James O. Taylor

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.

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 Alzheimers 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.

Established populations for epidemiologic studies of the elderly: Study design and methodology

A project initiated by the intramural Epidemiology, Demography and Biometry Program of the National Institute on Aging, entitled “Established Populations for Epidemiologic Studies of the Elderly” (EPESE), has developed information on death, chronic conditions, disabilities, and institutionalization for representative samples of elderly people living in communities. The EPESE consists of prospective epidemiologic studies of approximately 14 000 persons 65 years of age and older in four different communities: East Boston, Massachusetts; two rural counties in Iowa; New Haven, Connecticut; and segments of five counties in the north-central Piedmont area of North Carolina. The study design includes an initial baseline household interview followed by continued surveillance of morbidity and mortality. Participants are re-contacted annually in conjunction with the collection of data on cause of death and factors related to hospitalization and nursing home admissions. Concurrently, the investigators developed substudies focused on specific problems of the elderly. The value of this research lies in the longitudinal design which allows for analyses aimed at identifying risk factors of diseases, disabilities, hospitalizations, institutionalization, and mortality. (Aging Clin. Exp. Res. 5: 27–37, 1993)

Level of education and change in cognitive function in a community population of older persons

In a community population of persons over the age of 65, cognitive function was assessed using brief performance tests on two occasions 3 years apart. Those with fewer years of formal education consistently had greater declines in cognitive function, independently of age, birthplace, language of interview, occupation, and income. These prospective findings suggest that low educational attainment or a correlate predicts cognitive decline. It is not clear, however, whether this relation represents a direct effect of education on future cognition, whether education might be related to occurrence of a disease leading to cognitive decline in older persons, or whether education might be a surrogate for some variable not included in the study.

Evidence for a positive linear relation between blood pressure and mortality in elderly people

Many studies of blood pressure in the elderly have found higher death rates in groups with the lowest blood pressure than in those with intermediate values. In a large community study, we examined whether these findings are real or artifacts of short follow-up, co-morbidity, or low blood pressure in people near death. In 1982-83, we assessed drug use, medical history, disability, physical function, and blood pressure in 3657 residents of East Boston, Massachusetts, aged 65 and older. We identified all deaths (1709) up to 1992 and followed up survivors for an average of 10.5 (range 9.5-11.0) years. After adjustment for confounding variables (including frailty and disorders such as congestive heart failure and myocardial infarction) and exclusion of deaths within the first 3 years of follow-up, higher systolic pressure predicted linear increases in cardiovascular (p < 0.0001) and total (p < 0.0007) mortality. Higher diastolic pressure predicted increases in cardiovascular (p = 0.006) but not total (p = 0.48) mortality. These results differed from those for the first 3 years, during which groups with the lowest systolic and diastolic pressures had the highest death rates. In the long term, lower blood pressure in old age, as in middle age, is associated with better survival. Short-term findings may differ because of associations of co-morbidity and frailty with blood pressure near death. Overall, the findings support recommendations to treat high blood pressure in elderly people.

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.

Association of education with incidence of cognitive impairment in three established populations for epidemiologic studies of the elderly.

We analyzed the association of education, occupation, and sex with incidence of cognitive impairment using data from three communities in the Established Populations for Epidemiologic Studies of the Elderly (EPESE) projects (New Haven, East Boston, and Iowa). Participants were initially interviewed in 1981-1983, with follow-up 3 and 6 years later. Incident cognitive impairment was defined on the basis of either: (1) increase in the number of errors in Short Portable Mental Status Questionnaire (SPMSQ) (i.e. from a baseline level below the cutoff value to a score above the cutoff), or (2) inability to respond to interview questions at a follow-up contact (requiring a proxy informant), or (3) death with a recorded diagnosis of a dementing illness. In multiple logistic regression models, the major factors predicting the development of cognitive impairment were advanced age, any errors on baseline SPMSQ, 8 or fewer years of education, and occupation. Education and occupation remained significant predictors after controlling for age, site, sex, stroke, and baseline SPMSQ score.

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.

Effects of cigarette smoking on fasting triglyceride, total cholesterol, and HDL-cholesterol in women

We examined the relationships of cigarette smoking with fasting triglycerides, total cholesterol, and high-density lipoprotein cholesterol (HDL-C) levels among a group of 191 white women aged 20 to 40 years. The mean triglyceride level among current smokers was 100.0 mg/100 ml and among nonsmokers was 68.4 mg/dl (p less than 0.005). Mean total cholesterol values among current smokers and nonsmokers were, respectively, 197.0 and 189.1 mg/dl (p less than 0.1). Mean HDL-C levels were 45.0 mg/dl among women who were smoking and 52.1 mg/dl among nonsmokers (p less than 0.005). Simultaneous adjustments for the effects of age, weight, height, blood glucose, resting pulse, and oral contraceptive use did not materially alter these relationships. A modest portion of the effect of cigarette smoking on risk of coronary heart disease may be explained by an adverse effect of cigarette smoking on blood lipids.

Prediction of young adult blood pressure from childhood blood pressure, height, and weight

To assess the ability of childhood blood pressure, height, and weight to predict young adult blood pressure, the authors examined data obtained over multiple visits for four years on 339 children aged 8-18 years in East Boston, Massachusetts. These subjects were again seen 8-12 years later when they were aged 20-26 years. Multivariate regression models were used to predict true blood pressure in young adulthood from observed childhood measurements closest to age 10 (n = 219), adjusting for within-person variability. Without adjusting for childhood blood pressure, childhood height, weight and body mass index were at least marginally associated with young adult systolic blood pressure in boys and girls, with similar coefficients for each gender. The strongest predictor was weight (beta = 0.6 mmHg/10 lbs for girls, and beta = 0.7 mmHg/10 lbs for boys), and height was no longer predictive with weight in the model. With childhood blood pressure included, neither childhood height nor weight were predictors of future systolic blood pressure. However, change in height and weight were predictors of future systolic blood pressure. Weight change was a stronger predictor in girls than boys with beta = 0.9 mmHg/10 lbs. For diastolic blood pressure, height and weight had limited predictive ability in these data. These models, which allow for both between- and within-person variability in young adulthood, may be used to estimate the predictive value for future high blood pressure of a childs current blood pressure, height and weight, as well as future change in height and weight. These data suggest that the effects of childhood height and weight on future blood pressure may be negligible given childhood blood pressure, but that later height and weight remain predictive.