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Biomedical subjects

J O Taylor

Publications and source records attributed to J O Taylor.

At least 19 recordsLinked to original sources

Use of antihypertensive drugs and trends in blood pressure in the elderly.

BACKGROUND: During the 1980s data became available from randomized trials concerning the clear benefits of treating hypertension in the elderly. In three large communities, we examined the impact of these findings on rates of treatment, use of specific antihypertensive drugs, and rates of elevated blood pressure as well as distributions of levels. METHODS: In 1981 the National Institute on Aging initiated population-based cohort studies in the residents of three communities who were 65 years and older. East Boston, Mass; Washington and Iowa counties, Iowa; and New Haven, Conn. Participation rates ranged from 80% to 85% across sites with 10,294 community-dwelling participants in the combined cohorts. Baseline evaluation included inhome blood pressure assessment and medication inventory. Repeated in-home evaluations occurred 3 and 6 years after baseline and follow-up rates ranged from 71% to 88%. RESULTS: Use of antihypertensive drugs increased over time in all three communities: the age- and sex-adjusted rates of use were between 14% and 32% higher in 1988 and 1989 relative to 1982 and 1983. Parallel declines in the use of thiazide diuretics occurred in all three populations along with large increases in the use of angiotensin-converting enzyme inhibitors and calcium channel blockers. In East Boston and New Haven mean systolic blood pressure decreased substantially over time and the prevalence of elevated systolic pressure (> or = 160 mmHg) decreased overall as well as by age and sex. In Iowa the mean levels of systolic blood pressure were lowest at baseline and increased slightly. CONCLUSIONS: The reported evidence about the benefits of treatment for hypertension in the elderly was followed by substantial increases in treatment rates. The use of drugs with proven efficacy declined while the use of newer agents with theoretical advantages, not yet tested in clinical trials of mortality, increased. In the United States, the ongoing therapeutic efforts to lower elevated blood pressure in elderly populations may be contributing to the continuing decline in cardiovascular and stroke mortality.

Aged

Implications of small reductions in diastolic blood pressure for primary prevention.

OBJECTIVES: To estimate the impact of small reductions in the population distribution of diastolic blood pressure (DBP), such as those potentially achievable by population-wide lifestyle modification, on incidence of coronary heart disease (CHD) and stroke. DESIGN: Published data from the Framingham Heart Study, a longitudinal cohort study, and from the National Health and Nutrition Examination Survey II, a national population survey, were used to examine the impact of a population-wide strategy aimed at reducing DBP by an average of 2 mm Hg in a population including normotensive subjects. SETTING/PARTICIPANTS: White men and women aged 35 to 64 years in the United States. MAIN OUTCOME MEASURES: Incidence of CHD and stroke, including transient ischemic attacks (TIAs). RESULTS: Data from overviews of observational studies and randomized trials suggest that a 2-mm Hg reduction in DBP would result in a 17% decrease in the prevalence of hypertension as well as a 6% reduction in the risk of CHD and a 15% reduction in risk of stroke and TIAs. From an application of these results to US white men and women aged 35 to 64 years, it is estimated that a successful population intervention alone could reduce CHD incidence more than could medical treatment for all those with a DBP of 95 mm Hg or higher. It could prevent 84% of the number prevented by medical treatment for all those with a DBP of 90 mm Hg or higher. For stroke (including TIAs), a population-wide 2-mm Hg reduction could prevent 93% of events prevented by medical treatment for those with a DBP of 95 mm Hg or higher and 69% of events for treatment for those with a DBP of 90 mm Hg or higher. A combination strategy of both a population reduction in DBP and targeted medical intervention is most effective and could double or triple the impact of medical treatment alone. Adding a population-based intervention to existing levels of hypertension treatment could prevent an estimated additional 67,000 CHD events (6%) and 34,000 stroke and TIA events (13%) annually among all those aged 35 to 64 years in the United States. CONCLUSIONS: A small reduction of 2 mm Hg in DBP in the mean of the population distribution, in addition to medical treatment, could have a great public health impact on the number of CHD and stroke events prevented. Whether such DBP reductions can be achieved in the population through lifestyle interventions, in particular through sodium reduction, depends on the results of ongoing primary prevention trials as well as the cooperation of the food industry, government agencies, and health education professionals.

