Biomedical subjects

E Barrett-Connor

Publications and source records attributed to E Barrett-Connor.

At least 217 records · Page 12Linked to original sources

PubMed1991

Factors associated with paradoxical survival at higher blood pressures in the very old.

Paradoxically greater survival for persons aged 85 years and older with higher blood pressures has been reported in a Finnish population study (Br Med J 1988;296:887-9). In a previous report, the authors demonstrated improved 10-year survival with increasing diastolic blood pressure in men (but not in women) aged 75 years and older in the Rancho Bernardo Chronic Disease Study (Br Med J 1989;298:1356-7). However, few of the covariates which could potentially explain this effect were obtained at the visit used in that analysis. In an effort to confirm these reports of paradoxical survival and to explore possible reasons for them, the authors analyzed all-cause and cardiovascular mortality in 795 men and women aged 75-96 years (mean, 80.6), evaluated in 1984-1987 and followed prospectively for an average of 3 years after that comprehensive examination. Of 63 deaths, 48 (76%) were in men; 43 (68%) of all deaths were cardiovascular. Kaplan-Meier survival analyses showed a significant trend for improved survival with increasing diastolic pressure in men aged 80 years and older versus all-cause mortality (chi 2 p less than or equal to 0.01), and cardiovascular mortality (chi 2 p less than or equal to 0.00). These trends were not evident in men aged less than 80 years or in women in either age group. Results were not explained by differences in the use of antihypertensive medication, pulse pressure, history of hypertension, history of coronary heart disease, isolated systolic hypertension, interval change in diastolic pressure (over an average of 12 years), or by cholesterol, triglycerides, fasting plasma glucose, smoking, or body mass index. Thus, the paradoxical relation of improved all-cause and cardiovascular survival in men aged 80 years or older with higher diastolic pressure is not explained by a wide range of biologic and historical factors.

Age Factors↗

PubMed1991

Plasma lipids and gallbladder disease.

The relation between plasma lipids and gallbladder disease was examined by using data collected between 1984 and 1987 from 1,303 Rancho Bernardo, California, women aged 50 years and older. In univariate analyses and after adjustment for age and body mass index, high density lipoprotein cholesterol (HDL cholesterol) and low density lipoprotein cholesterol (LDL cholesterol) were inversely related and triglyceride level was positively related to gallbladder disease. However, using multiple logistic regression, only LDL cholesterol, triglycerides, age, and body mass index were significantly related to a history of gallbladder disease, whereas HDL cholesterol was no longer associated with gallbladder disease. The risk of gallbladder disease increased with greater age, body mass index, and triglyceride level, but decreased with increasing LDL cholesterol level. Total amount of alcohol consumed per week, number of cigarettes smoked per day, and current estrogen use were not significantly associated with gallbladder disease. The relation of HDL cholesterol and LDL cholesterol to the risk of gallbladder disease requires further investigation.

Age Factors↗

PubMed1991

Clustering of residence of multiple sclerosis patients at age 13 to 20 years in Hordaland, Norway.

Geographic and temporal variation and migration studies point to an exogenous agent in the etiology of multiple sclerosis. If infectious etiology is involved, space-time clustering would also be expected. The authors analyzed 381 patients with a clinical onset of multiple sclerosis between 1953 and 1987 in the county of Hordaland, Norway. Patients within the same birth cohort had lived significantly closer to each other than would be expected during ages 13-20 years, with peak clustering at age 18 years (p = 0.002). Clustering was also shown between patients in pairs comprised of one individual with initial remittent disease and the other with chronic progressive course of disease, suggesting a similar etiology for both clinical patterns. Clustering between cases with widely divergent dates of clinical onset provides evidence of marked variation in latency. No similar clustering was observed in age-, sex-, and area-matched hospital controls without multiple sclerosis, and no clustering was found among the cases when using fixed number of years before onset. These results are compatible with a common infectious agent, such as the Epstein-Barr virus, acquired in adolescence in genetically vulnerable persons who are also not protected by an infection acquired before this age of susceptibility. Susceptibility could be related to the route of transmission or to other age-related covariates or it may be hormonally mediated.

Adolescent↗

PubMed1991

Estrogen and coronary heart disease in women.

