Biomedical subjects

L A Mead

Publications and source records attributed to L A Mead.

31 records · Page 2Linked to original sources

PubMed1993

Serum cholesterol in young men and subsequent cardiovascular disease.

BACKGROUND: The increased risk of cardiovascular disease associated with higher serum cholesterol levels in middle-aged persons has been clearly established, but there have been few opportunities to examine a potential link between serum cholesterol levels measured in young men and clinically evident premature cardiovascular disease later in life. METHODS: We performed a prospective study of 1017 young men (mean age, 22 years) followed for 27 to 42 years to quantify the risk of cardiovascular disease and total mortality associated with serum cholesterol levels during early adult life. The mean serum cholesterol level at entry was 192 mg per deciliter (5.0 mmol per liter). RESULTS: During a median follow-up of 30.5 years, there were 125 cardiovascular-disease events, 97 of which were due to coronary heart disease. The serum cholesterol level at base line was strongly associated with the incidence of events related to coronary heart disease and cardiovascular disease, as well as to total mortality and mortality due to cardiovascular disease. The risks were similar whether the events occurred before or after the age of 50. In a proportional-hazards analysis adjusted for age, body-mass index (the weight in kilograms divided by the square of the height in meters), the level of physical activity, coffee intake, change in smoking status, and the incidence of diabetes and hypertension during follow-up, a difference in the serum cholesterol level at base line of 36 mg per deciliter (0.9 mmol per liter)--the difference between the 25th and 75th percentiles of cholesterol level in the study population at base line--was associated with an increased risk of cardiovascular disease (relative risk, 1.72; 95 percent confidence interval, 1.39 to 2.14), coronary heart disease (relative risk, 2.01; 95 percent confidence interval, 1.59 to 2.53), and mortality due to cardiovascular disease (relative risk, 2.02; 95 percent confidence interval, 1.23 to 3.32). A difference in the base-line serum cholesterol level of 36 mg per deciliter was significantly associated with an increased risk of death before the age of 50 (relative risk, 1.64; 95 percent confidence interval, 1.03 to 2.61), but not with the overall risk of death (relative risk, 1.21; 95 percent confidence interval, 0.93 to 1.58). CONCLUSIONS: These findings indicate a strong association between the serum cholesterol level measured early in adult life in men and cardiovascular disease in midlife.

Adult↗

PubMed1993

Validity of physicians' self-reports of cardiovascular disease risk factors.

To determine the accuracy of self-reported risk factors in 78 physicians, self-reported information was compared to findings on a standardized examination. Measured weight (r = 0.98), height (r = 0.95), body mass index (r = 0.96), systolic blood pressure (SBP) (r = 0.72), and diastolic blood pressure (DBP) (r = 0.60) were highly correlated with self-reported values (all P < 0.0001). Mean self-reported SBP and DBP did not differ from measured values; measured weight was 1.5 kg greater and measured height 1.4 cm less than self-reported values (both p < 0.0001). Regression of measured on self-reported values indicated excellent agreement except for DBP and heart rate. Differences between measured and self-reported values were not associated with a variety of variables except for a greater difference in SBP at higher levels of SBP. None of the 60 self-reported nonsmokers had expired carbon monoxide levels greater than 10 ppm. These results indicate that physicians' self-reports of height, body mass index, SBP, and smoking are extremely accurate and suitable for research purposes.

Aged↗

PubMed1992

Hippocampal electrical activity in the female rat: the estrous cycle, copulation, parturition, and pup retrieval.

