Gender Differences In Age-related Changes Research Articles

Gender-differences in age-related changes of corneal astigmatism in Korean cataract patients

BackgroundThis cross-sectional study investigated age-related changes in anterior, posterior, and total corneal astigmatism and evaluated sex differences in corneal astigmatism with increasing age in cataract patients.MethodsThis study evaluated eyes with cataracts from May 2009 and July 2013. All eyes underwent a complete ophthalmological examination and corneal Scheimpflug imaging by a Pentacam camera (Oculus, Wetzlar, Germany). Anterior, posterior, and total corneal astigmatism were determined. Power vector J0 and linear regression analyses were determined and compared with respect to age and sex.ResultsFour hundred and fifteen patients (217 men, 198 women) aged 20–89 years were evaluated. For anterior corneal astigmatism, 100% of patients who were 20–39 years old had with-the-rule (WTR) in both sexes. WTR was significantly lower in patients 80–89 years old (25.6% of men and 37.8% of women). For total corneal astigmatism, WTR also tended to decrease with increasing age: 93.3% of men and 100% of women 20–39 years old versus 20.9% of men and 31.1% of women 80–89 years old. The regression coefficient of both the anterior corneal and total corneal J0 vector values analyzed by age were − 0.018 in men and − 0.016 in women (both p < .001).ConclusionsThe against-the-rule shift was faster for total corneal astigmatism than for anterior corneal astigmatism and it occurred earlier in men than in women.Trial registrationRetrospectively registered. Registration number: KC15RISI0241. Registered April 20, 2016.

The Effects of Age, from Young to Middle Adulthood, and Gender on Resting State Functional Connectivity of the Dopaminergic Midbrain.

Dysfunction of the dopaminergic ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) is implicated in psychiatric disorders including attention-deficit/ hyperactivity disorder (ADHD), addiction, schizophrenia and movement disorders such as Parkinson’s disease (PD). Although the prevalence of these disorders varies by age and sex, the underlying neural mechanism is not well understood. The objective of this study was to delineate the distinct resting state functional connectivity (rsFC) of the VTA and SNc and examine the effects of age, from young to middle-adulthood, and sex on the rsFC of these two dopaminergic structures in a data set of 250 healthy adults (18–49 years of age, 104 men). Using blood oxygenation level dependent (BOLD) signals, we correlated the time course of the VTA and SNc to the time courses of all other brain voxels. At a corrected threshold, paired t-test showed stronger VTA connectivity to bilateral angular gyrus and superior/middle and orbital frontal regions and stronger SNc connectivity to the insula, thalamus, parahippocampal gyrus (PHG) and amygdala. Compared to women, men showed a stronger VTA/SNc connectivity to the left posterior orbital gyrus. In linear regressions, men but not women showed age-related changes in VTA/SNc connectivity to a number of cortical and cerebellar regions. Supporting shared but also distinct cerebral rsFC of the VTA and SNc and gender differences in age-related changes from young and middle adulthood in VTA/SNc connectivity, these new findings help advance our understanding of the neural bases of many neuropsychiatric illnesses that implicate the dopaminergic systems.

Physiological changes associated with aging and immobility.

Aging, an inevitable and extremely complex, multifactorial process, is characterised by the progressive degeneration of organ systems and tissues. It is largely determined by genetics, and influenced by a wide range of environmental factors, such as diet, exercise, exposure to microorganisms, pollutants, and ionising radiation. This explains why two people of the same age may differ markedly in terms of both physical appearance and physiological state. Gender also plays a part and, in most developed countries, women typically outlive men by 7–10 years [1]. Recent research has also demonstrated that distant experiences such as childhood personality and education, as well as behavioural factors, also contribute to longevity [2]. It is generally accepted that the aging process falls physiologically into three groups of changes that occur with advancing age [3]. The first group encompass changes in cellular homeostatic mechanisms, for example, body temperature, blood, and extracellular fluid volumes; the second group are related to a decrease in organ mass; the third and possibly the most important group of changes, in terms of their impact, involve a decline in and loss of the functional reserve of the body's systems. Loss of these functional reserves may impair an individual's ability to cope with external challenges such as surgery or trauma. Maintaining physiological function (health) in an aging population is of prime importance not only to the well-being of the aging individual, but also from a social perspective, helping to reduce the burden on medical services and systems [4]. It has also been long established that the physiological changes associated with normal aging are mirrored during periods of immobility, such as prolonged hospital bed rest, or after a fractured limb or a fall. It was with the above in mind and with the hope of collating research and knowledge examining the effects of normal aging and immobility that we developed the call for this special issue. Three of the seven papers in the Issue discuss physiological changes in muscle tissue: age-related loss of muscle strength is considered by G. Goldspink, who pays special consideration to declining levels of Mechano Growth Factor (MGF) with age and the positive effects seen on muscle cells when this factor is externally administered; J. Alwood et al. describe how their study in mice shows changes to the skeletal musculature following low dose ionising gamma radiation changes which are normally seen in elderly patients prior to the onset of age-related osteoporosis; a quantitative review of age-related changes in strength/power and balance and the consequence of falls risk assessment is presented by U. Granacher et al. Two papers in this special issue consider age-related cardiac function: G. A. Maranhao Neto et al. discuss how low levels of cardiorespiratory fitness (CRF) can be associated with health problems in elderly patients; the authors present a unique model of assessing levels of CRF, negating the use of aerobic exercise which often presents severe limitations as a test method; the study by S. Moodithaya and S. T. Avadhany highlights the findings that there are gender differences in age-related changes in cardiac autonomic control, suggesting that female sex hormones may play a part in cardiac autonomic modulation. Our penultimate paper by C. N. Ross et al. explores the potential for using translational research (using a population of nonhuman primates) to determine if certain body measurements and phenotypes are associated with age or increased mortality. Finally, R. Semprini et al. suggest a look at impaired cognition and apathy as markers for unsuccessful aging and frailty. The papers we present here certainly, in our minds, contribute to the further understanding of the physiological changes associated with aging and highlight the continued need to develop and expand our knowledge in this important field of research. Yamni Nigam John Knight Sharmila Bhattacharya Antony Bayer

