Recommendations for Blood Pressure Measurement in Humans and Experimental Animals

The association of cardiorespiratory fitness and physical activity with incidence of hypertension in men

BACKGROUND

Few prospective studies have simultaneously investigated the relationship between physical activity, cardiorespiratory fitness (CRF), and the development of hypertension in initially normotensive individuals. In the Aerobics Center Longitudinal Study (ACLS), we examined this association among initially healthy normotensive men.

METHODS

Participants were 16,601 men aged 20-82 years who completed a baseline examination during 1970-2002 and were followed for hypertension incidence. Physical activity was self-reported and CRF was quantified from the duration of a maximal treadmill test.

RESULTS

A total of 2,346 men reported hypertension during a mean 18 years of follow-up. Event rates per 10,000 man-years adjusted for age and examination year were 86.2, 76.6, and 66.7 across physical activity groups of sedentary, walker/jogger/runner (WJR), and sport/fitness, respectively, and 89.8, 78.4, and 64.6 for low, middle, and high CRF, respectively (trend P < 0.0001). These associations persisted after further adjustment for body mass index (BMI), smoking, alcohol intake, resting systolic blood pressure, baseline health status, family history of diseases, and survey response patterns.

CONCLUSION

Both physical activity and CRF are associated with lower risk of developing hypertension in a graded fashion. These findings provide a basis for health professionals to emphasize the importance of participating in regular physical activity to improve fitness for the primary prevention of hypertension in men.

C-reactive protein and cardiac vagal activity following resistance exercise training in young African-American and white men

African Americans have a greater prevalence of hypertension and diabetes compared with white Americans, and both autonomic dysregulation and inflammation have been implicated in the etiology of these disease states. The purpose of this study was to examine the cardiac autonomic and systemic inflammatory response to resistance training in young African-American and white men. Linear (time and frequency domain) and nonlinear (sample entropy) heart rate variability, baroreflex sensitivity, tonic and reflex vagal activity, and postexercise heart rate recovery were used to assess cardiac vagal modulation. C-reactive protein (CRP) and white blood cell count were used as inflammatory markers. Twenty two white and 19 African-American men completed 6 wk of resistance training followed by 4 wk of exercise detraining (Post 2). Sample entropy, tonic and reflex vagal activity, and heart rate recovery were increased in white and African-American men following resistance training (P < 0.05). Following detraining (Post 2), sample entropy, tonic and reflex vagal activity, and heart rate recovery returned to baseline values in white men but remained above baseline in African-American men. While there were no changes in white blood cell count or CRP in white men, these inflammatory markers decreased in African-American men following resistance training, with reductions being maintained following detraining (P < 0.05). In conclusion, resistance training improves cardiac autonomic function and reduces inflammation in African-American men, and these adaptations remained after the cessation of training. Resistance training may be an important lifestyle modification for improving cardiac autonomic health and reducing inflammation in young African-American men.

Blood pressure components and the risk for end-stage renal disease and death in chronic kidney disease

BACKGROUND AND OBJECTIVES

Mean arterial pressure has been used in clinical trials in nephrology to randomly assign and treat patients, yet the pulsatile component of BP is recognized to influence outcomes in older people. I examined the unique contributions of systolic (SBP) and diastolic BP (DBP) on the risk for ESRD and death in patients with chronic kidney disease (CKD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A single-center, prospective cohort study was conducted of 218 veterans with CKD (22% black, 4% women, mean age 68 yr, clinic BP 154.1 +/- 25.1/85.2 +/- 13.9 mmHg, 48% with diabetes).

RESULTS

During follow-up of up to 7 yr, 63 patients had ESRD and 102 patients died. Compared with those with controlled SBP (<130 mmHg), patients with moderate control (130 to 149 mmHg) had hazard ratio of 3.87 and those with poor control hazard ratio of 9.09 for ESRD. DBP had no direct ability to predict ESRD. For all-cause mortality, a J-shaped relationship was seen for SBP and an inverse relationship was seen for DBP. Considered jointly in the Cox model, a higher SBP and lower DBP improved the prediction of all-cause mortality compared with either BP component alone. The presence of J curve was especially pronounced in patients with advanced CKD, absence of clinical proteinuria, or age >65 yr.

CONCLUSIONS

In older patients with CKD, SBP predicts ESRD and a higher SBP and lower DBP predicts all-cause mortality. Lower BP of <110/70 mmHg is a marker of higher mortality in older individuals with advanced CKD.

The insulin gradient phenomenon: a manifestation of the effects of body weight on blood pressure and insulin resistance

The relationship between hyperinsulinemia and hypertension is frequently observed in overweight patients; however, population studies have not confirmed an independent association. A population study was conducted to assess whether differences in body mass index and levels of insulinemia modify cardiovascular hemodynamics and arterial pressure. In all, 322 healthy adults underwent a medical evaluation including insulin sensitivity and cardiac performance assessment with echocardiography. A direct relationship between body mass index and blood pressure (r=0.36; P<.01) was shown along with increments in fasting insulin levels. The underlying and progressive rise in insulin levels during blood pressure increase is named the insulin gradient. Left ventricular systolic indexes were significantly greater in the higher-insulin quartile. These findings suggest that body weight increases accompany a rise in systolic pressure and a drop in insulin sensitivity related to the insulin gradient. Increments in ejection fraction and cardiac output with normal total peripheral resistance are related to the blood pressure shift in these persons.

Circulating transforming growth factor-beta1 levels and the risk for kidney disease in African Americans

Transforming growth factor-β1 (TGF-β1) is well known to induce progression of experimental renal disease. Here we determined whether there is an association between serum levels of TGF-β1 and the risk factors for progression of clinically relevant renal disorders in 186 black and 147 white adults none of whom had kidney disease or diabetes. Serum TGF-β1 protein levels were positively and significantly associated with plasma renin activity along with the systolic and diastolic blood pressure in blacks but not whites after controlling for age, gender and body mass index. These TGF-β1 protein levels were also significantly associated with body mass index and metabolic syndrome and more predictive of microalbuminuria in blacks than in whites. The differential association between TGF-β1 and renal disease risk factors in blacks and whites suggests an explanation for the excess burden of end-stage renal disease in the black population but this requires validation in an independent cohort. Whether these findings show that it is the circulating levels of TGF-β1 that contributes to renal disease progression or reflects other unmeasured factors will need to be tested in longitudinal studies.

