Age-related changes in human brain functional connectivity using graph theory and machine learning techniques in resting-state fMRI data

Aging is the basis of neurodegeneration and dementia that affects each endemic in the body. Normal aging in the brain is associated with progressive slowdown and disruptions in various abilities such as motor ability, cognitive impairment, decreasing information processing speed, attention, and memory. With the aggravation of global aging, more research focuses on brain changes in the elderly adult. The graph theory, in combination with functional magnetic resonance imaging (fMRI), makes it possible to evaluate the brain network functional connectivity patterns in different conditions with brain modeling. We have evaluated the brain network communication model changes in three different age groups (including 8 to 15 years, 25 to 35 years, and 45 to 75 years) in lifespan pilot data from the human connectome project (HCP). Initially, Pearson correlation-based connectivity networks were calculated and thresholded. Then, network characteristics were compared between the three age groups by calculating the global and local graph measures. In the resting state brain network, we observed decreasing global efficiency and increasing transitivity with age. Also, brain regions, including the amygdala, putamen, hippocampus, precuneus, inferior temporal gyrus, anterior cingulate gyrus, and middle temporal gyrus, were selected as the most affected brain areas with age through statistical tests and machine learning methods. Using feature selection methods, including Fisher score and Kruskal-Wallis, we were able to classify three age groups using SVM, KNN, and decision-tree classifier. The best classification accuracy is in the combination of Fisher score and decision tree classifier obtained, which was 82.2%. Thus, by examining the measures of functional connectivity using graph theory, we will be able to explore normal age-related changes in the human brain, which can be used as a tool to monitor health with age.

Acute effects of static stretching on passive stiffness in older adults: A systematic review and meta-analysis

BACKGROUND

Static stretching has been demonstrated to improve the health of older adults. One of its goals is to decrease passive stiffness of the muscle-tendon unit (MTU) and/or muscles. Decreased passive stiffness in older adults could increase the range of motion and movement efficiency. Herein, we conducted a meta-analysis of the acute effects of static stretching on passive stiffness in older adults as well as a meta-analysis of differences in these effects between older and young adults.

BACKGROUND

PubMed, Web of Science, and EBSCO were searched for studies published before June 28, 2023. Manual searches were performed to identify additional studies. All included studies were critically reviewed by five authors. Meta-analyses of muscle and tendon injuries were performed using a random effect model. Of 4643 identified studies, 6 studies were included in the systematic review.

RESULTS

The main meta-analysis in older adults showed that static stretching could decrease the passive stiffness of the MTU or muscles (effect size, 0.55; 95 % confidence interval, 0.27 to 0.84; p < 0.01; and I2 = 0.0 %). Moreover, for the comparison between young and old adults, three studies were included in the meta-analysis. The results revealed no significant difference in the effects of static stretching interventions on stiffness between older and young adults (effect size, 0.136; 95 % confidence interval, -0.301 to 0.5738; p = 0.541; and I2 = 17.4 %). Static stretching could decrease the passive stiffness of the MTU and/or muscles in older adults to a small magnitude, and the effects were comparable between older and young adults.

Racial differences in whole-body sagittal alignment between Asians and Caucasians based on international multicenter data

PURPOSE

To examine inherent differences adjusted for age and clinical score in whole-body sagittal (WBS) alignment involving the lower extremities between Asians and Caucasians, and to determine the relationship between age and WBS parameters by race and sex.

METHODS

A total of 317 individuals consisting of 206 Asians and 111 Caucasians participated. WBS parameters including C2-7 lordotic angle, lower lumbar lordosis (lower LL, L4-S), pelvic incidence (PI), pelvic thickness, knee flexion (KF), sagittal vertical axis (SVA), and T1 pelvic angle (TPA) were evaluated radiologically. Propensity score-matching adjustments for age and the Oswestry Disability Index scores for comparative analysis between the two race cohorts and correlation analysis between age and WBS parameters for all subjects by race and sex were conducted.

