Sex Differences In Association Research Articles

Sex differences in association between dietary sodium intake and white matter hyperintensity volume

Abstract Background There is limited evidence on the relationship between dietary sodium intake (dNa) and brain health, and very little on sex differences in associations. Purpose To study the relationship between dNa and imaging measures of brain health in men and women from the INSIGHT 46 substudy of the MRC National Survey of Health and Development (British 1946 birth cohort). Methods Participants had measurements (dNa using 5-day food diary, anthropometrics, blood pressure (BP) body mass index (BMI)) at 60-64years. Whole-brain and hippocampal volumes, white matter hyperintensity volume (WMHV) and florbetapir amyloid-β positivity were measured using MRI-PET imaging at 69-71years. Associations (β (95% confidence intervals)) were estimated separately in men and women using generalized linear models with robust standard errors adjusted for potential confounders (age, diet quality, energy intake, socioeconomic status) or potential mediators (BMI, BP). Results Participants’ characteristics are shown in Table 1. In women but not men dNa was positively associated with higher WMHV (β[women]=32(1, 72) %/g; p=0.043; β[men]=-10(-27, 11)%/g; p=0.342); this relationship in women was independent of BMI (β = 32(1, 72)%/g; p = 0.043) or systolic BP (β = 31(1, 70)%/g; p=0.041). dNa was not associated with total brain volume, hippocampal volume or amyloid-β positivity in either sex. Conclusions Elevated sodium consumption in the diet is associated with cerebral small vessel disease in older age women but not men. This association was independent of BMI or BP.Table 1

8026 Growth Hormone Receptor (GHR) is Independently Associated with Body Composition and Glycemic Measures in Youth with Type 2 Diabetes (T2D)

Abstract Disclosure: C. Lu: None. D. Wolfs: None. L. El ghormli: None. L.M. Laffel: None. M. Patti: Advisory Board Member; Self; Fractyl Health. Consulting Fee; Self; AstraZeneca, Hamni, MBX Biosciences. Grant Recipient; Self; Dexcom. E. Isganaitis: None. Background: T2D is more severe in youth than in adults, with growth and puberty as potential drivers. Growth hormone (GH) action, which peaks during puberty, also regulates carbohydrate metabolism. We previously showed that higher plasma levels of GHR are associated with hyperglycemia, insulin resistance, and decreased insulin secretion in youth with T2D. Plasma GHR is higher in obesity, and reductions in GHR after bariatric surgery may mediate improvements in glycemia. The association of GHR with body composition in youth with T2D has not been previously studied. Hypothesis: We hypothesize that the association of GHR with glycemic outcomes in youth with T2D is mediated by differences in body composition, and that associations between GHR and body composition differ by sex. Methods: Utilizing plasma samples from Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study (N=398), we examined association of plasma GHR (ELISA; ng/mL) with a) body composition measures including zBMI, absolute lean mass (kg), percent body fat (dual-energy x-ray absorptiometry), and b) glycemic outcomes including hemoglobin A1c (HbA1c), fasting glucose (mg/dL), 1/fasting C-peptide (mL/ng), C-peptide index (ng/mL per mg/dL), and C-peptide oral disposition index (CODI; mL/uU x ng/mL per mg/dL), stratified by sex. Linear regressions were adjusted for age, race/ethnicity, and Tanner stage in the base models, with additional adjustments for HbA1c, zBMI, lean mass, or percent fat. Results: This subcohort of youth with T2D from the TODAY study included 150 males and 248 females, mean age 13.9 ± 2.0 years. Females had lower zBMI (+2.2 ± 0.4 vs. +2.3 ± 0.5, p=0.005), lower lean mass (51 ± 10 vs. 59 ± 14, p<0.001), and higher percent body fat (39 ± 5 vs. 34 ± 6, p<0.001). Higher log2 GHR was associated with higher zBMI (B=0.44, SE=0.04, p<0.001), higher lean mass (B=4.3, SE=1.2, p<0.001), and higher percent fat (B=4.4, SE=0.7, p<0.001), even after adjustment for HbA1c, and without sex-specific differences. Higher log2 GHR was associated with higher HbA1c (B=0.35, SE=0.08, p<0.001), higher fasting glucose (B=9.0, SE=2.6, p<0.001), lower 1/fasting C-peptide (B=-0.17, SE=0.01, p<0.001), and lower CODI (B=-0.001, SE=0.001, p=0.02). These associations did not change with further adjustments for zBMI, lean mass, or percent fat, suggesting that associations between GHR and glycemia are independent of obesity or body composition. In analyses stratified by sex, the effect of GHR on CODI was attenuated after adjustment for lean mass in males only. Conclusion: Plasma GHR is independently associated with body composition and glycemia in youth with T2D. There were no sex differences in associations of GHR with HbA1c and insulin resistance. However, the association of GHR with beta cell function may be mediated by lean mass in boys but not in girls, although power was more limited in the sex-stratified analyses. Presentation: 6/3/2024

