Effects Of Age-related Changes Research Articles

Orthodontic retention: a clinical guide for the GDP

Retention is normally required after active orthodontic tooth movement in order to maintain tooth position and minimize the effects of age-related changes to the dentition. The aim of this article is to define stability, retention and relapse with reference to the literature and to review the evidence with regards to clinical effectiveness of different types of fixed and removable retainers and wear regimens, with emphasis on systematic reviews and Randomized Controlled Trials (RCTs). Furthermore, to discuss the general dental practitioner's role and responsibility in managing patients after active orthodontic treatment. CPD/Clinical Relevance: It is common practice for orthodontists to review patients for one year after active orthodontic treatment. Beyond this period, monitoring of the patient's long-term retention is often carried out in general dental practice. This paper provides an overview of orthodontic retention, including retainer types, wear regimens and a discussion of the common problems associated with retainers and advice on management.

Age-related deficit accumulation and the diseases of ageing

With ageing, the potency of individual risk factors traditionally associated with common illnesses declines. Instead, it is becoming clear that the impact of a wide range of age-related deficits not traditionally considered as risk factors for these illnesses increases. These age-related deficits chiefly confer risk as a group, not individually. The many effects of age-related changes can be demonstrated epidemiologically, and in preclinical models, using a frailty index to distinguish between the contributions of traditional and non-traditional risk factors. Quantifying the contribution of age-related deficit accumulation in clinical and preclinical samples offers a powerful new tool for understanding mechanisms of age-related disease. It appears that a range of common late-life illnesses might be targeted by drugs aimed at ageing processes.

The effect of manual therapy and exercise on age-related lung function: study protocol for a randomised controlled trial

BackgroundAgeing is associated with a range of anatomical and physiological changes. Establishing whether a change is part of ‘normal’ ageing or the early signs of disease will affect management strategies. Progressive stiffening of the thoracic spine, decreasing chest wall compliance and declining lung function begin as early as 40 years of age. Administering an intervention such as manual therapy, which has the potential to mitigate age-related changes in the thoracic spine and chest wall, has the potential to improve thoracic compliance and lung function. The aims of this trial are to investigate whether manual therapy can mitigate the effects of age-related changes in lung function and whether there is a difference in effect between different forms of manual therapy.MethodsThe study design is a randomised controlled trial of 372 people with no history of respiratory disease between the ages of 50 and 65 years. The cohort will be divided into three equal groups. The first group will receive a simple 10-min treadmill walking program (Ex). The second group will receive joint mobilisation (MB) of the thoracic spine and ribs plus the same walking program (MB + Ex). The third group will receive joint manipulation (MT) of the thoracic spine and ribs plus the same walking program (MT + Ex). All interventions will be administered a total of six times over a 3-week period. The primary outcome measure is lung function: forced expiratory volume in the 1st second and forced vital capacity. The secondary outcome measures include chest wall expansion (tape measurements) and quality of life measurements (36-Item Short Form Health Survey). Outcome measurements will be taken by blinded assessors on four occasions over a 9-week period. Adverse event data will be gathered at the beginning of each intervention session.DiscussionThis randomised controlled trial is designed to investigate whether manual therapy can mitigate the effects of age-related changes in lung function and whether there is a difference in effect between different forms of manual therapy. This is the first fully powered trial designed to test this hypothesis on healthy males and females in this age range.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR), 12616001317482. Registered on 20 September 2016.

Effects of age-related changes in step length and step width on the required coefficient of friction during straight walking

BackgroundSlipping is one of the leading causes of falls among older adults. Older adults are considered to walk with a small anteroposterior (AP) component and a large mediolateral (ML) component of the required coefficient of friction (RCOF) owing to a short step length and a wide step width, respectively. However, limited information is available. Research questionWhat are the effects of aging on the resultant RCOF (RCOFres) and its ML (RCOFML) and AP (RCOFAP) components during straight walking? MethodsWe used the kinetic and kinematic data of 188 participants aged 20–77 years from a publicly available database (National Institute of Advanced Industrial Science and Technology Gait Database 2015). The participants were divided into the following three groups: young group (n = 56; age range, 20–34 years), middle-aged group (n = 50; age range, 35–64 years), and old group (n = 82; age range, 65–77 years). ResultsThe RCOFres and RCOFAP were lower in the old group than in the other groups, indicating a lower slip risk in this group. However, the RCOFML was higher and the step width was greater in the old group than in the other groups. The higher RCOFML and lower RCOFAP in the old group might be associated with slips in a more lateral direction. SignificanceOur findings suggest that older adults have a high risk of slipping in a more lateral direction. Shoes with high-slip resistance in the lateral direction are recommended to prevent hazardous lateral slips among older adults.