Adult

Lack of blood pressure effect with calcium and magnesium supplementation in adults with high-normal blood pressure. Results from Phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group.

Phase I of the Trials of Hypertension Prevention (TOHP) was a randomized, multicenter investigation that included double-blind, placebo-controlled testing of calcium and magnesium supplementation among 698 healthy adults (10.5% blacks and 31% women) aged 30 to 54 years with high-normal diastolic blood pressure (DBP) (80 to 89 mm Hg). Very high compliance (94 to 96% by pill counts) with daily doses of 1 g of calcium (carbonate), 360 mg of magnesium (diglycine), or placebos was corroborated for the active supplements by significant net increases in all urine and serum compliance measures in white men and for urine compliance measures in white women. Overall, neither calcium nor magnesium produced significant changes in blood pressure at 3 and 6 months. Analyses stratified by baseline intakes of calcium, magnesium, sodium, or initial blood pressures also showed no effect of supplementation. These analyses suggested that calcium supplementation may have resulted in a DBP decrease in white women and that response modifiers in this subgroup might have included lower initial urinary calcium levels, urinary sodium levels, or lower body mass index. However, overall analyses indicated that calcium and magnesium supplements are unlikely to lower blood pressure in adults with high-normal DBP. The subgroup analyses, useful to formulate hypotheses, raise the possibility of a benefit to white women, which requires testing in future trials.

Administration, Oral

Interrelationships of peak expiratory flow rate with physical and cognitive function in the elderly: MacArthur Foundation studies of aging.

BACKGROUND: Peak expiratory flow rate (PEFR) is correlated with several measures of health in the elderly, including physical and cognitive function. It is unclear, however, whether these relationships persist among the non-frail. METHODS: The Community-based Studies of the MacArthur Foundation Research Network on Successful Aging included measures of PEFR using a mini-Wright peak flow meter on a sample of 1,354 subjects selected from those aged 70-79 in three population samples. Subjects were chosen on the basis of simple measures of physical and cognitive function (high = 1192; medium = 80; low = 82), and were given a series of more detailed tests. RESULTS: Residual PEFR, adjusted for age, sex, height, weight, and smoking, was highly correlated (p < .001) with several physical performance measures, including number of steps in a tandem walk, number of seconds in a single leg stand, times to turn in a circle, write one's name, and walk 10 feet at a fast pace, foot-tapping (time per tap), and hand grip strength. The strongest association was evident for a combination of six physical function items. Residual PEFR was also correlated with cognitive performance, including tests of similarities, naming, spatial recognition, memory, and figure drawing. The strongest association was present for a combined measure. These associations persisted in analyses restricted to those in the "high" function group as well as with no history of previous myocardial infarction, stroke, or cancer. Residual PEFR also exhibited a strong independent association with urinary norepinephrine, as measured in 12-hour overnight urine specimens. This relation did not appear to be mediated by smoking or medication use.

Aged

Difficulty with holding urine among older persons in a geographically defined community: prevalence and correlates.

