Interdisciplinary Topics in Gerontology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Heterogeneity of reproductive aging in free-ranging female rhesus macaques.
Authors: Johnson RL, Kapsalis E Abstract We here examine interindividual variability in reproductive aging in free-ranging female rhesus macaques (Macaca mulatta). Our study site, Raccoon Key, is an island, about 81 hectares in area, situated in the Gulf of Mexico. Our data were collected from 1992 to 1998; the last 7 years a large population of provisioned macaques were resident on the island. We have previously demonstrated that the birth rate realized by the Raccoon Key rhesus in aggregate declined incrementally with female age beginning in the second half of the first decade of life. In this paper, we ...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Reproductive and behavioral characteristics of aging in female Asian colobines.
Authors: Borries C, Koenig A Abstract Data from four Asian colobine populations, wild (Ramnagar) and provisioned (Jodhpur) Hanuman langurs, wild Phayre's leaf monkeys (Phu Khieo Wildlife Sanctuary), and captive silvered langurs (Wildlife Conservation Society's Bronx Zoo) were analyzed with respect to reproductive and behavioral trends of aging. All but one female (from a total of seven) became menopausal 1.8 to 5+ years prior to death with a lag time between last parturition and death ranging from 3.0 to 9.0 years (n=8). Hormonal analysis revealed constantly low and acyclic levels of immunoreactive pregnan...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Reproductive aging in female chimpanzees (Pan troglodytes).
Authors: Videan EN, Fritz J, Heward CB, Murphy J Abstract Published age-specific fertility rates document a sharp decline in female chimpanzee fertility after age 35 years. However, in contrast to data on human females, little else is known regarding reproductive aging in chimpanzees. We documented age-related changes in estrous cycling, hormone profiles, and reproductive physiology in 14 female chimpanzees (Pan troglodytes) ranging in age from 32 to 50 years. Estrous data were analyzed from daily cycle charts, averaging 14.1 years of cycle data per subject, after omission of gestational periods and postpa...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Perimenopause and menopause: documenting life changes in aging female gorillas.
We present results from a nationwide zoo-based study on female western lowland gorillas during which we evaluated concentrations of progestogens via daily fecal sampling in 30 gorillas, 22 of whom were geriatric (>or=30). Whereas control females cycled regularly, ca. 23% of geriatric females were acyclic (menopausal), and approximately 1/3 showed variable hormonal patterns suggestive of perimenopause. Patterns included increased cycle variability, low luteal phase rises of progestogens - possibly indicative of anovulatory cycling - and peak height variability of progestogens in the luteal phase of the cycle. We discover...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Reproductive life history traits of female orangutans (Pongo spp.).
Authors: Shumaker RW, Wich SA, Perkins L Abstract Data from wild populations demonstrate that orangutans have the slowest life history of all the great apes. In this chapter, we provide an overview of reproduction and life history traits of female orangutans in the wild and captivity. This comparison of wild and captive data illustrates the variability that exists for orangutans. Wild orangutan females first reproduce at a mean age of 15.4 years, with an age range of 13-18 years, and they have a mean interbirth interval of 9.3 years. Wild male orangutans are conservatively estimated to live at least 58 yea...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Origins and health consequences of stress-induced ovarian dysfunction.
This article hypothesizes that, to the extent that cyclic ovarian function affords protection against CHD and osteoporosis, ovulatory abnormalities associated with estrogen deficiency in young women - even if mild and subclinical - prematurely accelerate development of these two diseases of 'aging'. Consistent with this hypothesis are observations in group-housed, premenopausal monkeys confirming that reproductive deficits are commonly induced by psychosocial stress (social subordination), and, in the presence of a typical Western diet, accelerate the development of CHD and bone loss. Furthermore, in this model premenopaus...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Primate reproductive aging: from lemurs to humans.
Authors: Atsalis S, Margulis S Abstract The scope of data now available for primates from long-term field and captive studies has opened up exciting possibilities for investigating age-related patterns of reproduction. Valuable information on the aging process can be gleaned through broad cross-taxonomic comparative studies that include lemurs, monkeys, apes and humans. Thus, across all taxa discussed in this volume, female reproduction was found to be complex and dynamic, affected by the interplay of multiple exogenous and endogenous factors. Throughout their lives, females differ in their individual repr...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Primate reproductive aging. Introduction.