Effects of Aging on Impairment Ratings: Part 3: Neurological and Associated Issues

Abstract This article is the third in a series of four that explore the effects of age-related changes in impairments as defined by the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth and Sixth Editions. Specifically, this article focuses on evaluation of disturbances of the nervous system, divided for discussion here into four parts—the central nervous system (CNS), the peripheral nervous system, vision, and hearing—and offers guidance in using the AMA Guides, Fifth and Sixth Editions, in a variety of specific disorders within each group. For example, the CNS discussions address disorders of consciousness and awareness; sleep and arousal disorders; alterations in metal status, cognition, and highest integrative function; aphasia or dysphagia; emotional or behavioral disorders resulting from CNS causation (fifth edition only); chronic pain; and others. One of the most challenging issues in evaluating peripheral neuropathy regards carpal tunnel syndrome, and rating physicians should provide references in their reports to justify their position. Rating visual problems usually requires attention to the medical records to document preinjury visual status. The AMA Guides, Fifth and Sixth Editions, do not use age-adjusted corrections in assessing age-related diminished hearing, but local jurisdictions and circumstances may apply apportionment. In apportioning impairment due to aging, the examiner must understand both the science and the specific legal processes involved.

Decreases in adiposity reduce the risk of hypertension: Results from a prospective cohort of adolescents

This study aimed to evaluate the effect of age-related changes in body mass index and waist circumference during adolescence on blood pressure levels and incidence of hypertension. Among the 2159 adolescents recruited at 13 years in Porto, Portugal, we evaluated those free of hypertension at baseline and followed-up at 17 years (n = 1377) - EPITeen cohort, 2003–2008. Changes in BMI percentage (BMI%) and waist circumference percentage (WC%) were evaluated continuously as the difference between 13 and 17 years, then categorized in sex-specific quartiles. Hypertension was defined as systolic and/or diastolic blood pressure ≥ 95th sex- age- and height-specific reference percentile. The association between changes in adiposity and incidence of hypertension was computed through generalized linear models with log link function and Poisson distribution [incidence rate ratios (IRR), 95% confidence intervals (95%CI)], adjusting for baseline adiposity, sex, and family history of hypertension. Overall incidence rate of hypertension was 23.8 (95%CI 19.6–28.8) per 1000 person-years. Participants presenting the highest decrease in BMI% from 13 to 17 years (1st quartile) presented lower SBP at 17y, while for those with increasing BMI% (4th quartile) SBP increased. In comparison to stable BMI% (3rd quartile), decreases in BMI% (1st quartile) were associated with 44% lower risk of hypertension at 17y (IRR = 0.56, 95%CI 0.32–0.97). Increases in BMI% (4th quartile) were associated with increased incidence, although without statistical significance (IRR = 1.11, 95%CI 0.66–1.85). Results were similar when considering changes in WC%. Decreases in BMI and WC throughout adolescence in the whole spectrum of adiposity levels presented potential benefit for blood pressure.

Age-dependent Changes in Plasma Amino Acids Contribute to Alterations in Glycoxidation Products.

SummaryBackgroundGlycative stress is involved in the pathogenesis of various degenerative disorders. This study sought to determine the effect of age-related changes in amino acids on serum levels of pentosidine and carboxymethyl-lysine (CML) in healthy individuals.MethodsThe subjects were 78 healthy individuals categorized into three age groups. The ages of the groups were as follows: 26 young adults (20–30 y, 25.2±3.03), 26 middle-aged adults (35–50 y, 39.46±6.97) and 26 older adults (60 y or older, 69.80±10.01). Serum levels of pentosidine and CML were measured by ELISA and levels of plasma amino acids were determined using HPLC.ResultsSerum levels of pentosidine and CML in the youngest group were higher than in the oldest group (p=0.026, 0.029, respectively). There was a positive correlation between the serum levels of pentosidine and CML and the levels of plasmaTyrosine (p=0.032, r=0.211 and p=0.037, r=0.224), Valine (p=0.037, r=0.224 and p=0.021, r=0.247) and Isoleucine (p=0.041, r=0.203 and p=0.021, r=0.247), respectively. Serum levels of pentosidine and CML may be modulated by the plasma levels of selected amino acids.ConclusionsBetter understanding of the role of these selective amino acids might provide new perception of how glycation pathways may be altered and pave the way for new therapeutic principles.