OBJECTIVE: The goal of this study was to estimate the prevalence and correlates of difficulty holding urine among a population of community-dwelling older people. DESIGN: Population-based cross-sectional study. SUBJECTS: A population census identified all residents aged 65 years and older residing in East Boston, Massachusetts, in 1982. MEASURES: Data collected via in-home interviews were used to estimate the prevalence of difficulty holding urine and to provide information regarding potential correlates of urinary difficulty. RESULTS: Of the 3809 study participants (85% response rate), 28% reported having "difficulty holding urine until they can get to a toilet" at least some of the time, and 8% reported difficulty "most" or "all of the time." Difficulty was associated with age and sex; 44% of women and 34% of men reported some difficulty (P < .001), and 9% of women and 6% of men (P < .001) reported difficulty most or all of the time. For respondents aged 65 to 74 years, 40% reported some difficulty, compared with 47% of those aged 85 and older (Ptrend < .001); difficulty most or all of the time was reported by 6% of those aged 65 to 74 and 12% of those aged 85 and older (Ptrend < .001). Difficulty holding urine was associated with important health and functional measures including depression, stroke, chronic cough, night awakening, fecal incontinence, problems with activities of daily living, decreased frequency and ease in getting out of the house, and poor self-perception of health. CONCLUSIONS: Difficulty holding urine is a prevalent condition among older people living in the community and is associated highly with a number of health conditions and functional problems.

Aged

Childhood blood pressure tracking correlations corrected for within-person variability.

The correlation coefficient between initial and subsequent blood pressure (BP) measurements is referred to as the tracking correlation. Childhood BP tracking correlations, although positive, have been considered too low to make accurate predictions for an individual. These correlations, however, can be raised substantially by averaging BP over multiple weekly visits in each year, which partially accounts for within-person variability. In a cohort of 333 school children, we measured BP 3 times on each of 4 successive weekly visits, in each of 4 consecutive years, using a random-zero sphygmomanometer. Approximately 90 per cent of subjects had data for one or more follow-up years, and 75 per cent of subjects who entered in the first year had data for all four years. With a model that allows estimation of correlations and that uses all available longitudinal data, we calculated tracking correlations completely corrected for within-person variability, the statistical equivalent of measuring BP on an infinite number (infinity) of visits and measurements per visit. Age-sex adjusted tracking correlations for 3 years of follow-up based on the means from 1,2,3,4, and infinity visits are, for systolic BP, 0.43, 0.56, 0.62, 0.66, and 0.73, respectively, and for diastolic BP, 0.20, 0.37, 0.46, 0.50, and 0.70, respectively. With longer follow-up, the use of corrected tracking correlations would allow determination of the maximal extent to which childhood BP can predict adult levels, and therefore the usefulness of screening to identify children at high risk of developing hypertension.

Adolescent

Assessing the validity of childhood blood pressure screening: unbiased estimates of sensitivity, specificity, and predictive values.

Blood pressure measurement in childhood can be considered as a screening test for future blood pressure levels. Evaluating this test involves calculating sensitivities, specificities, and predictive values for a blood pressure measurement at an initial time for predicting underlying true blood pressure at a subsequent time. We demonstrate the use of childhood blood pressure tracking correlations that are corrected for within-person variability to calculate unbiased estimates of these test characteristics. In a cohort of 333 schoolchildren, we measured blood pressure on multiple visits in each of 4 successive years. Using these data for within-person variances and corrected tracking correlations, and U.S. population data for means and total variances, we tabulated positive predictive values, sensitivities, and specificities for the case of predicting a 9-year-old male's true systolic blood pressure 3 years later. For example, if a 9-year-old's average blood pressure from 4 visits is 115 mmHg, the probability of his true blood pressure being greater than 116 mmHg (90th percentile) at age 12 is 0.50. With longer follow-up, the use of predictive values, sensitivities, and specificities that incorporate corrected correlations should allow determination of the accuracy of predicting adult blood pressure from childhood values, and therefore the usefulness of screening children for those at high risk of developing hypertension.

Adolescent

Blood pressure and mortality risk in the elderly.