Sex-associated Differences In Low QRS Voltage In Young Athletes

Sex-associated Differences In Low QRS Voltage In Young Athletes

Sex-Dependent Effects of Cardiometabolic Health and APOE4 on Brain Age: A Longitudinal Cohort Study.

The aging population is growing faster than all other demographic strata. With older age comes a greater risk of health conditions such as obesity and high blood pressure (BP). These cardiometabolic risk factors (CMRs) exhibit prominent sex differences in midlife and aging, yet their influence on brain health in females vs males is largely unexplored. In this study, we investigated sex differences in relationships between BP, body mass index (BMI), and brain age over time and tested for interactions with APOE ε4 genotype (APOE4), a known genetic risk factor of Alzheimer disease. The sample included participants from 2 United Kingdom-based longitudinal birth cohorts, the Lothian Birth Cohort (1936) and Insight 46 (1946). Participants with MRI data from at least 1 time point were included to evaluate sex differences in associations between CMRs and brain age. The open-access software package brainageR 2.1 was used to estimate brain age for each participant. Linear mixed-effects models were used to assess the relationships between brain age, BMI, BP, and APOE4 status (i.e., carrier vs noncarrier) in males and females over time. The combined sample comprised 1,120 participants (48% female) with a mean age (SD) of 73 (0.72) years in the Lothian Birth Cohort and 71 (0.68) years in Insight 46 at the time point 1 assessment. Approximately 30% of participants were APOE4 carriers. Higher systolic and diastolic BP was significantly associated with older brain age in females only (β = 0.43-0.56, p < 0.05). Among males, higher BMI was associated with older brain age across time points and APOE4 groups (β = 0.72-0.77, p < 0.05). In females, higher BMI was linked to older brain age among APOE4 noncarriers (β = 0.68-0.99, p < 0.05), whereas higher BMI was linked to younger brain age among carriers, particularly at the last time point (β = -1.75, p < 0.05). This study indicates sex-dependent and time-dependent relationships between CMRs, APOE4 status, and brain age. Our findings highlight the necessity of sex-stratified analyses to elucidate the role of CMRs in individual aging trajectories, providing a basis for developing personalized preventive interventions.

Androgen-type 2 innate lymphoid cells-dendritic cell axis modulates sex-associated differences in skin immune responses.

Androgen-type 2 innate lymphoid cells-dendritic cell axis modulates sex-associated differences in skin immune responses.

Abstract P381: Sex differences in association between gut microbiome and 24-hour blood pressure variability

Background: Blood pressure (BP) variability is an independent risk factor for cardiovascular disease (CVD). BP variability has been associated with cardiovascular organ damage and is a potential therapeutic target for the prevention of CVD. Recently, the gut microbiome (GM) has been shown to have a pathological role in hypertension, however, the association between GM and BP variability is poorly understood. Methods: 241 community-dwelling individuals free of symptomatic CVD from Hong Kong (113 males and 128 females, mean age 54±6 years) underwent ambulatory BP monitoring and stool microbiota shotgun sequencing. BP variability was determined as systolic/diastolic BP (SBP/DBP) coefficient of variation (CoV), nighttime dipping, and morning BP surge (MBPS). Sleep latency was estimated using 7-day Actigraphy data. Associations of BP variability with GM, and plasma and stool short-chain fatty acids (SCFAs) were analyzed under statistical models adjusting for age, sex, serum glucose and lipids, sodium intake assessed by urine analysis, menopause status, smoking, fatty liver, BP and sleep latency. Results: Women had a significantly higher 24-hour SBP ( p =0.0005) and DBP ( p =0.002) CoV than men. 24-hour SBP CoV had a negative association with GM α-diversity (Shannon and Simpson’s index: all P &lt;0.05) and a positive association with Firmicutes/Bacteroidetes ratio ( P &lt;0.05), suggesting gut dysbiosis in participants with higher systolic BP variability. Several GM species and SCFAs were significantly associated with the indices of BP variability in both men and women. Notably, Parabacteroides merdae had a negative association with both systolic and diastolic BP CoV (all P &lt;0.05-0.01). Bacteroidetes dorei and Bacteroides intestinalis were reduced in women with higher SBP CoV ( P &lt;0.05) and nondipping status ( P&lt; 0.01), respectively. Prewaking and sleepthrough MBPS had a positive association with Faecalibacterium prausnitzii in women (all P &lt;0.001) and plasma acetic acid levels in men ( P &lt;0.05-0.001). Further analysis indicated that Bacteroidetes dorei may mediate SBP CoV via plasma iso-butyric acid in women (bootstrapping 95% CI: -3.6 to -0.19; P &lt;0.05). Conclusions: This cross-sectional study suggests sex-specific associations between GM and BP variability. Most noteworthy, higher systolic BP variability was associated with a significant reduction in potentially beneficial bacterial species, primarily in women which may be explored for therapeutic potential.