Administration-time-dependent effects of olmesartan on the ambulatory blood pressure of essential hypertension patients

Previous studies established that a single daily dose of olmesartan remains effective for the entire 24 h without alteration of the day-night blood pressure (BP) pattern. On the other hand, the administration of valsartan or telmisartan at bedtime, as opposed to upon wakening, improves the sleep-time relative BP decline toward a greater dipper pattern without loss of 24 h efficacy. Yet to be determined is whether this administration-time-dependent efficacy is a class-related feature, characteristic of all angiotensin-receptor-blocker (ARB) medications. We studied 123 grade 1 and 2 hypertensive patients, 46.6+/-12.3 yrs of age, randomly assigned to receive olmesartan (20 mg/day) as a monotherapy either upon awakening or at bedtime for three months. BP was measured by ambulatory monitoring for 48 consecutive hours before and after treatment. The 24 h BP reduction was similar for both treatment times. Administration of olmesartan at bedtime, however, was significantly more efficient than morning administration in reducing the nocturnal BP mean. The sleep-time relative BP decline was slightly reduced with olmesartan ingestion upon awakening but significantly increased with ingestion at bedtime, thus reducing the prevalence of non-dipping from baseline by 48%. Olmesartan administration at bedtime, as opposed to in the morning, improved the awake/asleep BP ratio toward a greater dipper pattern without loss of 24 h efficacy. Nocturnal BP regulation was significantly better achieved with bedtime as compared to morning dosing of olmesartan. These effects are comparable to those previously reported for valsartan and telmisartan, thus suggesting that they may be class-related features of ARB medications in spite of differences in their half-life kinetics. These administration-time-dependent effects should be taken into account when prescribing ARB medications for treatment of essential hypertension.

Determinants of inappropriate circadian blood pressure variability in children with essential hypertension

BACKGROUND

Inappropriate daily profile of blood pressure deteriorates the clinical outcome of hypertension and increases distant cardiovascular risk. The problem is important, especially in children and adolescents in whom early intervention helps to prevent complications of hypertension such as left ventricular hypertrophy and hypertensive retinopathy.

OBJECTIVES

To assess circadian blood pressure profile and basic determinants of inappropriate daily blood pressure variability in hypertensive children.

METHODS

The project was conducted retrospectively in 106 children six to 18 years of age (mean [+/- SD] 14.9+/-2.5 years) with essential hypertension and no use of antihypertensive drugs. The study group included 43 children with inappropriate daily blood pressure variability ('nondippers') and 63 controls with appropriate daily blood pressure variability ('dippers').

RESULTS

Nondippers, compared with dippers, had higher systolic and diastolic blood pressure at night (systolic, 123.9+/-10.3 mmHg versus 113.9+/-8.2 mmHg; diastolic, 65.1+/-7.6 mmHg versus 59.5+/-6.5 mmHg; P<0.0001), and higher blood pressure load at night (systolic, 61.9% versus 27.6%; diastolic, 20.0% versus 9.6%; P<0.0001). Male sex increased the risk for nondipping by 2.5 times (logistic OR=2.45; 95% CI 0.87 to 6.87). However, the increase was statistically nonsignificant (P=0.08). No differences were observed between dippers and nondippers in terms of anthropometric profile, family history of hypertension, morphological and biochemical blood parameters, and birth weight.

CONCLUSIONS

Among hypertensive children, nondippers have a more severe degree of hypertension. Male sex increases the risk of nondipping. To assess determinants of nondipping more precisely, further clinical investigations are needed.

Dietary intake, physical activity and nutritional status in adults: the French nutrition and health survey (ENNS, 2006-2007)

The French National Programme on Nutrition and Health (Programme national nutrition santé (PNNS)), the aim of which is to reduce nutrition-related chronic diseases, necessitates monitoring of nutritional characteristics. Our objective was to describe dietary intake, physical activity and nutritional status in a national sample of adults, especially according to current French recommendations. The study is based on a cross-sectional population-based survey using a multistage sampling design (Etude nationale nutrition santé (ENNS)). Between February 2006 and March 2007, 3115 18-74-year-old adults were included (participation rate 59.7 %). Energy, macronutrient and food consumption were estimated through three randomly distributed 24 h recalls, and compared to PNNS recommendations; physical activity was described using International Physical Activity Questionnaire guidelines; anthropometry, blood pressure and biochemical measurements were assessed according to national and international references. When compared to current recommendations, intake of carbohydrates (>50 % energy intake without alcohol: 26.4 %), SFA ( < 35 % total lipids: 18.5 %) and total fibre (>25 g/d: 13.7 %) was frequently unsatisfactory. While overall consumption of 'meat, seafood and eggs' was satisfactory, that of fruits and vegetables ( > or = 400 g/d: 43.8 %) and seafood (two or more servings per week: 29.9 %) was frequently too low. The physical activity level was satisfactory at 63.2 %. Overweight was observed in 49.3 % of adults, while 30.9 % were hypertensive and 44.1 % had dyslipidaemia. Vitamin and iron-poor status was found to affect less than 10 % of the population. Based on the ENNS survey, overall nutrition remains a problem in France. Comparison of these data with those of other countries could contribute to a better understanding of variations in nutrition-related diseases.

In-use comparison of blood pressure measurements from an automated blood pressure instrument with those from a mercury sphygmomanometer

In addition to its ease of use and degree of independence from the subjectivity inherent in measurements made with the mercury sphygmomanometer (HgS), automated blood pressure measurement instruments (ABPMI) obviate the use of mercury-containing instrumentation and the attendant environmental issues. Thus, they have been widely used in healthcare facilities worldwide. Most evaluations of ABPMI have focused on their compliance with established international protocols, and there has been a paucity of studies examining their performance in actual use in healthcare facilities. The purpose of this study was to evaluate the ABPMI used in our institution--a large, urban, tertiary-care teaching hospital in the northeastern United States--under routine conditions. This device, the Dinamap ProCare 400 Monitor, was compared to HgS (considered the "gold standard" for non-invasive blood pressure measurement) with respect to key analytical variables, i.e., precision of measurements and correlation within a large (n=300) sample of patients. Several sources of observer bias with HgS were detected. Precision varied among parameter (systolic blood pressure [SBP]; diastolic blood pressure [DBP]; and mean arterial pressure [MAP]) and level (normotensive, moderately hypertensive, and severely hypertensive). Correlation and regression suggested a strong association between the methods and Bland-Altman analysis indicated an acceptably small systematic error (bias) but greater random error than that demonstrated by previous evaluations with international test protocols. We recommend that healthcare facilities evaluate ABPMI under actual conditions and that formal protocols be established for these evaluations under routine conditions of patient care.

Metabolic syndrome and risk of cancer mortality in men

BACKGROUND

Metabolic syndrome (MetS) has been linked with an increased risk of developing cancer; however, the association between MetS and cancer mortality remains less clear. Little research has focused on pre-cancer risk factors that may affect the outcome of treatment. The purpose of this study was to examine the association between MetS and all-cancer mortality in men.