Blood pressure was assessed between 1981 and 1983 in all persons over age 65 years in three communities (East Boston, Massachusetts; New Haven, Connecticut; and Iowa and Washington countries, Iowa), and cause-specific mortality was monitored annually over the subsequent 5 years as part of the National Institute on Aging-sponsored Established Populations for Epidemiologic Studies of the Elderly. Each community had 80% or more participation: in East Boston, 3,809 persons with 903 deaths, in New Haven, 2,812 persons with 804 deaths, and in Iowa, 3,673 persons with 763 deaths. At 2 years, odds of death from all causes were higher in the low (less than 130 mmHg) than the middle (130-159 mmHg) systolic blood pressure group for persons aged 65-79 years in all three populations. By 5 years, cardiovascular death increased with increasing systolic pressure in all three communities and reached significance in Iowa. Cancer death was highest in the low systolic pressure stratum in all three centers. All-cause, cardiovascular death, and cancer mortality was highest in the low (less than 75 mmHg) diastolic blood pressure group in East Boston, even at 5 years. Blood pressures obtained 9 years earlier in 2,079 (68%) of the East Boston participants showed a significantly higher risk of cardiovascular death with increasing systolic pressure and no relation between diastolic pressure and mortality risk. In the elderly, excess mortality at lower levels of blood pressure during early follow-up may in part be due to the effects of illness and disability present at baseline. This may obscure the usual rise in mortality with increasing systolic pressure. There is no consistent relation between diastolic pressure and mortality.

Aged

Peak expiratory flow rate and 5-year mortality in an elderly population.

During a population survey in 1982-1983 among all community-dwelling elderly aged 65 years and over in East Boston, Massachusetts, measurements of peak expiratory flow rate using the mini-Wright peak flow meter were made on 3,582 participants (80% of those eligible). The average peak flow rate was 315 liters/minute, and a measure of peak flow rate adjusted for age, sex, height, and weight was computed. This was a highly significant (p less than 0.0001) predictor of 5-year total mortality, whose ascertainment was virtually complete. The relative risk was 1.27 (95 percent confidence interval 1.19-1.36) per 100 liters/minute decrease in peak flow rate, using a proportional hazards model including terms for age, sex, and smoking. There was no apparent modification of the effect of this measure in various categories of smoking, with relative risks of 1.24 for nonsmokers, 1.29 for ex-smokers, and 1.26 for current smokers. This finding also persisted after adjustments for other covariates, including respiratory symptoms such as cough, phlegm, and wheeze; cardiovascular risk factors such as history of myocardial infarction and stroke; and systolic and diastolic blood pressures; socioeconomic status; scores on simple tests of cognitive function; measures of physical activity and functional ability; and self-assessed state of health. In a stepwise model including all of these variables, the relative risk was 1.16 (p less than 0.0001) per 100 liters/minute decrease in peak flow rate, indicating that peak flow rate is a strong independent predictor of total mortality in the elderly.

Activities of Daily Living

Use of brief cognitive tests to identify individuals in the community with clinically diagnosed Alzheimer's disease.

Two brief screening tests, the Short Portable Mental Status Questionnaire (SPMSQ) and the East Boston Memory Test (EBMT), were included in a population questionnaire administered to 3,811 persons 65 years of age and older. A detailed clinical evaluation was then administered to 467 persons (drawn from high, medium and low performers on the EBMT) to determine who was cognitively impaired and the disorders that were responsible for that cognitive impairment. The results showed that the EBMT was better at enriching the population of the poor performance group with persons who had Alzheimer's disease (AD). It had a lower refusal rate among non-proxy respondents: 2% for the EMBT versus 9% for the SPMSQ. The sensitivity and positive predictive value were also higher for the EBMT than the SPMSQ when the diagnosis of interest was AD. However, there were persons with AD in all strata of performance on both the EBMT and the SPMSQ, emphasizing the importance of selecting persons from all performance strata in multistage community studies of AD.

Aged

Use of multiple visits to increase blood pressure tracking correlations in childhood.