Hippocampal electrical activity was examined in female rats across the four phases of the estrous cycle, as well as during copulation, parturition, and pup retrieval. Possible hormonal effects on hippocampal activity were examined by recording daily during struggling and immobility throughout five estrous cycles. No differences in the characteristics of rhythmical slow activity (RSA), large-amplitude irregular activity (LIA), or their relation to behavior were found between the phases of the estrous cycle. Behaviors examined during copulation were lordosis, hopping, and ear wiggling. Lordosis and ear wiggling were both accompanied by irregular waves, with some low frequency RSA also present during lordosis. Hopping was accompanied by RSA which was greater in amplitude and frequency than RSA during walking. Parturition behaviors examined included body extensions, genital or pup licking, and 'body flattening'. Body extensions were found to be associated with irregular hippocampal activity, and appeared to be a Type 2 behavior. Interestingly, sudden suppressions of the hippocampal record lasting 1-5 s often preceded body extensions. Irregular hippocampal activity was present at all times during genital and pup licking. Body flattening was typically accompanied by very high amplitude irregular waves which, although the rats were awake, resembled a sleeping hippocampal pattern. Pup retrieval involved walking and was thus always accompanied by RSA.

Animals↗

PubMed1992

Early predictors of career achievement in academic medicine.

OBJECTIVE: To identify early personal and scholastic factors that predict academic career choice and long-term career achievement among academic physicians. DESIGN: A longitudinal cohort study. PARTICIPANTS: Nine hundred forty-four male physicians who graduated from The Johns Hopkins University School of Medicine, Baltimore, MD, from 1948 through 1964. OUTCOME MEASURES: Career achievement outcomes included attained faculty rank in 1990 and the number of citations (20 to 24 years after graduation) to published work. RESULTS: Of the 944 physicians, 424 (45%) had chosen academic careers. Scholastic performance and research experience in medical school were independently associated with having chosen an academic career (P less than .001). Among academicians, higher attained rank in 1990 was independently associated with the following: (1) membership in Alpha Omega Alpha (relative risk [RR] = 4.94, P = .0001); (2) rank in the top third of the graduating class (RR = 2.68, P = .01); and (3) research experience in medical school (RR = 3.11, P = .0001). These three factors were also independently associated with more citations to participants' published work (P less than .05). CONCLUSION: These data suggest that scholastic performance and research experience during medical school predict career achievement in academic medicine over 20 years in the future.

Achievement↗

PubMed1992

Vascular reactivity in young adults and cardiovascular disease. A prospective study.

Cardiovascular reactivity in response to the cold pressor test has been associated with an increased risk of coronary heart disease in middle-aged men. We studied 905 white male medical students, median age 22 years, in the Johns Hopkins Precursors Study. Systolic blood pressure, systolic blood pressure change during the cold pressor test, smoking, cholesterol, Quetelet index, and family history of coronary heart disease were measured on enrollment during 1948-1964. Incidence of cardiovascular morbidity and mortality was ascertained by annual questionnaires and death certificates. There was no association between change in systolic blood pressure during the cold pressor test, whether examined as a continuous variable or a 20 mm Hg or more rise, and the risk of subsequent cardiovascular disease or coronary heart disease. These findings did not change after adjustment for cardiovascular disease risk factors. Previously reported associations may have been due to preexisting arteriosclerosis, which increases the rise in systolic blood pressure during the cold pressor test. We conclude that cardiovascular reactivity to the cold pressor test in young adulthood is not a strong predictor of future cardiovascular disease.

Adult↗

PubMed1991

Incidence and risk factors for gout in white men.

OBJECTIVE: To identify potentially modifiable risk factors for the development of gout. DESIGN: Longitudinal cohort study (The Johns Hopkins Precursors Study). PARTICIPANTS: Of 1337 eligible medical students, 1271 (95%) received a standardized medical examination and questionnaire during medical school. The participants were predominantly male (91%), white (97%), and young (median age, 22 years) at cohort entry. OUTCOME MEASURE: The development of gout. RESULTS: Sixty cases of gout (47 primary and 13 secondary) were identified among 1216 men; none occurred among 121 women (P = .01). The cumulative incidence of all gout was 8.6% among men (95% confidence interval, 5.9% to 11.3%). Body mass index at age 35 years (P = .01), excessive weight gain (greater than 1.88 kg/m2) between cohort entry and age 35 years (P = .007), and development of hypertension (P = .004) were significant risk factors for all gout in univariate analysis. Multivariate Cox proportional hazards models confirmed the association of body mass index at age 35 years (relative risk [RR] = 1.12; P = .02), excessive weight gain (RR = 2.07; P = .02), and hypertension (RR = 3.26; P = .002) as risk factors for all gout. Hypertension, however, was not a significant risk factor for primary gout. CONCLUSIONS: Obesity, excessive weight gain in young adulthood, and hypertension are risk factors for the development of gout. Prevention of obesity and hypertension may decrease the incidence of and morbidity from gout; studies of weight reduction in the primary and secondary prevention of gout are indicated.