METHODS

The participants included 33,230 men aged 20-88 years who were enrolled in the Aerobics Centre Longitudinal Study and who were free of known cancer at the baseline.

RESULTS

At baseline 28% of all the participants had MetS. During an average of 14 years follow-up, there were a total of 685 deaths due to cancer. MetS at baseline was associated with a 56% greater age-adjusted risk in cancer mortality.

CONCLUSION

These data show that MetS is associated with an increased risk of all-cause cancer mortality in men. Based on these findings, it is evident that successful interventions should be identified to attenuate the negative effects of MetS.

Depression is associated with decreased blood pressure, but antidepressant use increases the risk for hypertension

The present study compared blood pressure levels between subjects with clinical anxiety and depressive disorders with healthy controls. Cross-sectional data were obtained in a large cohort study, the Netherlands Study of Depression and Anxiety (N=2981). Participants were classified as controls (N=590) or currently or remittedly depressed or anxious subjects (N=2028), of which 1384 were not and 644 were using antidepressants. Regression analyses calculated the contributions of anxiety and depressive disorders and antidepressant use to diastolic and systolic blood pressures, after controlling for multiple covariates. Heart rate and heart rate variability measures were subsequently added to test whether effects of anxiety/depression or medication were mediated by vagal control over the heart. Higher mean diastolic blood pressure was found among the current anxious subjects (beta=0.932; P=0.03), although anxiety was not significantly related to hypertension risk. Remitted and current depressed subjects had a lower mean systolic blood pressure (beta=-1.74, P=0.04 and beta=-2.35, P=0.004, respectively) and were significantly less likely to have isolated systolic hypertension than controls. Users of tricyclic antidepressants had higher mean systolic and diastolic blood pressures and were more likely to have hypertension stage 1 (odds ratio: 1.90; 95% CI: 0.94 to 3.84; P=0.07) and stage 2 (odds ratio: 3.19; 95% CI: 1.35 to 7.59; P=0.008). Users of noradrenergic and serotonergic working antidepressants were more likely to have hypertension stage 1. This study shows that depressive disorder is associated with low systolic blood pressure and less hypertension, whereas the use of certain antidepressants is associated with both high diastolic and systolic blood pressures and hypertension.

Impact of patient-general practitioner short-messages-based interaction on the control of hypertension in a follow-up service for low-to-medium risk hypertensive patients: a randomized controlled trial

The evaluation in real-life settings of services for the follow-up and control of hypertensive patients is a complex intervention, which still needs analysis of the roles, tasks, and resources involved in the basic items: patient, healthcare professional, and the interaction between the two. To evaluate the impact of patient-general practitioner (GP) short-messages-based interaction, isolated from other items, on the degree of hypertension control in the follow-up of medium-to-low-risk patients in primary care, a randomized controlled trial has been performed: 38 GPs enrolled 285 hypertensive patients who recorded the results of self-blood-pressure (BP) monitoring, heart rate, and body weight, and completed an optional questionnaire in an identical manner over a six-month period. The telemedicine group (TmG) sent the data to a telemedicine-based system that enabled patient-GP interaction; the control group (CG) recorded the data on paper and could only deliver it to their GP personally in the routine visits. In the TmG, the results were better, but not significantly so, for: 1) degree of hypertension control, in terms of the percentage of uncontrolled hypertensives at the final visit (TmG versus CG: 31.7% versus 35.6%; p = 0.47); 2) reduction in hypertension during follow-up, comparing measurements (performed by a professional) at the initial and final visits of systolic BP (15.5 versus 11.9; p = 0.13) and diastolic BP (9.6 versus 4.4; p = 0.40); and 3) adherence to the protocol within compliance levels of interest in a real-life follow-up service: >>50% (84.8% versus 73.3%) and >>25% (92.4.8% versus 75.4%) ( p = 0.053). Other factors such as average values of self-measured systolic BP, diastolic BP and heart rate, acceptability of the protocol, and median number of consultations and hospital admissions were similar in both groups. Outcomes show that, taken alone, the patient-GP short-messages-based interaction has very little impact on the degree of hypertension control in patients with this profile. In complex interventions, to discriminate the impact of each of its components in isolation will enable us to design an efficient follow-up service, little demanding in terms of healthcare professional dedication, and optimized in other basic aspects.

Purification and mechanism of action of "cortexin," a novel antihypertensive protein hormone from kidney and its role in essential hypertension in men

Because kidney tissue damage is associated with both hypertension and impaired nitric oxide (NO) production, we investigated the possibility whether the kidney tissue contains any activator of endothelial NO synthase (eNOS) that could be important in essential hypertension. An activator protein of M(r) 43000 Da for eNOS from the goat kidney cortex homogenate was purified to homogeneity by chromatographic techniques. This activator trivially, called "cortexin," was determined by enzyme-linked immunosorbent assay using anticortexin antibody. NO was determined by the formation of methemoglobin. Injection of 0.5 nmol cortexin/kg body weight to rabbit pretreated with l-epinephrine that increased the systolic and diastolic pressures to 195 +/- 3.40 mm Hg and 98.14 +/- 6.64 mm Hg, respectively, reduced and kept the elevated pressures at normal ranges of 133.57 +/- 12.14 (systolic) and 51.03 +/- 3.21 (diastolic) for 45 hours with simultaneous increase of plasma NO level. The inhibition of cortexin-induced NO synthesis nullified the antihypertensive effect of cortexin. The plasma cortexin level in newly diagnosed persons with essential hypertension was 0 pmol/mL (median), which contrasted with 218.94 pmol cortexin/mL (median), in normotensive persons (P < .0005; n = 25). We concluded that the impaired production of cortexin in the cortex of kidney might lead to essential hypertension.

Efficacy and safety of the single pill combination of amlodipine 10 mg plus valsartan 160 mg in hypertensive patients not controlled by amlodipine 10 mg plus olmesartan 20 mg in free combination

BACKGROUND AND OBJECTIVE

For patients with moderate hypertension (grade 2, defined as systolic blood pressure [SBP] 160-179 mmHg and/or diastolic blood pressure [DBP] 100-109 mmHg), current guidelines recommend initial combination therapy and rapid dose-adjustment to achieve blood pressure goal. In this study we investigated the efficacy and tolerability of the single pill combination of amlodipine 10 mg plus valsartan 160 mg (A 10 + Val 160) in patients not controlled by the free combination of amlodipine 10 mg plus olmesartan 20 mg (A 10 + O 20).