Previous studies of childhood blood pressure have shown tracking correlations, which estimate the magnitude of association between initial and subsequent measurements, to be lower than corresponding adult values. Inasmuch as this disparity could arise from failing to account for a larger week-to-week variability in children, blood pressure was measured for 4 successive years, on four weekly visits in each year, and with three measurements at each visit, using a random-zero sphygmomanometer, in a cohort of 333 schoolchildren aged 8 through 15 at entry. Ninety percent of subjects had measurements in 1 or more years of follow-up. For all follow-up periods (1, 2, and 3 years from baseline), the Pearson correlation coefficient (r) for both systolic and diastolic blood pressure rose substantially with the number of weekly visits used to calculate each subject's yearly blood pressure (P less than .0001). For systolic pressure, the 3-year r values for 1, 2, 3, and 4 visits were .45, .55, .64, and .69, respectively. For diastolic pressure (Korotkoff phase 4), the corresponding values were .28, .41, .47, and .54. These higher multiple-visit estimates of tracking approximate published adult values and raise the possibility that prediction of adult blood pressure from childhood measurements may be improved by averaging readings from multiple weekly visits.

Adolescent

Blood pressure, stroke, and coronary heart disease. Part 2, Short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context.

There are 14 unconfounded randomised trials of antihypertensive drugs (chiefly diuretics or beta-blockers): total 37,000 individuals, mean treatment duration 5 years, mean diastolic blood pressure (DBP) difference 5-6 mm Hg. In prospective observational studies, a long-term difference of 5-6 mm Hg in usual DBP is associated with about 35-40% less stroke and 20-25% less coronary heart disease (CHD). For those dying in the trials, the DBP difference had persisted only 2-3 years, yet an overview showed that vascular mortality was significantly reduced (2p less than 0.0002); non-vascular mortality appeared unchanged. Stroke was reduced by 42% SD 6 (95% confidence interval 35-50%; 289 vs 484 events, 2p less than 0.0001), suggesting that virtually all the epidemiologically expected stroke reduction appears rapidly. CHD was reduced by 14% SD 5 (95% CI 4-22%; 671 vs 771 events, 2p less than 0.01), suggesting that just over half the epidemiologically expected CHD reduction appears rapidly. Although this significant CHD reduction could well be worthwhile, its size remains indefinite for most circumstances (though beta-blockers after myocardial infarction are of substantial benefit). At present, therefore, a sufficiently high risk of stroke (perhaps because of age, blood pressure, or, in particular, history of cerebrovascular disease) may be the clearest indication for antihypertensive treatment.

Antihypertensive Agents

Aspirin in the primary prevention of angina pectoris in a randomized trial of United States physicians.

PURPOSE: The objective of this study was to examine the effect of low-dose aspirin (325 mg on alternate days) on the primary prevention of angina pectoris in the United States Physicians' Health Study. Despite a postulated role of platelets in atherogenesis and myocardial ischemia, the effect of chronic platelet inhibition on the development of clinical angina pectoris is unknown. SUBJECTS AND METHODS: The Physicians' Health Study is a randomized, double-blind, placebo-controlled trial among 22,071 male physicians aged 40 to 84 years, free from previous myocardial infarction, stroke, and transient cerebral ischemia at entry, and followed for an average of 60.2 months. The 21,738 physicians who were also free from angina pectoris at baseline constituted the study population for the present analyses. RESULTS: During 106,652 person-years of follow-up, 331 patients with confirmed angina pectoris were diagnosed, 194 of whom underwent a coronary revascularization procedure (coronary artery bypass graft surgery or coronary angioplasty). As compared to participants assigned placebo, the relative risk of confirmed angina pectoris in the aspirin group was 1.10 (95% confidence interval [CI], 0.88 to 1.38). For coronary revascularization, the relative risk was 1.19 (95% CI, 0.88 to 1.59). After simultaneous control for other coronary risk factors in a proportional-hazards model, these relative risks remained near unity at 1.07 (95% CI, 0.84 to 1.36) and 1.11 (95% CI, 0.81 to 1.52), respectively. When the risks of angina pectoris were examined according to year of randomization in the trial, there was no pattern of increasing benefit with longer duration of treatment. CONCLUSION: These randomized trial data indicate that chronic platelet inhibition with low-dose aspirin for an average duration of 60.2 months does not reduce the incidence of angina pectoris.

Adult

Short-term variability of measures of physical function in older people.

