The bioelectrical impedance analysis (BIA) international database: aims, scope, and call for data

BACKGROUND

Bioelectrical impedance analysis (BIA) is a technique widely used for estimating body composition and health-related parameters. The technology is relatively simple, quick, and non-invasive, and is currently used globally in diverse settings, including private clinicians' offices, sports and health clubs, and hospitals, and across a spectrum of age, body weight, and disease states. BIA parameters can be used to estimate body composition (fat, fat-free mass, total-body water and its compartments). Moreover, raw measurements including resistance, reactance, phase angle, and impedance vector length can also be used to track health-related markers, including hydration and malnutrition, and disease-prognostic, athletic and general health status. Body composition shows profound variability in association with age, sex, race and ethnicity, geographic ancestry, lifestyle, and health status. To advance understanding of this variability, we propose to develop a large and diverse multi-country dataset of BIA raw measures and derived body components. The aim of this paper is to describe the 'BIA International Database' project and encourage researchers to join the consortium.

METHODS

The Exercise and Health Laboratory of the Faculty of Human Kinetics, University of Lisbon has agreed to host the database using an online portal. At present, the database contains 277,922 measures from individuals ranging from 11 months to 102 years, along with additional data on these participants.

CONCLUSION

The BIA International Database represents a key resource for research on body composition.

Can change in phase angle predict the risk of morbidity and mortality during an 18-year follow-up period? A cohort study among adults

Introduction

Phase angle (PhA, degrees), measured via bioimpedance (BIA, 50 kHz), is an index that has been used as an indicator of nutritional status and mortality in several clinical situations. This study aimed to determine the relationship between 6-year changes in PhA and total mortality as well as the risk of incident morbidity and mortality from cardiovascular disease (CVD) and coronary heart disease (CHD) during 18 years of follow-up among otherwise healthy adults.

Methods

A random subset (n = 1,987) of 35-65 years old men and women was examined at the baseline in 1987/1988 and 6 years later in 1993/1994. Measures included weight, height, and whole-body BIA, from which PhA was calculated. Information on lifestyle was obtained through a questionnaire. The associations between 6-year PhA changes (ΔPhA) and incident CVD and CHD were assessed by Cox proportional hazard models. The median value of ΔPhA was used as the reference value. The hazard ratio (HR) model and confidence intervals (CIs) of incident CVD and CHD were used according to the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles of ΔPhA.

Results

During 18 years of follow-up, 205 women and 289 men died. A higher risk of both total mortality and incident CVD was present below the 50th percentile (Δ = -0.85°). The highest risk was observed below the 5th percentile (ΔPhA = -2.60°) in relation to total mortality (HR: 1.55; 95% CI: 1.10-2.19) and incident CVD (HR: 1.52; 95% CI: 1.16-2.00).

Discussion

The larger the decrease in PhA, the higher the risk of early mortality and incident CVD over the subsequent 18 years. PhA is a reliable and easy measure that may help identify those apparently healthy individuals who may be at increased risk of future CVD or dying prematurely. More studies are needed to confirm our results before it can be definitively concluded that PhA changes can improve clinical risk prediction.

Can Phase Angle Be Associated With Muscle Strength in Healthy Male Army Cadets?

INTRODUCTION

Phase angle (PhA) determined by bioelectrical impedance (BIA) is related to body fluid balance and cell membrane integrity. Handgrip strength (HGS) is used to assess muscle strength and as an indicator of health. We aimed to determine the relationship between PhA and HGS in healthy young males and to verify whether this relationship is dependent on body components.

MATERIALS AND METHODS

Hundred and sixty-three healthy male army cadets (18.8 ± 0.6 years old) participated in the study. PhA was determined by BIA, HGS was assessed by a hydraulic dynamometer, and dual-energy X-ray absorptiometry determined: fat mass (FM), bone mineral content (BMC), and lean soft tissue (LST). Participants were divided according to the PhA tertile (first tertile: PhA < 7.14°, second tertile: 7.14° ≤ PhA < 7.83°, and third tertile: PhA ≥ 7.83°).

RESULTS

Youth from the first tertile of PhA had lower BMC (2.8 kg vs. 3.0 kg and vs. 3.1 kg) and LST (51.7 vs. 53.8 kg and vs. 57.6 kg) compared to youth from the second and third tertile of PhA (P < .001), respectively. Additionally, lower HGS (83.0 kg vs. 93.1 kg) was found in the first tertile compared to the third tertile of PhA (P < .001). PhA explained 3% of the HGS variation (R2 = 0.029), while LST and BMC explained 39% (R2 = 0.385) and 22% (R2 = 0.221), respectively. Furthermore, the correlation between PhA and HGS was dependent on LST (P = .567) and BMC (P = .182).

CONCLUSION

In this sample, PhA showed a small relationship with HGS, remaining dependent on BMC and LST values. These results reinforce the importance of maintaining a physically active lifestyle with great lean mass and muscle strength values.

The role of medications in successful aging

Successful aging includes good health and low levels of disability. To that end, primary prevention is far better than managing subsequent organ damage. When medication is needed to prevent or manage disease, the preferred choice should be associated with the greatest benefits and fewest adverse effects. Cardiovascular diseases are the leading cause of morbidity and mortality in postmenopausal women worldwide. Considering disease-adjusted life years, other leading causes are chronic obstructive pulmonary disease, diabetes mellitus, dementias, hearing loss, cancers of the breast, lung and bowel, osteoporosis, fractures and falls, depression, osteoarthritis, refractive errors of the eye and non-diabetic chronic kidney disease. This review explores the global prevalence of these diseases in women aged 50 years and older, and medications commonly used for them, and contrasts the effects of menopausal hormone therapy (MHT) with others. When initiated early, there is good evidence for MHT benefit in all-cause mortality and primary prevention of cardiovascular disease, diabetes and osteoporosis; fair evidence for benefit in dementias, depression and osteoarthritis; limited evidence for benefit in chronic obstructive pulmonary disease, hearing loss, non-diabetic chronic kidney disease and colorectal cancer; null effects on lung cancer and refractive errors; and varied effects on breast cancer and stroke. Relative benefits and adverse effects of other medications warrant consideration.