METHODS

In this prospective, open-label, non-randomized trial, 257 patients with mean sitting DBP of 100-109 mmHg at trough entered a 4 week treatment phase with A 10 + O 20 in free combination once daily. Patients in whom DBP remained uncontrolled were switched in a second 4 week treatment phase to A 10 + Val 160. The primary efficacy variable was the reduction in DBP at week 8 compared to week 4 in the intent-to-treat population.

RESULTS

In the total cohort, baseline SBP/DBP of 164.2 +/- 9.8/103.6 +/- 2.1 mmHg decreased by 19.2 +/- 12.4/14.1 +/- 7.4 mmHg at week 4. In patients who did not achieve BP control (n = 175), subsequent treatment with A 10 + Val 160 for 4 weeks reduced SBP from 149.6 +/- 11.1 at week 4 by 7.9 mmHg at week 8 (95% CI: 6.1-9.6, p < 0.0001) and DBP from 93.4 +/- 3.9 mmHg by 9.1 mmHg (95% confidence interval: 8.1-10.2, p < 0.0001). The combination of A 10 + Val 160 was well tolerated, and the observed adverse events (15.3% of patients in phase 2) were consistent with the known drug profiles.

CONCLUSIONS

In a study designed to reflect typical clinical practice, in patients not controlled by the free combination of A 10 + O 20, the single pill combination of A 10 + Val 160 produced a statistically and clinically significant additional BP reduction and was well tolerated. Potential limitations of the design (open-label, non-controlled design, short term treatment) have to be taken into account.

The association of red blood cell counts with endothelin-1 in African and Caucasian women

The literature shows an increase in endothelin-1 with increased levels of erythrocytes. There are also indications that inflammation and elevated endothelin-1 levels interact with erythropoiesis. In this study, the association of erythrocytes and endothelin-1 in women of different ethnicities was investigated. Blood pressure, vascular resistance, and C-reactive protein (P = 0.09) were significantly higher in the African women (n = 102) compared to the Caucasian women (n = 115), while arterial compliance was significantly lower in the African women with no significant differences for endothelin-1. In single, partial, and multiple regression analyses, there was a significant positive correlation between the red blood cell count and log endothelin-1 in the Caucasians while in the Africans there was a weak negative correlation. This is an indication that endothelin-1 might interfere with erythrocyte production in Africans with higher levels of inflammation.

Reduction in adverse symptoms as blood pressure becomes controlled

STUDY OBJECTIVES

To evaluate trends in adverse symptoms as blood pressure becomes controlled, and to determine if these symptoms are influenced by social support and self-efficacy.

DESIGN

Secondary analysis from a randomized controlled study of physician-pharmacist collaboration to improve blood pressure control.

SETTING

Five university-affiliated primary care clinics.

PATIENTS

A total of 179 patients (aged 21-85 yrs) with uncontrolled primary hypertension who were taking no antihypertensive drugs or up to three antihypertensive drugs at baseline were randomized to the intervention group, in which pharmacists were involved in their care, or to the control group, who received usual care from their physicians. Of these patients, 160 completed the study: 92 were in the intervention group, and 68 were in the control group.

INTERVENTION

In both groups, patient-reported symptoms suggestive of adverse drug reactions (ADRs) were recorded at each study visit with use of a structured ADR questionnaire. Social support and self-efficacy questionnaires were also administered at each study visit.

MEASUREMENTS AND MAIN RESULTS

Patients' ADR scores decreased significantly from baseline to the end of the study in both the control (from a mean of 26.5 to 18.4) and intervention (from 29.9 to 22.7) groups (p<0.0001 for both comparisons), although no significant difference was noted between groups. The mean +/- SD number of antihypertensive drugs/patient increased in both the intervention (from 1.5 +/- 1.0 to 2.4 +/- 0.9 drugs) and control (from 1.4 +/- 1.0 to 1.9 +/- 1.0 drugs) groups; however, the difference between groups was significant only at the end of the study. Additional analyses were performed on self-efficacy and social support to determine a potential reason for the reduction in ADR scores despite an increase in drug use. Improvements in self-efficacy and social support scores were significantly and independently associated with improvement in ADR score (p<0.05).

CONCLUSIONS

In both groups, ADR scores improved despite an increase in antihypertensive drug use. Improvements in social support and, to a lesser extent, self-efficacy were associated with improvements in ADR scores. Patients should not expect an increase in distressful symptoms as their blood pressure becomes controlled with antihypertensive drugs, especially when adequate social support is available.

Disparate estimates of hypertension control from ambulatory and clinic blood pressure measurements in hypertensive kidney disease

Ambulatory blood pressure (ABP) monitoring provides unique information about day-night patterns of blood pressure (BP). The objectives of this article were to describe ABP patterns in African Americans with hypertensive kidney disease, to examine the joint distribution of clinic BP and ABP, and to determine associations of hypertensive target organ damage with clinic BP and ABP. This study is a cross-sectional analysis of baseline data from the African American Study of Kidney Disease Cohort Study. Masked hypertension was defined by elevated daytime (>or= 135/85 mm Hg) or elevated nighttime (>or= 120/70 mm Hg) ABP in those with controlled clinic BP (<140/90 mm Hg); nondipping was defined by a Collapse

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MESH Headings

• Adolescent
• Adult
• Black or African American/ethnology
• Aged
• Ambulatory Care Facilities
• Blood Pressure/physiology
• Blood Pressure Monitoring, Ambulatory
• Circadian Rhythm/physiology
• Cohort Studies
• Cross-Sectional Studies
• Female
• Humans
• Hypertension, Renal/ethnology
• Hypertension, Renal/physiopathology
• Kidney/physiopathology
• Kidney Diseases/ethnology
• Kidney Diseases/physiopathology
• Male
• Middle Aged
• Prevalence
• Reproducibility of Results
• Severity of Illness Index
• Young Adult

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Grants

• P20-RR11145 NCRR NIH HHS
• M01 RR00827 NCRR NIH HHS
• 5M01 RR-00071 NCRR NIH HHS
• 2P20 RR11104 NCRR NIH HHS

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Affiliation(s)

Velvie Pogue Division of Nephrology, Department of Medicine, Columbia University Medical Center, Harlem Hospital Center, New York, NY 10037, USA.
Mahboob Rahman
Michael Lipkowitz
Robert Toto
Edgar Miller
Marquetta Faulkner
Stephen Rostand
Leena Hiremath
Mohammed Sika
Cynthia Kendrick
Bo Hu
Tom Greene
Lawrence Appel
Robert A Phillips

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Comparison of noninvasive blood pressure measurements in patients with atrial fibrillation

BACKGROUND AND RESEARCH OBJECTIVE

Limited research is available on the accuracy of automatic blood pressure (BP) measurement devices in patients with irregular rhythms. The purpose of this study was to examine the agreement between different methods for noninvasive BP measurement in patients with atrial fibrillation.

