Evaluation Of Age-related Changes Research Articles

Evaluation of Age-Related Changes in Teneligliptin Pharmacokinetics in Japanese and European Descent Subjects Using a Physiologically Based Pharmacokinetic Model.

Drugs often show differing pharmacokinetic (PK) profiles, such as higher plasma concentrations, in older people than in younger people owing to age-related decreasesin physiological functions. However, it is difficult to evaluate the PK in older populations. Therefore, we simulated the plasma age-related changes in the PK of teneligliptin, a dipeptidyl peptidase-4 inhibitor, using physiologically based PK (PBPK) models. The previously developed PBPK model was revalidated by comparison between simulated data and clinical study data that included older subjects (up to 75years old). We then simulated the plasma concentration-time profiles for teneligliptin at a dose of 20mg (single and multiple doses) in virtual Japanese (20-70years old) and European descent(20-98years old) subjects. PK parameters were calculated by race and age group. We confirmed the validity of the previous PBPK model by comparison between simulated data and clinical study data. In the evaluation of age-related changes in PK after single and multiple doses using the PBPK model, the area under the plasma concentration-time curve (AUC) of teneligliptin tended to increase slightly with age in both populations up to 70years old. However, no clear age-related change in the maximum plasma concentration (Cmax) of teneligliptin was observed. In the European descent subjects aged ≥ 70years, the AUC tended to increase but the ratio of the change in Cmax was smaller than that in AUC. In both populations, there were positive correlations between AUC and age, but not between Cmax and age. The simulation using a PBPK model showed a tendency for the AUC of teneligliptin to increase with age, whereas Cmax was less affected by age than AUC.

CT Evaluation of Age-Related Changes in Epaxial Muscle Attenuation and Cross-Sectional Area for Sarcopenia and Myosteatosis in Small Breed Dogs

CT Evaluation of Age-Related Changes in Epaxial Muscle Attenuation and Cross-Sectional Area for Sarcopenia and Myosteatosis in Small Breed Dogs

Evaluation of age-related changes in the vitreous using magnetic resonance imaging

Objectives: Age-related liquefaction of vitreous humor may result in posterior vitreous detachment, retinal tear, and detachment. The purpose of this study is to determine the normative values of age-related changes in the vitreous in the normal population using different MRI sequences. Methods: A total of 180 eyes of 90 healthy cases were enrolled in this retrospective study. Patients were divided into nine groups according to age, and each group was of equal size with 10 patients(5 male and 5 female). The T1, T2, standardized T1, standardized T2 signals and ADC values determined for each vitreous humor of each eye. MRI parameters of the vitreous were compared within and between age groups. Results: No difference was detected within the decadic age groups for mean T1W for the right and left (p = 0.912 and p = 0.903, respectively), T2W for the right and left (p = 0.966 and p = 0.983, respectively), standardized T2W for the right and left (p = 0.915 and p = 0.899, respectively), and ADC for right and left values (p = 0.622 and p = 0.524, respectively). A significant difference was found between decadic age groups in terms of the standardized T1W values for right and left (p < 0.001 and p < 0.001, respectively). Standardized T1W values of vitreous fluid show a moderate degree of correlation with age for the right (r=0.514, p < 0.001) and left eyes (r=0.534, p < 0.001). Conclusions: This study provides comprehensive normative data on the different MRI signal properties of the human vitreous and its change with age. Using MRI, especially with standardized T1 measurements, age-related changes in the vitreous humor can be revealed non-invasively.