Phase angle measured by bioelectrical impedance analysis and the risk of cardiovascular disease among adult Danes

OBJECTIVE

This study aimed to examine associations between phase angle (PhA) and incident cardiovascular disease (CVD) morbidity and mortality in a healthy Danish subpopulation free of major chronic diseases.

METHODS

A random subset (n = 2601) of adult men and women born in 1922, 1932, 1942, and 1952 and examined in 1987 and 1988 were included, and followed over 24 y during which 643 men and 570 women developed CVD. Measures at baseline included age, weight, height, whole-body bioimpedance, from which PhA was calculated, and information on lifestyle, obtained by a self-administered questionnaire. The association between PhA and incident CVD was assessed by Cox proportional hazard model with age as the underlying time scale and with additional adjustment for covariates. To explore nonlinear associations, all results were presented using restricted cubic splines, with the median value of PhA as the reference.

RESULTS

PhA was lower among women who later developed CVD than among women who did not (6.3 vs. 6.0; P < 0.001). The highest risk of CVD was observed at the 5th percentile (hazard ratio: 1.33; 95% confidence interval, 1.11-1.60). Among men, PhA was not significantly associated with risk of CVD (7.1 vs. 7.0; P = 0.246).

CONCLUSIONS

Among apparently healthy Danish men and women, a lower PhA value was associated with a higher incidence of CVD over 24 y, also after adjusting for potential confounders, and particularly among women. These findings may encourage the future use of PhA as an additional index in predicting CVD. However, more studies are needed to confirm our results.

Hormone replacement therapy - where are we now?

Hormone replacement therapy (HRT) was the standard of care for menopause management until 2002, when perceptions changed following release of the initial results from the Women's Health Initiative (WHI) trial. Fears of breast cancer and heart attacks engendered by that report were not supported by the data, especially for recently menopausal women. Clinically, HRT is usually initiated near menopause. The WHI tested something different - the effects of HRT started a decade or more after menopause. As it turned out, age at starting HRT is critical in determining benefit/risk. HRT use plummeted following the WHI in 2002 and has remained low, prompting strong interest in alternative treatments. None provide the range of benefits across multiple organ systems offered by estrogen. Most have concerning adverse effects in their own right. HRT can provide effective relief for a wide range of health conditions, potentially avoiding the need for multiple treatments for separate problems. Unfortunately, among many women and clinicians, the perception of HRT benefit/risk is distorted, and its use avoided, leading to unnecessary distress. Following the WHI, many clinicians have not received adequate training to feel comfortable prescribing HRT. When initiated within 10 years of menopause, HRT reduces all-cause mortality and risks of coronary disease, osteoporosis, and dementias.

Accuracy of Bioelectrical Impedance Analysis in Estimated Longitudinal Fat-Free Mass Changes in Male Army Cadets

Introduction

Bioelectrical impedance analysis (BIA) is a practical and rapid method for making a longitudinal analysis of changes in body composition. However, most BIA validation studies have been performed in a clinical population and only at one moment, or point in time (cross-sectional study). The aim of this study is to investigate the accuracy of predictive equations based on BIA with regard to the changes in fat-free mass (FFM) in Brazilian male army cadets after 7 mo of military training. The values used were determined using dual-energy X-ray absorptiometry (DXA) as a reference method.

Materials and Methods

The study included 310 male Brazilian Army cadets (aged 17-24 yr). FFM was measured using eight general predictive BIA equations, with one equation specifically applied to this population sample, and the values were compared with results obtained using DXA. The student's t-test, adjusted coefficient of determination (R2), standard error of estimation (SEE), Lin's approach, and the Bland-Altman test were used to determine the accuracy of the predictive BIA equations used to estimate FFM in this population and between the two moments (pre- and post-moment).

Results

The FFM measured using the nine predictive BIA equations, and determined using DXA at the post-moment, showed a significant increase when compared with the pre-moment (p < 0.05). All nine predictive BIA equations were able to detect FFM changes in the army cadets between the two moments in a very similar way to the reference method (DXA). However, only the one BIA equation specific to this population showed no significant differences in the FFM estimation between DXA at pre- and post-moment of military routine. All predictive BIA equations showed large limits of agreement using the Bland-Altman approach.

Conclusion

The eight general predictive BIA equations used in this study were not found to be valid for analyzing the FFM changes in the Brazilian male army cadets, after a period of approximately 7 mo of military training. Although the BIA equation specific to this population is dependent on the amount of FFM, it appears to be a good alternative to DXA for assessing FFM in Brazilian male army cadets.

Adaptive thermogenesis and changes in body composition and physical fitness in army cadets

BACKGROUND

To analyze the association between a 34-week military training on body composition, physical fitness and compensatory changes in resting energy expenditure (REE) recognized as adaptive thermogenesis (AT). We also explored if regional body composition changes were related to AT.

METHODS

Twenty-nine male army cadets, aged 17 to 22 years were tested at baseline (T0) and after 34-weeks military training (T1). Physical training was performed 5 days/week during 90 minutes/day. Measurements included body composition by dual-energy x-ray absorptiometry; physical fitness by 3000-m running, pull-up, 50-m freestyle swimming, push-up and sit-up tests; REE measured by indirect calorimetry (REEm) and predicted from fat-free mass (FFM), fat mass (FM) and ethnicity at T0 (REEp). %AT was calculated using values at T1: 100(REEm/REEp-1); and AT (kcal/day) as %AT/100 multiplied by baseline REEm.

RESULTS

Physical training was associated with increases of lean soft tissue (LST) (∆1.2±1.3 kg), FM (∆1.4±1.3 kg), FFM (∆1.2±1.3 kg) and physical fitness (P<0.01), but no REE changes (∆59.6±168.9 kcal/day) and AT were observed (P>0.05). Though a large variability was found, AT was partially explained by trunk LST (r2=0.17, P=0.027). Individuals showing a higher AT response demonstrated a higher trunk LST increase (∆0.8±0.7 kg, P<0.05).