SUBJECTS AND METHODS

In a convenience sample of hospitalized patients with atrial fibrillation, a method-comparison study design was used to examine the agreement between 2 noninvasive devices for BP measurement (manual, automated). Blood pressure was obtained sequentially, with each device following manufacturer's directions and American Heart Association guidelines for BP determination and with BP order determined by random assignment. Heart rate and rhythm were determined from a continuous electrocardiographic monitoring. Heart rate was also recorded from the automated BP device. Differences and limits of agreement between the automated and reference standard (manual) BP devices were calculated and graphed according to the Bland-Altman method. Student t test was used to test differences in BP obtained with the 2 devices, as well as heart rate differences between the electrocardiographic monitor and automated BP device. The level of significance for all tests was set at 0.05.

RESULTS

53 participants were observed. Bland-Altman analysis found a bias plus/minus precision of -0.91 +/- 11.4 mm Hg for systolic BP and 3.3 +/- 6.9 mm Hg for diastolic BP. A significant difference was found for the diastolic BP obtained with the automated device and with that of the manual device (t52 = 3.51, P = .0009) and for heart rate differences between the automated BP device and the cardiac monitor (t52 = 2.4, P = .0217).

CONCLUSION

This study confirms that in the presence of irregular cardiac rhythms, diastolic BP and heart rate cannot reliably be measured with an automated BP device.

Gender differences in office and ambulatory control of hypertension

BACKGROUND

Gender differences in hypertension control have not been explored fully.

METHODS

We studied 15,212 white men and 13,936 white women with treated hypertension who were drawn from the Spanish Ambulatory Blood Pressure Registry. For each participant, we obtained office blood pressure (BP) (average of 2 readings) and 24-hour ambulatory BP (average of measurements performed every 20 minutes during day and night).

RESULTS

Only 16.4% of women and 14.7% of men had both office (<140/90 mm Hg) and ambulatory (<130/80 mm Hg) BP controlled (P<.001). Women had a lower frequency of masked hypertension (office BP<140/90 mm Hg and ambulatory BP> or =130/80 mm Hg) than men (5.9% vs 7.9%, P<.001). Women had a higher frequency of isolated office hypertension (office BP> or =140/90 mm Hg and ambulatory BP<130/80 mm Hg) (32.5% vs 24.2%, P<.001). Although office BP control (office BP<140/90 mm Hg, regardless of ambulatory values) was similar in women and men (22.3% vs 22.6%, P=.542), ambulatory BP control (ambulatory BP<130/80 mm Hg, regardless of office values) was higher in women than in men (48.9% vs 38.9%, P<.001). After adjustment for age, number of antihypertensive drugs, hypertension duration, and risk factors, gender differences in BP control remained practically unchanged.

CONCLUSION

Ambulatory BP control was higher in women than in men. This may be due to the higher frequency of isolated office hypertension in women, and it is not explained by gender differences in other important clinical characteristics.

Prediction of pre-eclampsia by a combination of maternal history, uterine artery Doppler and mean arterial pressure

OBJECTIVES

To determine the value of combined screening for pre-eclampsia by maternal history, and mid-trimester uterine artery (UtA) Doppler imaging and maternal blood pressure.

METHODS

In 3529 singleton pregnancies attending for routine care at 22-24 weeks' gestation we recorded maternal variables, and made UtA Doppler and mean arterial pressure (MAP) measurements. Multiple regression analysis was used to determine the significant predictors of pre-eclampsia, gestational hypertension and small-for-gestational age (SGA) among maternal characteristics, UtA pulsatility index (PI) and MAP.

RESULTS

Complete pregnancy outcomes were available in 3359/3529 (95.2%) cases. Pre-eclampsia developed in 101 (3.0%) pregnancies, including 23 (0.7%) in which delivery was before 34 weeks (early pre-eclampsia) and 78 (2.3%) with delivery at 34 weeks or more (late pre-eclampsia); 74 (2.2%) developed gestational hypertension, 366 (10.9%) delivered SGA newborns with no hypertensive disorders, and 2806 (83.8%) were unaffected by pre-eclampsia, gestational hypertension or SGA. Multiple regression analysis demonstrated that maternal characteristics, UtA-PI and MAP provided a significant independent contribution in the prediction of pre-eclampsia, gestational hypertension and SGA. For a false-positive rate of 10%, the estimated detection rates of early and late pre-eclampsia were 100% and 56.4%, respectively.

CONCLUSIONS

The combination of maternal demographic characteristics, and UtA Doppler and maternal blood pressure measurements is an effective screening tool for the prediction of pre-eclampsia.

Aliskiren and valsartan in stage 2 hypertension: subgroup analysis of a randomized, double-blind study

INTRODUCTION

Patients with stage 2 hypertension require large absolute reductions in blood pressure (BP) to achieve recommended BP goals. Combination therapy with the direct renin inhibitor, aliskiren, and the angiotensin receptor blocker, valsartan, has been shown to produce greater BP reductions than either agent alone in a double-blind study in 1797 hypertensive patients.

METHODS

This post-hoc analysis evaluated the BP-lowering efficacy of aliskiren in combination with valsartan in a subset of patients (n=581) with stage 2 hypertension (baseline mean sitting systolic BP [msSBP] > or =160 mmHg). Patients were randomized to receive aliskiren/valsartan 150/160 mg, aliskiren 150 mg, valsartan 160 mg, or placebo once daily for 4 weeks followed by 4 weeks at double the initial dose. Mean changes from baseline in msSBP and mean sitting diastolic BP were assessed at week-8 endpoint (intent-to-treat population).

RESULTS

Aliskiren/valsartan 300/320 mg reduced BP from baseline by 22.5/11.4 mmHg at week-8 endpoint. BP reductions with combination therapy were significantly greater than with aliskiren 300 mg (17.3/8.9 mmHg, P<0.05), valsartan 320 mg (15.5/8.3 mmHg, P<0.01), or with placebo (7.9/3.7 mmHg, P<0.0001). BP control rates (<140/90 mmHg) were also significantly higher (P<0.05) with aliskiren/valsartan 300/320 mg (29.8%) compared with either aliskiren 300 mg (19.0%) or valsartan 320 mg (13.8%) monotherapy, or placebo (8.9%). All treatments were generally well tolerated.

CONCLUSION

Combination therapy with aliskiren and valsartan provided significantly greater BP reductions over aliskiren or valsartan monotherapy and is an appropriate option for management of BP in patients with stage 2 hypertension.