RESULTS

The comparative analysis included 136 subjects (age: Asians 41.1 ± 13.5, Caucasians 42.3 ± 16.2 years, p = 0.936). Racial differences in WBS parameters were observed in C2-7 lordotic angle (-1.8 ± 12.3 vs. 6.3 ± 12.2 degrees, p = 0.001), and lower LL (34.0 ± 6.6 vs. 38.0 ± 6.1 degrees, p < .001). In correlation analysis with age, moderate or more significant correlations with age were found in KF for all groups, and in SVA and TPA for females of both racial groups. Age-related changes in pelvic parameters of PI and pelvic thickness were more significant in Caucasian females.

CONCLUSION

Analysis of the correlation between age and WBS parameters suggested that age-related WBS changes vary between races and should be considered during corrective spinal surgery.

Bone permeability and mechanotransduction: Some current insights into the function of the lacunar-canalicular network

Lacunar-canalicular (LC) permeability involves the passage of fluids, nutrients, oxygen, ions, and signalling molecules through bone tissue, facilitating the maintenance of bone vitality and function and responses to various physiological conditions and diseases. LC permeability and fluid flow-shear stress/drag force play important roles in mechanotransduction in bone tissue by inducing mechanical stimuli in osteocytes, modulating cellular functions, and determining bone adaptation. Alterations in LC structure may therefore influence the fluid flow pattern through the LC network, thereby affecting the ability of osteocytes to sense and translate mechanical signals and possibly contributing to bone remodelling. Several bone-health conditions are associated with changes in LC structure and function and may affect mechanotransduction and responses, although the mechanisms underlying these associations are still not fully understood. In this review, recent studies of LC networks, their formation and transfer mechanical stimuli, and changes in structure, functional permeability, and mechanotransduction that result from age, pathology, and mechanical loading are discussed. Additionally, applications of vibration and low-intensity pulsed ultrasound in bone healthcare and regeneration fields are also presented.

Assessing age-related heart changes by comparing cases of sudden death during bathing and control cases in Japan

We analyzed 400 deaths that occurred in the bathtub during a 10-year period in the central area of Kanagawa prefecture in Japan. There were 72 (18%) medico-legal autopsy cases. The average age at death was 76.4 ± 11.9 years. Drowning (n = 21, 70.8%) was the most common cause of death in the 72 autopsy cases. The study examined the bodies of 40 cases within a postmortem interval of 3 days. The mean age of the 40 cases of sudden death during bathing was 68.6 ± 12.5 years. Results revealed cardiac hypertrophy in 12 cases (30%), lipofuscin deposition in 39 cases (97.5%), basophilic degeneration in 12 cases (30%), anisocytosis of the nucleus of myocardial cells in 18 cases (45%), perivascular fibrosis in 17 cases (42.5%), amyloid deposits in 1 case, and aortic valve calcification in 1 case. The hearts of control subjects who had lived to 20-99 years were also examined; the frequency of each change was higher in people older than 70 years. There was no statistically significant difference in age-related cardio-pathological changes between cases of sudden death during bathing in people in their 70s and controls in their 70s. It can be concluded that this age-related histopathological index is not related to sudden death during bathing. A large number of elderly people, including those without heart disease, have died during bathing. Preventive measures against sudden death during bathing are strongly recommended, e.g., elderly people should not be left totally unsupervised while they bathe.

Age-associated network controllability changes in first episode drug-naïve schizophrenia

BACKGROUND

Recent neuroimaging studies revealed dysregulated neurodevelopmental, or/and neurodegenerative trajectories of both structural and functional connections in schizophrenia. However, how the alterations in the brain's structural connectivity lead to dynamic function changes in schizophrenia with age remains poorly understood.

METHODS

Combining structural magnetic resonance imaging and a network control theory approach, the white matter network controllability metric (average controllability) was mapped from age 16 to 60 years in 175 drug-naïve schizophrenia patients and 155 matched healthy controls.