Self reported physical function was assessed in telephone interviews approximately 3 weeks apart for a sample of 193 persons aged 69 or older. Three measures of physical function were used: a modified Activities of Daily Living scale, three items proposed by Rosow and Breslau, and five items from among those used by Nagi. Agreement between first and second interviews was very good; most subjects reported no impairment in function at either interview. Among those who reported some impairment, the degree of limitation within the specific activities reported as limited and the total number of activities with any degree of limitation agreed exactly for most and within one level for almost all subjects. There was no evidence to suggest that age or cognitive impairment affected the variability of the responses, and reported declines and improvements in function were about equally common.

Activities of Daily Living

Prevalence of Alzheimer's disease in a community population of older persons. Higher than previously reported.

Clinically diagnosed Alzheimer's disease and other dementing illnesses were assessed in a geographically defined US community. Of 3623 persons (80.8% of all community residents over 65 years of age) who had brief memory testing in their homes, a stratified sample of 467 persons underwent neurological, neuropsychological, and laboratory examination. Prevalence rates of Alzheimer's disease were calculated for the community population from the sample undergoing clinical evaluation. Of those over the age of 65 years, an estimated 10.3% (95% confidence limits, 8.1% and 12.5%) had probable Alzheimer's disease. This prevalence rate was strongly associated with age. Of those 65 to 74 years old, 3.0% (95% confidence limits, 0.8 and 5.2) had probable Alzheimer's disease, compared with 18.7% (95% confidence limits, 13.2 and 24.2) of those 75 to 84 years old and 47.2% (95% confidence limits, 37.0 and 63.2) of those over 85 years. Other dementing conditions were uncommon. Of community residents with moderate or severe cognitive impairment, 84.1% had clinically diagnosed Alzheimer's disease as the only probable diagnosis. These data suggest that clinically diagnosed Alzheimer's disease is a common condition and that its public health impact will continue to increase with increasing longevity of the population.

Age Factors

Correlates of headache in a population-based cohort of elderly.

Data from a community-based study of 3811 persons aged 65 years and older were used to describe the characteristics of headache in the elderly. Subjects were asked whether they experienced headache in the past year, the frequency and severity of their headaches, and whether they experienced three symptoms of migraine: unilaterality, nausea or vomiting, an aura preceding the headache. Prevalence of headache in those aged more than 65 years declined with age in both men and women; women had a higher prevalence in each age group. The same was true for frequent, severe, and migrainous headache. We examined age- and sex-adjusted correlations of headache with several medical and social factors. Prevalence of any headache was strongly associated with joint pain, depression, bereavement, waking during the night, use of eyeglasses, symptoms of temporomandibular joint dysfunction, and self-assessment of health. Similar variables were associated with frequency, severity, and migrainous symptoms, and thus could not be distinguished among these various types.

Aged

Peak expiratory flow rate in an elderly population.

A population survey was conducted in 1982-1983 among 3,812 persons aged 65 years and older residing in East Boston, Massachusetts, a geographically defined urban community. Three measurements of peak expiratory flow rate were obtained by using calibrated mini-Wright meters. Peak expiratory flow rate was strongly related to age, sex, smoking, and years smoked. After adjustment for these factors, low peak expiratory flow rate was associated with chronic respiratory symptoms (cough, wheeze, shortness of breath, exertional dyspnea, orthopnea, and paroxysmal nocturnal dyspnea; p less than 0.0001) and with certain cardiovascular variables (history of stroke, p = 0.0014; angina, p = 0.05; and high pulse rate, p = 0.004). No significant associations were found with history of myocardial infarction or systolic and diastolic blood pressures. Peak expiratory flow rate was positively related to education (p less than 0.0001) and income (p less than 0.0001). Peak expiratory flow rate also was strongly related (p less than 0.0001) to measures of functional ability and physical activity, self-assessment of health, and simple measures of cognitive function. The correlations of peak expiratory flow rate with pulmonary symptoms and other indices of chronic disease raise the possibility that peak expiratory flow rate will predict mortality in an elderly population.

Age Factors