Authors: Atlsalis S, Margulis SW, Hof PR PMID: 18666340 [PubMed - indexed for MEDLINE] (Source: Interdisciplinary Topics in Gerontology)
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Contribution of adipose tissue to health span and longevity.
Authors: Huffman DM, Barzilai N Abstract Adipose tissue accounts for approximately 20% (lean) to >50% (in extreme obesity) of body mass and is biologically active through its secretion of numerous peptides and release and storage of nutrients such as free fatty acids. Studies in rodents and humans have revealed that body fat distribution, including visceral fat (VF), subcutaneous (SC) fat and ectopic fat are critical for determining the risk posed by obesity. Specific depletion or expansion of the VF depot using genetic or surgical strategies in animal models has proven to have direct effects on metabol...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Obesity paradox during aging.
Authors: Chapman IM Abstract Although obesity in young people is a risk factor for morbidity and mortality, the effect of obesity in the elderly is much more complex. For example, the body weight associated with maximal survival increases with increasing age. Even more striking is the 'obesity paradox' in the elderly, in which overweight is associated with increased risk for cardiovascular disease but decreased mortality from these diseases. Thus, although intentional weight loss by obese older people is probably safe, and likely to be beneficial if they have obesity-related morbidities, caution should be ...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Central control of food intake in aging.
Authors: Kmiec Z Abstract Energy homeostasis and fuel metabolism undergo significant modifications in the course of aging. This presents in elderly subjects either as increased body mass and glucose intolerance - which may lead to obesity and type 2 diabetes - or loss of appetite, which may also seriously compromise health. The hypothalamic expression of neuropeptide Y (NPY), the most potent orexigen, and its receptors, was highly suppressed in old rats. Moreover, induction of the NPY-dependent responses was severely blunted in old animals. Similar reductions, although of a lower magnitude, were reported f...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Changes in food intake and its relationship to weight loss during advanced age.
Authors: McDonald RB, Ruhe RC Abstract The results of extensive human and animal studies suggest that declining food intake and body weight observed in the later stages of life may be part of the normal progression of physiological decline observed during aging. Proposed etiologies cover a wide range of biological and psychological conditions. Studies in humans suggest an imbalance in homeostatic mechanisms governing hunger and satiety. That is, while older vs. younger individuals retain a similar drive (hunger) to eat, satiety occurs sooner during a meal in aged people and leads to an overall decrease in ...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Changes in body composition in response to challenges during aging in rats.
Authors: Wolden-Hanson T Abstract Body composition changes over the lifespan of Brown Norway rats, in patterns similar to those of humans. Young adults are lean, with little fat, much of which is intra-abdominal. As they age, rats exhibit linear growth, and both lean and fat mass increase until late middle to early old age. Fat mass continues to accumulate throughout the lifespan, both viscerally and subcutaneously; aging animals carry a higher proportion of their fat mass peripherally. After middle age, skeletal muscle mass begins to decline, and sarcopenia develops when animals reach senescence. Finally,...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

New haystacks reveal new needles: using Caenorhabditis elegans to identify novel targets for ameliorating body composition changes during human aging.
Authors: Wolkow CA Abstract Dramatic changes in body composition accompany aging in humans, particularly with respect to adiposity and the musculature. People accumulate fat as they age and lose muscle mass and strength. Caenorhabditis elegans nematodes are small, hermaphroditic soil nematodes that offer a flexible model for studying genetic pathways regulating body composition in humans. While there are significant physiological differences between worms and people, many of the genetic pathways relevant to human lipid and muscle homeostasis are present in worms. Initial studies indicate that adiposity inc...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research

Sarcopenia: prevalence, mechanisms, and functional consequences.
Authors: Berger MJ, Doherty TJ Abstract Aging is associated with significant decline in neuromuscular function and performance. Sarcopenia, often defined as age-related loss of muscle mass, strength, and functional decline, is the most characteristic feature of age-related changes in the neuromuscular system. Strength decline in upper and lower limb muscles is typically 20-40% by the 7th decade and greater in older adults. This is accompanied by similar losses of limb muscle cross-sectional area. Whole body or appendicular muscle mass determination has become the method of choice for defining sarcopenia. L...
Source: Interdisciplinary Topics in Gerontology - November 25, 2014 Category: Geriatrics Tags: Interdiscip Top Gerontol Source Type: research