We review herein the evidence that estrogen is protective against the development of cardiovascular disease in women. To our knowledge, no studies in women have looked at endogenous estrogen levels as predictors of cardiovascular disease. Studies of surrogate measures of endogenous estrogen such as parity, age at menarche, and age at menopause have provided inconsistent results. Current use of oral contraceptives increases risk in older women who smoke cigarettes, but most studies of past use show no increased risk. Most, but not all, studies of hormone replacement therapy in postmenopausal women show around a 50% reduction in risk of a coronary event in women using unopposed oral estrogen. These important observations need to be confirmed in a double-blind, randomized clinical trial, since the protection is biologically plausible and the magnitude of the benefit would be quite large if selection factors can be excluded.

Age Factors↗

PubMed1991

Sex differences in fasting glycemia as a risk factor for ischemic heart disease death.

The relation between fasting plasma glucose and mortality from ischemic heart disease was examined in a population of 3,458 nondiabetics (aged 40-79 years) in Rancho Bernardo, California, who were free of heart disease at baseline and were followed for an average of 14 years, from 1972 to 1987. A linear increase of age-adjusted ischemic heart disease mortality rates with fasting glucose was observed in men, and a threshold relation at 110 mg/100 ml plasma glucose was observed in women. On the basis of Cox proportional hazards analysis, the observed sex differential in the association between plasma glucose and ischemic heart disease mortality proved to be statistically significant and independent of the effects of age, systolic blood pressure, body mass index, plasma cholesterol, plasma triglyceride, and, in women, estrogen use. In sex-specific multivariate models, interaction terms representing a threshold effect at glucose levels greater than or equal to 110 mg/100 ml were statistically significant in women (p = 0.007), but not in men, and interaction between sex and the glucose threshold term was observed in multivariate analysis of men and women combined (p = 0.07). The authors conclude that sex differences in the effect of fasting glycemia on ischemic heart disease mortality among nondiabetics exist and are unexplained. Elucidation may hold a key to the sex difference in heart disease and the relatively greater importance of diabetes and impaired glucose tolerance as risk factors for ischemic heart disease in women compared with men.

Adult↗

PubMed1991

A population-based comparison of quantitative dual-energy X-ray absorptiometry with dual-photon absorptiometry of the spine and hip.

Dual photon absorptiometry (DPA) is currently the most widely used method for noninvasive bone mineral density (BMD) measurement of the axial skeleton. Dual energy X-ray absorptiometry (DEXA) is a recently developed technique that uses an X-ray tube as a photon source; it has demonstrated several significant advantages over DPA in preliminary studies. We report here a quantitative comparison of the DEXA and DPA technologies using a Hologic DEXA (Hologic QDR model 1000, Waltham, MA) scanner and a Lunar DPA (Lunar Radiation DP3, gandolineum-153 source) scanner at both the proximal femur and lumbar spine sites using bone density measurements from a population-based sample of older white men and women who had complete DEXA and DPA measurements of the hip (n = 217) or the spine (n = 176). To examine the relationship of BMD measured by the DPA scanner to BMD measured on the DEXA scanner, normal least squares linear regression was used to regress the DPA BMD on the DEXA BMD for each site. DEXA values were consistently lower than DPA values, with an average difference of 16%. The squared multiple correlation (R2) values were at or above 0.95 for almost all sites, with Ward's triangle having the lowest value (0.89). The slope for all sites was similar, ranging from 0.94 to 1.1. Research and clinical centers that wish to change to DEXA technology because of its shorter examination time and greater precision can therefore compare DEXA with DPA values using representative conversion factors.

Absorptiometry, Photon↗

PubMed1991

Fasting plasma glucose levels and endogenous androgens in non-diabetic postmenopausal women.

