The effect of duration and age of initiation of dietary restriction (DR) on the spontaneous occurrence of leukemia was studied in male F344 rats. Four nutritional paradigms were employed: Group 1, ad libitum fed; Group 2...The effect of duration and age of initiation of dietary restriction (DR) on the spontaneous occurrence of leukemia was studied in male F344 rats. Four nutritional paradigms were employed: Group 1, ad libitum fed; Group 2, dietary restricted starting at 6 weeks of age; Group 3, dietary restricted from 6 weeks to 6 months of age; Group 4, dietary restricted starting at 6 months of age. The relative incidence (relative onset rate) of leukemia was highest in the rats of Groups 1 and 3 and lowest in the rats of Group 2. The age of onset was earliest in Group 1 followed by Groups 3, 4, and 2 in that order. The progression (duration from onset to death) did not differ significantly between the groups. These results indicate that the duration of DR correlates with the incidence and age of onset of leukemia but not with its progression. The age of initiation of DR is not as important a determinant as the duration of DR in regard to incidence and age of onset. The incidence and the age of onset of leukemia appear to relate to the total cumulative energy intake of the rat (i.e., age multiplied by mean daily energy intake).
Dietary restriction (DR) retards aging in rodents, but its mechanism of action remains unclear. Free radicals have been hypothesized to be involved in aging and in DR's actions. We investigated the influences of age and...Dietary restriction (DR) retards aging in rodents, but its mechanism of action remains unclear. Free radicals have been hypothesized to be involved in aging and in DR's actions. We investigated the influences of age and DR on the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD) in skeletal muscle from 11-, 26- and 34-mo-old (BN x Fischer 344) F1 rats fed either ad libitum (AL) or subjected to a 30% DR from 14 weeks of age. The mass of the upper hindlimb muscles recoverable in 34-mo-old AL rats was only 52% that of 11-mo-old AL rats, whereas rats on DR showed a stable, intermediate value at both ages. CAT and GPX activities increased progressively and markedly in muscle of AL animals with aging. The increase in CAT activity was partially attenuated by DR, while that of GPX was entirely prevented. These effects of aging and DR were more profound in 12,000 x g pellets than in cytosolic fractions. SOD activities were more variable and not clearly influenced by age or DR. These data agree with prior reports of an age-related increase in skeletal muscle antioxidant enzyme activities. Further, DR attenuates this alteration and does so most profoundly in the 12,000 x g pellet, the fraction which is enriched in mitochondria.
We evaluated the possibility that age-related decreases in circulating and/or bone-associated insulin-like growth factor-I (IGF-I) and its binding proteins (BPs) were associated with the development of osteopenia in 8-,...We evaluated the possibility that age-related decreases in circulating and/or bone-associated insulin-like growth factor-I (IGF-I) and its binding proteins (BPs) were associated with the development of osteopenia in 8-, 16-, and 24-month-old specific pathogen-free Brown Norway/Fischer 344 male rats. We measured bone mineral densities (BMD) of femurs by dual-energy x-ray absorptiometry. IGFs and IGFBPs were extracted from bone and separated by molecular exclusion HPLC before quantitation by specific radioligand assays. BMD did not change significantly between 8 and 24 months of age. IGF-I levels decreased by about 30% between 8 and 24 months in both serum and bone. Similarly, both circulating and bone-derived IGFBPs also declined (30% and 60%, respectively) with age. Thus, maintenance of femoral BMD throughout most of the adult rat life span was dissociated from the age-related decline in circulating and bone-associated IGF-I and IGFBPs.
