Self-rated health and mortality in the high-functioning elderly--a closer look at healthy individuals: MacArthur field study of successful aging.

BACKGROUND: This study tested the predictive value of self-rated health on 3-year mortality, with attention focused on healthy, high-functioning elders. METHODS: Data from the MacArthur Field Study of Successful Aging were utilized. Subjects were 70-79-year-old (at baseline) residents of the communities of East Boston, MA, New Haven, CT, and a five-county area in and around Durham County, NC (N = 1192) which comprise three sites of the Established Populations for Epidemiologic Studies of the Elderly (EPESE). In-home interviews were conducted in 1988 and 1991. Logistic regression was performed to create odds ratios adjusted for age, sex, race, marital status, education, alcohol consumption, cigarette smoking, chronic diseases, past hospitalizations, and cognitive function. The sample was then divided into healthy and less healthy cohorts based on number of chronic diseases, and the analyses were repeated. RESULTS: The adjusted odds ratios for self-rated health (poor/bad ratings compared to excellent ratings) in relation to mortality were 19.56 in the general sample, 93.51 in the healthy cohort, and 2.75 in the less healthy cohort. CONCLUSION: Self-rated health is predictive of mortality in controlled analyses, with the greatest impact seen in healthy individuals. Health care professionals should be sensitive to the significance of poor self-rated health in apparently healthy patients.

Measured versus estimated creatinine clearance in a high-functioning elderly sample: MacArthur Foundation Study of Successful Aging.

OBJECTIVE: To assess the validity of several equations for estimating creatinine clearance in a large sample of high-functioning, community-dwelling elderly. DESIGN: Serum and 12-hour urine samples were collected and assayed for creatinine using the Jaffe total chromagen method. Fifteen clearance-estimating equations were evaluated for bias, accuracy, correlation with measured clearance values, and frequency of erroneous placement into renal function categories. Stepwise regression modeling and reliability testing were performed on a split sample to construct and assess a novel creatinine-clearance-estimating equation. SETTING: New Haven, Connecticut, East Boston, Massachusetts, and a five-county region in and around Durham, North Carolina. PARTICIPANTS: A subsample of community-dwelling men and women (age range 70-79 years) from the Established Populations for Epidemiological Studies of the Elderly was screened for physical and cognitive functioning and placed into high-, medium-, and low-functioning groups (n = 1354). High-functioning respondents who provided blood and complete urine samples (n = 762) were included in the present study. RESULTS: In general, estimated creatinine clearance was more closely correlated to measured values in males than in females. Most equations underestimated creatinine clearance, with average bias ranging from -33.1 mL/min to +19.6 mL/min. Predictive accuracy ranged from 18.2 mL/min to 38.0 mL/min. Equations were variable in their erroneous placement of individuals into renal function categories. Regression modeling yielded an equation which contained novel components but failed to provide better estimates of creatinine clearance than those already available. CONCLUSIONS: The equations evaluated here provide unacceptable predictions of creatinine clearance in normally aging individuals. We advocate the use of serum drug concentration measurements when available and encourage investigation into timed urine collections of short duration as alternatives to clearance-estimating equations in the elderly.

Rhythmicity and response to A.M. and P.M. CRH challenge in elderly subjects.

Cortisol and ACTH exhibit circadian rhythmicity, peaking in the early morning. These peaks are associated with increased activity and alertness. We sought to determine whether self-reported daily rhythms predict outcome of a.m. and p.m. CRH challenge in elderly subjects. We surveyed 96 elderly subjects to determine daily rhythms in activity levels, mood, alertness, and performance. Seven healthy subjects were given a cumulative activity score reflecting propensity toward morningness or eveningness. Subjects underwent CRH challenge testing during the morning and evening hours of different days. Baseline plasma ACTH and cortisol concentrations were higher in the morning than in the evening and lower values were associated with lower activity scores (i.e., greater morningness). No trends were apparent between activity score and net hormone response or percent change in hormone concentration.

Cytophotometric assessment of T-2 toxin induced alterations in azure B-RNA and Coomassie-protein in supraoptic-magnocellular neurons of rat hypothalami.

Quantitative cytophotometry was used to monitor T-2 toxin-induced alterations in azure B-RNA and Coomassie-total cell protein in supraoptic-magnocellular neurons of rat hypothalami. Thirty male Sprague-Dawley rats (200-220g) were given a single i.p. injection of T-2 toxin (0.5, 0.75, 1.00 and 1.50 x LD50), a trichothecene mycotoxin; rats were decapitated 8 hours post-dosing. After stoichiometric azure B-RNA and Coomassie-protein staining of brain sections, scanning-integrating microdensitometry was used to quantify toxin-induced alterations in these well established indices of neuronal toxicity. Within the magnocellular neurons of the supraoptic nuclei, significant reductions in azure B-RNA reactivity were observed in the 0.75, 1.00 and 1.50 x LD50 groups (i.e. 11%, 13% and 8%, respectively); no differences in RNA levels were observed between controls and the 0.50 x LD50 group. In addition, a decrease in Coomassie-total cell protein was seen in animals receiving 0.50, 0.75 and 1.50 x LD50 T-2 toxin (i.e. 33%, 21% and 12%, respectively); however, toxin administration did not alter protein levels in the 1.00 x LD50 group. Furthermore, a dose-dependent decrease in systolic blood pressure was observed at 8 hr. post-injections (i.e., approximately -39%, -52%, -66% and -64% for the 0.50, 0.75, 1.00 and 1.50 x LD50 groups, respectively). Additional observations include pronounced polydipsia, ascites, abdominal and subdural hemorrhage, and horripilation (piloerection) in experimental groups. It is postulated that the T-2 toxin-induced reductions in azure B-RNA and Coomassie-protein represent an early indication of impaired metabolic activity. Since these neurons are important sites of vasopressin (antidiuretic hormone) synthesis, these data suggest an impaired osmoregulatory ability. The pronounced polydipsia which occurred shortly after intoxication is further evidence of this impairment. Although these findings do not provide insight relating to the mechanism of osmoregulatory disruption, it is advanced that the supraoptic-magnocellular compartment represents an important site in T-2 toxin mycotoxicosis. Moreover, these findings support previous claims that T-2 toxin intoxication may critically impair the vasopressinergic response to toxin-induced cardiovascular collapse.