A radiomorphometric evaluation of age-related changes in mandibular morphology

AIMS: The main aim of this study was to determine, compare and differentiate the morphologically related changes of the mandible in dentate males and females among different age groups on digital panoramic images and to assess their authenticity in age estimations to provide evidence in forensics.
 MATERIALS AND METHODS: Digital panoramic images were made of 620 subjects, belonging to into four groups of ages ranging between 1218 years, 1940 years, 4160 years, and older than 60 years. Measurements such as gonial angle, condylar length, ramus length, cortical bone thickness, and ramal notch width were measured and evaluated. The data obtained was then subjected to descriptive statistical analysis followed by a Paired t-test and a Two-way ANOVA test to arrive at the results.
 RESULTS: On measuring an angular and four linear measurements a statistically significant differences were found among all the age groups with p 0.05 and also increased on aging except for the gonial angle. Among all the parameters, the gonial angle, ramus length, and ramal notch width depicted a statistically significant difference between the right and left sides and with p 0.05.
 CONCLUSION: Age estimation with linear and angular measurements of the mandible was possible among the study population. It is found that all parameters except gonial angle are reliable for age determination. It was found that as age increased, the mean value of all the parameters increased and showed a significant difference between all age groups except the gonial angle. Hence, this study positively recommends the use of all parameters except gonial angle for the purpose of age estimation in the field of forensics.

The computational age‐at‐death estimation from 3D surface models of the adult pubic symphysis using data mining methods

Age-at-death estimation of adult skeletal remains is a key part of biological profile estimation, yet it remains problematic for several reasons. One of them may be the subjective nature of the evaluation of age-related changes, or the fact that the human eye is unable to detect all the relevant surface changes. We have several aims: (1) to validate already existing computer models for age estimation; (2) to propose our own expert system based on computational approaches to eliminate the factor of subjectivity and to use the full potential of surface changes on an articulation area; and (3) to determine what age range the pubic symphysis is useful for age estimation. A sample of 483 3D representations of the pubic symphyseal surfaces from the ossa coxae of adult individuals coming from four European (two from Portugal, one from Switzerland and Greece) and one Asian (Thailand) identified skeletal collections was used. A validation of published algorithms showed very high error in our dataset—the Mean Absolute Error (MAE) ranged from 16.2 and 25.1 years. Two completely new approaches were proposed in this paper: SASS (Simple Automated Symphyseal Surface-based) and AANNESS (Advanced Automated Neural Network-grounded Extended Symphyseal Surface-based), whose MAE values are 11.7 and 10.6 years, respectively. Lastly, it was demonstrated that our models could estimate the age-at-death using the pubic symphysis over the entire adult age range. The proposed models offer objective age estimates with low estimation error (compared to traditional visual methods) and are able to estimate age using the pubic symphysis across the entire adult age range.

Evaluation of age-related changes in middle-ear structures by wideband tympanometry

Background Presbycusis is bilateral sensorineural hearing loss associated with the progressive degeneration of cochlear and central auditory pathways with aging. Aims/Objectives We aimed to reveal age-related changes in middle ear function by using wideband tympanometry (WBT). Materials and Methods Fifty-eight patients diagnosed with presbycusis were compared to 52 audiologically healthy participants. WBT measurement was performed on both ears via wideband click stimulus with a tympanometer device using probe tone frequencies of 226–8000 Hz. Results There were no statistically significant differences detected among the resonance frequencies or maximum absorbance ratios measured in both ears between groups (p > .05). The mean absorbance of the right and left ears at 4000 and 8000 Hz was statistically higher in the patient group than in the healthy controls (r = 0.038, 0.030; l = 0.015, 0.012). Moreover, mean compliance values were found to be significantly lower in the patient group than in the control group (r = 0.030 and l = 0.040). Conclusion The significant differences detected in compliance and absorbance values for high frequencies in presbycusis patients were remarkable. Thus, it has been shown that WBT yields an advantage compared to traditional tympanometry in the diagnosis and treatment of middle ear diseases.