To evaluate the therapeutic potential of insulin-like growth factor-I (IGF-I) as an anabolic agent during aging, we determined its effects on IGF binding proteins (BPs) in male rats of 2, 8, 16, and 24 months of age. In...To evaluate the therapeutic potential of insulin-like growth factor-I (IGF-I) as an anabolic agent during aging, we determined its effects on IGF binding proteins (BPs) in male rats of 2, 8, 16, and 24 months of age. In control animals, a striking increase (143%) in the predominant 39-45 kDa serum IGFBP (BP-3), with little change in serum IGF-I, accompanied the marked deceleration of growth which occurred between 2 and 8 months; the levels of IGF-I and its BPs declined by 15% and 34%, respectively, later in life. Infusion of IGF-I (1.2 mg/kg/day) for 2 weeks produced progressively larger increases in circulating IGF-I with age, from 24% to 95% between 2 and 24 months, consistent with an age-related decrease in exogenous IGF-I clearance. We attributed these results to the large increase in IGFBPs that occurred with maturation, as well as an induction of IGFBP-3 (34-68%) and a larger increase in the 30-34 kDa IGFBP (BP-2; 136-235%) following IGF-I treatment in the older (16-24 months) animals. Anabolic actions of IGF-I, which were seen only in the older rats, included modes increases in weight velocity (5.2 +/- 1.2 g/week), serum phosphorous (20%), and alkaline phosphatase (26%) compared to age-matched controls. In conclusion, differential changes in the relative levels of the different IGFBPs with IGF-I treatment in older animals appeared to profoundly influence both the half-life and tissue accessibility of exogenous IGF-I, thus modulating the potential benefits of IGF-I as an anabolic agent during aging.
In order to determine the contribution of suppressive factors secreted from macrophages to the age-associated decline in T-cell mediated mitogenic responses, experiments were conducted to characterize eicosanoid and H2O2...In order to determine the contribution of suppressive factors secreted from macrophages to the age-associated decline in T-cell mediated mitogenic responses, experiments were conducted to characterize eicosanoid and H2O2 production, total cellular fatty acid, and vitamin E composition of splenocytes isolated from young (4 mo) and old (24 mo) C57BL/6NIA mice. An age-related increase was observed in Ca++ ionophore A23187-stimulated ex-vivo production of prostaglandin (PG) E2, leukotriene (LT) B4, and LTC4 (p < .01), and in concanavalin A (ConA)-stimulated PGE2 production (p < .01). No age-related difference was observed in ex-vivo production of 12- and 15-hydroxyeicosatetranoic acid (HETE). The age-related increase in PGE2 production was also observed in lipopolysaccharide-stimulated peritoneal macrophages of C57BL/6NIA mice and ConA and phytohemagglutinin (PHA)-stimulated splenocytes isolated from DBA mice. Inhibition of cyclooxygenase with indomethacin resulted in increased ConA-stimulated proliferation of splenocytes from old mice (p < .01), while 5-lipoxygenase inhibition did not have an effect on mitogen induced proliferation. Furthermore, PGE2 addition to purified splenic T-cells decreased their proliferation. No age-related differences were observed in total cellular fatty acid composition, vitamin E level, or ex-vivo production of H2O2 from splenocytes stimulated with 10 or 100 ng phorbol myristate acetate (PMA). These data indicate that aging is associated with increased production of PG and LT from activated splenocytes. Inhibition of PGE2 but not LT production enhances mitogenic responses of old mice, suggesting a contributory role for PGE2 in the age-associated decline of T-cell responsiveness to polyclonal mitogens.
The purpose of this study was to assess the effects of chronic beta-adrenergic antagonists on parotid and submandibular gland secretions in men and women of different ages. Unstimulated and stimulated saliva flow rates,...The purpose of this study was to assess the effects of chronic beta-adrenergic antagonists on parotid and submandibular gland secretions in men and women of different ages. Unstimulated and stimulated saliva flow rates, total protein concentrations, and protein secretion rates were compared from medicated (various beta-antagonists, n = 25) and control (n = 60) subjects. Age-related decreases were found in unstimulated parotid saliva flow rate (p = .011) and protein secretion rate (p = .04), unstimulated submandibular salivary flow rate (p = .005) and protein secretion rate (p = .010), and in stimulated submandibular flow rate (p = .002) and protein secretion rate (p = .006). A drug-related effect was observed only in unstimulated parotid salivary flow (p = .033) and protein secretion rate (p = .04) from medicated subjects. Results from this study indicate that age and beta-adrenergic blockade alter salivary glandular function, but their effects differ with the type of salivary secretion examined.
This study focused on gender differences in functional disability among older adults, their reliance on personal assistance and technical aids, and relationships among the use of these sources of assistance, functional d...This study focused on gender differences in functional disability among older adults, their reliance on personal assistance and technical aids, and relationships among the use of these sources of assistance, functional disability, and subjective feelings of well-being. The analyses employ data from interviews conducted with 1,406 community-dwelling elders living in Manitoba, Canada. The results reveal (a) greater disability and somewhat greater use of personal assistance among women, and (b) differences between men and women in relationships between both personal and technical resources and subjective feelings of well-being across levels of functional disability.