RESULTS

Compared with controls, the schizophrenia patients demonstrated the lack of age-related decrease on average controllability of default mode network (DMN), as well as the right precuneus (a hub region of DMN), suggesting abnormal maturational development process in schizophrenia. Interestingly, the schizophrenia patients demonstrated an accelerated age-related decline of average controllability in the subcortical network, supporting the neurodegenerative model. In addition, compared with controls, the lack of age-related increase on average controllability of the left inferior parietal gyrus in schizophrenia patients also suggested a different pathway of brain development.

CONCLUSIONS

By applying the control theory approach, the present study revealed age-related changes in the ability of white matter pathways to control functional activity states in schizophrenia. The findings supported both the developmental and degenerative hypotheses of schizophrenia, and suggested a particularly high vulnerability of the DMN and subcortical network possibly reflecting an illness-related early marker for the disorder.

The Association of Sleep Habits and Advancing Age in Japanese Older Adults: Results from the National Center for Geriatrics and Gerontology Study of Geriatric Syndromes

BACKGROUND

The association of sleep habits with "advancing age among older adults" is not fully understood.

OBJECTIVES

The purpose of the present study was to examine the association of sleep habits with advancing age among community-dwelling older adults in Japan.

METHODS

A total of 18,005 older people (mean age: 73.2 ± 6.0 years; 8,070 men and 9,935 women) from the National Center for Geriatrics and Gerontology Study of Geriatric Syndromes were analyzed. Participants were asked in face-to-face interviews about the times they usually go to bed, fall asleep, wake-up, and get up. The amount of time spent in bed and self-reported sleep duration were then calculated from the differences between these times. As other parameters, the subjects were also asked about sleep latency, time spent in bed after waking up, number of nocturnal awakenings, and duration of napping in a typical day.

RESULTS

The results of the Jonckheere-Terpstra test showed that all sleep parameters shifted to an earlier time (going to bed, falling asleep, waking up, and getting out of bed), longer duration (sleep duration, time spent in bed, sleep latency, time spent in bed after waking up, and napping), or more nocturnal awakenings with advancing age (all p < 0.01). Among the men, the time of waking up was not significantly associated with age, while among the women, the time of getting up was not significantly associated with age.

CONCLUSION

These results from a large cohort show the age-related trends of sleep habits in community-dwelling older adults in Japan. Our results revealed that a longer duration and earlier timing of sleep are associated with advancing age.

Trends and patterns of thoracic intervertebral disc degeneration in symptomatic subjects: a magnetic resonance imaging analysis

PURPOSE

This study aimed to analyse the trends and patterns of IVD degeneration in different age groups at each level of the thoracic spine.

METHODS

This cross-sectional MRI study included 1000 symptomatic patients who had undergone upright thoracic spine MRI. A total of 13,000 thoracic IVDs from C7/T1 to T12/L1 were classified into five grades using Pfirrmann classification. Patients were divided according to their ages into five groups (n = 200/group). The severity and pattern of IVD degeneration were analysed in each age group. A predictive model of the severity and pattern of IVD degeneration in each age group was proposed.

RESULTS

The total grade of IVD degeneration and the number of degenerated levels increased with increasing age (P < 0.001). The most common degenerated level was T6/7 (13.3%), while the least common degenerated level was T12/L1 (1.8%). The most common grades were grade I in group 1 (60.5%), grade II in groups 2 (39%) and 3 (37.3%), and grade III in groups 4 (42.5%) and 5 (44.6%). Adjacent-level degenerations were more common than skip-level degenerations. Severe disc degeneration (Pfirrmann grades IV or V) could be predicted to occur more in group 5 (patients with 60 years and above) (margin = 0.79, 95% CI = 0.73-0.84, P < 0.001).

CONCLUSIONS

The severity of thoracic IVD degeneration and the number of degenerated levels increased with age. Disc degeneration was more accelerated in the mid-thoracic spine. Adjacent-level degeneration was more common than skip-level degenerations.