Effects of Aging on Impairment Ratings: Part 1: Internal Medicine Issues

Abstract This article is the first of four to explore the effects of age-related changes in impairment evaluations as defined by the fifth and sixth editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). With respect to the cardiovascular system, impairment ratings for the following conditions commonly are affected by the aging process: coronary artery disease, valvular heart disease, arrhythmias/dysrhythmias, hypertension, and peripheral vascular disease. Impairment ratings in the fifth and sixth editions of the AMA Guides for the pulmonary system apply corrections for age with respect to certain measurements such as forced vital capacity. The normal aging process does not significantly affect impairment ratings for either hematological impairments or the endocrine system, nor does normal aging significantly affect the impairment ratings for mammary glands. With careful attention to the diagnosis and causative factors, evaluators may find that the normal aging process can affect impairment ratings associated with metabolic bone disease. Evaluating physician typically must determine impairment secondary to a specific cause (eg, injury or exposure) and therefore must consider if other factors are contributing to the impairment.

Age-related changes in ON and OFF responses to luminance increments and decrements.

Impulse response functions for an incremental luminous pulse (ON flash) or a decremental luminous pulse (OFF flash) were derived for twelve young (19-24 years old) and ten old (65-84 years old) observers. Thresholds were measured for two pulses separated by stimulus-onset-asynchronies from 13.3 to 186.7 ms. The pulses had a spatial Gaussian shape and were presented as increments or decrements on a 15 cd/m2 equal-energy white background, having the same chromaticity as the pulse. A spatial four-alternative forced-choice method was combined with a staircase procedure. Retinal illuminance was equated individually by heterochromatic flicker photometry and using a 2.3-mm exit pupil in a Maxwellian-view optical system to reduce the effects of age-related changes and individual variations in lens density and pupil size. Luminance ON- and OFF-impulse response functions calculated from the threshold data revealed significant age-related changes in the response amplitude of both first excitatory and first inhibitory phases. However, there were no significant changes in the time to the first peak or the second peak. These age-related changes in luminance varying ON- and OFF-impulse response functions (IRFs), reflecting putative properties of the magnocellular pathway, are discussed in relation to motion detection and the balance of ON and OFF pathways across the life span.

Thoracolumbar spine loading associated with kinematics of the young and the elderly during activities of daily living

Excessive mechanical loading of the spine is a critical factor in vertebral fracture initiation. Most vertebral fractures develop spontaneously or due to mild trauma, as physiological loads during activities of daily living might exceed the failure load of osteoporotic vertebra. Spinal loading patterns are affected by vertebral kinematics, which differ between elderly and young individuals. In this study, the effects of age-related changes in spine kinematics on thoracolumbar spinal segmental loading during dynamic activities of daily living were investigated using combined experimental and modeling approach.Forty-four healthy volunteers were recruited into two age groups: young (N = 23, age = 27.1 ± 3.8) and elderly (N = 21, age = 70.1 ± 3.9). The spinal curvature was assessed with a skin-surface device and the kinematics of the spine and lower extremities were recorded during daily living tasks (flexion–extension and stand-sit-stand) with a motion capture system. The obtained data were used as input for a musculoskeletal model with a detailed thoracolumbar spine representation. To isolate the effect of kinematics on predicted loads, other model properties were kept constant. Inverse dynamics simulations were performed in the AnyBody Modeling System to estimate corresponding spinal loads.The maximum compressive loads predicted for the elderly motion patterns were lower than those of the young for L2/L3 and L3/L4 lumbar levels during flexion and for upper thoracic levels during stand-to-sit (T1/T2–T8/T9) and sit-to-stand (T3/T4–T6/T7). However, the maximum loads predicted for the lower thoracic levels (T9/T10–L1/L2), a common site of vertebral fractures, were similar compared to the young. Nevertheless, these loads acting on the vertebrae of reduced bone quality might contribute to a higher fracture risk for the elderly.