1. The clinical association between glucose intolerance, hyperinsulinaemia, insulin resistance and hyperandrogenism is well recognized in premenopausal women with polycystic ovarian disease. We examined the hypothesis that fasting plasma glucose levels might be related to endogenous androgen levels in postmenopausal women in the absence of overt clinical disease. 2. In a Southern Californian cohort of 848 nondiabetic postmenopausal women aged 50-79 years, fasting plasma glucose levels positively correlated with levels of the endogenous androgens dehydroepiandrosterone sulphate and free testosterone and negatively with sex-hormone-binding globulin across the whole range of glucose and hormone levels. Mean dihydroepiandrosterone sulphate and free testosterone levels were 16% and 46% higher, respectively, and mean sex-hormone-binding globulin levels 27% lower in the top compared with the bottom quartile of fasting plasma glucose levels. This relationship was independent of age, body mass index, cigarette smoking habit and exogenous oestrogen use. 3. These findings raise questions about the possible physiological role of androgens in the regulation of glucose metabolism and insulin resistance and, possibly, in the mediation of the some of the cardiovascular consequences of diabetes in women.

Age Factors↗

PubMed1991

Calcium intake: covariates and confounders.

One common nutrient postulated to be protective against osteoporosis, hypertension, and colon cancer is dietary calcium. We report here nutrient patterns by calcium intake in older adult residents of a geographically defined community in Southern California. The analysis included all 426 men and 531 women aged 50-79 y with complete 24-h diet data. Nutrient-density-adjusted calcium intake was divided into tertiles: low intake (less than 284 mg/1000 kcal), mid intake (284-440 mg/1000 kcal), and high intake (greater than 440 mg/1000 kcal). The distribution of the reported 24-h nutrient density of protein, fat, fiber, caffeine, trace minerals, vitamin D, and vitamin C was examined in relation to the calcium-intake tertiles. In both men and women, the adjusted intakes of protein, saturated fatty acids, vitamin D, magnesium, and phosphorus were significantly higher in the high-calcium-intake group than in the low- and mid-calcium-intake groups. In both men and women, alcohol intake was significantly lower in the high-calcium-intake group. Studies postulating a protective role for calcium will need to consider the multicolinearity in the Western diet.

Aged↗

PubMed1991

Nutrition epidemiology: how do we know what they ate?

It is generally believed but difficult to prove that diet plays a role in the risk of various diseases. This paper reviews strengths and deficiencies of select diet-assessment methods used in epidemiologic studies with particular reference to their use in the study of osteoporosis. Direct observation or weighed food records are useful primarily as validation for less intrusive methods. Complete food history by interview or food diary (by self report) is expensive and time consuming. A 24-h diet recall obtained by a trained dietitian can provide accurate, quantitative information on recent intake but does not represent usual intake. Food frequency questionnaires provide better estimates of usual diet but are less quantitative and subject to problems of recall and seasonality. No method is universally the best. Lack of an expected diet-disease association may reflect exposure misclassification, inadequate statistical power, or limited range of the nutrients studied. Given the differences in diet-assessment methods, studies of dietary calcium and osteoporotic fracture have had surprisingly similar results.

Calcium, Dietary↗

PubMed1991

Type 2 diabetes and depressive symptoms in older adults: a population-based study.

The prevalence of depressive symptoms and its association with Type 2 (non-insulin-dependent) diabetes was examined in a population-based study of 1586 men and women aged 50 years or older. Men and women with previously diagnosed diabetes had significantly higher mean Beck Depression Inventory total, somatic subscale, and affective subscale scores than normal men and women and individuals with newly diagnosed diabetes. The age- and sex-adjusted rates of Inventory scores of 13 or greater among individuals with previously diagnosed diabetes was 3.7 times greater than the rates among individuals with newly diagnosed diabetes (p less than 0.05). Medication use and fasting plasma glucose were unrelated to symptom score. The number of other chronic conditions and age were significant independent predictors of depressive symptoms in all diabetic men and women. Results suggest that depressive symptoms in individuals with Type 2 diabetes may be related to awareness of diabetic condition in addition to poor health.

Adult↗

PubMed1991

Relation between leisure-time physical activity and blood pressure in older women.