Age-related changes in CB1 receptor expression and function and the behavioral effects of cannabinoid receptor ligands

Cannabinoid use has increased among aging individuals. However, little information on age-related differences in the behavioral effects of these agents is available. To explore potential differences in the behavioral effects of cannabinoids, we determined effects of Δ9-tetrahydrocannabinol (THC, 1–10 mg/kg) or rimonabant (0.3–3.2 mg/kg) on operant fixed-ratio responding (FR10) for food in young adult (6 months) and aged (29 months) rats. THC dose-dependently decreased responding for food. Rimonabant alone had little or no effect on responding up to 1.0 mg/kg, but disrupted responding following a 3.2 mg/kg dose. Rimonabant (1.0 mg/kg) partially antagonized response disruption by THC. These effects were similar in young adult and aged rats. However, aging has been reported to change the neurobiology of cannabinoid CB1 receptors. To confirm our rats exhibited such differences, we assessed CB1 receptor binding sites and function in six subcortical (caudate, nucleus accumbens CA1, and CA2/CA3), and three cortical regions (medial prefrontal, temporal, entorhinal) in young adult (6 months) or aged (26 months) male Lewis rats using quantitative autoradiography. CB1 receptor binding sites were reduced in cortical, but not subcortical brain regions of aged rats. CB1 receptor function, at the level of receptor-G protein interaction, was not different in any region studied. Results indicate that down-regulation of CB1 receptor binding sites observed in cortical regions of aged rats was not accompanied by a commensurate decrease in CB1 receptor-stimulated [35S]GTPγS binding, suggesting a compensatory increase in receptor function in cortical areas. Together, our results provide additional evidence of age-related changes in central CB1 receptor populations. However, the functional compensation for decreased CB1 receptor binding may mitigate changes in behavioral effects of cannabinoids. With the rising use of cannabinoid-based therapeutics among aging populations, further evaluation of age-related changes in the cannabinoid system and the impact of these changes on effects of this class of drugs is warranted.

Eyelid Crease Height Affects the Evaluation of Age-related Changes in the Eyelids.

Background:Although the functional and anatomical differences between the left and right eyelids are important in the evaluation of age-related changes in the eyelids, they have not been described clearly as indications for surgical treatments. This study aimed to investigate how laterality of the eyelids affects evaluation of age-related changes.Methods:Photographs of either one or both eyelids of 100 people were evaluated in four stages by 10 plastic surgeons. To investigate the consistency of the results between evaluations, surgeons evaluated the single-eyelid photographs (group U) or two-eyelid photographs (group B). It was investigated whether the difference in margin reflex distance 1, height of the upper eyelid crease, height of eyebrow, and levator contractile function were associated with mismatched evaluations.Results:The weighted kappa coefficient for groups B and U was 0.77 (substantial agreement). One-point difference in scores was observed in 23 cases. In the multiple logistic regression analysis, only the laterality the height of the eyelid crease was significantly different between patients whose evaluations were matched and those whose evaluations were mismatched (0.9 ± 0.1 mm versus 1.7 ± 0.2 mm; OR = 1.06, 95%CI: 1.01–1.10; P = 0.01).Conclusions:Besides the structure and function of each eyelid, the laterality of the height of the eyelid crease was important in the evaluation of the age-related changes in the eyelids. This factor may be important in evaluating the aesthetic and visual impressions of age-related changes in the eyelids.

Effects of Head Motion on the Evaluation of Age-related Brain Network Changes Using Resting State Functional MRI.

Purpose:The estimation of functional connectivity (FC) measures using resting state functional MRI (fMRI) is often affected by head motion during functional imaging scans. Head motion is more common in the elderly than in young participants and could therefore affect the evaluation of age-related changes in brain networks. Thus, this study aimed to investigate the influence of head motion in FC estimation when evaluating age-related changes in brain networks.Methods:This study involved 132 healthy volunteers divided into 3 groups: elderly participants with high motion (OldHM, mean age (±SD) = 69.6 (±5.31), N = 44), elderly participants with low motion (OldLM, mean age (±SD) = 68.7 (±4.59), N = 43), and young adult participants with low motion (YugLM, mean age (±SD) = 27.6 (±5.26), N = 45). Head motion was quantified using the mean of the framewise displacement of resting state fMRI data. After preprocessing all resting state fMRI datasets, several resting state networks (RSNs) were extracted using independent component analysis (ICA). In addition, several network metrics were also calculated using network analysis. These FC measures were then compared among the 3 groups.Results:In ICA, the number of voxels with significant differences in RSNs was higher in YugLM vs. OldLM comparison than in YugLM vs. OldHM. In network analysis, all network metrics showed significant (P < 0.05) differences in comparisons involving low vs. high motion groups (OldHM vs. OldLM and OldHM vs. YugLM). However, there was no significant (P > 0.05) difference in the comparison involving the low motion groups (OldLM vs. YugLM).Conclusion:Our findings showed that head motion during functional imaging could significantly affect the evaluation of age-related brain network changes using resting state fMRI data.