Effects of 30Years of Disuse on Exceptional Memory Performance.

In the mid-1980s, Dario Donatelli (DD) participated in a laboratory study of the effects of around 800h of practice on digit-span and increased his digit-span from 8 to 104 digits. This study assessed changes in the structure of his memory skill after around 30years of essentially no practice on the digit-span task. On the first day of testing, his estimated span was only 10 digits, but over the following 3 days of testing it increased to 19 digits. Further analyses of his recall performance and verbal reports identified which mechanisms of the original memory skill he could retrieve or reacquire over the 3days of practice. We discuss theoretical implications for the retention of skilled memory performance, the effects of age-related changes in memory on it, and for the future study of the effects of disuse on exceptional performance and complex skill.

Babies Smell Wonderful to Their Parents, Teenagers Do Not: an Exploratory Questionnaire Study on Children\u2019s Age and Personal Odor Ratings in a Polish Sample

IntroductionInfant body odor is subjectively pleasant to parents and activates reward areas in the brain. Hence, body odor perception might contribute to parental bonding. However, it is unknown whether the perceived pleasantness of children’s body odor varies over the course of a child’s development.MethodsTwo hundred and thirty-five parents (M = 36.9 years, SD = 7.3) were asked to assess the personal odor pleasantness of their children (N = 367; M = 9.3 years, SD = 6.4).ResultsOdor pleasantness was found to decrease as a function of children’s age. Neither sex of the parent nor sex of the child contributed significantly to this effect.ConclusionsWe propose that the effect of age-related changes on personal odor pleasantness reflects olfactory modulation of parental-child relationships.ImplicationsOur study suggests that perception of young children’s personal odor as pleasant may contribute to bonding and thereby caretaking, which is needed to a lesser degree after puberty than before.

Sagittal spino-pelvic alignment in adults: The Wakayama Spine Study.

ObjectivesTo establish the normal values of spino-pelvic alignment and to clarify the effect of age-related changes using large, community-based cohorts.MethodsIn this study, data from 1461 participants (466 men, 995 women) were analyzed. On lateral standing radiographs, the following parameters were measured: thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), and C7 sagittal vertical axis (SVA). All values are expressed as the mean±standard deviation. The Spearman rank correlation coefficient was used to examine correlations between variables of spino-pelvic parameters. Finally, we analyzed the relationship between age and spino-pelvic parameters. Therefore, we entered values for the body mass index (BMI), SVA, TK, and PI-LL into a multiple regression model to adjust for potential confounding factors.ResultsThe SVA, TK, and PT increased with age, and LL decreased with age. Regarding sex differences, the TK was statistically significantly larger in men than in women, and LL, PT, and PI were statistically significantly smaller in men than in women. Correlation coefficients between the SVA and TK, between the SVA and PI-LL, and between TK and PI-LL were none, strong, and weak, respectively. Results of multiple regression analysis between age and spino-pelvic parameters showed that the standardized partial regression coefficients for the SVA, TK, and PI-LL were 0.17, 0.30, and 0.23, respectively, in men and 0.29, 0.32, and 0.23, respectively, in women.ConclusionsWe found that all parameters were significantly associated with age in men and women. The SVA, TK, and PT increased with age, and LL decreased with age. Results of multiple regression analysis also demonstrated that the SVA, TK, and PI-LL are related to age. Indeed, the PI-LL value increased with age. In this study, a more excessive PI-LL mismatch was shown, indicating an increased risk of spinal malalignment. Differences in the absolute values of spino-pelvic parameters in each sex were small yet statistically significant. Thus, further study should be performed to corroborate this finding.

Age-Related Changes in Resting-State EEG Activity in Attention Deficit/Hyperactivity Disorder: A Cross-Sectional Study.