CONCLUSIONS

The military training increased LST, FM, FFM and physical fitness. Though no mean changes in AT occurred, a large individual variability was observed with some participants increasing REE beyond the expected body composition changes, suggesting a spendthrift phenotype. Changes of trunk LST may play an important role in the AT response observed in these individuals.

The evidence base for HRT: what can we believe?

Prior to the unexpected early termination of the Women's Health Initiative (WHI) trial of continuous conjugated equine estrogens (CEE) and medroxyprogesterone acetate (MPA), the prevailing view was that hormone replacement therapy (HRT) was a low-risk intervention with immediate value for symptom relief in recently menopausal women, and that it probably conferred long-term protection against the major chronic diseases that affect women after menopause. Rather than replicating prior studies, the WHI was designed to test whether the beneficial associations consistently seen in women starting HRT near menopause would be found in women well beyond menopause. Views of the benefits and risks of HRT changed dramatically in 2002 with the unexpected early termination of the CEE + MPA trial and the alarming initial WHI report. HRT use plummeted world-wide, driven by fear of breast cancer and skepticism about cardiovascular benefits. Stunningly, the contrasting findings of the WHI trial of CEE alone reported 2 years later - suggesting prevention of coronary heart disease in women who began HRT at age <60 years, and a reduction in breast cancer overall - were largely ignored. Key lessons from the WHI are that the effects of HRT on most organ systems vary by age and time since last physiologic exposure to hormones and that there are differences between regimens. In the years since the first WHI report, we have learned much about the characteristics of women who are likely to benefit from HRT. The range of HRT regimens has also increased. Not all women have indications for HRT, but for those who do and who initiate within 10 years of menopause, benefits are both short-term (vasomotor, dyspareunia), and long-term (bone health, coronary risk reduction). Critically, the 'facts' that most women and clinicians consider in making the decision to use, or not use, HRT are frequently wrong or incorrectly applied.

Validity of Bioelectrical Impedance Analysis to Estimation Fat-Free Mass in the Army Cadets

Background: Bioelectrical Impedance Analysis (BIA) is a fast, practical, non-invasive, and frequently used method for fat-free mass (FFM) estimation. The aims of this study were to validate predictive equations of BIA to FFM estimation in Army cadets and to develop and validate a specific BIA equation for this population. Methods: A total of 396 males, Brazilian Army cadets, aged 17–24 years were included. The study used eight published predictive BIA equations, a specific equation in FFM estimation, and dual-energy X-ray absorptiometry (DXA) as a reference method. Student’s t-test (for paired sample), linear regression analysis, and Bland–Altman method were used to test the validity of the BIA equations. Results: Predictive BIA equations showed significant differences in FFM compared to DXA (p < 0.05) and large limits of agreement by Bland–Altman. Predictive BIA equations explained 68% to 88% of FFM variance. Specific BIA equations showed no significant differences in FFM, compared to DXA values. Conclusion: Published BIA predictive equations showed poor accuracy in this sample. The specific BIA equations, developed in this study, demonstrated validity for this sample, although should be used with caution in samples with a large range of FFM.

The cardiovascular safety aspects of calcium supplementations: where does the truth lie? A personal perspective

Clinical guidelines may change with time, as more information from topline studies emerges. Calcium plus vitamin D supplementation became routine decades ago, especially in the older population, based on the assumption that it may promote bone health and prevent fractures, and perhaps induce additional favorable health outcomes. During the past years, an ongoing debate defies this paradigm, mainly because of a potential cardiovascular risk on the one hand, and uncertainty in regard to the extent of the beneficial bone effects on the other hand. The following article summarizes the main recent developments, trying to put some order into the controversial information and opinions which have been published in the medical literature. We conclude that the best current evidence supports a primary strategy of obtaining recommended intakes of calcium and vitamin D from dietary sources. But, since most western diets are inadequate in that regard, and since there is no clear evidence of harm from modest supplementation (up to 1000 mg of elemental calcium and 400 IU of vitamin D3), supplementation is appropriate when dietary intake is inadequate.

Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events

BACKGROUND

The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS.

DESIGN

An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events.

METHODS

Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events.

RESULTS

In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women.

CONCLUSIONS

An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

Have we come full circle - or moved forward? The Women's Health Initiative 10 years on

In mid-summer 2002, the announcement that the Women's Health Initiative (WHI) trial of combination hormone therapy (HRT) had stopped jolted the field of women's health. It set off a cascade that first stunned, then meaningfully changed the future for millions of women, their partners, and tens of thousands of clinicians and scientists. With 10 years' hindsight, we can begin to put the lessons learned from the WHI HRT trials into perspective. These trials were primarily designed to test whether women considerably past menopause, and mostly asymptomatic, experienced treatment benefits from HRT expected from studies of generally symptomatic women who started near menopause. The definitive answer was 'no'. Unfortunately, the findings were generalized to all postmenopausal women regardless of age. Data accumulated from the WHI and other studies over the past decade have shown that, in women with symptoms or other indications, initiating HRT near menopause - the classic pattern of use - will probably provide a favorable benefit : risk ratio. Spurred by the WHI, many hypotheses and some insights about potential mechanisms for HRT effects on diverse organ systems have emerged, along with new perspectives on regimens, compounds, and routes of administration. This overview provides an historical perspective on the WHI design and the evolution of its message; summarizes current perspectives and insights contributed by eminent colleagues; reviews the state of the art; and looks to the future. We have come full circle in some ways, with mounting evidence supporting benefit for HRT started near menopause and with hard lessons learned about pathophysiology, publicity and interpreting data. Now we move on.