Factors characterizing gait performance of patients before and soon after knee arthroplasty

[Purpose] For monitoring patients with knee osteoarthritis undergoing knee arthroplasty, the Timed Up and Go and maximum walking speed tests are commonly used. To provide appropriate peri-surgical rehabilitation, we evaluated the factors associated with postsurgical changes in Timed Up and Go and maximum walking speed results. [Participants and Methods] We enrolled 545 knee osteoarthritis patients undergoing either of the following knee arthroplasties: conventional total knee arthroplasty, minimally invasive total knee arthroplasty, and unicompartmental knee arthroplasty. Comfortable Timed Up and Go, maximum Timed Up and Go, and maximum walking speed were measured 2 weeks before and soon after surgery. Factors (gender, age, and surgical mode) that might influence changes in test results were evaluated by multiple regression analysis and a two-factor stratification diagram. [Results] Multiple regression analysis revealed that postsurgical changes in comfortable/maximum Timed Up and Go and maximum walking speed results were associated with age and surgical mode after adjustment for preoperative values. Two-factor diagrams showed that the older the patient, the greater was the slowdown in the Timed Up and Go test performed postoperatively. The levels of slowdown in the postoperative Timed Up and Go and maximum walking speed tests were the smallest in those who underwent conventional total knee arthroplasty, followed by those who underwent minimally invasive and unicompartmental knee arthroplasty. Among patients whose preoperative Timed Up and Go and maximum walking speed were slow, slowdown in Timed Up and Go was pronounced with age, and slowdown in maximum walking speed was higher in conventional total knee arthroplasty. [Conclusion] The changes in Timed Up and Go and maximum walking speed results 2 weeks after knee arthroplasty depended on age and surgical modes. These findings are relevant for the implementation of appropriate peri-surgical rehabilitation.

Age-related changes in oral tactile and thermal sensation throughout adulthood

Although the life expectancy of women is over 80 years in many countries, oral sensation has scarcely been compared between adults ≥ 80 years and younger age groups. The purpose of this study was to clarify age-related changes in oral sensation throughout adulthood. After exclusion of individuals with factors that might have confounded somatosensory performance, 123 female participants were divided into four age groups: 20-39 years, 40-59 years, 60-79 years, and 80-96 years. Perceptions of tactile and thermal sensations were examined at points on the anterior and posterior palate, anterior and posterior tongue, lower labial-attached gingiva, lower lip, and buccal mucosa; two-point discrimination was examined only on the tongue. The tactile and two-point discrimination thresholds for the anterior and posterior tongue were significantly higher in the 80-96-year-old group than in any other age group (p < 0.05). The tactile threshold for the buccal mucosa was significantly higher in the 80-96-year-old group than in the 60-79-year-old group (p < 0.05). The percentage of participants able to perceive a warm stimulus (50 °C) in the buccal mucosa was significantly lower in the 80-96-year-old group than in the 20-39-year-old group (p < 0.05). Only the topography of the warm sensation perception changed with age. This cross-sectional study suggests that oral tactile and thermal sensation for warm stimuli deteriorates with age in a site-specific manner, especially after the age of 80 years, but the same does not occur with cool stimuli.

Deterioration of sagittal spinal alignment with age originates from the pelvis not the lumbar spine: a 4-year longitudinal cohort study

PURPOSE

There is controversy regarding age-related deterioration of spinal sagittal alignment in cross-sectional study. Although we reported that deterioration in spinal alignment originated at the cervical spine in males and the pelvis in females, others studies have indicated that the lumbar spine is initially implicated in both sexes. The purpose of this study was to clarify these differences in a longitudinal cohort study.

METHODS

Our analysis was based on 237 individuals aged 60-89 years who participated in our health screening study in 2014 and 2018. They were classified into six groups by birth year and sex: 60-69 years (26 males, 49 females); 70-79 years (35 males, 88 females); and 80-89 years (19 males, 20 females). The following parameters were measured from standing radiographs: pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis, T1 slope, cervical lordosis, C7 sagittal vertical axis (C7 SVA), and C2-7 SVA.

