS: Adjusted mean serum 25OHD was lowest in non-Hispanic blacks (49 nmol/L), intermediate in Mexican Americans (68 nmol/L), and highest in non-Hispanic whites (79 nmol/L). When participants were divided into 25OHD quintiles, mean (standard error) systolic BP was 3.0 (0.7) mm Hg lower (P = .0004) and diastolic BP was 1.6 (0.6) mm Hg lower (P = .011) for participants in the highest quintile (25OHD > or =85.7 nmol/L) compared with the lowest (25OHD < or =40.4 nmol/L), adjusting for age, sex, ethnicity, and physical activity. Further adjustment for body mass index (BMI) weakened the inverse association between 25OHD and BP, which remained significant for systolic BP (P < .05). The inverse association between 25OHD and systolic BP was stronger in participants aged > or =50 years than younger (P = .021). Ethnic differences in 25OHD explained about half of the increased hypertension prevalence in non-Hispanic blacks compared with whites. CONCLUSIONS: Vitamin D status, which is amenable to intervention by safely increasing sun exposure or vitamin D supplementation, was associated inversely with BP in a large sample representative of the US population.

Tansey E, Bell C. · Cardiovascular Health Unit, Department of Physiology, Trinity College Dublin, Dublin 2, Ireland. · Clin Exp Hypertens. · Pubmed #16820348 No free full text.

Abstract: The authors have assessed arterial baroreflex gain in urethane-anesthetized normotensive and New Zealand genetically hypertensive (GH) rats and investigated the effect of gonadectomy in adult animals at 3 weeks of age postnatally. No gender differences in resting blood pressures existed for either normotensive or GH strains. In normotensive animals, bradycardic gain was greater than tachycardic gain and was lower in females than in males. Tachycardic gain was similar in GH and normotensive rats of either sex, but bradycardic gain was lower in GH. Gonadectomy had no effect on baroreflex gain in male or female animals of either strain.

Jackson MR, Ali AT, Bell C, Modrall JG, Welborn MB, Scoggins E, Valentine RJ, D'Addio VJ, Clagett GP. · Department of Surgery, University of Texas Southwestern Medical Center, Dallas, USA. · J Vasc Surg. · Pubmed #15218456 No free full text.

Abstract: PURPOSE: Previous studies have documented poor patency rates in "young" patients (age 55 years or younger) with premature atherosclerosis undergoing aortofemoral bypass (AFB) to treat aortoiliac occlusive disease. Given the high reported graft patency rates with superficial femoral vein (SFV) grafts performed because of aortic graft infection, we evaluated the role of SFV grafts for AFB as primary therapy for premature atherosclerosis in a case-control study. METHODS: Over 10 years 31 patients aged 55 year or younger underwent AFB with use of SFV (V-AFB). Case controls consisted of all patients 55 years of age or younger who underwent AFB with use of Dacron (D-AFB) during the same period (n = 80). In all cases this was the initial therapy (no repeat operations). The two groups were well matched for age, sex, weight, preoperative ankle-brachial index, and the comorbid conditions of smoking, coronary artery disease, chronic obstructive pulmonary disease, hyperlipidemia, hypertension, and renal insufficiency. There were more patients with diabetes in the V-AFB group (34% vs 16%; P =.05). Patients in the V-AFB group had more advanced disease, and the surgical indication was more frequently critical ischemia compared with the D-AFB group (90% vs 46%; P <.001). RESULTS: There was only one perioperative death in each group. There were no differences in cardiac, pulmonary, or gastrointestinal complications. However, fasciotomy occurred more frequently with V-AFB (44% vs 1%; P <.001). Surgery time was longer with V-AFB (7.3 vs 4.5 hours; P <.001). Despite these short-term drawbacks, V-AFB proved superior at long-term follow-up. The 5-year primary patency rate was significantly higher with V-AFB than with D-AFB (100% vs 56%; P =.013). There was also a trend for higher limb salvage at 5 years (90% vs 62%). Four graft infections occurred with D-AFB, and none with V-AFB (P =.32). CONCLUSIONS: AFB performed with SFV grafts is a far more durable operation than standard D-AFB in young patients with aortoiliac occlusive disease. However, V-AFB is far more likely to require lower extremity fasciotomy, and takes almost twice as long to perform.

Brady F, Bakhle YS, Bell C. · Department of Physiology, Trinity College, Dublin, Ireland. · Acta Physiol Hung. · Pubmed #12489754 No free full text.

Abstract: The attenuation of baroreflex gain associated with hereditary hypertension could involve abnormal signalling by nitric oxide or substance P. Baroreflex gain was measured in age-matched male genetically hypertensive (GH) and nonnotensive (N) anaesthetised rats from heart rate changes in response to i.v. phenylephrine or sodium nitroprusside. In subgroups of these animals, nitric oxide synthesis was inhibited using NG-nitro-L-arginine methyl ester (L-NAME, 30 mg x kg(-1) i.v.), substance P transmission was blocked using the antagonist SR 140333 (360 nmoles x kg(-1) i.v.) or substance P release was inhibited with resiniferatoxin (4 doses of 0.3 microg x kg(-1) i.v. at 4 min intervals). Baroreflex gain was markedly reduced in GH compared to N animals (N -0.37 +/- 0.04 beat x min(-1) x mm Hg(-1), GH -0.17 +/- 0.02 beat x min(-1) x mm Hg(-1), p < 0.0001). Inhibition of nitric oxide synthase increased baroreflex gain in each strain, but the inter-strain difference in gain persisted (post-treatment N -0.57 +/- 0.07 beat x min(-1) x mm Hg(-1), GH -0.24 +/- 0.05 beat x min(-1) x mm Hg(-1) (p < 0.001). Blockade of receptors or inhibition of substance P release did not affect gain in either strain. Nitric oxide, but not substance P, appears to play an inhibitory role in the rat arterial baroreflex. Impairment of baroreflex gain in GH rats is not secondary to altered nitric oxide signaling.

Bell C. · No affiliation provided · Hypertension. · Pubmed #16380521 links to  free full text

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