In an animal model nephrogenic systemic fibrosis cannot be induced by intraperitoneal injection of high-dose gadolinium based contrast agents

AIM AND OBJECTIVE

Nephrogenic systemic fibrosis (NSF) has been reported in humans to be most likely induced by gadolinium based contrast agents (GBCA), namely by gadodiamide, gadopentetate dimeglumine, and gadoversetamide, rarely by other GBCA. The pathogenesis of NSF remains unclear; different hypotheses are under discussion. The objective of the study is to assess if in the animal model human-like NSF changes can be induced by high-dose, intraperitoneal GBCA injections over four weeks.

MATERIALS AND METHODS

After approval by the institutional animal ethics committee, six rats each were randomly assigned to groups, and treated with seven different GBCA. Intraperitoneal (IP) injections - proven in the animal model to be effective - were chosen to prolong the animals' exposure to the respective GBCA. GBCA doses of previous intravenous (IV) animal studies were applied. After five weeks all rats were sacrificed. Sham controls were treated with IP saline injections, employing the same regimen.

RESULTS

No findings comparable with human NSF were observed in all animals after IP treatment with all seven GBCA at daily doses of 2.5 and 5.0 mmol/kg body weight (BW). No histopathological abnormalities of all examined organs were noted. Weight loss was stated in weeks three and four with GBCA injections at doses of 5.0 mmol/kg BW, but rats regained weight after cessation of GBCA treatment.

CONCLUSIONS

NSF-comparable pathological findings could not be induced by high dose intraperitoneal injection of seven GBCA.

On the need to clarify and disseminate contemporary knowledge of hormone therapy initiated near menopause

The dramatic change in opinion on postmenopausal hormone therapy (HT) following initial reports from the Women's Health Initiative (WHI) came about as the 'baby boom' generation of women created the largest population of newly menopausal women in history. That trial of conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA) focused on outcomes in women starting HT a decade or more after menopause. Yet clinical practice has focused on initiation near menopause. Recent findings in the limited numbers of younger menopausal women in the WHI CEE + MPA trial, and findings in the CEE-only trial, suggest that age at initiating HT strongly influences outcomes, and that benefits greatly exceed risk for most women who start within 10 years of menopause. Findings in other cohorts support this view. Benefits are both short (vasomotor, dyspareunia) and long term (bone health, possible coronary risk reduction). Not all postmenopausal women have indications for HT, but, even if the fraction is one-third, the numbers affected are staggering. Low-dose and non-oral regimens, and other compounds, were introduced in the wake of the WHI. Emerging evidence suggests that these may further reduce risk in some population subgroups. The demonizing of HT may already have caused a burden of chronic disease that could have been mitigated or delayed. It is time for action to re-establish appropriate clinical context based on this emerging evidence, to reverse the inappropriate broad generalization of the WHI findings to younger menopausal women, and to support outcomes studies of current regimens in younger menopausal women.

In vitro assessment of the antibiotic efficacy of contrast media and antibiotics and their combinations at various dilutions

Discography is a controversial diagnostic procedure involving the injection of radiographic contrast medium (RCM) into the intervertebral disc. Iatrogenic bacterial discitis is a rare but serious complication. The intervention has been increasingly performed in our patients here in the United Arab Emirates. Prophylactic intravenous antibiotic administration can reduce post-interventional discitis; however, this may favour the development of bacterial resistance. Direct intradiscal injection of an antibiotic together with the RCM is a potential alternative. To date, there has been only one study on the efficacy of antibiotics added to an RCM. Equally, there are only limited data regarding the potential direct effect of RCM on bacterial growth. The purpose of this study was to determine whether the efficacy of antibiotics is affected when RCM are added. In an in vitro study, the effect of non-ionic RCM on the growth of five laboratory bacterial strains, alone and in combination with three broad-spectrum antimicrobials, was tested. Bacterial growth was assessed in the absence and the presence of RCM, antibiotics and their combinations. All three RCM alone demonstrated some inhibition of bacterial growth at high concentrations. In the presence of the RCM, all three antibiotics retained their inhibitory effect on bacterial growth. In conclusion, our in vitro experiments did not reveal any changes in the antimicrobial efficacy of the three antibiotics in the presence of the three tested RCM. Subsequent clinical trials will need to assess whether intradiscal antibiotic administration may be a suitable substitute for, or a supplement to, prophylactic systemic antibiotics before discography.

Ankle brachial index combined with Framingham Risk Score to predict cardiovascular events and mortality: a meta-analysis

CONTEXT

Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction.

OBJECTIVE

To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction.

DATA SOURCES

Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies.

STUDY SELECTION

Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality.

DATA EXTRACTION

Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease.

RESULTS

Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women.

CONCLUSION

Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.

Elevated blood pressure in primary care varies in relation to circadian and seasonal changes

Blood pressure (BP) is known to vary by time of day and day of year. Studies differ substantially on the magnitude of the effect and there is doubt whether variation is clinically meaningful. We used more than 2 million BP measurements obtained between 1996 and 2004 from Geisinger Clinic primary care patients. General estimating equations were used to determine the effect of time of day and month of year on the probability of identifying BP values above four diagnostic cutoff points (SBP > or =120 mm Hg, SBP > or =140 mm Hg, DBP > or =80 mm Hg, DBP > or =90 mm Hg). Time of day and month of year were significantly associated with the odds of measuring elevated BP, regardless of definition. The odds ratio (OR) for SBP > or =120 mm Hg in the evening (1900 hours) versus midday (1200 hours) was 1.32 (P < 0.001). The OR for SBP > or =120 mm Hg in winter to summer months was 1.24 (P < 0.001). Similar results were found for each age/gender group. These data indicate that in clinical practice, measurement of an elevated BP may vary by 40% depending on the time of day and month of year. The magnitude of the variability in BP measurement attributable to the combined effect of these temporal factors is clinically significant. Anticipation of changes in BP attributable to temporal factors may improve accuracy of diagnosis and precision of therapy.