RESULTS

In males, the first significant change was an increase in the PT angle (19°, in 2014, to 21°, in 2018) in the 80-89 years age group (P < 0.05), with no significant deterioration in cervical parameters. In females, spinal deterioration included a change in the SS (32°-30°), PT (18°-20°), and SVA (- 8 to 6 mm) in the 60-69 years age group (P < 0.05), with no change in the LL.

CONCLUSIONS

Contrary to prior studies, our longitudinal data indicated that deterioration in spinal alignment originates in the pelvis for both sex but develops earlier in females than males.

Differences of lumbopelvic sagittal parameters among community-dwelling middle-age and elderly individuals: Relations with locomotor physical function

This study aims to establish radiographic parameters of lumbopelvic sagittal alignment, gender related differences, and age-related changes in a middle-aged community, to investigate whether age-related changes of lumbopelvic alignment reflect the risk of locomotive syndrome (LS). This study included 448 healthy Japanese volunteers who attended a basic health checkup supported by the local government. The subjects (184 males and 264 females, mean age: 62.7 years) were grouped according to their age by decade. Sagittal lumbopelvic parameters were collected by lateral spine radiographs including lumbar lordosis (L1-S1, LL), lower lumbar lordosis (L4-S1, LLL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). The three tests (stand-up test, two-step test, and 25-question geriatric locomotive function scale [GLFS-25]) composing the LS risk test were performed. LL was significantly lower in males than in the females. A significant decrease of LL and LLL was observed from 60 s to 70 s in the females. PI did not markedly change with aging in either gender but was lower in males. A remarkable increase of PT was seen from 60 s to 70 s in the females. SS did not markedly change with aging and was lower in males in all decades. The prevalence of LS risk in males and females increased gradually with age and was greater in females in any decade. 70 s females with LS risk had significantly lower LL and higher PT compared to them without LS risk. Radiographic parameters of lumbopelvic sagittal alignment were established in community-dwelling middle-age and elderly individuals.

Change in Anterior Crowding over 20 Years from Third Decade of Life in Untreated Angle Class I Crowding

Many studies have investigated age-related change in normal occlusion and during the post-retention phase of orthodontic treatment. None, however, have investigated such change in malocclusion. The purpose of this study was to compare age-related change in Angle Class I crowding with that in normal occlusion. Dental casts obtained from 10 men and 2 women in their 20s and then again in their 40s were digitized with a 3-dimensional laser scanner to measure anterior crowding, angulation, inclination, andarch width and length. A paired t -test was used to evaluate change in these values betweenthe two sets of casts. A student's t -test was used to compare values between the crowdingand normal groups. The casts obtained from individuals with untreated Angle Class Icrowding revealed that anterior crowding increased with age due to a decrease in thelength of the maxillary arch. Clear lingual inclination of the maxillary incisors and mesiolingual inclination of the maxillary canines were also observed. A decrease was observedin the anterior arch width and an increase in crowding due to lingual inclination of themandibular canines in the mandible. The space between the mandibular central incisors and between the mandibular lateral incisors and canines was particularly associated withan increase in crowding, suggesting that this was age-related. A comparison betweenpatients in their 40s with Angle Class I crowding and those with normal occlusion revealedthat the increase in maxillary anterior crowding was greater in the former. Mandibularanterior crowding increased at around the same rate, however.

Local Sagittal Alignment of the Lumbar Spine and Range of Motion in 627 Asymptomatic Subjects: Age-Related Changes and Sex-Based Differences

Study Design

Prospective cohort imaging study.

Purpose

This study aimed to evaluate lumbar sagittal alignment and range of motion (ROM) using radiographs in a large asymptomatic cohort and identify sex-based differences and age-related changes in the subjects.

Overview of Literature

Several researchers have tried to establish normal alignment and kinematic behavior of the lumbar spine, using plain radiographs. Few studies have employed a large and sex-and age-balanced cohort.

Methods

Total 627 healthy volunteers (at least 50 males and 50 females in each age decade, from the 3rd to the 8th decade) underwent whole spine radiography in the standing position; lumbar spine radiography was performed for all subjects in the recumbent position. Lumbar lordosis (LL, T12-S1) and ROM during flexion and extension were measured using a computer digitizer.

