Bothersome symptoms at midlife in relation to body fat percentage.

OBJECTIVES: Increasing obesity has been associated with a higher frequency of symptoms at midlife. Bothersomeness represents an important measure of perceived symptom severity, but has received relatively little consideration, and relationships between symptom bothersomeness and obesity are not known. We evaluated the association between body fat percentage (%BF) and the bothersomeness of symptoms at midlife. METHODS: This cross-sectional study included women aged 40-60 in Qatar (n = 841). Participants reported frequency and bothersomeness of midlife symptoms hypothesized to be related to body composition. Initially, we characterized the relationship between continuous %BF and presence (yes/no) and bothersomeness (yes/no) for each symptom using restricted cubic spline (RCS) models to test nonlinearity. Subsequently, we used multinomial logistic regressions to evaluate associations between %BF and multilevel symptom outcomes, where categories were: (a) no symptoms or bother, (b) symptoms without bothersomeness, and (c) symptoms with bothersomeness. RESULTS: The highest frequency of bothersomeness was reported for aches/stiffness in joints (51%), followed by trouble sleeping (34%), night sweats (21%), urinary incontinence (18%), hot flashes (16%), and shortness of breath (15%). In unadjusted multinomial logistic regressions, aches/stiffness in joints with and without bothersomeness had the same significant relationship with %BF. Bothersome night sweats, urinary incontinence, and hot flashes were significantly associated with %BF (p < .05), but those same symptoms without bothersomeness were not significantly associated with %BF. CONCLUSIONS: Our findings suggest that bothersomeness is an important variable that tracks with body fat and gives different information than report of the presence/absence of a symptom alone.

Bone mineral density in midlife women: the Study of Women's Health in Qatar.

OBJECTIVES: The aim of this study is to investigate bone mineral density (BMD) for a large cross-section of midlife Arab women living in Qatar and to evaluate the association of body mass index (BMI), menopause status, and nationality, on BMD of the spine and femur. STUDY DESIGN: A cross-sectional study was conducted among women aged 40-60 years recruited from nine primary-care health centers in Qatar. BMD (g/m(2)) was assessed at the lumbar spine and the femur. RESULTS: The combined prevalence of osteopenia and osteoporosis was 4% at the femur and 16.2% at the spine. BMI and menstrual status were both independently associated with BMD at the spine and at the femur (all p values < 0.001). As BMI increased, BMD increased at both the spine and femur. Women who menstruated in the past 12 months had 0.82 g/cm(2) and 0.61 g/cm(2) greater BMD at the spine and femur, respectively, compared with women who had not menstruated in 12 months. Nationality was not associated with mean BMD of the spine or the femur. CONCLUSIONS: No significant differences were observed between Qatari and non-Qatari women in terms of mean BMD values at the spine and the femur except for the femur in the age group 55-60, where values were lower among non-Qataris (p = 0.04). Multivariable analyses showed that BMI and menstrual status were found to be strongly associated with BMD levels at the spine and femur. The high prevalence of obesity observed in this sample may explain the low levels of osteopenia and osteoporosis observed.

Use of complementary and alternative medicine among midlife Arab women living in Qatar.

The prevalence of use of complementary and alternative medicine (CAM) is widespread and is growing worldwide. This cross-sectional study in Qatar examined the use of CAM and its correlates among Arab women in their midlife years. Women aged 40-60 years (n = 814) were recruited at primary care centres in Qatar and completed a specially designed, pre-tested questionnaire. Overall, 38.2% of midlife women in Qatar had used CAM in the previous 12 months. Nutritional remedies and herbal remedies were the most commonly used CAM therapies, followed by physical methods. Qatari nationality and higher level of education were independently associated with CAM use. Menopause transition status was not independently associated with use of CAM. The prevalence of CAM use by women in Qatar was high, consistent with other reports worldwide. It is essential to educate and inform patients and health-care providers about the benefits and limitations associated with CAM.