Comparison of two imaging protocols for acute stroke: unenhanced cranial CT versus a multimodality cranial CT protocol with perfusion imaging

The aim of the study was to validate a multimodality cranial computed tomography (CCT) protocol for patients with acute stroke in the United Arab Emirates as a basic imaging procedure for a stroke unit. Therefore, a comparative study was conducted between two groups: retrospective, historical group 1 with early unenhanced CCT and prospective group 2 undergoing a multimodality CCT protocol. Follow-up unenhanced CCT>48 h served as gold standard in both groups. Group 1: Early unenhanced CCT of 50 patients were evaluated retrospectively, using Alberta Stroke Program Early CT Score, and compared with the definite infarction on follow-up CCT. Group 2: 50 patients underwent multimodality CCT (unenhanced CCT, perfusion studies: cerebral blood flow, cerebral blood volume, mean transit time and CT angiography)<8 h after clinical onset and follow-up studies. Modified National Institute of Health Stroke Scale was used clinically in both groups. Group 1 showed 38 men, 12 women, clinical onset 2-8 h before CCT and modified National Institute of Health Stroke Scale 0-28. Group 2 included 38 men, 12 women, onset 3-8 h before CCT, modified National Institute of Health Stroke Scale 0-28. Sensitivity was 58.3% in group 1 and 84.2% in group 2. Computed tomography angiography detected nine intracranial occlusions/stenoses. The higher sensitivity of the multimodality CCT protocol justifies its use as a basic diagnostic tool for the set-up of a first-stroke unit in the United Arab Emirates.

Iosimenol, a new non-ionic dimeric contrast medium, does not induce immunoreactivity in the popliteal lymph node assay

Animal studies in mice were conducted to determine the potential immunoreactivity of the new non-ionic dimeric contrast medium (CM) iosimenol using the PLNA and flow cytometric analyses. Comparative studies were performed with iodixanol. The known immune-reactive substance strepozotocin (STZ) and vehicle injections served as positive and negative controls, respectively. Our experiments did not show any immunological effect of iosimenol, concluding that the new CM iosimenol may be beneficial for use in high-risk patients.

Six-month patient outcomes in a preventive cardiology center

More effective ways to improve lifestyle behaviors need to be developed. Two hundred forty adult patients at a preventive cardiology clinic were randomly assigned to receive either one or five sessions of behavioral instruction to improve cardiovascular risk behaviors. Results for 102 patients from 6-month follow-up data revealed few significant differences between the two groups. However, in the two groups combined, there were significant reductions in total calories, percent of calories from total fat, percent of calories from saturated and monounsaturated fat, and dietary cholesterol. Reductions were also found in systolic blood pressure, triglycerides, body mass index, and weight. In multiple regression analyses, changes in physiologic variables were primarily associated with baseline and demographic characteristics. Changes in total calories, percent of calories from polyunsaturated fat, and walking were predicted by changes in social support or knowledge. Although most patients improved, the intensity of behavior change instruction was not related to the amount of change in cardiovascular risk factors. (c) 2001 by CHF, Inc.

Short version of the CES-D (Burnam screen) for depression in reference to the structured psychiatric interview

A new screen for depression was compared with clinician diagnoses based on the Structured Clinical Interview for DSM-IV (SCID) as the standard. Post-menopausal women (n=436) completed the Burnam screen, a short version of the Center for Epidemiologic Studies Depression Scale (CES-D). The Burnam screen had a sensitivity of 74% and a specificity of 87% for current major depression and dysthymia, but the positive predictive value was low (20%) and the overall error rate was 14%. For lifetime mood disorders, sensitivity was very low for detecting affected subjects, even though specificity and positive predictive value were higher than for current conditions. Substituting a more sensitive cutpoint slightly improved the screen's ability to detect subjects with lifetime mood disorders. Even algorithms that used coefficients optimized for these data gave little improvement in the psychometric properties of the Burnam screen. These results re-emphasize the difficulty of using a one-stage screen to detect accurately a depressive diagnosis.

Common femoral vein dimensions and hemodynamics including Valsalva response as a function of sex, age, and ethnicity in a population study

PURPOSE

In this study we assessed the normal common femoral vein (CFV) dimensions and related hemodynamics in a cohort assembled to permit contrasts by means of sex, age, and ethnicity.

METHODS

The CFV diameter and the flow velocity were analyzed by means of duplex ultrasonography at rest and with a standardized Valsalva maneuver, with the subject in a 15% reverse Trendelenberg position. Mean levels of each of the CFV measurements were analyzed with age category, sex, and ethnicity, each adjusted for the other two. Multiple linear regression was used as a means of assessing the independent associations of age, sex, ethnicity, body mass index (BMI), and height to the CFV measurements.

RESULTS

The average CFV diameter at rest was 11.84 mm, increasing to 14.27 mm during the Valsalva maneuver. There was a significant (P <.0001) decline in both diameter measures beginning in patients 60 years old. The CFV diameter was larger in men (12.90 mm) than in women (11.22 mm; P <.0001). The average CFV diameter in Hispanics, Africian Americans, and Asians was significantly smaller (P <.001) than in the non-Hispanic whites in multivarate analysis. The independence of these associations was confirmed by means of multivariate analysis, and positive associations of CFV diameter with height and BMI were documented. The Valsalva response was higher in men than in women (2.67 mm vs 2.29 mm), but the percentage change was similar. CFV velocity at rest decreased significantly (P <.0001) in patients older than 50 years. The mean CFV velocity was 13.87 cm/s, and the values were significantly (P <.0001) higher in women (14.58 cm/s) than in men (12.67 cm/s). In multivariate analysis CFV velocity was higher in African Americans than in the other ethnic groups. We also documented an independent inverse association of CFV with BMI. The CFV velocity response (peak expiration post-Valsalva) increased significantly at all ages, from 52% to 83%. The percentage increase in women (68%) was slightly higher than that in men (58%). African American subjects had a somewhat higher percentage increase (74%) than the other three ethnic groups (63% to 64%). Because the flow rate is determined more by the diameter than the velocity, CFV flow associations were similar to those for diameter. Because an older age predicted both decreased diameter and velocity, the flow reduction with age was pronounced.