Results

The mean LL was 36.8°±13.2° in the recumbent position and 49.8°±11.2° in the standing position. The LL was greater in the standing position than in the recumbent position; further, LL was higher in females as compared to that in males. Local lordosis at each disk level increased incrementally with distal progression through the lumbar spine in both the positions. Local lordosis at L4- S1 was 29.8°±8.0° in the recumbent position and 34.2°±8.3° in the standing position and occupied 85.1% and 70.8% of the total LL, respectively. However, local lordosis in the standing position decreased with age at L2-3, L3-4, and L4-5 levels. Total lumbar ROM (T12-S1) decreased with age. The ROM in females was higher than that in males.

Conclusions

We established the standard value and age-related changes in the lumbar alignment and ROM in each age decade in asymptomatic subjects. These data will be useful and provide the normal values for comparison in clinical practice to identify sexbased differences and age-related changes.

Changes in and Interactions between Physical and Mental Health in Older Japanese: The Nakanojo Study

BACKGROUND

An age-related decrease in functional capacity is consistently reported, but it is not consistently related to a worsening of health-related quality of life (HRQOL) or psychological adjustment. A poor functional capacity and HRQOL have been associated with anxiety or depression, but the possible causal nature and direction of the relationship remain to be explored using long-term longitudinal data.

OBJECTIVE

The purpose of this study was to examine age-related changes in functional capacity, HRQOL, and scores on the Hospital Anxiety and Depression Scale (HADS), and possible causal interrelationships between these variables.

METHODS

Study participants were 5,124 Japanese aged ≥65 years. After the baseline study (2003), annual follow-up observations continued for 10 years. Generalized linear mixed models examined age-related changes in Barthel index (BI), Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), HRQOL, and HADS. Cross-lagged effects models tested possible causal interrelationships.

RESULTS

With age, functional capacity and HRQOL scores showed similar declines in both sexes. Changes in mental health, anxiety, and depression developed more slowly than decreases in physical health (BI, TMIG-IC, and physical functioning scores). Cross-lagged effects models demonstrated that functional capacity had positive effects on psychological adjustment, and that psychological adjustment had positive effects on functional capacity 5 years later. Interactions between functional capacity and psychological adjustment showed no sex differences. A decline in functional capacity negatively affected psychological adjustment, but reduced psychological adjustment had no significant impact on functional capacity 5 and 10 years later. Moreover, functional capacity and poor psychological adjustment showed no interactions in either sex.

CONCLUSION

Functional capacity and mood state are interrelated. Greater function could sustain vitality and mental health, possibly reducing anxiety and depression.

A longitudinal quantitative trait locus mapping of chicken growth traits

Since the growth traits of chickens are largely related to the production of meat and eggs, it is definitely important to understand genetic basis of growth traits. Although many quantitative trait loci (QTLs) that affect growth traits have recently been reported in chickens, little is known about genetic architecture of growth traits across all growth stages. Therefore, we conducted a longitudinal QTL study of growth traits measured from 0 to 64 weeks of age using 134 microsatellite DNA markers on 26 autosomes from 406 F₂ females, which resulted from an intercross of Oh-Shamo and White Leghorn chicken breeds. We found 27 and 21 independent main-effect QTLs for body weight and shank length, respectively. Moreover, 15 and 4 pairs of epistatic QTLs were found for body weight and shank length, respectively. Taken together, the present study revealed 48 QTLs for growth traits on 21 different autosomes, and these loci clearly have age-specific effects on phenotypes throughout stages that are important for meat and egg productions. Approximately 60% of Oh-Shamo-derived alleles increased the phenotypic values, corresponding to the fact that Oh-Shamo traits were higher than those of White Leghorn. On the other hand, remaining Oh-Shamo alleles decreased the phenotypic values. Our results clearly indicated that the growth traits of chickens are regulated by several main and epistatic QTLs that are widely distributed in the chicken genome, and that the QTLs have age-dependent manners of controlling the traits. This study implies importance of not only cross-sectional but also longitudinal growth data for further understanding of the complex genetic architecture in animal.