Although there is some evidence that physical activity may decrease blood pressure in young and middle-aged women, the physical activity-blood pressure association in older women has rarely been studied. As part of an ongoing community-based study of chronic disease, 641 Caucasian women between the ages of 50 and 89 years had blood pressure measured following the Hypertension Detection and Follow-up Program protocol. They also answered selected Health Interview Survey questions about their leisure-time activity and were classified into categories of light (58%), moderate (24%), heavy (6%), or no physical activity (12%) by the estimated metabolic rate required for each activity. Women who engaged in any physical activity were significantly younger and thinner than sedentary women and had lower fasting and 2-hour postchallenge insulin levels. They did not differ in alcohol consumption, cigarette use, or prevalence of coronary heart disease or diabetes. Rates of systolic and diastolic hypertension were significantly lower in women participating in light, moderate, or heavy physical activity compared with sedentary women. Blood pressure levels decreased with each increase in reported activity intensity (p less than 0.005 for trend), with systolic blood pressure approximately 20 mm Hg lower in the heaviest activity group compared with systolic blood pressure in sedentary women. Intergroup differences remained statistically significant after adjustment for age and body mass index. Although physical activity was associated with lower fasting and 2-hour postchallenge insulin levels (p less than 0.01 for trend), adjustment for insulin levels did not alter blood pressure differences among activity groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

Evaluation of fasting plasma glucose as screening test for NIDDM in older adults. Rancho Bernardo Study.

OBJECTIVE: To examine the efficiency of fasting plasma glucose (FPG) as a screening test for non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH AND METHODS DESIGN: A population-based evaluation was made of FPG as screening test for NIDDM in an upper middle-class white community of Rancho Bernardo, California. NIDDM was defined by 2-h postchallenge plasma glucose (PCPG) level greater than or equal to 11.1 mM, the cutoff point recommended by the World Health Organization. Participants comprised a population-based sample of 1851 men and women 50-79 yr of age that represented 80% of surviving participants surveyed between 1972 and 1974 for the Lipid Research Clinic Prevalence Study. Those with insulin-dependent diabetes were excluded. RESULTS: Analyses were stratified by age after logistic regression indicated that FPG and age (but not gender) were significantly related to probability of disease. As FPG cutoff points increased, sensitivity and percentage of the population to be recalled for confirmation decreased, whereas specificity and positive predictive value increased. Negative predictive value was consistently in the 90% range. Specificity did not change with age. In contrast, at virtually every FPG cutoff point, sensitivity decreased with increasing age. For example, at FPG greater than or equal to 6.7 mM, sensitivity was 65.6% for those 50-64 yr of age and 40.0% for those 65-79 yr of age. At FPG greater than or equal to 7.2 mM, these sensitivities were 46.9 and 28.5%, respectively. Positive predictive value increased with increasing age, reflecting the increasing prevalence of NIDDM with age. CONCLUSIONS: Poorer sensitivity with increasing age reflects the fact that the numerator of the sensitivity equation is not affected by age (mean FPG did not vary significantly between age-groups), whereas the denominator increases with age (mean PCPG increased from 6.6 mM for subjects 50-64 yr of age to 8.2 mM for subjects 65-79 yr of age). Nevertheless, because the clinical significance of increasing PCPG with age in older adults is unknown, age-specific screening criteria probably are not warranted.

Age Factors↗

PubMed1990

Dehydroepiandrosterone sulfate and breast cancer risk.

It has been suggested that dehydroepiandrosterone (DHEA) and its sulfate ester, dehydroepiandrosterone sulfate (DHEAS), have a protective effect against breast cancer. In our investigation, DHEAS levels were measured in plasma obtained and frozen in 1972-1974 from 534 women aged 50-79 yr. This group, which has been followed for 15 yr, included 21 incident cases of breast cancer, 20 cases with earlier diagnosis, and ten cases with unknown date of onset who were identified from death certificates only. Two sets of analyses were done: one using all women and one which excluded women using estrogen. No significant differences in age-adjusted DHEAS levels were found between any case type and noncases. Age-adjusted rates of breast cancer by DHEAS tertile also showed no significant trends or differences among tertiles for any case type. A multivariate model in which the DHEAS level was adjusted for age, body mass index, estrogen use, and cigarette smoking status also showed no significant association between DHEAS and risk of breast cancer. These results do not support a protective role for plasma DHEAS in breast cancer risk in postmenopausal women.

Age Factors↗

PubMed1990

A prospective, population-based study of androstenedione, estrogens, and prostatic cancer.