CONCLUSION

Quantitative normative data that are age-, sex-, and ethnic group-specific are reported on CFV diameter, velocity, and total flow rate, both at rest and with the Valsalva maneuver. CFV diameter, velocity, and flow rate varied significantly as a function of age, sex, ethnicity, height, and BMI. The data also provide a baseline assessment for subsequent evaluations of changes with time in this cohort.

Metabolic syndrome and ischemic heart disease in elderly men and women

Associations between metabolic syndrome components and prevalent ischemic heart disease (IHD) were investigated in a cross-sectional, community-based study of elderly men (n = 1,015) and women (n = 1,259) in Rancho Bernardo, California, in 1984-1987. In both sexes, there were significant positive associations between IHD defined by resting electrocardiogram criteria and age, systolic blood pressure, fasting and postchallenge hyperglycemia, total cholesterol/high density lipoprotein cholesterol (HDL cholesterol) ratio, and triglycerides and an inverse significant association with HDL cholesterol. High collinearity and interactions between serum insulin and metabolic syndrome variables were accounted for by uncorrelated principal components identified by factor analysis. In both men and women, three uncorrelated principal components were identified, representing a central metabolic factor (body mass index, fasting and 2-hour serum insulin, high serum triglycerides, and low HDL cholesterol), a glucose factor, and a blood pressure factor. In a multivariate model with age and sex, all three factors were significantly associated with IHD by electrocardiogram criteria; central metabolic factor (odds ratio (OR) = 1.6, p = 0.001), glucose factor (OR = 1.4, p < 0.001), blood pressure factor (OR = 1.2, p = 0.005), age (10 years) (OR = 1.8, p < 0.001), and female sex (OR = 0.5, p < 0.02). Similar results were obtained in analyses using clinically manifest IHD as the outcome. These results support the thesis that the metabolic syndrome exerts effects through different risk factors by different mechanisms.

Sleep detection with an accelerometer actigraph: comparisons with polysomnography

Two validation studies were conducted to optimize the sleep-detection algorithm of the Actillume. The first study used home recordings of postmenopausal women (age range: 51 to 77 years), which were analyzed to derive the optimal algorithm for detecting sleep and wakefulness from wrist activity data, both for nocturnal in-bed recordings and considering the entire 24 h. The second study explored the optimal algorithm to score in-bed recordings of healthy young adults (age range: 19 to 34 years) monitored in the laboratory. In Study I, the algorithm for in-bed recordings (n=39) showed a minute-by-minute agreement of 85% between Actillume and polysomnography (PSG), a correlation of.98, and a mean measurement error (ME) of 21 min for estimates of sleep duration. Using the same algorithm to score 24-h recordings with Webster's rules, an agreement of 89%, a correlation of.90, and 1 min ME were observed. A different algorithm proved optimal to score in-bed recordings (n=31) of young adults, yielding an agreement of 91%, a correlation of.92, and an ME of 5 min. The strong correlations and agreements between sleep estimates from Actillume and PSG in both studies suggest that the Actillume can reliably monitor sleep and wakefulness both in community-residing elderly and healthy young adults in the laboratory. However, different algorithms are optimal for individuals with different characteristics.

Sleep-wake patterns among postmenopausal women: a 24-hour unattended polysomnographic study

BACKGROUND

Circadian sleep-wake profiles in postmenopausal women were examined to explore relationships between nocturnal and out-of-bed sleep.

METHODS

Twenty-one home recordings were obtained with unattended polysomnography from women ranging from 56 to 77 years of age.

RESULTS

While maintaining their daily routines, volunteers slept an average of 439 minutes throughout the 24-hour recordings. Ten percent of the accumulated sleep time was recorded out of bed.

CONCLUSIONS

Greater age was associated with more afternoon-evening sleep. Sleep was also frequently observed shortly after volunteers arose from bed in the morning.

Circadian sleep, illumination, and activity patterns in women: influences of aging and time reference

Patterns of sleep, illumination, and activity of women of different ages were continuously monitored in their natural environments with a wrist activity monitor. Partial correlation analyses were performed to determine relationships between age and sleep and several circadian rhythm measures including the amplitudes, mesors, and timings of sleep, of illumination, and of activity. We found no age-related decline in actigraphic sleep duration. Age was not a significant correlate of circadian rhythm parameters of sleep. Moreover, no age effects were found on daily illumination exposure or on the circadian timing of illumination and activity patterns. However, the level and amplitude of the circadian activity rhythm showed a gradual decline with aging, independent of the time reference (i.e., Daylight Saving Time versus Standard Time) when recordings were obtained. As expected, significant associations were observed between local time reference and the level and timing of peak of illumination patterns. However, changes in local time reference were not significantly and consistently associated with actigraphic sleep or activity measures.

Quantitative and qualitative progression of peripheral arterial disease by non-invasive testing

There is little information on the progression of peripheral arterial disease (PAD) over time. A series of 508 patients with a prior examination for PAD were contacted and brought in for follow-up to evaluate the natural history of PAD. A total of 85 patients were excluded because they had interventions in both limbs prior to their return visit. Progression was assessed in the remaining 423 patients for a total of 755 limbs, both quantitatively and qualitatively using six categories of PAD severity. There was a modest overall categorical progression of disease: 228 limbs (30.2%) displayed categorical progression, while 172 limbs (22.8%) improved over a 4.6-year average follow-up. Through analysis of quantitative change, it was determined that more quantitative progression occurred than was evident from categorical progression. Two of the three non-invasive tests employed, the ankle/brachial index (ABI) and posterior tibial peak forward flow velocity (peak PT), showed statistically significant progression during follow-up: mean ABI change = -0.019, 95% confidence interval (CI)= -0.031 to -0.007; mean peak PT change = -2.32 cm/s, 95% CI = -3.20 to -1.44. The toe/brachial index (TBI) also suggested progression: mean change= -0.013, but the 95% CI included no change. Standard scores (sum of the Z-scores for ABI, peak PT and TBI) were calculated. The standard score progressed approximately 0.34 units (standard deviations), p-value <0.001, over 4.6 years; or about 0.07 standard deviations per year. There were independent and statistically significant (p<0.05) associations between the rate of PAD progression (standard score change) and age, diabetes, classic ('Rose') intermittent claudication, moderate to severe PAD in the same limb, moderate to severe PAD in the contralateral limb and future therapeutic intervention. There were independent and suggestive associations (0.05<p-value<0.15) between PAD progression and pain at rest, mild PAD in the same limb, and mild PAD in the contralateral limb. PAD progression was not associated with gender, atypical claudication, or amputation status. Thus, in this cohort of PAD patients, PAD on average progressed significantly over 4.6 years. This progression was independently related to age, diabetes and several markers of disease severity.