Numerous studies indicate that attention deficit/hyperactivity disorder (ADHD) is related to some developmental trends, as its symptoms change widely over time. Nevertheless, the etiology of this phenomenon remains ambiguous. There is a disagreement whether ADHD is related to deviations in brain development or to a delay in brain maturation. The model of deviated brain development suggests that the ADHD brain matures in a fundamentally different way, and does not reach normal maturity at any developmental stage. On the contrary, the delayed brain maturation model assumes that the ADHD brain indeed matures in a different, delayed way in comparison to healthy age-matched controls, yet eventually reaches proper maturation. We investigated age-related changes in resting-state EEG activity to find evidence to support one of the alternative models. A total of 141 children and teenagers participated in the study; 67 diagnosed with ADHD and 74 healthy controls. The absolute power of delta, theta, alpha, and beta frequency bands was analyzed. We observed a significant developmental pattern of decreasing absolute EEG power in both groups. Nonetheless, ADHD was characterized by consistently lower absolute EGG power, mostly in the theta frequency band, in comparison to healthy controls. Our results are in line with the deviant brain maturation theory of ADHD, as the observed effects of age-related changes in EEG power are parallel but different in the two groups.

下肢骨格筋の加齢性変化が歩容に及ぼす影響に関する順動力学歩行シミュレーション

下肢骨格筋の加齢性変化が歩容に及ぼす影響に関する順動力学歩行シミュレーション

The Effect of Age-Related Changes and Explicit and Implicit Awareness on Mixed Motor Sequence Learning and its Consolidation

Introduction: This study aimed to investigate the effects of age-related changes and explicit and implicit knowledge on mixed motor sequence learning and its consolidation. Materials and Methods: In this study, 96 right-handed boys who were healthy considering nervous system with age range of 6-18 years were selected via convenience sampling method. Serial reaction time task (SRTT) was used to evaluate and compare the performance in two components of response time and accuracy. The intervention was consisted of 10 stages (8 blocks for acquisition and 2 blocks for consolidation) in which the performances of groups were compared. The data were analyzed using mixed ANOVA test in 2 (type of learning) × 4 (age groups) × 8 (blocks) and Bonferroni test was used for paired comparisons. Results: In acquisition phase for response time, significant main effects were observed for block (P = 0.031) and age (P = 0.001), not learning conditions (P = 0.431). For response accuracy, significant main effects were observed for block (P = 0.001), age (P = 0.001) and learning conditions (P = 0.003). In addition, the performances of groups across the two first blocks of practice on the second day were better compared with the first day in response time (P = 0.001) and accuracy (P = 0.001), which represented the consolidation of motor learning. Conclusion: The findings showed that among different age groups, there were age-related functional changes in the acquisition and consolidation of response time and accuracy for motor sequence task. Moreover, the various components of the movement (speed and accuracy) can be performed and consolidated in different ways. This matter should be considered in educational and rehabilitation interventions related to children and adolescents.

Introducing a forced-choice recognition task to the California Verbal Learning Test – Children’s Version

ABSTRACTThe importance of performance validity tests (PVTs) is increasingly recognized in pediatric neuropsychology. To date, research has focused on investigating whether PVTs designed for adults function similarly in children. The downward extension of adult cutoffs is counter-intuitive considering the robust effect of age-related changes in basic cognitive skills in children and adolescents. The purpose of this study was to examine the signal detection properties of a forced-choice recognition trial (FCR-C) for the California Verbal Learning Test – Children’s Version. A total of 72 children aged 6–15 years (M = 11.1 , SD = 2.6) completed the FCR-C as part of a larger neuropsychological assessment battery. Cross-validation analyses revealed that the FCR-C had good signal detection performance against reference PVTs. The first level of failure (≤14/15) produced the best combination of overall sensitivity (.31) and specificity (.87). A more conservative FCR-C cutoff (≤13) resulted in a predictable trade-off between sensitivity (.15) and specificity (.94), but also a net loss in discriminant power. Lowering the cutoff to ≤12 resulted in a slight improvement in specificity (.97) but further deterioration in sensitivity (.14). These preliminary findings suggest that the FCR-C has the potential to become the newest addition to a growing arsenal of pediatric PVTs.

Age-Related Changes in Hepatic Function: An Update on Implications for Drug Therapy.