Normative data for parameters of sagittal spinal alignment in healthy subjects: an analysis of gender specific differences and changes with aging in 626 asymptomatic individuals

PURPOSE

This study aims to establish normative data for parameters of spino-pelvic and spinal sagittal alignment, gender related differences and age-related changes in asymptomatic subjects.

METHODS

A total of 626 asymptomatic volunteers from Japanese population were enrolled in this study, including 50 subjects at least for each gender and each decade from 3rd to 8th. Full length, free-standing spine radiographs were obtained. Cervical lordosis (CL; C3-7), thoracic kyphosis (TK; T1-12), lumbar lordosis (LL; T12-S1), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) and sagittal vertical axis (SVA) were measured.

RESULTS

The average values (degrees) are 4.1 ± 11.7 for CL, 36.0 ± 10.1 for TK, 49.7 ± 11.2 for LL, 53.7 ± 10.9 for PI, 14.5 ± 8.4 for PT, and 39.4 ± 8.0 for SS. Mean SVA is 3.1 ± 12.6 mm. Advancing age caused an increase in CL, PT and SVA, and a decrease in LL and SS. There was a significant gender difference in CL, TK, LL, PI, PT and SVA. From 7th decade to 8th decade, remarkable decrease of LL & TK and increase of PT were seen. A large increase of SVA was also seen between 60' and 70'.

CONCLUSION

Standard values of spino-pelvic sagittal alignment were established in each gender and each decade from 20' to 70'. A remarkable change of spino-pelvic sagittal alignment was seen from 7th decade to 8th decade in asymptomatic subjects.

Age-related changes in thickness of anterior lower uterine segment in normal singleton pregnancy during 20-35 weeks' gestation

PURPOSE

To observe age-related changes in the anterior lower uterine segment (LUS) thickness in normal pregnancy from 20 to 35 weeks' gestation.

METHODS

Subjects were 235 uncomplicated singleton cases that underwent single ultrasound examination at 4-week intervals during 20-35 weeks' gestation. Sagittal LUS sections were evaluated with transvaginal ultrasonography. Anterior LUS thickness (Th) was measured every centimeter from the lowest bladder point (Th0cm) to 4 cm from that point (Th4cm). Th values were standardized by dividing by the Th0cm value. Intragroup comparisons of standardized Th values and intergroup comparisons of actual Th values were made according to gestational age. Statistical analyses were performed with the Kruskal-Wallis and Tukey honest standard deviation tests; significance was set at p < 0.05.

RESULTS

In the 20-23-, 24-27- and 32-35-week groups, standardized Th decreased from Th0cm to Th2cm; in the 28-31-week group standardized Th decreased from Th0cm to Th3cm. Median Th3cm values decreased from 5.0 mm at 20-23 weeks to 3.0 mm at 28-31 weeks, but remained unchanged thereafter.

CONCLUSIONS

The anterior LUS gradually thinned from Th0cm to Th3cm at 20-35 weeks' gestation. Th3cm became increasingly thin between 20-23 and 28-31 weeks' gestation.

Effects of senescence on the expression of BDNF and TrkB receptor in the lateral geniculate nucleus of cats

To explore the neural mechanisms mediating aging-related visual function declines, we compared the expressions of brain-derived neurotrophic factor (BDNF) and its high affinity receptor-tyrosine kinase B (TrkB) between young and old adult cats. Nissl staining was used to display neurons in each layer of the lateral geniculate nucleus (LGN). The BDNF- and TrkB receptor-immunoreactive neurons were labeled immunohistochemically, observed under optical microscope and photographed. Their neuronal density and immunoreactive intensity were measured. Results showed that the mean density of the Nissl stained neurons in each LGN layer were comparable between old and young adult cats, and their BDNF and TrkB proteins were widely expressed in all LGN layers. However, compared with young adult cats, both the density and optical absorbance intensity of BDNF- and TrkB-immunoreactive cells in each LGN layer in old cats were significantly decreased. These findings indicate that the decreased expressions of BDNF and TrkB proteins in the LGN may be an important factor inducing the compromised inhibition in the central visual nucleus and the functional visual decline in senescent individuals.