Use of complementary and alternative medicine among midlife Arab women living in Qatar

The prevalence of use of complementary and alternative medicine [CAM] is widespread and is growing worldwide. This cross-sectional study in Qatar examined the use of CAM and its correlates among Arab women in their midlife years. Women aged 40-60 years [n = 814] were recruited at primary care centres in Qatar and completed a specially designed, pre-tested questionnaire. Overall, 38.2% of midlife women in Qatar had used CAM in the previous 12 months. Nutritional remedies and herbal remedies were the most commonly used CAM therapies, followed by physical methods. Qatari nationality and higher level of education were independently associated with CAM use. Menopause transition status was not independently associated with use of CAM. The prevalence of CAM use by women in Qatar was high, consistent with other reports worldwide. It is essential to educate and inform patients and health-care providers about the benefits and limitations associated with CAM

L'utilisation des médecines complémentaires et parallèles est largement prévalent et en augmentation dans le monde. La présente étude transversale au Qatar à examiné le recours aux médecines complémentaires et parallèles et ses corrélats chez des femmes arabes en milieu de vie. Des femmes âgées de 40 à 60 ans [n = 814] ont été recrutées dans des centres de soins de santé primaires au Qatar et ont rempli un questionnaire spécialement conçu ayant été testé au préalable. Au total 38,2% des femmes en milieu de vie interrogées vivant au Qatar avaient eu recours aux médecines complémentaires et parallèles durant les 12 mois précédents. Des remèdes nutritionnels et à base de plantes étaient les traitements complémentaires et parallèles les plus fréquemment utilisés, suivis par des méthodes physiques. La nationalité qatarie et un niveau d'études plus élevé étaient indépendamment associés à l'utilisation de médecines complémentaires et parallèles. Le statut de transition ménopausique n'était pas indépendamment associé à l'utilisation de ces médecines. La prévalence de leur utilisation chez les femmes au Qatar était élevée et concordait avec les études menées sur le sujet dans d'autre pays du monde. Il est essentiel d'éduquer et d'informer les patientes et les prestataires de soins de santé sur les bénéfices et les limites associés aux médecines complémentaires et parallèles

إن استخدام الطب المتمم والبديل منتر عى نطاق واسع، وهو في تزايد في جميع أنحاء العالم. وقد قامت هذه الدراسةالمستعرضة في قَطَر بدراسة استخدام الطب المتمم والبديل وارتباطاته لدى نساء عربيات في سنوات منتصف أعمارهن. فقد تطوعت60 سنة )العدد = 814 ( في مراكز الرعاية الصحية الأولية في قَطَر، وقمنَ بملء استبيان مصمَّم خصيصاً تم اختباره - نساء بأعار 40مسبقاً. فكان ما إجماليه 38.2 % من النساء في منتصف العمر في قَطَر قد استخدمن الطب المتمم والبديل في ال 12 شهراً السابقة.وكانت العلاجات الغذائية والعلاجات العشبية أكثر معالجات الطب المتمم والبديل شيوعاً في الاستخدام، تلتها الطرق الفيزيائية.وكانت الجنسية القطرية ومستوى التعليم الأعى مرتبطة - بشكل مستقل - مع استخدام الطب المتمم والبديل. ولم تكن حالة سنالإياس الانتقالية مرتبطة - بشكل مستقل - مع استخدام الطب المتمم والبديل. وكان انتشار استخدام الطب المتمم والبديل منقِبَل النساء في قَطَر مرتفعاً، با يتفق مع تقارير أخرى من جميع أنحاء العالم. وخلصت الدراسة إلى أن من الروري تثقيف المرضىومقدِّمي الرعاية الصحية وإطلاعهم عى الفوائد والقيود المرتبطة بالطب المتمم والبديل

Severe and moderate haemophilia A and B in US females.

