Journals of Gerontology. Series A, Biological Sciences and Medical Sciences

The homeostatic properties of reproduction in aging female Drosophila melanogaster are investigated. Classic studies based on cohort analysis suggest that homeostatic capacity declines gradually as daily oviposition rates decline in aging flies. Analysis at the level of individuals gives a very different picture: reproductive homeostasis remains relatively constant for most of adult life until a critical point when oviposition either ceases entirely or continues in dysregulated fashion. The collapse of homeostatic capacity is abrupt...

Background: Although balance impairment after hip fracture surgery (HFS) can constitute a long-term problem of limiting mobility and increasing the risk of falls in older adults, little is known about the effect of balance training (BT) on physical functioning after HFS. Thus, we performed a meta-analysis to evaluate whether BT improved the overall physical functioning of patients after HFS. Methods: We searched the PubMed-Medline, Embase, and Cochrane Library databases in January 2018 and included all randomized controlled trials comparing BT with usual care after HFS...

Background: Geriatric health charts that are similar to pediatric growth charts could facilitate monitoring health changes and predicting care needs in older adults. We aimed to validate an existing composite score (Health Assessment Tool [HAT]) and provide provisional age-specific reference curves for the general older population. Methods: Data came from the SNAC-K population study (n=3363 participants 60+ years examined clinically at baseline and 3 years later)...

BACKGROUND: This study examines the relationship between self-reported instances of major discrimination and inflammation among older adults, and explores whether this relationship varies in accordance with race/ethnicity. We hypothesized that self-reported instances of major discrimination would be associated with higher levels of high-risk inflammation, and that this relationship would be stronger for racial/ethnic minorities than Whites. METHODS: Data from the 2006/2008 Health and Retirement Study (HRS), an ongoing biennial nationally representative sample of older adults in the United States, was used to collect measures of self-reported instances of major discrimination and high-risk C-reactive protein (CRP), which was assayed from blood samples...

Background: Hearing impairment (HI) could be a risk factor for cognitive decline, but cognition could plausibly also affect psychoacoustic assessment of hearing with audiometry. We examined the temporal sequence of hearing and cognitive function among non-demented, community-dwelling older adults. Methods: Hearing and cognition were assessed between 2012-2015 and two years thereafter in 313 non-demented participants aged ≥60 years in the Baltimore Longitudinal Study of Aging...

Understanding the effect of molecular pathways involved in the age-dependent deterioration of stem cell function is critical for developing new therapies. The overexpression of Klotho (KL), an anti-aging protein, causes treated animal models to enjoy extended lifespans. Now, the question stands: Does KL-deficiency accelerate stem cell aging and telomere shortening? If so, what are the specific mechanisms by which it does this, and is cycloastragenol (CAG) treatment enough to restore telomerase activity in aged stem cells? We found that KL-deficiency diminished telomerase activity by altering the expression of TERF1 and TERT, causing impaired differentiation potential, pluripotency, cellular senescence, and apoptosis in stem cells...

Background: Few studies have examined impairment in multiple senses (multisensory impairment) and risk of dementia in comparison to having a single or no sensory impairment. Methods: We studied 1,810 black and white non-demented participants from Health, Aging, and Body Composition (Health ABC) Study aged 70-79 at enrollment. Sensory impairment was determined at our study baseline (Year 3-5 of Health ABC) using established cut-points for vision (Bailey-Lovie visual acuity and Pelli-Robson contrast sensitivity test), hearing (audiometric testing), smell (12-item Cross-Cultural Smell Identification Test), and touch (peripheral nerve function tests)...

BACKGROUND: Maintaining good fitness and good level of physical activity are important factors for maintaining physical independence later in life. The aim was to investigate the relationship between self-reported fitness and objectively measured physical activity (PA) and sedentary behavior (SB) in the elderly. METHODS: Same-sex twin pairs born 1940-1944 in Finland were invited to the study. Altogether 787 individuals (mean age 72.9 years), of whom 404 were female, used a hip-worn triaxial accelerometer for at least four days and answered a question on perceived fitness...

Increased adiposity is associated with reduced skeletal muscle function in older adults, but the mechanisms underlying this relationship remain unclear. To explore whether skeletal muscle properties track with adiposity, whole-muscle, cellular, and molecular function were examined in relation to adiposity measured at various anatomical levels in healthy older (60-80 years) men and women. Although women had greater absolute and relative body and thigh fat than men, quadriceps muscle attenuation, an index of intramuscular lipid content, was similar between sexes...

NFB is a transcription factor that controls immune and inflammatory signaling pathways. In skeletal muscle, NFB has been implicated in the regulation of metabolic processes and tissue mass; yet, its affects on mitochondrial function in this tissue are unclear. To investigate the role of NFB on mitochondrial function and its relationship with muscle mass across the lifespan, we study a mouse model with muscle-specific NFB suppression (MISR mice). In wild type mice there was a natural decline in muscle mass with aging that was accompanied by decreased mitochondrial function and mRNA expression of electron transport chain subunits...