Micronized progesterone: a new therapeutic option

The recent release of micronized progesterone adds a new physiologic alternative to the available therapeutic agents for common indications in both pre- and postmenopausal women. This compound overcomes problems with absorption through the gut associated with exogenous progesterone administration so that it can be used orally to achieve required serum and tissue levels of a hormone that is structurally identical to endogenous progesterone. Available data suggest that it is functionally equivalent to synthetic progestogens for common applications, such as secondary amenorrhea, while offering the advantage of a more physiologic metabolic profile that could be important for sustained use in applications such as postmenopausal hormone replacement therapy.

The epidemiology of peripheral arterial disease: importance of identifying the population at risk

Data from the Framingham Study and other population studies indicate that intermittent claudication (IC) sharply increases in late middle age and is somewhat higher among men than women. Noninvasive testing in populations indicates that the true prevalence of peripheral arterial disease (PAD) is at least five times higher than would be expected based on the reported prevalence of IC. Peripheral arterial disease correlates most strongly with cigarette smoking and either diabetes or impaired glucose tolerance. Other risk factors for PAD include hypertension; low levels of high-density lipoprotein cholesterol; and high levels of triglycerides, apolipoprotein B, lipoprotein(a), homocysteine, fibrinogen and blood viscosity. Individuals with PAD are more likely to have coronary heart disease and cerebrovascular disease than those without PAD. Because of the high risk of both nonfatal and fatal cardiovascular disease (CVD) events in PAD patients, individuals with evidence of PAD should undergo both a careful examination of the entire cardiovascular system and aggressive modification of CVD risk factors.

The correlation between symptoms and non-invasive test results in patients referred for peripheral arterial disease testing

The WHO/Rose questionnaire has served as the epidemiologic and clinical standard in the assessment of leg pain in patients with peripheral arterial disease (PAD) for over three decades. However, the structure of this questionnaire does not allow assessment of leg-specific (i.e. right versus left) symptoms. We studied 508 patients aged 39-95 years (mean 68 years), initially referred for PAD non-invasive testing. A revised questionnaire, the San Diego Claudication Questionnaire, was administered which allowed determination of leg-specific symptoms and evaluated thigh and buttock as well as calf pain. Leg-specific symptoms were categorized into no pain, pain at rest, non-calf claudication, non-Rose calf claudication, and Rose claudication. At the same visit, the ankle brachial index, the toe brachial index, and peak posterior tibial flow velocity were measured by Doppler ultrasound and five categories of non-invasive results by type and severity of PAD were defined. Legs with previous intervention (Rx), surgery or angioplasty, were evaluated separately. Claudication was reported in 42% of no Rx legs and 50% of Rx legs; 40% of claudication was atypical (not Rose); 64% of no Rx and 81% of Rx legs had PAD by non-invasive testing, and 27% of affected legs had severe PAD. The correlation between the severity of symptoms and the severity of ipsilateral PAD in no Rx legs was r = -0.40, p < 0.001. In Rx legs, this correlation was somewhat less (r = 0.27, p < 0.001) due to more symptomatology at lesser degrees of PAD, suggesting reporting bias and/or more residual disease than evident from non-invasive testing. To our knowledge, these results provide the first comparison between a standardized assessment of leg pain and the severity of ipsilateral PAD by non-invasive testing.

The effects of insurance coverage and ethnicity on mammography utilization in a postmenopausal population

Despite the effectiveness of mammography as a method to detect breast cancer in women ages 50 and older, many women do not obtain screening mammograms. This study used the self-reported mammography history and demographic information obtained during the screening of 2453 post-menopausal women ages 50 to 79 at the San Diego Women's Health Initiative (WHI) center. We used this data to examine individual and social factors that predict mammography use. The WHI center comprised two clinics, one of which focused on Hispanic recruitment and thus provided the opportunity to examine the roles of ethnicity, income, education, marital status, age, and access to medical services on mammography use. Bivariate analysis indicated that the following factors were all strongly associated with women having had a mammogram in the previous two years: having health insurance, a regular medical provider, an annual household income greater than $20,000, and a high-school diploma, as well as being 65 years or older or white (P < 0.001). Multiple logistic regression analysis demonstrated that, when adjusting for all of these factors, having a medical provider (P < 0.001) was significant. Having insurance (P = 0.04) was suggestive, but did not meet the multiple-comparisons significance cutoff of P = 0.006. After adjusting for the above factors, it was found that ethnicity was not significant. The results suggest that improved access to a regular provider could increase the use of screening mammography in underserved populations.

Transvaginal ultrasonography compared with endometrial biopsy for the detection of endometrial disease. Postmenopausal Estrogen/Progestin Interventions Trial

BACKGROUND

Transvaginal ultrasonography is a noninvasive procedure that may be used to detect endometrial disease. However, its usefulness in screening for asymptomatic disease in postmenopausal women before or during treatment with estrogen or estrogen-progesterone replacement is not known.

METHODS

We compared the sensitivity and specificity of transvaginal ultrasonography and endometrial biopsy for the detection of endometrial disease in 448 postmenopausal women who received estrogen alone, cyclic or continuous estrogen-progesterone, or placebo for three years.

