Fighting against Skin Aging Zhang, Shoubing; Duan, Enkui
Cell Transplantation,
05/2018, Letnik:
27, Številka:
5
Book Review, Journal Article
Recenzirano
Odprti dostop
As the most voluminous organ of the body that is exposed to the outer environment, the skin suffers from both intrinsic and extrinsic aging factors. Skin aging is characterized by features such as ...wrinkling, loss of elasticity, laxity, and rough-textured appearance. This aging process is accompanied with phenotypic changes in cutaneous cells as well as structural and functional changes in extracellular matrix components such as collagens and elastin. In this review, we summarize these changes in skin aging, research advances of the molecular mechanisms leading to these changes, and the treatment strategies aimed at preventing or reversing skin aging.
Background:
Serum osmolality is an accurate indicator of hydration status in older adults. Glucose, urea, and electrolyte concentrations are used to calculate serum osmolarity, which is an indirect ...estimate of serum osmolality, but which serum osmolarity equations best predict serum osmolality in the elderly is unclear.
Objective:
We assessed the agreement of measured serum osmolality with calculated serum osmolarity equations in older people.
Design:
Serum osmolality was measured by using freezing point depression in a cross-sectional study. Plasma glucose, urea, and electrolytes were analyzed and entered into 38 serum osmolarity-prediction equations. The Bland-Altman method was used to evaluate the agreement and differential bias between measured osmolality and calculated osmolarity. The sensitivity and specificity of the most-promising equations were examined against serum osmolality (reference standard).
Results:
A total of 186 people living in UK residential care took part in the Dehydration Recognition In our Elders study (66% women; mean ± SD age: 85.8 ± 7.9 y; with a range of cognitive and physical impairments) and were included in analyses. Forty-six percent of participants had impending or current dehydration (serum osmolality ≥295 mmol/kg). Participants with diabetes (
n
= 33; 18%) had higher glucose (
P
< 0.001) and serum osmolality (
P
< 0.01). Of 38 predictive equations used to calculate osmolarity, 4 equations showed reasonable agreement with measured osmolality. One calculated osmolarity = 1.86 × (Na
+
+ K
+
) + 1.15 × glucose + urea +14; all in mmol/L was characterized by narrower limits of agreement and the capacity to predict serum osmolality within 2% in >80% of participants, regardless of diabetes or hydration status. The equation's sensitivity (79%) and specificity (89%) for impending dehydration (≥295 mmol/kg) and current dehydration (>300 mmol/kg) (69% and 93%, respectively) were reasonable.
Conclusions:
The assessment of a panel of equations for the prediction of serum osmolarity led to identification of one formula with a greater diagnostic performance. This equation may be used to predict hydration status in frail older people (as a first-stage screening) or to estimate hydration status in population studies. This trial was registered at the Research Register for Social Care (http://www.researchregister.org.uk) as 122273.
Obesity impairs cognition and health-related quality of life (HRQOL) in older adults; however, the appropriate treatment of obese older adults remains controversial.
The objective was to determine ...the independent and combined effects of weight loss and exercise on cognition, mood, and HRQOL in obese older adults.
One hundred seven frail, obese older adults were randomly assigned to a control, weight-management (diet), exercise, or weight-management-plus-exercise (diet-exercise) group for 1 y. In this secondary analysis, main outcomes were Modified Mini-Mental State Examination (3MS) and total Impact of Weight on Quality of Life-Lite (IWQOL) scores. Other outcomes included Word Fluency Test, Trail Making Test Parts A and B, and Geriatric Depression Scale (GDS) scores.