Haemophilia A and B are rare X-lined hemorrhagic disorders that typically affect men. Women are usually asymptomatic carriers, but may be symptomatic and, rarely, also express severe (factor VIII (FVIII) or factor IX (FIX) <0.01 U mL(-1)) or moderately severe (FVIII/FIX 0.01-0.05 U mL(-1)) phenotypes. However, data on clinical manifestations, genotype and the psychosocial ramifications of illness in severely affected females remain anecdotal. A national multi-centre retrospective study was conducted to collect a comprehensive data set on affected US girls and women, and to compare clinical observations to previously published information on haemophilic males of comparable severity and mildly affected haemophilic females. Twenty-two severe/moderate haemophilia A/B subjects were characterized with respect to clinical manifestations and disease complications; genetic determinants of phenotypic severity; and health-related quality of life (HR-QoL). Clinical data were compared as previously indicated. Female patients were older than male patients at diagnosis, but similarly experienced joint haemorrhage, disease- and treatment-related complications and access to treatment. Gynaecological and obstetrical bleeding was unexpectedly infrequent. F8 or F9 mutations, accompanied by extremely skewed X-chromosome inactivation pattern (XIP), were primary determinants of severity. HR-QoL was diminished by arthropathy and viral infection. Using systematic case verification of participants in a national surveillance registry, this study elucidated the genetics, clinical phenotype and quality of life issues in female patients with severe/moderate haemophilia. An ongoing international case-controlled study will further evaluate these observations. Novel mechanistic questions are raised about the relationship between XIP and both age and tissue-specific FVIII and FIX expression.

The hopeless age? A qualitative exploration of the experience of menopause in Arab women in Qatar.

OBJECTIVE: The aim of this study was qualitatively to describe and examine the expectations and experiences of the midlife transition in Arab women living in Qatar. METHOD: Six focus groups were conducted with Arab women living in Qatar: three groups of local Qatari women, and three groups of non-Qatari Arab women originating from neighboring countries. A purposive sample of 41 pre-, peri-, and postmenopausal women aged 40-60 years participated. The semi-structured group format encouraged discussion around knowledge about menopause; physical, emotional and social experiences related to menopause; and cultural differences that may exist related to menopause. RESULTS: The majority of women considered menopause as a maturing experience, although the term 'menopause' was considered to have negative connotations. Postmenopausal women described menopausal symptoms consistent with general knowledge, but many premenopausal women were unaware of symptoms, even if they knew someone who had experienced menopause. Postmenopausal women were more socially active than before and were able to participate in religious activities that they previously could not attend during menses. How a woman experienced menopause depended on the husband's level of support, and some women believed that Western women did not have the appropriate support from husbands and families that Arab women have; they felt this lack of support could lead to negative outcomes such as being at an increased risk for suicide caused by depression during menopause. CONCLUSION: Qatari and non-Qatari women had many similarities in how they perceived and experienced menopause, although they collectively believed that the experiences of Western women are different.

[Measurement of body composition in daily practice]. / Messung der Köperzusammensetzung im Praxisalltag. Genauigkeit sowie Sinn und Unsinn von Geräten zur Bestimmung der Körperzusammensetzung.

During the last few years bioimpedance analysis (BIA) devices have been heavily promoted for body composition measurements in daily medical practice. The accuracy of these devices is not exactly known. Accordingly we compared in this study 6 different BIA devices, 3 different skinfold callipers with dual energy x-ray absorptiometry (DXA) as the reference methodology. The correlation coefficient between the fat mass assessed by the BIA devices as compared to the DXA methodology varied between r = 0.880 and r = 0.947 (p for all < 0.001). The accuracy of the measurements was better in women than in men and better in individuals with a BMI > 25 kg/m2 than in individuals with a BMI < 25 kg/m2. For daily use the BIA devices are much more user-friendly than the skinfold callipers. It is obvious that the use of the BIA measurement in daily practice does not help much in the assessment of obesity but more so in the assessment (quantification) of the lean body mass (LBM).