MONITORING HEALTH INDICES IN FEMALES OF DIFFERENT AGE GROUPS

Introduction. Health - is a complex and at the same integral multivariable dynamic state, developing in the process of realization of the genetic potential in a particular social and ecological environment, which permits a person to carry out its biological and social functions. Material and methods Health indices deteriorate with age. In this situation, special attention should be paid to older age groups. However, recent studies prefer to investigate young people. Data about health status of different age groups is not well investigated. Survey of 415 women aged 20 to 59 years residing on Yaroslavl region has been performed. Evaluation of age-related changes in health indices included questionnaire, morphological and functional examination, definition of physical development and adaptative potential according to the calculated indices and reference values. Results. The study examined the dynamics of health indices and established a statistically significant difference in the gain in body weight, blood pressure, total blood cholesterol, decreased lung capacity relative to body mass and adaptive capacity of the cardiovascular system with the age. Analysis of the incidence showed that chronic diseases incidence has increased from 56% in the 20-29 years group to 88% among 50-59 years old persons. Diseases of cardiovascular and musculoskeletal system (48-49%) become predominant pathology with age. Evaluation of lifestyle shows that poor physical activity and sleep disorders were registered in 77% and 32% respectively regardless of age. Eating disorders were registered in 41% patients aged of 20-29 years. Ratio tobacco users decreased from 23% to 10% with age, while the number of cigarettes smoked per day was increased. Сonclusion. The study established the negative dynamics of health indices to be typical for women aged 20-59 years, while the rate of deterioration exceeds the average one in the Russian population. Self-preservation behavior is not predominant in all age groups, it is typical only for 3% of young women and 11-15% of other groups.

Quantitative evaluation of age-related changes to pelvic floor muscles in magnetic resonance images from 369 patients.

This study aimed to establish and validate a quantitative evaluation method for pelvic floor muscles using magnetic resonance images (MRI) and to examine the morphological change of pelvic floor muscles with aging. Data from 369 consecutive patients (163 men, 206 women; median age 58 years; range 17-92 years) who underwent coronal T2-weighted pelvic MRI at Osaka General Hospital between January 2016 and December 2016 were retrospectively examined. MRI of the levator ani muscle was evaluated. The MRI image blinded the patient information and was evaluated by a radiology specialist with 22 years of experience. In coronal T2-weighted MRI of the pelvis, the levator ani muscle was evaluated using the slice; it showed the most upward and downward convexity. We measured the thickness of the levator ani muscle, and the distance at the most convex part from a straight line connecting the origin and insertion of the levator ani muscle on both the left and right sides. Upward and downward convexity was recorded in positive and negative values, respectively. The levator ani muscle was able to be evaluated quantitatively in all cases. Both men and women showed thinning (men: mean 3.316 mm, r = -0.388, P < 0.0001; women: mean 3.947 mm, r = -0.359, P < 0.0001) and concavity (men: mean 1.412 mm, r = -0.362, P < 0.0001; women: mean 4.979 mm, r = -0.630, P < 0.0001) of the levator ani muscle with aging. A quantitative evaluation method for pelvic floor muscles using MRI was established. Aging was associated with morphological changes in the pelvic floor muscles in both men and women. Geriatr Gerontol Int 2019; 19: 834-837.