Adult↗

PubMed1991

Familial and psychological predictors of cancer.

The hypothesis that the quality of human relationships is a component in the development of cancer was investigated in a prospective study of former medical students. Findings from two psychological measures are presented: the Closeness to Parents Scale, which showed that students who subsequently developed cancer were more likely to describe a lack of closeness with their parents than their healthy classmates; and the Rorschach Interaction Scale, which demonstrated less satisfactory relationships among male cancer victims as contrasted with the rest of the cohort. The findings suggest that internal self-other representations, as measured by these two tests, are involved as regulators of biologic systems and manifestations of illness, such as cancer.

Attitude↗

PubMed1990

Dyslipidemias with desirable plasma total cholesterol levels and angiographically demonstrated coronary artery disease.

The National Cholesterol Education Program treatment guidelines define a plasma total cholesterol of less than 200 mg/dl as "desirable" and recommend no further evaluation of plasma lipid or lipoprotein levels in patients with coronary artery disease (CAD). To determine the prevalence of dyslipidemias in the presence of coexistent CAD and total cholesterol less than or equal to 200 mg/dl, a retrospective case-control study of 1,000 patients who underwent diagnostic coronary angiography was performed. Of 351 patients with total cholesterol less than or equal to 200 mg/dl, 76% of the men (244) and 44% of the women (107) had angiographically demonstrated CAD. In men with CAD and total cholesterol less than or equal to 200 mg/dl, there was a significantly greater prevalence of low levels of high density lipoprotein (HDL) cholesterol (less than or equal to 35 mg/dl), age greater than 50 years, systemic hypertension and diabetes mellitus compared to non-CAD control subjects. In women with CAD and total cholesterol less than or equal to 200 mg/dl, HDL cholesterol less than or equal to 45 mg/dl and diabetes mellitus were also significantly prevalent. Multiple logistic regression analyses revealed that HDL cholesterol, hypertension and age in men and very low density lipoprotein cholesterol in women were significantly associated with CAD after adjustment for other risk factors. These results suggest that a complete lipid and lipoprotein analysis be obtained in all patients with CAD, irrespective of the plasma (or serum) total cholesterol level.

Adult↗

PubMed1990

The prediction of midlife coronary heart disease and hypertension in young adults: the Johns Hopkins multiple risk equations.

Educating medical students about the identification of risk factors for coronary disease and hypertension should be enhanced by exercises in which medical students identify their own risk factors and visualize the impact of current risk status on future risk of disease. A cohort of 1,130 former Johns Hopkins medical students were examined in medical school and followed annually from 1948 to 1964 to identify youthful factors associated with the development of coronary heart disease and hypertension in midlife. In the ensuing years through 1984, 51 cases of coronary heart disease and 114 cases of hypertension developed. Multiple risk equations using Cox proportional hazards regression were developed to predict these endpoints. Incidence of coronary heart disease was predicted best by an equation containing age, serum cholesterol at baseline, cigarette smoking at baseline, and paternal history of coronary disease. Hypertension was predicted best by an equation containing age, systolic blood pressure at baseline, paternal history of hypertension, and Quetelet index. These equations were applied to a class of present-day medical students to demonstrate the considerable variability in 30-year risk of coronary disease or hypertension. Thus, coronary heart disease and hypertension in midlife can be predicted by factors identified in youth. The Johns Hopkins multiple risk equations may be valuable as tools in preventive cardiology education to illustrate risk assessment and the importance of risk factor interventions.

Adult↗

PubMed1989

Cardiovascular reactivity to the cold pressor test as a predictor of hypertension.