Association of leptin levels with obesity and blood pressure: possible common genetic variation.

OBJECTIVE: To ascertain the extent to which relationships between obesity (OB) and blood pressure (BP) can be explained by an individual's leptin plasma levels. DESIGN: Pedigree-based cross-sectional study in an apparently healthy population of European origin. SUBJECTS: The study sample is comprised of 90 nuclear and more complex families totaling 210 male and 213 female subjects aged 18-75 y, randomly recruited in Bashkorstan Autonomic region, Russia. MEASUREMENTS: Various fatness and fat distribution traits (including nine circumferences (CRCs), and eight skinfolds (CKFs) by anthropometry), blood pressure, and plasma leptin levels (by ELISA kits). RESULTS: Adjustment for circulating leptin led to attenuation of the magnitude of correlations between OB and BP, regardless of trait pair and sex cohort. Some of these correlations became statistically nonsignificant. All familial effects were gone, and heritability estimates became virtually zero after adjustment of each of the OB traits and systolic blood pressure (SBP) in offspring for leptin values in parents. CONCLUSION: BP and OB covariation is substantially mediated by circulating leptin levels. As a result, body fat has only a weak independent effect on BP variation after adjustment for leptin levels. Our findings also strongly suggest that genetic variation in body mass index, SKFs, and even body CRCs, as well as of SBP is due to genetic variation of leptin. Genetic variation of diastolic blood pressure in the present sample, however, shared very little with that of leptin.

Low-dose alpha/beta blockade in the treatment of essential hypertension.

Despite the recent emphasis on combination drug therapy for hypertension, little attention has been given to alpha/beta blockade using agents other than labetalol. The purpose of this study was to 1) compare the efficacy of low-dose alpha/beta blockade using doxazosin + betaxolol, versus monotherapy with an angiotensin converting enzyme inhibitor (quinapril) and a diuretic (hydrochlorothiazide [HCTZ]), and 2) assess the efficacy of low-dose doxazosin. In a crossover study, 21 hypertensive subjects were treated for 3 weeks each with HCTZ, 12.5 to 25 mg/day, quinapril, 10 to 40 mg/day, and a combination of doxazosin, 1 to 4 mg + betaxolol, 5 to 10 mg daily. Doses were titrated to achieve a systolic pressure <130 mm Hg, as assessed by self-recorded home measurements. Home blood pressure decreased 11.5/7.5 mm Hg after HCTZ, 12.9/8.8 mm Hg after quinapril, and 21.2/16.5 mm Hg after doxazosin + betaxolol (P < .001/< .001 v HCTZ and P < .002/< .001 v quinapril). The target systolic pressure was achieved by 33%, 43%, and 71% of subjects, respectively (P = .04 v HCTZ, and .03 v quinapril). Among the 8 subjects in whom doxazosin dosage was increased to the maximum of 4 mg, the mean blood pressure achieved at 4 mg did not differ from that achieved at 2 mg (136/87 v 136/88 mm Hg). We conclude that oral alpha/beta blockade is superior to monotherapy with an angiotensin converting enzyme inhibitor or a diuretic and that maximal or near maximal efficacy can be achieved at a 2-mg dose of doxazosin. Low-dose oral alpha/beta blockade merits greater consideration in the drug therapy of essential hypertension.

Familial factors of blood pressure and adiposity covariation.