Evaluation of age-related changes in lumbar facet joints using T2 mapping

BackgroundThe purpose in this study is to investigate the T2 value of lumbar facet joint (FJ) in subjects without lumbar spinal disorders, age from 20s to 70s, using T2 mapping, and to evaluate the correlation between age and T2 value. And also, we investigated the T2 value of lumbar intervertebral disc (IVD) in the same way as FJ, and evaluated the correlation between the T2 value of FJ and that of IVD. MethodsWe investigated 60 volunteers (30 male, 30 female), who were recruited from six age groups, 20s–70s (10 subjects in each decade; 5 male, 5 female). We measured the T2 values of FJ at the L4/5 level in axial image and those of IVD (nucleus pulposus; NP, anterior and posterior annulus fibrosus; AAF and PAF) at the L4/5 level in midline sagittal image. We investigated the correlation between age and T2 value of FJ, and the correlation between the T2 value of FJ and that of IVD. ResultsThere was a strong positive correlation between age and T2 value of FJ (r = 0.717). Age and T2 values of IVD were negatively correlated (NP; r = −0.728, AAF; r = −0.696, PAF; r = −0.580). There was a negative correlation between T2 value of FJ and that of IVD (NP; r = −0.575, AAF; r = −0.617, PAF; r = −0.492). ConclusionsT2 value of FJ was significantly increased as age rose. Our results suggest that T2 mapping could detect the degenerative changes of FJ related to aging even in subjects without lumbar spinal disorders. The results of this study will be the reference data of FJ T2 value in order to evaluate the relationship between low back pain and FJ using T2 mapping.

Age estimation of adult human remains from hip bones using advanced methods

The assessment of age-at-death is an important and challenging part of investigations of human skeletal remains. The main objective of the present study was to apply different mathematical approaches in order to reach more accurate and reliable results in age estimation. A multi-ethnic dataset (n=941) of evaluated age-related changes on the pubic symphysis and the auricular surface of the hip bone was used. Two research groups examined nine different mathematical approaches. The best results were reached by Multi-linear regression, followed by the Collapsed regression model, with MAE values of 9.7 and 9.9 years, respectively, and with RMSE values of 12.1 and 12.2, respectively. The mean accuracy of decision tree models ranged between 30.7% and 72.3%, with the model using only the PUSx indicator performing the best. Moreover, our results indicate that the limiting factor of age estimation can be the visual evaluation of age-related changes. Further research is required to objectify the proposed methods for estimating age.

Development of the maxillary sinus from birth to age 18. Postnatal growth pattern

ObjectivesAnatomical and developmental descriptions of the maxillary sinus may be of great clinical importance. An understanding of age-related changes in the dimensions and volume of the normal maxillary sinus may help in the evaluation of radiographs and identification of sinus abnormalities. The aim of the present study was to define growth patterns of maxillary sinuses in children up to the age of 18 years and evaluate the correlation between normal age-related changes in dimensions and volume. MethodsThe research sample consisted of CT scans of 170 patients subdivided into 17 groups based on age. Normal developmental changes were investigated and linear dimensions measured. ResultsThe maxillary sinus, present at birth, increases in size until the end of the 18th year.The growth pattern includes changes in vertical, horizontal and antero-posterior directions.No bilateral dimorphism was observed, but gender-related differences were found in children over the age of 8 years. The most extensive period of growth occurs during the first 8 years and by the end of the 16th year the maximal values of all diameters and volume are reached. ConclusionsA CT study of developing maxillary sinuses allowed a precise evaluation of age-related changes in all diameters and volume to be made.