Endogenous androgens have been suggested as determinants of risk of prostatic cancer. To examine this possibility, baseline sex hormone levels were measured in 1008 men ages 40-79 years who had been followed for 14 years. There were 31 incident cases of prostatic cancer and 26 identified from death certificates with unknown dates of diagnosis. In this study, total testosterone, estrone, estradiol, and sex hormone-binding globulin were not related to prostate cancer, but plasma androstenedione showed a positive dose-response gradient. Age-adjusted relative risks of prostatic cancer for low (0-2.2 nM), middle (2.3-3.1 nM), and high (3.2+ nM) tertiles of androstenedione were 1.00, 1.34, and 1.98, respectively (P trend less than 0.05). The linear gradient of risk persisted after adjustment for age and body mass index. If confirmed, these data suggest that androstenedione might increase the occurrence of clinically manifest prostatic cancer.

Adult↗

PubMed1990

Self-reported arthritis among men and women in an adult community.

In the Rancho Bernardo, California population of older adults, the age-adjusted prevalence rate of self-reported arthritis was higher in women than men for all types combined (38.6 vs. 22.3%, p less than 0.05), and for osteoarthritis (18.1 vs 12.9%). Men and women with osteoarthritis and disabling arthritis were significantly more likely to report co-morbid conditions. Women with osteoarthritis were significantly less likely to drink alcohol and more likely to be taking estrogen replacement therapy. At 15 years of follow up, mortality rates were not significantly increased in men or women with arthritis or osteoarthritis compared to those without arthritis.

Activities of Daily Living↗

PubMed1990

The biocultural context of social networks and depression among the elderly.

The association between the size and structure of social networks and the prevalence of depressive symptoms was examined in a population-based study of 1615 men and women age 65 years and older. Age was significantly associated with marital status, social network index quartile, and the social relationship to the primary source of support. Women and men differed with respect to current marital status, number of close friends and relatives, frequency of face-to-face contact, and participation in voluntary associations and religious institutions. Regardless of their marital status, women were also less likely than men to point to a spouse as their primary source of support. Beck Depression Inventory mean scores and rates of depressive symptoms were inversely associated with social network index and participation in voluntary associations and religious institutions for both men and women. Individuals with no primary source of support or who depended on a relative had significantly higher than expected mean scores and rates of depressive symptoms. Both social network index and social distance to primary source of support were independently associated with depression after controlling for age, sex, and number of chronic conditions. Participation in voluntary associations, social distance from primary source of support, church membership, and number of close friends were also significant independent predictors of depressive symptoms. Results indicate that depressive symptoms are inversely associated with the size of social networks. The structure of these networks, in turn, is influenced by biological factors such as age, physical disability, and mortality of network members, and by culturally-determined rules that define the individuals and institutions available for support. However, these rules appear to differ for men and women.

Aged↗

PubMed1990

Chronic illness and depressive symptoms in the elderly: a population-based study.

A cross-sectional study of the distribution of depressive symptoms and association between depressed mood and chronic illness was conducted in a geographically defined population in southern California of 1617 men and women aged 65 years and older. The prevalence of depressed mood for the total population was 5.2%. Women exhibited a significantly higher mean depressive symptom score and a prevalence rate almost twice that of men. Depressive symptoms were associated with several risk factors in both sexes, including age, self-perception of current health status, number of reported chronic diseases and medications and amount of exercise. However, the relationship between physical illness and depressive symptoms appeared to differ by sex with respect to the nature of the disease or disability and the type of medication currently used. These findings indicate that the risk of depression does not diminish with age among the elderly as other studies have suggested.

Age Factors↗

PubMed1990

The relationship between reproductive history and cholecystectomy in older women.

We examined the relationship of reproductive history to cholecystectomy in a population-based sample of 1093 women aged 50 years and older. Number of pregnancies ranged from 0 to 13. Age and obesity were each significantly and independently associated with an increased risk of cholecystectomy. When adjusted for differences in age and obesity, those who had had five or more pregnancies had a significantly increased risk of cholecystectomy. We conclude that an increased risk of gallbladder disease may follow either obesity or multiple pregnancies. One possibly unifying hypothesis for the obesity and pregnancy association is sustained hyperestrogenemia.

Aged↗