In the present study, we used the maximum likelihood approach as implemented by variance analysis and attempted to quantify genetic and environmental components of variance in systolic (SBP) and diastolic (DBP) blood pressure in 514 individuals who belonged to a total of 135 nuclear families of Chuvasha, Russia, ethnic origin. The extent to which these interindividual differences depend on age, gender, body mass index (BMI) and other anthropometric measurements was investigated. Major findings include the following. (1) The variation in both SBP and DBP was significantly affected by genetic factors (h(2)(SBP)=0.51+/-0.13, h(2)(DBP)=0.20+/-0.09), shared household environment, and age. These effects were stronger with respect to SBP, which also showed significant gender differences in baseline values and rate of SBP increase with age. (2) Genetic and common household factors, as well as undetected residual effects, were not completely independent. The respective 3 facets of correlation between SBP and DBP were significant: 0.66+/-0.10, 0.76+/-0.11, and 0.55+/-0.14. (3) SBP and DBP each showed significant phenotypic correlations with BMI and anthropometric factors. These correlations had a substantial genetic component but were not equal for SBP and DBP. SBP showed the highest genetic correlation with arm circumference (r(G)=0.63), whereas for DBP, this was found with hip skinfold (r(G=)0.88). (4) Bivariate heritability estimates, as well as adjustment of BP measurements for BMI and selected anthropometrics, indicated that DBP likely does not have independent genetic heritability. The residual genetic variance of adjusted SBP remained significant, although substantially lower in comparison with the nonadjusted h(2).

Association of urinary albumin concentration with casual and ambulatory blood pressure: a similar relationship in normotensive and hypertensive subjects.

BACKGROUND: The urinary albumin level has been found to be positively correlated with blood pressure in hypertensive patients. To our knowledge, this relationship has not been evaluated in normotensive subjects and compared with that in hypertensives using casual and ambulatory blood pressure measurements. METHODS: In this cross-sectional study, a cohort of 234 normotensive and hypertensive participants wore an ambulatory blood pressure monitor for 24 h, standardized casual blood pressure measurements being taken. The urinary albumin concentration was determined by the dipstick Micral Test. The bivariate and multivariate relationship between urinary albumin concentration and demographic and blood pressure measures was investigated using correlational and regression analyses. RESULTS: The prevalence of microalbuminuria was significantly greater in the hypertensive than normotensive participants. The urinary albumin concentration was positively associated with both casual and ambulatory measures of blood pressure in both the normotensive and hypertensive subsamples, stronger correlations being found for systolic blood pressure. The relationship between systolic blood pressure and urinary albumin concentration was similar in the normotensive and hypertensive subsamples. CONCLUSIONS: These findings confirm earlier reports of the greater prevalence of microalbuminuria in patients with hypertension than in normotensive participants, as well as those reporting a continuous relationship in hypertensive participants. This study extends prior research to a normotensive subsample, in whom a similar relationship of blood pressure to microalbuminuria, using both ambulatory and casual measures of blood pressure, was found. Future research should investigate the causal direction of this relationship.

Effect of body weight changes on changes in ambulatory and standardized non-physician blood pressures over three years.

PURPOSE: This study examines the relationship of changes in body mass index (BMI) to changes in measures of both casual and ambulatory blood pressures over three years. METHODS: In this prospective study of men aged 30-60 years, a cohort of 198 participants was followed for three years. Height, weight, demographic characteristics, and casual and ambulatory measures of blood pressure (BP) were obtained at baseline and 3-year follow-up. RESULTS: Change in BMI was significantly associated with change in all ambulatory (awake, work, home, and sleep) and casual systolic and diastolic blood pressures. After controlling for age and race/ethnicity, the association remained significant for nine of the twelve BP change measures. Further tests show that the effect of a change in BMI on BP change does not vary across the six systolic blood pressures or across the six diastolic measures. An average-height man gaining 5 kg (11 pounds) typically exhibited a 2.5 mm Hg increase in systolic and a 1.8 mm Hg increase in diastolic casual and ambulatory BPs. There is no evidence that changes in BP were associated with age, race/ethnicity (blacks vs. Hispanics vs. whites), or the average of the baseline and follow-up levels of BMI. In addition, the impact of weight gain is similar in magnitude, but in the opposite direction, to that of weight loss. CONCLUSIONS: Changes in BMI over three years predict changes in ambulatory and standardized non-physician BPs. These changes in BP are not related to average BMI level or age.

The nutrient-toxin dosage continuum in human evolution and modern health.