RESULTS

Concurrent ultrasonographic and biopsy results were available for 577 examinations in the 448 women, 99 percent of whom were undergoing routine annual follow-up. Endometrial thickness was less than 5 mm in 45 percent of the examinations, 5 to 10 mm in 41 percent, more than 10 mm in 12 percent, and not measured in 2 percent, and it was higher in the women receiving estrogen alone than in the other groups. Biopsy detected 11 cases of serious disease: 1 case of adenocarcinoma, 2 cases of atypical simple hyperplasia, and 8 cases of complex hyperplasia. Biopsy also detected simple hyperplasia in 20 cases. At a threshold value of 5 mm for endometrial thickness, transvaginal ultrasonography had a positive predictive value of 9 percent for detecting any abnormality, with 90 percent sensitivity, 48 percent specificity, and a negative predictive value of 99 percent. With this threshold, a biopsy would be indicated in more than half the women, only 4 percent of whom had serious disease.

CONCLUSIONS

Transvaginal ultrasonography has a poor positive predictive value but a high negative predictive value for detecting serious endometrial disease in asymptomatic postmenopausal women.

Women's health initiative. Why now? What is it? What's new?

Studies collectively named the Women's Health Initiative (WHI) are currently enrolling 164,500 postmenopausal women in several overlapping clinical trials and an observational study. The overall goals of WHI are to understand the determinants of postmenopausal women's health and to evaluate the efficacy of practical interventions in preventing the major causes of morbidity and mortality in older women. This article reviews the research leading to the WHI studies; describes the study designs and protocols, with an emphasis on what's new about WHI from a psychological perspective; and outlines the major psychosocial hypotheses under investigation and the major challenges WHI presents to psychological science.

Given diabetes, is fat better than thin?

OBJECTIVE

To evaluate the association between BMI and mortality in women and men with type II diabetes.

RESEARCH DESIGN AND METHODS

Fasting plasma glucose (FPG), height and weight measurements, and medical history were obtained from 4,483 community-dwelling adults, aged 40-79 years, in 1972-1974. A total of 373 persons with either a history of diabetes or FPG > or = 7.77 mmol/l were studied. Subjects were grouped into four sex-specific weight categories based on U.S. population data. Vital status after 14 years was known for 99.9% of the patients studied. Cox models were used to assess relative survival by weight category.

RESULTS

Diabetic men and women of average weight had the lowest mortality. A J-shaped relative risk curve by weight category was found, with a poorer survival rate for those who were thin, overweight, or obese. This effect was not explained by early mortality or cigarette smoking.

CONCLUSIONS

Being thin may not provide a mortality benefit for diabetic men and women. Average weight appears to be desirable.

A randomized trial of cardiovascular risk factor reduction: patterns of attrition after randomization and during follow-up

BACKGROUND

The Preventive Cardiology Center compared two intensities of behavior modification for cardiovascular disease (CVD) risk factors in persons at risk and their families. Characteristics of drop-outs both before and after intervention were compared with subjects who completed the 6-month trial.

METHODS

A total of 333 individuals of all ages were enrolled in the study and randomly assigned by family to a single-session ('skills' group-low-intensity) or a five-session ('practice' group-high intensity) intervention. Baseline and follow-up assessments included a personal and family health questionnaire, nutritional intake survey, and clinic visit to obtain blood pressure, lipids, and height and weight data.

RESULTS

Two hundred and forty adults over 18 years of age were randomly assigned to one of the two intervention groups. Of these, 68 subjects (28.3%) did not participate in the intervention. Multivariate analysis revealed that these 'early drop-outs' were significantly more likely to be non-white and to have had a lower LDL cholesterol. Of the 172 subjects attending the intervention, 70 (40.7%) did not attend the 6-month follow-up ('late drop-outs'). Multivariate analysis revealed that, compared with follow-up attendees, non-attendees were significantly more likely to be white and to be current smokers.

CONCLUSIONS

Both early and late drop-outs in a randomized trial of CVD risk reduction were significantly different than continuing participants in several key factors. These differences suggest the use of caution in both interpreting and making generalizations about behavioral trials of risk factor reduction when attrition is high.

Women's health initiative. Why now? What is it? What's new?

Studies collectively named the Women's Health Initiative (WHI) are currently enrolling 164,500 postmenopausal women in several overlapping clinical trials and an observational study. The overall goals of WHI are to understand the determinants of postmenopausal women's health and to evaluate the efficacy of practical interventions in preventing the major causes of morbidity and mortality in older women. This article reviews the research leading to the WHI studies; describes the study designs and protocols, with an emphasis on what's new about WHI from a psychological perspective; and outlines the major psychosocial hypotheses under investigation and the major challenges WHI presents to psychological science.

IgE predicts future nonfatal myocardial infarction in men

Established risk factors cannot explain all the variance in coronary heart disease (CHD). Immunoglobin E (IgE), a mediator of allergy, can affect platelets and arterial smooth muscle. We previously demonstrated a cross-sectional association between IgE and cardiovascular disease (CVD) in men. The present study evaluated this relationship prospectively in 278 men and 343 women followed for a mean of 8.9 years. There was an association between IgE and coronary disease in men, but not in women. There was no association for CVD, stroke, or all-cause mortality. The age-adjusted relative risk (RR) for coronary mortality in men with baseline IgE > or = 200 kU/L was 1.66 (p < or = 0.66), but for nonfatal myocardial infarction (MI) it was 6.46 (p < or = 0.01). This association was independent of smoking and other risk factors, and unrelated to allergy. Thus, elevated IgE was a strong independent prospective risk factor for nonfatal, but not fatal, MI in men.

The epidemiology of hypertension control in populations

Despite an aging population, prevalence rates for hypertension in the U.S. remain stable due to a decrease in rates in women but a corresponding increase in rates for men. Epidemiological factors which may contribute to these rates are discussed. The lack of a threshold for the association between blood pressure and disease events means that the majority of events occur in the larger number of people with mild disease. Because the efficacy and cost-effectiveness of medical therapy to lower mildly elevated blood pressure remains controversial, population-based strategies to effect behavior change are the most prudent course for this, the largest group at risk. Targeted, resource-intensive medical intervention for those at high risk combined with hygienic measures for the population with mildly elevated blood pressure from the basis for an effective public health strategy.