Gender Differences in Age-Related Changes in Cardiac Autonomic Nervous Function

Ageing is associated with changes in cardiac autonomic control as measured by Heart Rate Variability (HRV). Not many studies have explored the influence of gender on age-related changes in cardiac autonomic regulation. This study evaluated the gender differences in age-associated changes in cardiac autonomic nervous activity by assessing HRV using frequency domain analysis of short-term stationary R-R intervals. HRV was studied in healthy males and females ranging in age from 6 to 55 years. Total power and absolute power in High-Frequency (HF) and Low-Frequency (LF) components as well as HF in normalized unit declined significantly with ageing. The HF/LF ratio was significantly higher in the adolescent and adult females compared to male of these age groups. This study suggests that gender differences exist in age-related changes in HRV. The finding that gender differences are limited to adolescent and adult age groups may indicate a role for female sex hormones in cardiac autonomic modulation.

Gender Differences in Age-Related Changes in Left and Right Ventricular Geometries and Functions

The purpose of the present study was to investigate gender differences in age-related changes of left ventricular (LV) and right ventricular (RV) geometries and functions throughout the entire adult age range using the Japanese Normal Values for Echocardiographic Measurements Project (JAMP) study database. Seven hundred healthy volunteers (aged 20-79 years) underwent 2-dimensional and Doppler echocardiography. The subjects were stratified into 6 different age groups and then stratified by gender in each age group. LV diastolic function was assessed from pulsed wave Doppler measurements of mitral early (E) and late (A) inflow velocities and tissue Doppler measurements of mitral early (e') and late (a') annular velocities. LV volume decreased and LV mass increased with age to a similar extent in both men and women. Furthermore, for subjects <50 years, women had significantly greater E, E/A ratio and e' than men, but these parameters were similar between genders in subjects >50 years. In addition, there was a significant interaction between age and gender that affected the differences in E, e' and E/e' among the groups (P<0.03, P<0.01, and P<0.03, respectively; ANOVA). There were no gender differences in age-related changes in RV parameters. Gender differences were found in age-related changes in LV diastolic function in a healthy population. Gender differences should be considered for optimal diagnosis and management of cardiovascular disease.

Gender differences in age effect on brain atrophy measured by magnetic resonance imaging.

A prospective sample of 69 healthy adults, age range 18-80 years, was studied with magnetic resonance imaging scans (T2 weighted, 5 mm thick) of the entire cranium. Volumes were obtained by a segmentation algorithm that uses proton density and T2 pixel values to correct field inhomogeneities ("shading"). Average (+/- SD) brain volume, excluding cerebellum, was 1090.91 ml (+/- 114.30; range, 822.19-1363.66), and cerebrospinal fluid (CSF) volume was 127.91 ml (+/- 57.62; range, 34.00-297.02). Brain volume was higher (by 5 ml) in the right hemisphere (P less than 0.0001). Men (n = 34) had 91 ml higher brain and 20 ml higher CSF volume than women (n = 35). Age was negatively correlated with brain volume [r(67) = -0.32, P less than 0.01] and positively correlated with CSF volume (r = 0.74, P less than 0.0001). The slope of the regression line with age for CSF was steeper for men than women (P = 0.03). This difference in slopes was significant for sulcal (P less than 0.0001), but not ventricular, CSF. The greatest amount of atrophy in elderly men was in the left hemisphere, whereas in women age effects were symmetric. The findings may point to neuroanatomic substrates of hemispheric specialization and gender differences in age-related changes in brain function. They suggest that women are less vulnerable to age-related changes in mental abilities, whereas men are particularly susceptible to aging effects on left hemispheric functions.