The relationship between physical ability and social class in later life was explored through an interview survey conducted on a nationally representative sample of persons aged 77-98 (N = 537). Physical ability was meas...The relationship between physical ability and social class in later life was explored through an interview survey conducted on a nationally representative sample of persons aged 77-98 (N = 537). Physical ability was measured with activities of daily living, an index of mobility, and performance tests. Social class was measured according to previous occupation. Physical function was found to be correlated with social class, that is, former white-collar workers had better function than blue-collar workers. The differences were significant for all three measures of physical function.
This study investigated gender differences in spousal caregiving in a sample of 353 currently married people with cancer who were undergoing outpatient treatment. Results indicate that husbands were less likely than wive...This study investigated gender differences in spousal caregiving in a sample of 353 currently married people with cancer who were undergoing outpatient treatment. Results indicate that husbands were less likely than wives to help their sick spouses with household tasks, and husbands who helped were more likely to have other helpers, whereas wives tended to be sole caregivers. Wives provided approximately twice the hours of care that husbands provided. Women undergoing treatment who experienced high levels of morbidity received more hours of help with household tasks from nonspousal sources than men with comparable levels of morbidity, thus compensating for the deficit in hours of care provided by their husbands. At lower levels of morbidity, however, compensatory help to women was not sufficient to fill the gap in care. Women were more likely than men to report unmet need for assistance with household tasks, although not with personal care.
This study drew on a life course approach and a sample of 293 women from four birth cohorts in upstate New York to examine the relationship over time between women's paid work and their informal caregiving of aging or in...This study drew on a life course approach and a sample of 293 women from four birth cohorts in upstate New York to examine the relationship over time between women's paid work and their informal caregiving of aging or infirm relatives. We find that such caregiving is an increasingly likely role for women, both as they age and across birth cohorts. One in four (24%) women became caregivers at some time between ages 35-44, and over one in three (36%) of these same women became caregivers between ages 55-64. Only 45 percent of the oldest cohort (born 1905-1917) were ever caregivers, compared to 64 percent of the most cohort (born 1927-1934), an increase of almost 20 percent. Clearly changes in the labor force participation of more recent cohorts of women do not appear to alter their caregiving responsibilities. In fact, women in this sample were equally likely to become caregivers, regardless of whether or not they were employed.
The risk of hip fracture among the 7,527 respondents to the Longitudinal Study on Aging (LSOA) is prospectively modeled using logistic regression techniques. Based on existing studies, a seven-stage hierarchical model se...The risk of hip fracture among the 7,527 respondents to the Longitudinal Study on Aging (LSOA) is prospectively modeled using logistic regression techniques. Based on existing studies, a seven-stage hierarchical model serially introduces ecological, demographic, and social factors as well as general health status before considering symptoms and diseases conductive to hip fracture, falling history and body mass, and previous hip fracture. Interaction terms involving age and White women are then introduced to explore novel hypothesis. Of the LSOA respondents, 368 (4.9%) experienced hip fracture between 1984 and 1991. Significant risks of hip fracture were associated with age, female gender, White race, being hospitalized (for any cause) in the year prior to baseline, having fallen at least once in the year prior to baseline, and leaner body mass. The risk associated with increasing age diminishes over the life course. Similarly, the protective effect of body mass diminishes over the life course. Finally, previous ecological findings are clarified by identifying an elevated risk for White women living in the rural South.
This study analyzed auditory reaction time (RT) data from 1,265 community-dwelling volunteers (833 males and 432 females) who ranged in age from 17 to 96. Cross-sectional analyses revealed slowing of simple (SRT) and rel...This study analyzed auditory reaction time (RT) data from 1,265 community-dwelling volunteers (833 males and 432 females) who ranged in age from 17 to 96. Cross-sectional analyses revealed slowing of simple (SRT) and relatively greater slowing of disjunctive (DRT; aka "go-no-go") reaction time across decades for both males and females. Repeated testing within participants (longitudinal analyses) over eight years showed consistent slowing and increased variability with age. Males were faster than females cross age groups, RT tasks, and visits. Beginning at about age 20, RTs increased at a rate of approximately 0.5 msec/yr for SRT and 1.6 msec/yr for DRT. Errors also increased, making unlikely a tradeoff of accuracy for faster responses. The findings are consistent with the hypotheses that slowing of behavior is: (a) a continuous process over the adult life span; (b) characterized by age-associated increases in within-participant variability; (c) a direct function of task complexity and, presumably, the degree of mediation by higher regions in the central nervous system; and (d) greater in women than men.