Recent findings support the long-recognized principle that nutritive and toxic effects of an ingested material depend not only on its nature but very much on its quantity. The well known observation that essential nutrients can be toxic at high dosages suggests that the same reversal of effect may be true of many substances that could be beneficial but not essential at low dosages (the phenomenon of hormesis). This has been demonstrated for many well known toxins. We suggest a mathematical model that describes these dosage effects as an expected result of the evolution of human metabolic and dietary adaptations for maximizing benefits and minimizing costs of the ingestion or other intake of any substance. Evolved mechanisms for achieving benefits may be unrelated to those for reducing costs. These evolutionary considerations suggest important consequences demonstrable by experimental or epidemiological studies. They also suggest ways in which our evolved dietary adaptations may be currently maladaptive, and individual development of taste preferences poorly calibrated by early experience in modern environments. The apparent reality of hormesis raises the possibility of counterproductive effects of current dosage recommendations and limits for nutrients and pollutants. We propose that some conceptual and factual problems are urgently in need of resolution. Fundamental to evolutionary biology is the tendency for organisms to become increasingly adapted to those environments to which they are most commonly exposed (Parsons 1990).

Relationship of body size and body mass to blood pressure: sex-specific and developmental influences.

The relationship of body mass and body fat distribution to blood pressure has been recognized for many years. This relationship has formed the basis for much additional research, including the impact of growth and developmental factors on blood pressure levels. Blood pressure in children is related to somatic growth and is tied to increases in height, skeletal maturation, and sexual maturation. Sexual and ethnic differences in blood pressure levels are already apparent during childhood and may also be related to the process of growth and sexual maturity. Body size exerts a profound influence on a variety of physiological functions, including blood pressure and the onset of sexual maturity. In general, studies have reported a strong linear relationship between height and blood pressure and between body mass and blood pressure such that tracking correlations from childhood to adulthood for both blood pressure and body mass index are significant for most sex and ethnic groups. Studies evaluating the effects of hormone replacement therapy on post-menopausal women have thus far generated results suggesting that the age-related rise of blood pressure is not due directly to hormonal changes associated with menopause. The interrelated effects of growth, maturation, body weight, and body fat are influenced by both genetic and environmental factors. Environmental influences may modify relationships established much earlier, perhaps as early as prenatally, during infancy, or during early childhood. Directions for future research and implications resulting from the complex relationship between body weight and blood pressure are discussed.

Assessment of a new dipstick test in screening for microalbuminuria in patients with hypertension.

The prevalence of elevated urinary albumin levels is significantly greater in hypertensive than in normotensive subjects. To determine the sensitivity and specificity of a new dipstick test for microalbunimuria (the Micral-Test), 171 hypertensive patients were studied at a union-sponsored hypertension treatment program. Sensitivity, specificity, predictive values, and correlation coefficients between urinary albumin concentration results obtained by the Micral-Test and by nephelometry were determined in three urine samples. Sensitivity values of the Micral-Test, compared with 24-h nephelometry, were 81%, 75%, and 92% in a 24-h, overnight, and random sample, respectively. Specificity values were 89%, 90%, and 63% in the three samples, respectively. Positive predictive value ranged from 41% to 67%, whereas negative predictive value ranged from 93% to 97%. Correlation coefficients between the logarithms of albumin concentrations obtained from the three different urine specimens using nephelometry fell between 0.71 and 0.78, whereas those obtained with the Micral-Test fell between 0.49 and 0.71, and across techniques, 0.29 to 0.53 (all P < .001). Results obtained with both nephelometry and the Micral-Test using overnight and random urine collections approximated those obtained with 24-h collection. These results, coupled with the ease and convenience of both specimen collection and the Micral-Test itself, support the use of the test as a valuable screening tool for microalbuminuria in patients with hypertension.

Impact of shift work and race/ethnicity on the diurnal rhythm of blood pressure and catecholamines.