Background: We aimed to find the best predictive model for 14-day mortality in antibiotic-treated nursing home residents with dementia and pneumonia by first applying an existing model to the recent PneuMonitor study. Second, we evaluated whether model performance improved by revising variables or adding variables related to recent changes in the care for older people. Methods: The original prognostic model included gender, respiratory rate, respiratory difficulty, pulse rate, decreased alertness, fluid intake, eating dependency and pressure sores...

Sirtuin 3 (SIRT3) and angiotensin play a major role in aging-related disorders. Both modulate oxidative stress and neurodegeneration. We investigated the interaction between SIRT3 and angiotensin II (AngII) in the dopaminergic system. Both in vivo and in vitro, treatment with AngII decreased SIRT3 expression, which was reversed by angiotensin type 1 receptor (AT1) antagonists. Aged animals showed enhanced pro-oxidative RAS activity and low nigral SIRT3 levels, which significantly increased with treatment with the AT1 antagonist candesartan or AT1 deletion...

Experimental evidence to-date largely supports an association between the stress hormone cortisol and cognitive performance. Older adults, in particular, may be vulnerable to the neurotoxic effects of prolonged increases in cortisol, however the assessment of chronic hormone levels has previously been challenging. Hair cortisol analysis has advantages over other cortisol metrics for this purpose as it facilitates the assessment of total hormone secretion over several months. Cortisol and cortisone were measured in the scalp hair of 1,876 older adults from The Irish Longitudinal Study on Ageing...

Sarcopenia is the aging-associated progressive loss of skeletal muscle, however the pathogenic mechanism of sarcopenia is not clear. The orexigenic hormone ghrelin stimulates growth hormone secretion, increases food intake, and promotes adiposity. Here we showed that fasting-induced muscle loss was exacerbated in old ghrelin-null (Ghrl-/-) mice, exhibiting decreased expression of myogenic regulator MyoD and increased expression of protein degradation marker MuRF1, as well as altered mitochondrial function. Moreover, acylated ghrelin (AG) and unacylated ghrelin (UAG) treatments significantly increased mitochondrial respiration capacity in muscle C2C12 cells...

Background: Prolonged sitting is common in older adults and associated with insulin resistance and poor cardiometabolic health. We investigate whether breaking prolonged sitting with regular short bouts of standing or light walking improves postprandial metabolism in older white European and South Asian adults and whether effects are modified by ethnic group. Methods: Thirty South Asian (15 women) and 30 white European (14 women) older adults (65-79 years) undertook three experimental conditions in random order...

Telomeres progressively shorten with age, and it has been proposed that critically short and dysfunctional telomeres contribute to aging and aging-associated diseases in humans. For many years it was thought that telomere erosion was strictly a consequence of the "end replication problem", or the inability of replicative polymerases to completely duplicate linear DNA ends. It is becoming increasingly evident, however, that telomere shortening of cultured human cells is also caused due to other replication defects in telomeric repeats, those that cause fragile telomeres and other aberrant telomeric structures that can be detected on metaphase chromosomes...

Age-related gait dysfunction and balance disorders are a major cause of falls and injury in the elderly population. Epidemiological studies have shown that disturbances in gait coordination which manifest with age are associated with increased morbidity and mortality, impaired cognitive capacity, as well as reduced level of function and loss of independence. In geroscience mice are the most frequently used model system to test efficiency of anti-aging interventions. Despite the clinical importance of age-related gait abnormalities in older adults, the impact of aging on mouse gait coordination is not well documented in the literature...

Background: Physical performance and activity have both been linked to fall risk, but the way they are jointly associated with falls is unclear. We investigated how these two factors are related to incident falls in older men. Methods: In 2741 men (78.8±5 years) we evaluated the associations between activity and physical performance and how they jointly contributed to incident falls. Activity was assessed by accelerometry. Physical performance was measured by gait speed, dynamic balance (narrow walk), chair stand time, grip strength and leg power...

Background: Growth/differentiation factors 8 (GDF8) and 11 (GDF11) have attracted attention as targets for rejuvenating interventions. The biological activity of these proteins may be affected by circulating antagonists such as their respective prodomains, follistatin (FST315), WFIKKN1, and WFIKKN2. Reports of the relationship of GDF8 and GDF11 and their antagonists with aging and aging phenotypes such as skeletal muscle strength have been conflicting possibly because of difficulties in measuring these proteins and polypeptides...

Background: Gait variability is an early fall predictor. However, it is unknown how gait variability of older adults at high risk of falls is affected by an obstacle negotiation task. We aimed to compare gait performance between older adults with significant history of falls (i.e. fallers) and non-fallers while approaching an obstacle crossing. Methods: 137 older adults without dementia were enrolled (72.2 ±5.1 years of age; 60.5 % of women) from the "Gait and Brain Study"...