Age deficits in visual search often are attributed to difficulties in comparing display items to target representations. In the presence-absence search paradigm, however, these comparisons are frequently confounded with...Age deficits in visual search often are attributed to difficulties in comparing display items to target representations. In the presence-absence search paradigm, however, these comparisons are frequently confounded with age differences in the latency and velocity of saccadic eye movements, reductions in the useful field of view (FOV), and retention of information concerning previously searched locations. To circumvent these shortcomings, 20 young and 20 older adults were compared in the speed of their same-different judgments of two perifoveal stimuli. The two stimuli were either identical or varied along one or more of the dimensions of size, shape, and color. In both age groups, RT for correct "different" judgments increased with stimulus similarity, an effect which was more pronounced in the elderly subjects. Results suggest that age differences in free search are due, in part, to an age-related decline in the speed of evaluating object congruence.
Musical processing involves long-term memory representations of invariant properties of auditory patterns and working memory representations of patterns heard in the present moment. Musical scales are formalized sets of...Musical processing involves long-term memory representations of invariant properties of auditory patterns and working memory representations of patterns heard in the present moment. Musical scales are formalized sets of pitches on which much of musical composition and improvisation is based, and frequency relations among scale notes are invariant within categorical boundaries. Studies of young adults have indicated that adjustments of frequency relations are better detected when melodies are based on culturally familiar scales than on culturally unfamiliar scales. A proposed account for this finding has been that knowledge about musical frequency relations is stored in long-term memory. In the present study, old and young adults performed equivalently well in detection of frequency relation adjustments in a culturally familiar scale context, but young adults performed better than old adults in culturally unfamiliar scale contexts. The performance of old adults in a culturally unfamiliar scale context was correlated with high-frequency (8 kHz) hearing sensitivity. These findings suggest that influences of aging on processing of auditory events involve relations of auditory cognition and hearing sensitivity.
To determine the usefulness of the Center for Epidemiological Studies Depression Scale (CES-D) as a measure of depressive symptoms among frail and disabled elderly, we conducted a first- and second-order confirmatory fac...To determine the usefulness of the Center for Epidemiological Studies Depression Scale (CES-D) as a measure of depressive symptoms among frail and disabled elderly, we conducted a first- and second-order confirmatory factor analysis testing the four-factor structure of the CES-D and the existence of a single underlying second-order factor. We also examined the relative contribution of the somatic factor of the total symptom score, and relationships of age, race, functional status, and health with the four factors. We found that the factor structure is replicated when used with frail elderly, and scores are not distorted by the disproportionate influence of somatic items. Age and health do not affect the somatic subscale more than the other three subscales. Functional limitations are associated with higher somatic scores. We conclude that the CES-D is an appropriate tool to measure depressive symptoms in frail elderly.
In order to investigate some of the relationships between age concealment and gender, 269 adults completed on anonymous questionnaire dealing with signs of aging and the use of techniques to conceal them. Although most o...In order to investigate some of the relationships between age concealment and gender, 269 adults completed on anonymous questionnaire dealing with signs of aging and the use of techniques to conceal them. Although most of the signs of aging were considered unattractive for both males and females, aging women were seen as particularly unappealing. More women than men were expected to use age concealment techniques and female subjects were indeed more likely to use them. Both men and women who concealed their age were likely to be judged harshly by others, although individuals indicated a willingness to use age concealment techniques themselves. The results are consistent with the hypothesis that there are two different double standards of aging, one indicating that aging is judged differently depending on the gender of the person doing the judging and the target, and one indicating that people may judge the use of age concealment techniques more harshly in others than in themselves.