Scores on the 3MS improved more in the diet (mean ± SE: 1.7 ± 0.4), exercise (2.8 ± 0.4), and diet-exercise (2.9 ± 0.4) groups than in the control group (0.1 ± 0.4) (between-group P = 0.0001–0.04); scores in the diet-exercise group improved more than in the diet group but not more than in the exercise group. Scores on the Word Fluency Test improved more in the exercise (4.1 ± 0.8) and diet-exercise (4.2 ± 0.7) groups than in the control group (−0.8 ± 0.8; both P = 0.001). For the Trail Making Test Part A, scores in the diet-exercise group (−11.8 ± 1.9) improved more than in the control group (−0.8 ± 1.9) (P = 0.001); a similar finding was observed for the Trail Making Test Part B. Scores on the IWQOL improved more in the diet (7.6 ± 1.6), exercise (10.1 ± 1.6), and diet-exercise (14.0 ± 1.4) groups than in the control group (0.3 ± 1.6) (P = 0.0001–0.03); scores in the diet-exercise group improved more than in the diet group but not more than in the exercise group. In the diet-exercise group, peak oxygen consumption and strength changes were independent predictors of 3MS changes; weight and strength changes were independent predictors of IWQOL changes. GDS scores did not change.
Weight loss and exercise each improve cognition and HRQOL, but their combination may provide benefits similar to exercise alone. These findings could inform practice guidelines with regard to optimal treatment strategies for obese older adults. This trial was registered atclinicaltrials.govas NCT00146107.
Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature ageing disease, characterized by premature arteriosclerosis and degeneration of vascular smooth muscle cells (SMCs). ...HGPS is caused by a single point mutation in the lamin A (LMNA) gene, resulting in the generation of progerin, a truncated splicing mutant of lamin A. Accumulation of progerin leads to various ageing-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin. Here we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature ageing. Upon differentiation of HGPS-iPSCs, progerin and its ageing-associated phenotypic consequences are restored. Specifically, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescence phenotypes associated with vascular ageing. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs, also known as PRKDC) as a downstream target of progerin. The absence of nuclear DNAPK holoenzyme correlates with premature as well as physiological ageing. Because progerin also accumulates during physiological ageing, our results provide an in vitro iPSC-based model to study the pathogenesis of human premature and physiological vascular ageing.
Obesity is a risk factor for disability, but risk of specific adipose depots is not completely understood.
We investigated associations between mobility limitation, performance, and the following ...adipose measures: body mass index (BMI) and areas and densities of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) in older adults.
This was a prospective population-based study of men (n = 1459) and women (n = 1552) initially aged 70–79 y and free from mobility limitation. BMI was determined from measured height and weight. Adipose tissue area and density in Hounsfield units were measured in the thigh and abdomen by using computed tomography. Mobility limitation was defined as 2 consecutive reports of difficulty walking one-quarter mile or climbing 10 steps during semiannual assessments over 13 y. Poor performance was defined as a gait speed <1 m/s after 9 y of follow-up (n = 1542).
In models adjusted for disability risk factors, BMI, and areas of VAT, abdominal SAT, and IMAT were positively associated with mobility limitation in men and women. In women, thigh SAT area was positively associated with mobility limitation risk, whereas VAT density was inversely associated. Associations were similar for poor performance. BMI and thigh IMAT area (independent of BMI) were particularly strong indicators of incident mobility limitation and poor performance. For example, in women, the HR (95% CI) and OR (95% CI) associated with an SD increment in BMI for mobility limitation and poor performance were 1.31 (1.21, 1.42) and 1.41 (1.13, 1.76), respectively. In men, the HR (95% CI) and OR (95% CI) associated with an SD increment in thigh IMAT for mobility limitation and poor performance were 1.37 (1.27, 1.47) and 1.54 (1.18, 2.02), respectively.
Even into old age, higher BMI is associated with mobility limitation and poor performance. The amount of adipose tissue in abdominal and thigh depots may also convey risk beyond BMI.
Lesbian, gay, bisexual, and transgender (LGBT) people are a health disparate population as identified in Healthy People 2020. Yet, there has been limited attention to how LGBT older adults maintain ...successful aging despite the adversity they face. Utilizing a Resilience Framework, this study investigates the relationship between physical and mental health-related quality of life (QOL) and covariates by age group.
A cross-sectional survey of LGBT adults aged 50 and older (N = 2,560) was conducted by Caring and Aging with Pride: The National Health, Aging, and Sexuality Study via collaborations with 11 sites across the U.S. Linear regression analyses tested specified relationships and moderating effects of age groups (aged 50-64; 65-79; 80 and older).