To evaluate the effects of shift work and race/ethnicity on the diurnal rhythm of blood pressure and urinary catecholamine excretion of healthy female nurses, 37 African American women and 62 women of other races underwent ambulatory blood pressure monitor and urine collection for 24 hours that included a full work shift: day shift (n=61), evening shift (n=11), and night shift (n=27). Awake and sleep times were evaluated from subjects' diaries. Of African Americans, 79% who were working evenings or nights and 32% working day shifts were nondippers (<10% drop in systolic pressure during sleep), whereas only 29% of others working evening+night and 8% working day shifts were nondippers. Regression analyses indicated that evening+night shift workers had a 5.4 mm Hg (P<0.001) smaller drop than day shift workers, and African Americans had a 4.0 mm Hg (P<0.01) smaller drop than others. The odds of an evening+night shift worker being a nondipper were 6.1 times that of a day shift worker (P<0.001), and the odds of an African American were 7.1 times that of others (P<0.001). Total sleep time was significantly greater in the non-African American day shift workers than in the other 3 groups. After controlling for work shift and race/ethnicity, we determined that longer sleep times predicted less dipping (absolute and relative) in blood pressure. Urinary norepinephrine and epinephrine were higher during work than nonwork in both racial groups of day shift workers, but in evening+night shift workers the difference was small and in the opposite direction. These results indicate that being African American and working evening or night shifts are independent predictors of nondipper status. Higher sleep blood pressure may contribute to the known adverse effects of shift work.

Response to the captopril test is dependent on baseline renin profile.

OBJECTIVE: To determine prospectively the relationship between the renin-sodium profile and the renin response to captopril challenge in patients with essential hypertension. DESIGN: A standard captopril test was performed in 108 uncomplicated, untreated hypertensive subjects with normal renal function and urinary sodium excretion in the range 50-240 mmol/day. The subjects were selected from a working population with a low expected prevalence of renovascular disease. METHOD: The captopril test was considered positive if the captopril-induced rise in plasma renin activity met all three criteria established by Müller et al. Patients with a positive test and those meeting only one or two of the three criteria were further investigated for renovascular hypertension by measuring renal venous renins and by digital subtraction intravenous angiography. Renin responses were analyzed according to baseline renin-sodium profile. RESULTS: Nine of 108 subjects had a false-positive captopril test result. Among the subjects with a low or normal renin-sodium profile, 1% (one of 82) had a false-positive result. In contrast, false-positive results were seen in 31% (eight of 26) of high-renin subjects. False-positive test results were not related to urinary sodium excretion or to excessive decrease in blood pressure. The magnitude of the renin response to captopril was strongly and directly related to the baseline plasma renin activity. CONCLUSION: An exaggerated renin response to captopril challenge is common in patients with high-renin essential hypertension. Therefore, in a population with a low probability of renovascular hypertension, caution is recommended in interpreting a positive test result in patients with a high baseline renin.

Differences in urinary albumin excretion rate between normotensive and hypertensive, white and nonwhite subjects.

Eighty-one normotensive and 61 hypertensive white and nonwhite subjects were studied cross-sectionally to determine the prevalence and determinants of elevated urinary albumin levels. Twenty-four-hour urinary albumin excretion was determined by radioimmunoassay. The prevalence of elevated urinary albumin level (greater than or equal to 15 mg/24 h) was significantly greater in hypertensive than in normotensive subjects (31.1% and 8.6%). Among hypertensive subjects, a much greater proportion of whites than nonwhites had urinary albumin levels of 15 mg/24 h or greater (39.5% and 17.4%). The independent association of blood pressure with urinary albumin level was affirmed by logistic regression analyses for white normotensive and hypertensive subjects combined, and for hypertensive subjects alone. Furthermore, among hypertensive subjects, whites were five times as likely as nonwhites to have elevated urinary albumin levels. Thus, blood pressure and ethnicity were the important determinants of urinary albumin excretion among hypertensive subjects.