BACKGROUND: The purpose of the study was to determine if bone mineral density (BMD) in elderly Chinese subjects was associated with indices of calcium metabolism (parathyroid hormone, vitamin D), osteocalcin, and other n...BACKGROUND: The purpose of the study was to determine if bone mineral density (BMD) in elderly Chinese subjects was associated with indices of calcium metabolism (parathyroid hormone, vitamin D), osteocalcin, and other nonbiochemical factors. METHOD: 104 men (mean age 74 +/- 6 yrs) and 213 women (mean age 76 +/- 8 yrs) with no previous history of fractures were recruited from old age hostels and community centers. BMD was measured with dual energy X-ray absorptiometry. RESULTS: BMD in both sexes was associated with body mass index (BMI), arm circumference, and skinfold thicknesses. Additionally, in women there was a positive association with grip strength and load-bearing activities, a negative association with age in all sites except for the lumbar spine, and negative associations with indices of bone turnover (osteocalcin, urinary hydroxyproline/creatinine and calcium/creatinine ratios). After adjusting for BMI, women with hypertension or taking antihypertensive drugs had higher mean BMD at the lumbar spine. Multivariate analyses showed that only BMI predicted BMD in men, while age, BMI, and arm circumference were predictors of BMD in women. CONCLUSION: Indices of calcium metabolism were not correlated with BMD in this elderly Chinese population, suggesting that the age-related rise in parathyroid hormone and reduced intestinal absorption of calcium may not be important factors in determining BMD in elderly Chinese men and women.
BACKGROUND: Vasopressin has been shown to improve electrophysiological signs of cognitive stimulus processing in young human subjects. This study compared the effects of arginine vasopressin (AVP) on central nervous stim...BACKGROUND: Vasopressin has been shown to improve electrophysiological signs of cognitive stimulus processing in young human subjects. This study compared the effects of arginine vasopressin (AVP) on central nervous stimulus processing in old and young mentally healthy subjects. To assess aspects of cognitive stimulus processing, event-related potentials (ERPs) were recorded. METHOD: A total of 22 old and 28 young subjects were tested on two subsequent days. Substances were administered intranasally 22, 12, and 1 hour(s) prior to experimental sessions. Prior to the first session, all subjects received placebo. Prior to the second session, 11 of the elderly and 15 of the young subjects received AVP (3 x 10 IU in each nostril) while the remaining subjects again received placebo. The study was held double blind. The subjects performed an auditory "oddball" task consisting of rare target tones (requiring a button press response) interspersed throughout a sequence of frequent standard tones while an electroencephalogram was recorded. RESULTS: Differences between young and aged subjects were more pronounced for ERPs to targets than standard pips. Latencies of the N2 and P3 waves of the ERP to targets were significantly prolonged, and the P3 amplitude was diminished in the elderly subjects (p < .01). N2 amplitude was enhanced in both age groups by vasopressin (p < .05). However, AVP treatment significantly enlarged the N2-P3 difference amplitude only in young subjects. CONCLUSIONS: The results indicate that AVP improves ERP signs of stimulus processing associated with attentional mechanisms. However, the ERP signs of age-related cognitive impairment remained unimproved after AVP.
BACKGROUND: Chronic cognitive impairment is a major problem in U.S. nursing homes, yet traditional assessment systems in most facilities included only limited information on cognitive status. Following the Congressional...BACKGROUND: Chronic cognitive impairment is a major problem in U.S. nursing homes, yet traditional assessment systems in most facilities included only limited information on cognitive status. Following the Congressional mandate in the Omnibus Reconciliation Act of 1987 (OBRA '87), U.S. nursing homes now complete the Minimum Data Set (MDS), a standardized, comprehensive assessment of each resident's functional, medical, psychosocial, and cognitive status. We designed a Cognitive Performance Scale (CPS) that uses MDS data to assign residents into easily understood cognitive performance categories. METHODS: Information was drawn from three data sets, including two multistate data sets constructed for the Health Care Financing Administration. The prevalence and reliability of the MDS cognitive performance variables were established when assessed by trained nursing personnel. Five selected MDS items were combined to create the single, functionally meaningful seven-category hierarchical Cognitive Performance Scale. RESULTS: The CPS scale corresponded closely with scores generated by the Mini-Mental State Examination and the Test for Severe Impairment, nursing judgments of disorientation, and neurological diagnoses of Alzheimer's disease and other dementias. CONCLUSIONS: The new CPS provides a functional view of cognitive performance, using readily available MDS data. It should prove useful to clinicians and investigators using the MDS to determine a resident's cognitive assets.