Sources of variation analysis and derivation of reference intervals for ALP, LDH, and amylase isozymes using sera from the Asian multicenter study on reference values

BACKGROUND

Sources of variation (SV) of ALP, LDH, and amylase isozymes were explored.

METHODS

We analyzed 3511 sera from well-defined healthy individuals recruited during the 2009 Asian project for derivation of common reference intervals (RIs). Up-to-date electrophoresis auto-analyzer and reagents were employed for high resolution and reproducibility. SVs including sex, age, body mass index (BMI), ABO blood groups, and levels of drinking, smoking, and exercise were analyzed by multiple regression analysis. RIs were determined by parametric methods after refining healthy individuals by use of latent reference values exclusion method.

RESULTS

Age-related changes in ALP2-3 were different in females: ALP2, linear increase from 20-64y; ALP3, lowering until 45 y and rising steeply thereafter. ALP2 increased with BMI especially in females. ALP5 was barely detectable except in blood-types O and B. Age-related increases in LDH1-LDH3 were noted in females, whereas BMI-related increases were found only for LDH2-LDH5 in both sexes. Pancreatic amylase showed age-related increase in females and was slightly higher in blood-type O. RIs for absolute and relative activities of each isozyme were derived in consideration of sex and age.

CONCLUSIONS

Investigation of these isozymes revealed various age-, BMI-, and blood-type-related changes that are all relevant in clinical interpretation of enzyme test results.

Evolution of pancreas in aging: degenerative variation or early changes of disease?

Pancreatic changes in aging have been described for many decades. They involve not only pancreatic parenchyma but also pancreatic ductal, microscopic, and exocrine functional changes. There have been many studies of these changes based on pathology and various imaging modalities, as well as functional studies. The pancreatic volume was found to decrease with advancing age, with a higher incidence of pancreatic steatosis, as demonstrated in autopsy and imaging studies. The pancreatic ductal structure has been described with wide ranges of normal variation, but many studies have shown a tendency toward enlargement with advancing age. By endoscopic ultrasound imaging, the aging pancreas may exhibit abnormal findings similar to chronic pancreatitis. Microscopically, there has been evidence of patchy lobular fibrosis and papillary hyperplasia and demonstrable k-ras mutation in both normal and dysplastic ductal mucosa. The evidence of pancreatic exocrine insufficiency has yielded conflicting results, but most studies have shown a tendency toward decreased pancreatic exocrine function in the elderly. Differentiating pancreatic change in the elderly from early chronic pancreatitis may be difficult as there are limited studies to compare these two conditions in terms of structural and functional changes.

Variability in self-reported normal sleep across the adult age span

OBJECTIVES

Illustrate the importance of examining within- and between-person differences in sleep across the adult age span.

METHOD

Two weeks of sleep diary data were analyzed for 592 normal sleepers ranging in age from 20 to 96 years. Variability in total sleep time (TST), number of nighttime awakenings (NWAK), sleep-onset latency (SOL), and wake-time after sleep onset (WASO) were examined overall and by age, sex, and race utilizing multilevel models and multiple regression.

RESULTS

Night-to-night differences in sleep within the same individual generally exceeded differences between individuals for TST, SOL, and WASO. The amount of intraindividual variability in TST and NWAK decreased with older age. Further, the degree of reduction in variability in TST associated with age depended on sex and race, with young black females showing the greatest variability. In general, females tended to have more intraindividual variability in SOL and NWAK than males, while race differences were complicated by high variability between blacks.

DISCUSSION

To truly assess and understand individual differences in the sleep of older adults, future research needs to take into account night-to-night variability (including what makes sleep vary from one night to the next), in addition to average sleep.