Usefulness of self-reported periodontal disease to identify individuals with elevated inflammatory markers at risk of cardiovascular disease

Periodontal disease has been associated with cardiovascular disease (CVD), and inflammation may represent a common pathophysiology. Oral health screening in the context of CVD risk assessment represents a potential opportunity to identify individuals at risk for CVD. The purposes of this study were to determine if self-reported oral health status is independently associated with inflammatory markers and if oral health assessment as part of CVD risk screening can identify at-risk individuals without traditional CVD risk factors. A baseline analysis was conducted among participants in the National Heart, Lung, and Blood Institute's Family Intervention Trial for Heart Health (FIT Heart; n = 421, mean age 48 +/- 13.5 years, 36% nonwhite) without CVD or diabetes who underwent standardized assessment of oral health, lifestyle, CVD risk factors, and the inflammatory markers high-sensitivity C-reactive protein and lipoprotein-associated phospholipase A(2). Statistical associations between oral health, risk factors, and inflammatory markers were assessed, and logistic regression was used to adjust for effects of lifestyle and potential confounders. Periodontal disease was independently associated with being in the top quartile of lipoprotein-associated phospholipase A(2) compared with the lower 3 quartiles (odds ratio 1.9, 95% confidence interval 1.1 to 3.2) after adjustment for lifestyle and risk factors. Histories of periodontal disease were reported by 24% of non-overweight, non-hypertensive, non-hypercholesterolemic participants, and of these participants, 37% had elevated high-sensitivity C-reactive protein (> or =3 mg/L) or lipoprotein-associated phospholipase A(2) (> or =215 ng/ml) levels. In conclusion, self-reported periodontal disease is independently associated with inflammation and common in individuals without traditional CVD risk factors.

Measuring blood pressure knowledge and self-care behaviors of African Americans

The purpose of this study was to develop and conduct preliminary psychometric assessment of instruments measuring knowledge and self-care practices regarding behaviors needed for blood pressure (BP) control among African Americans. Items were empirically derived and scored on a 7-point, bipolar scale. The instruments were evaluated in a sample of 306 community-dwelling African Americans. Results revealed acceptable reliability and validity of the BP Knowledge Scale. Results for the BP Self-Care Scale were mixed. A structural equation model of these scales, recorded BP, and covariates fit well. There was an unexpected positive correlation between self-care and BP suggesting a potential bi-directional relationship. The scales demonstrated acceptable psychometric properties and, with minor revisions, may have clinical utility as measures of BP knowledge and self-care.

Additive effects of obstructive sleep apnea and hypertension on early markers of carotid atherosclerosis

Obstructive sleep apnea (OSA) has emerged as an independent risk factor for atherosclerosis. However, OSA is frequently associated with several risk factors for atherosclerosis, including hypertension (HTN). The impact of OSA and HTN alone compared with the association of both conditions on carotid atherosclerosis is not understood. We studied 94 middle-aged participants free of smoking and diabetes mellitus who were divided into 4 groups: controls (n=22), OSA (n=25), HTN (n=20), and OSA+HTN (n=27). All of the participants underwent polysomnography and carotid measurements of intima-media thickness, diameter, and distensibility with an echo-tracking device. Compared with controls, intima-media thickness and carotid diameter were similarly higher in OSA (713+/-117 and 7117+/-805 microm), and HTN groups (713+/-182 and 7191+/-818 microm), with a further significant increase in OSA+HTN patients (837+/-181 and 7927+/-821 microm, respectively; P<0.01). Carotid distensibility was significantly lower in HTN (P<0.05) and OSA+HTN subjects (P<0.001) compared with controls. In the OSA+HTN group, carotid distensibility was significantly lower than in the OSA group and controls (P<0.05 for each comparison). Multivariate analysis showed that intima-media thickness was positively related to systolic blood pressure and apnea-hypopnea index. Apnea-hypopnea index was the only factor related to carotid diameter. Age and systolic blood pressure were independently related to carotid distensibility. In conclusion, the association of OSA and HTN has additive effects on markers of carotid atherosclerosis. Because early markers of carotid atherosclerosis predict future cardiovascular events, including not only stroke but also myocardial infarction, these findings may help to explain the increased risk of cardiovascular disease in patients with OSA.

A novel family-based intervention trial to improve heart health: FIT Heart: results of a randomized controlled trial

BACKGROUND

Family members of patients with cardiovascular disease (CVD) may be at increased risk due to shared genes and lifestyle. Hospitalization of a family member with CVD may represent a "motivational moment" to take preventive action.

METHODS AND RESULTS

A randomized, controlled clinical trial was conducted in healthy adult family members (N=501; 66% female; 36% nonwhite; mean age, 48 years) of patients hospitalized with CVD to evaluate a special intervention (SI) with personalized risk factor screening, therapeutic lifestyle-change counseling, and progress reports to physicians versus a control intervention (CIN) on the primary outcome, mean percent change in low-density lipoprotein cholesterol (LDL-C), and other risk factors. Validated dietary assessments and standardized risk factors were obtained at baseline and 1 year (94% follow-up). At baseline, for 93% of subjects, saturated fat comprised > or = 7% of total caloric intake, and 79% had nonoptimal LDL-C levels (of which 50% were unaware). There was no difference in the SI versus the CIN with respect to the mean percent change in LDL-C (-1% versus -2%, respectively; P=0.64), owing to a similar significant reduction in LDL-C in both groups (-4.4 mg/dL and -4.5 mg/dL, respectively). Diet score significantly improved in the SI versus the CIN (P=0.04). High-density lipoprotein cholesterol declined significantly in the CIN but not in the SI (-3.2% [95% CI, -5.1 to -1.3] versus +0.3% [95% CI, -1.7 to +2.4]; P=0.01). At 1 year, SI subjects were more likely than controls to exercise >3 days per week (P=0.04).

CONCLUSIONS

The SI was not more effective than the CIN in reducing the primary end point, LDL-C. The screening process identified many family members of hospitalized patients with CVD who were unaware of their risk factors, and further work is needed to develop and test interventions to reduce their CVD risk.

Cardiorespiratory Fitness as a Predictor of Fatal and Nonfatal Stroke in Asymptomatic Women and Men

Background and Purpose— Prospective data on the association between cardiorespiratory fitness (CRF) and stroke are largely limited to studies in men or do not separately examine risks for fatal and nonfatal stroke. This study examined the association between CRF and fatal and nonfatal stroke in a large cohort of asymptomatic women and men.

Methods— A total of 46 405 men and 15 282 women without known myocardial infarction or stroke at baseline completed a maximal treadmill exercise test between 1970 and 2001. CRF was grouped as quartiles of the sex-specific distribution of maximal metabolic equivalents achieved. Mortality follow-up was through December 31, 2003, using the National Death Index. Nonfatal stroke, defined as physician-diagnosed stroke, was ascertained from surveys during 1982 to 2004. Cox regression models quantified the pattern and magnitude of association between CRF and stroke.