Cardiovascular reactivity to stress is hypothesized to be a marker for subsequent neurogenic cardiovascular disease, but few prospective studies of this hypothesis are available. We studied 910 white male medical students who had their blood pressure and pulse rate measured before and during a cold pressor test in the years 1948-1964. Hypertensive status (requiring drug treatment) was ascertained by annual questionnaires in the 20- to 36-year follow-up period. An association was observed between maximum change in systolic blood pressure and later hypertension, with a cumulative incidence of hypertension by age 44 of 6.7%, 3.0%, and 2.4% for a change in systolic blood pressure in the upper, middle two, and lowest quartiles, respectively (Kaplan-Meier, p less than 0.02). After adjustment for study entry age, Quetelet Index, cigarette smoking, pretest systolic blood pressure, and paternal or maternal history of hypertension in a Cox model, the association persisted. The excess risk associated with systolic blood pressure reactivity was not apparent until the population aged some 20 years and was most apparent among those in whom hypertension developed before age 45 (relative risk = 2.5, 95% confidence intervals = 1.47, 4.71 for a 20 mm Hg change). Diastolic blood pressure and heart rate changes were not associated with later hypertension. These data suggest that persons prone to later hypertension manifest an altered physiology at a young age.

Adult↗

PubMed1986

Coffee consumption and the incidence of coronary heart disease.

We conducted a prospective investigation of the effect of coffee consumption on coronary heart disease in 1130 male medical students who were followed for 19 to 35 years. Changes in coffee consumption and cigarette smoking during follow-up were examined in relation to the incidence of clinically evident coronary disease in comparisons of three measures of coffee intake--base-line intake, average intake, and most recent intake reported before the manifestation of coronary disease. Clinical evidence of coronary disease included myocardial infarction, angina, and sudden cardiac death. In separate analyses for each measure of coffee intake, the relative risks for men drinking five or more cups of coffee per day, as compared with nondrinkers, were approximately 2.80 for all three measures in the univariate analyses (maximum width of 95 percent confidence intervals, 1.27 to 6.51). After adjustment for age, current smoking, hypertension status, and base-line level of serum cholesterol, the estimated relative risk for men drinking five or more cups of coffee per day (using the most recent coffee intake measure), as compared with those drinking none, was 2.49 (maximum width of 95 percent confidence interval, 1.08 to 5.77). The association between coffee and coronary disease was strongest when the time between the reports of coffee intake and the coronary event was shortest. These findings support an independent, dose-responsive association of coffee consumption with clinically evident coronary heart disease, which is consistent with a twofold to threefold elevation in risk among heavy coffee drinkers.

Adult↗

PubMed1986

A possible relationship between figure drawing data collected in medical school and later health status among physicians.

Figure drawings obtained while subjects were in medical school were scored using two different scales: (a) Sophistication-of-Body-Concept, a scoring system that measures the overall quality of the drawings; and (b) Conventionality/deviancy of the drawings, as determined by the relative frequency with which 42 different characteristics occurred in the total sample of drawings. Figure drawings were obtained from 1951 to 1964. As of 1984, subjects were classified into 1 of 11 health outcome (disease) categories plus a "healthy" category. Statistical analysis included one-way analyses of variance and multiple logistic regression in which age and cigarette consumption were controlled. Several statistically significant differences among groups were noted with respect to Conventionality/deviancy, but not with respect to Sophistication-of-Body-Concept.

Adult↗

PubMedDate not supplied

The Rorschach Interaction Scale as a potential predictor of cancer.

In a long-term prospective study, medical students who later developed cancer, in contrast to the rest of the cohort, gave Rorschach test responses indicating less satisfactory interpersonal relationships as assessed by the Rorschach Interaction Scale (RIS). The scale remained as a predictor of cancer after adjusting for smoking, serum cholesterol level, and age in medical school, and after taking into account the date of diagnosis and length of follow-up time. An exploration of the relationship between the RIS and specific types of cancer suggested that cancers of the lung may be less influenced by this psychologic factor than are other cancers. The findings were interpreted to suggest that internal self-other representations as measured by the RIS are involved as regulators of biologic systems and manifestations of illness, such as cancer.

Adult↗