Diffusional kurtosis imaging: a promising technique for detecting microstructural changes in neural development and regeneration

Diffusional kurtosis imaging: a promising technique for detecting microstructural changes in neural development and regeneration

Articular Cartilage Changes in Maturing Athletes

Context:Articular cartilage has a unique functional architecture capable of providing a lifetime of pain-free joint motion. This tissue, however, undergoes substantial age-related physiologic, mechanical, biochemical, and functional changes that reduce its ability to overcome the effects of mechanical stress and injury. Many factors affect joint function in the maturing athlete—from chondrocyte survival and metabolism to structural composition and genetic/epigenetic factors governing cartilage and synovium. An evaluation of age-related changes for joint homeostasis and risk for osteoarthritis is important to the development of new strategies to rejuvenate aging joints.Objective:This review summarizes the current literature on the biochemical, cellular, and physiologic changes occurring in aging articular cartilage.Data Sources:PubMed (1969-2013) and published books in sports health, cartilage biology, and aging.Study Selection:Keywords included aging, athlete, articular cartilage, epigenetics, and functional performance with age.Study Design:Systematic review.Level of Evidence:Level 3.Data Extraction:To be included, research questions addressed the effect of age-related changes on performance, articular cartilage biology, molecular mechanism, and morphology.Results:The mature athlete faces challenges in maintaining cartilage health and joint function due to age-related changes to articular cartilage biology, morphology, and physiology. These changes include chondrocyte loss and a decline in metabolic response, alterations to matrix and synovial tissue composition, and dysregulation of reparative responses.Conclusion:Although physical decline has been regarded as a normal part of aging, many individuals maintain overall fitness and enjoy targeted improvement to their athletic capacity throughout life. Healthy articular cartilage and joints are needed to maintain athletic performance and general activities. Genetic and potentially reversible epigenetic factors influence cartilage physiology and its response to mechanical and injurious stimuli. Improved understandings of the physical and molecular changes to articular cartilage with aging are important to develop successful strategies for joint rejuvenation.

Morphological analysis of age-related iridocorneal angle changes in normal and glaucomatous cases using anterior segment optical coherence tomography

PurposeTo analyze age-related morphological changes of the iridocorneal angle in normal subjects and glaucomatous cases, using anterior segment optical coherence tomography (AS-OCT).MethodsThis study involved 58 eyes of 58 open-angle glaucoma cases and 72 eyes of 72 age-matched normal-open-angle control subjects. Iridocorneal angle structures in nasal and temporal regions and anterior chamber depth (ACD) were measured using AS-OCT. Axial length and refractive error were measured by use of an ocular biometer and auto refractor keratometer. Angle opening distance (AOD), angle recess area (ARA), and trabecular-iris space area (TISA), measured at 500 μm (TISA500) and 750 μm (TISA750) distant from the scleral spur, were calculated, in the nasal and temporal regions. A new index, the peripheral angle frame index (PAFI), which represents the peripheral angle structure, was proposed, and was defined as (TISA750-TISA500)/TISA500.ResultsRefractive power in the glaucoma cases was less than in control cases (P<0.0001). Axial length (P<0.0001) and ACD (P=0.0004) were longer and deeper, respectively, in the glaucoma cases, compared with the control cases. In both control and glaucoma groups, ACD, AOD, ARA, and TISA decreased linearly in an age-dependent manner, while PAFI stayed at relatively constant values throughout the age distribution. AOD in the glaucoma group was longer than in the control group, in both the temporal and nasal regions; ARA and TISA were larger in the glaucoma than in the control group. However, no significant differences in nasal or temporal PAFI were found between the glaucoma and control groups.ConclusionThe findings of this study show that AS-OCT is useful for the quantitative evaluation of age-related changes in peripheral angle structure in glaucoma and control cases.

Evaluation of age-related changes in translocator protein (TSPO) in human brain using 11C-[R]-PK11195 PET