Results— There were 692 strokes during 813 944 man-years of exposure and 171 strokes during 248 902 woman-years of exposure. Significant inverse associations between CRF and age-adjusted fatal, nonfatal, and total stroke rates were observed for women and men ( P trend ≤0.05 each). After adjusting for several cardiovascular disease risk factors, the inverse association between CRF and each stroke outcome remained significant ( P trend <0.05 each) in men. In women, the multivariable-adjusted relationship between CRF and nonfatal and total stroke remained significant ( P trend ≤0.01 each), but not between CRF and fatal stroke ( P trend =0.18). A CRF threshold of 7 to 8 maximal metabolic equivalents was associated with a substantially reduced rate of total stroke in both men and women.

Conclusions— These findings suggest that CRF is an independent determinant of stroke incidence in initially asymptomatic and cardiovascular disease-free adults, and the strength and pattern of the association is similar for men and women.

Long-term outcome after exercising throughout pregnancy: fitness and cardiovascular risk

OBJECTIVE

The objective of the study was to test the null hypothesis that continuing vigorous weight-bearing exercise throughout pregnancy has no discernible long-term effect on indices of fitness and/or cardiovascular risk.

STUDY DESIGN

This was a follow-up observational study of the fitness and cardiovascular risk profile of 39 women conducted on the General Clinical Research Center at the University of Vermont. Data were analyzed using the paired Student t test, analysis of variance, and linear regression.

RESULTS

Women who voluntarily maintain their exercise regimen during pregnancy continue to exercise over time at a higher level than those who stop. Over time they also gain less weight (3.4 vs 9.9 kg), deposit less fat (2.2 vs 6.7 kg), have increased fitness, and have a lower cardiovascular risk profile than those who stop.

CONCLUSION

Women who continue weight-bearing exercise during pregnancy maintain their long-term fitness and have a low cardiovascular risk profile in the perimenopausal period.

Tool to assess likelihood of fasting glucose impairment (TAG-IT)

PURPOSE

Fifty-four million people in the United States have impaired fasting glucose (IFG); if it is identified, they may benefit from prevention strategies that can minimize progression to diabetes, morbidity, and mortality. We created a tool to identify those likely to have undetected hyperglycemia.

METHODS

We undertook a cross-sectional analysis of existing data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 of 4,045 US adults aged 20 to 64 years who did not have a diagnosis of diabetes who had a measured fasting plasma glucose. Using characteristics that are self-reported or measured without laboratory data, we developed a logistic regression model predicting IFG and undiagnosed diabetes. Based on this model, we created TAG-IT (the Tool to Assess likelihood of fasting Glucose ImpairmenT), validated it using NHANES III, examined race and ethnicity subsets, and compared it with body mass index (BMI) alone.

RESULTS

Predictors in the final tool were age, sex, BMI, family history of diabetes, resting heart rate, and history of hypertension (or measured high blood pressure), which yielded an area under the curve (AUC) of 0.740, significantly better than BMI alone (AUC = 0.644).

CONCLUSIONS

The TAG-IT efficiently identifies those most likely to have abnormal fasting glucose and can be used as a decision aid for screening in clinical and population settings, or as a prescreening tool to help identify potential participants for research. The TAG-IT represents an improvement over BMI alone or a list of risk factors in both its utility in younger adult populations and its ability to provide clinicians and researchers with a strategy to assess the risks of combinations of factors.

Inter-arm blood pressure differences in pregnant women

OBJECTIVE

To determine the prevalence of blood pressure inter-arm difference (IAD) in early pregnancy and to investigate its possible association with maternal characteristics.

DESIGN

A cross-sectional observational study.

SETTING

Routine antenatal visit in a university hospital.

POPULATION

A total of 5435 pregnant women at 11-14 weeks of gestation.

METHODS

Blood pressure was taken from both arms simultaneously with a validated automated device.

MAIN OUTCOME MEASURES

The presence of inter-arm blood pressure difference of 10 mmHg or more.

RESULTS

The IAD in systolic and diastolic blood pressure was 10 mmHg or more in 8.3 and 2.3% of the women, respectively. Systolic IAD was found to be significantly related to systolic blood pressure and pulse pressure, and diastolic IAD was found to be significantly related to maternal age, diastolic blood pressure and pulse pressure. The systolic and diastolic IAD were higher in the hypertensive group compared with the normotensive group and absolute IAD increased with increasing blood pressure. About 31.0 and 23.9% of cases of hypertension would have been underreported if the left arm and the right arm were used, respectively, in measuring the blood pressure.

CONCLUSIONS

There is a blood pressure IAD in a significant proportion of the pregnant population, and its prevalence increases with increasing blood pressure. By measuring blood pressure only on one arm, there is a one in three chance of underreporting hypertension. Therefore, it would be prudent that during the booking visit blood pressure should be taken in both arms and thus provide guidance for subsequent blood pressure measurements during the course of pregnancy.

Hypertensive crises

The key points of this article are: (1) A hypertensive crisis is present when markedly elevated blood pressure is accompanied by progressive or impending acute target organ damage. (2) Most instances of very elevated blood pressure encountered in the office setting will not be crises and will not require acute reduction of blood pressure. (3) Hypertensive crises are largely preventable and often result from inadequate management of hypertension or poor adherence to therapy. (4) Effective triage of patients into categories of severe hypertension, hypertensive urgency, and hypertensive emergency through an expeditious history, examination, and testing should guide therapy. (5) Hypertensive urgency is managed with oral medications and usually on an outpatient basis; a hypertensive emergency warrants intensive care unit admission and parenteral therapy. (6) Ensuring adequate follow-up after treatment of very elevated blood pressure is a critical step that is often mishandled.

Automated device that complies with current guidelines for office blood pressure measurement: design and pilot application study of the Microlife WatchBP Office device

OBJECTIVE

Current guidelines for office blood pressure (BP) measurement recommend mercury devices, both arms measurement in the initial assessment and at least duplicate measurements at follow-up visits. This study presents the design and a pilot application study of an automated device that fulfils American, European, and International guidelines for office BP measurement.

DESIGN AND FUNCTIONS

The Microlife WatchBP Office is a professional electronic mercury-free device with three function modes designed for: (a) initial assessment: triplicate automated simultaneous oscillometric both arms measurement at 60-s intervals and when there is a consistent interarm difference more than 20 mmHg systolic and/or more than 10 mmHg diastolic, the arm with the higher BP is indicated. (b) Follow-up assessment: triplicate automated oscillometric single arm measurements at 60-s intervals and their average is displayed. (c) Auscultatory measurement: by an observer using a stethoscope and a digital countdown BP display for patients with arrhythmias and other individuals in whom the oscillometric measurement is not accurate.