The accumulation of deficits with increasing age results in a decline in the functional capacity of multiple organs and systems. These changes can have a significant influence on the pharmacokinetics and pharmacodynamics of prescribed drugs. Although alterations in body composition and worsening renal clearance are important considerations, for most drugs the liver has the greatest effect on metabolism. Age-related change in hepatic function thereby causes much of the variability in older people's responses to medication. In this review, we propose that a decline in the ability of the liver to inactivate toxins may contribute to a proinflammatory state in which frailty can develop. Since inflammation also downregulates drug metabolism, medication prescribed to frail older people in accordance with disease-specific guidelines may undergo reduced systemic clearance, leading to adverse drug reactions, further functional decline and increasing polypharmacy, exacerbating rather than ameliorating frailty status. We also describe how increasing chronological age and frailty status impact liver size, blood flow and protein binding and enzymes of drug metabolism. This is used to contextualise our discussion of appropriate prescribing practices. For example, while the general axiom of 'start low, go slow' should underpin the initiation of medication (titrating to a defined therapeutic goal), it is important to consider whether drug clearance is flow or capacity-limited. By summarising the effect of age-related changes in hepatic function on medications commonly used in older people, we aim to provide a guide that will have high clinical utility for practising geriatricians.

Keeping track of who said what: Performance on a modified auditory n-back task with young and older adults.

A modified auditory n-back task was used to examine the ability of young and older listeners to remember the content of spoken messages presented from different locations. The messages were sentences from the Coordinative Response Measure (CRM) corpus, and the task was to judge whether a target word on the current trial was the same as in the most recent presentation from the same location (left, center, or right). The number of trials between comparison items (the number back) was varied while keeping the number of items to be held in memory (the number of locations) constant. Three levels of stimulus uncertainty were evaluated. Low- and high-uncertainty conditions were created by holding the talker (voice) and nontarget words constant, or varying them unpredictably across trials. In a medium-uncertainty condition, each location was associated with a specific talker, thus increasing predictability and ecological validity. Older listeners performed slightly worse than younger listeners, but there was no significant difference in response times (RT) for the two groups. An effect of the number back (n) was seen for both PC and RT; PC decreased steadily with n, while RT was fairly constant after a significant increase from n = 1 to n = 2. Apart from the lower PC for the older group, there was no effect involving age for either PC or RT. There was an effect of target word location (faster RTs with a late-occurring target) and an effect of uncertainty (faster RTs with a constant talker-location mapping, relative to the high-uncertainty condition). A similar pattern of performance was observed with a group of elderly hearing-impaired listeners (with and without shaping to ensure audibility), but RTs were substantially slower and the effect of uncertainty was absent. Apart from the observed overall slowing of RTs, these results provide little evidence for an effect of age-related changes in cognitive abilities on this task.

A computational analysis on the implications of age-related changes in the expression of cellular signals on the role of IGF-1 in intervertebral disc homeostasis

Insulin-like growth factor-1 (IGF-1) is a well-known anabolic agent in intervertebral discs (IVD), promoting both proteoglycan (PG) biosynthesis and cell proliferation. Accordingly, it is believed that IGF-1 plays a central role in IVD homeostasis. The IGF-mediated anabolic activity in IVD occurs when the growth factor, free from binding proteins (IGFBP), binds to IGF cell surface receptors (IGF-1R). Previous studies reported that, with aging, cellular expression of IGFBP increases, while that of IGF-1R decreases. Both changes in cellular signals are thought to be among the factors that are responsible for the age-related decline in IGF-mediated PG biosynthesis, which ultimately leads to disc degeneration.In this study, a computational model describing the role of IGF-1 in the homeostasis of IVD was deployed in a parametric analysis to investigate the effects of age-related changes in expression of IGF-1R and IGFBP on the IGF-mediated upregulation of PG biosynthesis and cellular proliferation.It was found that changes in the expression of IGF-1R and IGFBP mostly affected the nucleus pulposus, while in the most external disc regions (annulus fibrosus and cartilage endplates) the IVD homeostatic balance was unaltered. It was shown that a decrease of IGF-1R expression caused reduction of both PG levels and cell density in the tissue. In contrast, increase in IGFBP expression increased both PG and cell concentration, suggesting that such change in cellular signaling may be a plausible defense mechanism from age-related IVD degeneration.