BackgroundWe studied the distribution and expression of translocator protein in the human brain using 11C-[R]-PK-11195 positron emission tomography (PK11195 PET) and evaluated age-related changes.MethodsA dynamic PK11195 PET scan was performed in 15 normal healthy adults (mean age: 29 ±8.5 years (range: 20 to 49); 7 males) and 10 children (mean age: 8.8 ±5.2 years (range: 1.2 to 17); 5 males), who were studied for potential neuroinflammation but showed no focally increased PK11195 binding. The PET images were evaluated by calculating standard uptake values and regional binding potential, based on a simplified reference region model, as well as with a voxel-wise analysis using statistical parametric mapping.ResultsPK11195 uptake in the brain is relatively low, compared with the subcortical structures, and symmetrical. The overall pattern of PK11195 distribution in the brain does not change with age. PK11195 uptake was lowest in the frontal-parietal-temporal cortex and highest in the pituitary gland, midbrain, thalamus, basal ganglia, occipital cortex, hippocampus and cerebellum, in descending order. White matter showed negligible PK11195 uptake. Overall, brain PK11195 uptake increased with age, with midbrain and thalamus showing relatively higher increases with age compared with other brain regions.ConclusionsThe brain shows low PK11195 uptake, which is lower in the cortex and cerebellum compared with subcortical structures, suggesting a low level of translocator protein expression. There is no hemispheric asymmetry in PK11195 uptake and the overall pattern of PK11195 distribution in the brain does not change with age. However, brain PK11195 uptake increases with age, with the thalamus and midbrain showing relatively higher increases compared with other brain regions. This increase in uptake suggests an age-related increase in translocator protein expression or the number of cells expressing these receptors or both.

Age-related testosterone decline in a Brazilian cohort of healthy military men

Androgen decline in the aging man has become a topic of increasing clinical relevance worldwide, as the reduction in testosterone levels has been reported to be accompanied by loss of muscle mass, accumulation of central adiposity, impaired mobility and increase risk of bone fractures. Although well-established in studies conducted in developed countries, progressive decline in serum testosterone levels with age has been poorly investigated in Brazil. To determine the pattern of blood testosterone concentrations decline with age in a cohort of Brazilian healthy military men. We retrospectively reviewed data on serum testosterone measurements of healthy individuals that had undergone a routine check-up at the Military Biology Institute. Blood samples were obtained early in the morning, and total testosterone concentration was determined using a commercial chemoluminescent immunoassay. Mean values were analyzed in five age groups: ≤ 40, 41 to 50, 51 to 60, 61 to 70, and > 70 years. Mean total testosterone levels. 1,623 subjects were included in the analysis; mean age was 57 years (24 to 87), and mean testosterone level was 575.5 ng/dL (25.0 to 1308.0 ng/dL). The evaluation of age-related changes in total testosterone levels revealed a progressive reduction in serum levels of this hormone with increasing age. Testosterone levels below 300 ng/dL were reported in 321 participants, a prevalence of nearly 20% in the study population. In agreement with other findings, a reduction of total testosterone levels with age was reported for healthy Brazilian men.

Evaluation of Age-related Changes in Human Palpebral Conjunctiva and Meibomian Glands by In Vivo Confocal Microscopy

To investigate the age-related changes in human palpebral conjunctiva and meibomian glands by in vivo confocal microscopy. Forty-nine healthy volunteers (20 men and 29 women; mean age, 43.4 ± 22.7 years; range, 9-85 years) were recruited from the community. Laser scanning confocal microscopy was used to observe and measure the upper palpebral conjunctiva and meibomian glands. Customized software was used to analyze the images. The quantitative parameters included the mean densities of goblet cells, conjunctival basal epithelium, Langerhans cells, and meibomian glandular acinar units. Mean densities of goblet cells, conjunctival basal epithelium, Langerhans cells, and meibomian glandular acinar units were 1050 ± 495 cells per square millimeter, 2979 ± 510 cells per square millimeter, 32 ± 16 cells per square millimeter, and 71 ± 27 glands per square millimeter in total subjects, respectively. No statistically significant difference in these 4 parameters was observed between the male and female subjects. Significant negative correlations were noted between age and goblet cell density (r = -0.646; P < 0.0001) and meibomian glandular acinar unit density (r = -0.585; P < 0.0001). However, no significant correlation was detected between the densities of conjunctival basal epithelium or Langerhans cell density and age. Age-related changes under laser scanning confocal microscopy included decreased densities of goblet cells in human palpebral conjunctiva and the acinar units in meibomian glands.