PILOT APPLICATION STUDY

The 'initial assessment' mode was applied by three physicians in 63 patients (189 readings). Average interarm systolic BP difference was 0.04+/-5.1 mmHg and diastolic 0.4+/-3.2 mmHg. A value more than 10 mmHg interarm difference in nine systolic BP readings (5%) and three (2%) diastolic. No patient had a consistent interarm difference more than 10 mmHg in all three or two of the three readings.

CONCLUSION

The Microlife WatchBP Office professional device fulfils current international requirements for office BP measurement and seems to overcome several limitations of this method when applied in clinical practice.

Physician adherence to blood pressure guidelines and its effect on seniors

STUDY OBJECTIVE

To compare physician adherence to guidelines from the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure for patients younger than 65 years of age with those aged 65 years and older, and to analyze whether factor groupings (subsets of criteria used to determine adherence) were predictive of blood pressure control.

DESIGN

Retrospective medical record review.

SETTING

Five university-affiliated family medicine and internal medicine outpatient clinics.

PATIENTS

One hundred seventy-nine patients (age range 21-85 yrs) with uncontrolled hypertension: 105 patients were younger than 65 years (nonsenior), and 74 patients were 65 years or older (senior).

MEASUREMENTS AND MAIN RESULTS

Data abstracted from each patient's medical record were used to evaluate adherence to 17 process-of-care criteria, identified to assess physician adherence to the guidelines. A computer algorithm generated scores for each criterion as well as an overall adherence score. The relationship between the adherence score and blood pressure control was then examined. Separate factor analyses were conducted to ascertain differences in the way that the criteria were grouped. Factor scores were calculated for each patient, and the scores were evaluated in the context of blood pressure control. Guideline adherence scores were significantly higher for nonsenior patients than for senior patients (59.3% vs 56.1%, p=0.024). Blood pressure control rate was also higher, although not significantly, in nonseniors versus seniors (68.6% vs 56.8%, p=0.063). No factors in the senior group were significantly associated with blood pressure control, but one was significantly correlated in the nonsenior group (p<0.0001). It included diuretic therapy, adjusting a drug when a patient's blood pressure was uncontrolled, documentation of uncontrolled blood pressure in the medical record at the visit, documentation of the correct blood pressure goal, documentation of cardiovascular risk factors, and measurement of urine albumin level.

CONCLUSION

Overall physician adherence to blood pressure guidelines was significantly higher for the nonsenior group than for the senior group. Similarly, control of blood pressure was better in the nonsenior group. However, no significant relationship between overall adherence scores and blood pressure control was found in either group. In nonseniors, one factor grouping was significantly correlated with blood pressure control. Future studies should evaluate the process-of-care criteria to determine if and how they are related to blood pressure control in senior patients.

Changes in home versus clinic blood pressure with antihypertensive treatments: a meta-analysis

Home blood pressure (HBP) monitoring is recommended for assessing the effects of antihypertensive treatment, but it is not clear how the treatment-induced changes in HBP compare with the changes in clinic blood pressure (CBP). We searched PubMed using the terms "home or self-measured blood pressure," and selected articles in which the changes in CBP and HBP (using the upper arm oscillometric method) induced by antihypertensive drugs were presented. We performed a systematic review of 30 articles published before March 2008 that included a total of 6794 subjects. As there was significant heterogeneity in most of the outcomes, a random effects model was used for the meta-analyses. The mean changes (+/-SE) in CBP and HBP (systolic/diastolic) were -15.2+/-0.03/-10.3+/-0.03 mm Hg and -12.2+/-0.04/-8.0+/-0.04 mm Hg respectively, although there were wide varieties of differences in the reduction between HBP and CBP. The reductions in CBP were correlated with those of HBP (systolic BP; r=0.66, B=0.48, diastolic BP; r=0.71, B=0.52, P<0.001). In 7 studies that also included 24-hour BP monitoring, the reduction of HBP was greater than that of 24-hour BP in systolic (HBP; -12.6+/-0.06 mm Hg, 24-hour BP; -11.9+/-0.04 mm Hg, P<0.001). In 5 studies that included daytime and nighttime systolic BP separately, HBP decreased 15% more than daytime ambulatory BP and 30% more than nighttime ambulatory BP. In conclusion, HBP falls approximately 20% less than CBP with antihypertensive treatments. Daytime systolic BP falls 15% less and nighttime systolic BP falls 30% less than home systolic BP.

Genetic variants in the alpha2C-adrenoceptor and G-protein contribute to ethnic differences in cardiovascular stress responses

OBJECTIVES

Cardiovascular responses to stressors are regulated by sympathetic activity, increased in black Americans, and associated with future cardiovascular morbidity. Our aim was to determine whether two functional variants in genes regulating sympathetic activity, a deletion in the alpha2C-adrenergic receptor (ADRA2C del322-325) and a G-protein beta3-subunit variant (GNB3 G825T), affect cardiovascular responses to physiologic stressors and contribute to their ethnic differences.

METHODS

We measured heart rate and blood pressure responses to a cold pressor test (CPT) in 79 healthy participants (40 blacks, 39 whites), aged 25.7+/-5.3 years, and determined genotypes for the ADRA2C and GNB3 variants. We examined the response variables (increase in heart rate and blood pressure) in multiple linear regression analyses adjusting first for baseline measures, ethnicity, and other covariates, and then additionally for genotypes.

RESULTS

Black participants had a greater heart rate response to CPT than whites [mean difference, 9.9 bpm; 95% confidence interval (CI), 4.1 to 15.6; P=0.001]. Both the ADRA2C del/del (15.8 bpm; 95% CI, 8.0-23.7; P<0.001) and GNB3 T/T genotypes (6.8 bpm; 95% CI, 0.9-12.7; P=0.026) were associated with greater heart rate response. After adjusting for genotypes, the ethnic difference was abrogated (1.3 bpm; 95% CI, -5.4-8.0; P=0.70), suggesting that the genetic variants contributed substantially to ethnic differences.

CONCLUSION

Variation in genes that regulate sympathetic activity affects hemodynamic stress responses and contributes to their ethnic differences. This study elucidates how genetic factors may in part explain ethnic differences in cardiovascular regulation.

Preventive health for women: screening and immunizations

Women's preventive health issues are frequently encountered in the outpatient setting. Many general internists feel uncomfortable meeting the needs of women due to a general lack of knowledge of women's health and inadequate training in the evaluation of female-specific care. In this article, the authors summarize evidence-based guidelines for preventive health and immunizations for women.