Physical and mental health QOL were negatively associated with discrimination and chronic conditions and positively with social support, social network size, physical and leisure activities, substance nonuse, employment, income, and being male when controlling for age and other covariates. Mental health QOL was also positively associated with positive sense of sexual identity and negatively with sexual identity disclosure. Important differences by age group emerged and for the old-old age group the influence of discrimination was particularly salient.
This is the first study to examine physical and mental health QOL, as an indicator of successful aging, among LGBT older adults. An understanding of the configuration of resources and risks by age group is important for the development of aging and health initiatives tailored for this growing population.
Abstract
Biological aging is a proposed mechanism through which social determinants drive health disparities. We conducted proof-of-concept testing of 8 DNA-methylation (DNAm) and blood-chemistry ...quantifications of biological aging as mediators of disparities in healthspan between Black and White participants in the 2016 wave of the Health and Retirement Study (n = 9,005). We quantified biological aging from 4 DNAm “clocks” (Horvath, Hannum, PhenoAge, and GrimAge clock), a DNAm pace-of-aging measure (DunedinPoAm), and 3 blood-chemistry measures (PhenoAge, Klemera-Doubal method biological age, and homeostatic dysregulation). We quantified Black-White disparities in healthspan from cross-sectional and longitudinal data on physical performance tests, self-reported limitations in activities of daily living, and physician-diagnosed chronic diseases, self-rated health, and survival. DNAm and blood-chemistry quantifications of biological aging were moderately correlated (Pearson’s r = 0.1–0.4). The GrimAge clock, DunedinPoAm, and all 3 blood-chemistry measures were associated with healthspan characteristics (e.g., mortality effect-size hazard ratios were 1.71–2.32 per standard deviation of biological aging) and showed evidence of more advanced/faster biological aging in Black participants than in White participants (Cohen’s d = 0.4–0.5). These measures accounted for 13%–95% of Black-White differences in healthspan-related characteristics. Findings suggest that reducing disparities in biological aging can contribute to building health equity.
Data on the protein requirements of elderly adults are limited, because it is impractical to conduct repeated nitrogen balance protocols in these vulnerable humans.
This study was designed to ...determine the dietary protein requirement of elderly women by using the recently developed minimally invasive indicator amino acid oxidation (IAAO) technique.
Six white women aged 80–87 y mean ± SEM: 82 ± 1 y and body mass index (in kg/m2) 26 ± 2 completed a 3-d protocol 7 times. Each woman consumed an adaptation diet for 2 d and on day 3 consumed a complete test diet with a crystalline amino acid mixture containing 1 of 7 protein intakes (0.1, 0.3, 0.6, 0.9, 1.2, 1.5, or 1.8 g · kg−1 · d−1) tested randomly. A group-based protein requirement was assessed by using a nonlinear mixed model of protein intake and l-1-13Cphenylalanine oxidation. The breakpoint, at which there was no further decline in the rate of appearance of 13C in the breath, was used as an index of the mean protein requirement.
The mean protein requirement (95% CI) was 0.85 (0.60, 1.09) g · kg−1 · d−1. This requirement is 29% higher than the current Estimated Average Requirement (EAR) for adults of 0.66 g · kg−1 · d−1 based on the nitrogen balance technique, although the 95% CI includes the current EAR. The corresponding adequate protein allowance of 1.15 (0.77, 1.54) g · kg−1 · d−1 is 44% higher, although the 95% CI includes the Recommended Dietary Allowance (RDA) of 0.80 g · kg−1 · d−1.
Notwithstanding uncertainty about the validity of the use of the IAAO technique to assess protein requirements, the results of this study with octogenarian women suggest that the current EAR and RDA for elderly women may be underestimated. The limitations of this short-term, noninvasive method underscore the need for new research that uses alternative experimental designs and measuring physiologic, morphologic, and health-related outcomes. This trial was registered at clinicaltrials.gov as NCT01193946.
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