Sex differences in association of healthy eating pattern with all-cause mortality and cardiovascular mortality

BackgroundAlthough the Healthy Eating Index (HEI) is widely recommended to reduce the risk of cardiovascular disease and all-cause death, there are significant differences in physiological and nutritional factors between the sexes. The potential impact of sex on adult dietary health is still poorly understood. The study was designed to assess whether the health benefits of diet differed by sex.MethodsIn a prospective study of 39,567 U.S. adults (51.2% female, age 46.8 ± 17.6 years), we examined sex-specific, multivariable-adjusted associations of HEI with all-cause mortality and cardiovascular disease mortality. Restricted cubic splines (RCS), subgroup analysis, propensity score matching (PSM), random forest feature importance, and sensitivity analysis were also used.ResultsDuring 328,403 person-years of follow-up, a total of 4754 all-cause deaths were recorded, including 1481 cardiovascular deaths. Compared to the lowest quartile of HEI, the all-cause mortality rate of females and males in the highest quartile array decreased by 34% (HR 0.66 [95% CI 0.55–0.8]) and 15% (HR 0.85 [95% CI 0.73–0.99]), respectively. The restricted cubic spline showed a linear inverse association between baseline HEI and all-cause mortality and CVD mortality, with similar sex-specific results. Similarly, component scores were sex-specific for mortality risk, with females benefiting more from diet. The benefits of dairy products, vegetables, and sodium scores on the risk of all-cause death were higher in males and females. However, the benefits of vegetable, sodium, and fatty acid scores on the risk of cardiovascular death were different.ConclusionsIn the adult population of the U.S., there are more opportunities for females to reduce the risk of all-cause mortality and cardiovascular mortality from the same dose of healthy dietary intake than males. These findings could reduce the risk of death by motivating the population, especially females, to consume healthy dietary components, especially vegetables and dairy products.

Sex-associated differences in sclerochronology and sensitivity to thermal stress in Caribbean and eastern Pacific reef-building corals

Sex-associated differences in sclerochronology and sensitivity to thermal stress in Caribbean and eastern Pacific reef-building corals

Sex differences in Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is an underdiagnosed sequela of acute pulmonary embolism with varied clinical presentation causing significant morbidity among the affected population. There exist important differences in the occurrence, clinical features and diagnosis of CTEPH between men and women, with women carrying a greater predisposition for the disease. Ongoing studies have also pointed out variations among men and women, in the treatment offered and long-term outcomes including mortality. This focused review article highlights important sex-associated differences in multiple aspects of CTEPH including its epidemiology, clinical features, diagnosis, treatment and outcomes as reported in current literature and highlights the need for future research to facilitate a clearer understanding of these differences.

Sex differences in association of joint glycemic, blood pressure and lipid control and two-year risk of falls among older adults with diabetes

AimsTo characterize the risk of falls among males and females by joint glycemic, blood pressure (BP) and cholesterol control among older adults (≥65 years) with diagnosed diabetes in USA. MethodsUsing longitudinal data from the Health and Retirement Study (2006–2019), we studied the association of joint glycemic (HbA1c < 7.5 %), BP (systolic <140 and diastolic <90 mmHg) and cholesterol (total < 200 mg/dL) control with two-year risk of falls. We estimated risk ratios (RR) to describe the associations for joint ABC control and independent biomarker control by sex, using modified Poisson regressions after adjusting for known individual and household risk factors. ResultsThe analytic sample consisted of 4509 observations from 2829 older adults (54.7 % female) with a mean age of 72.2 (SD: 6.6) years and duration of diabetes of 9.9 years. Joint ABC control was not associated with risk of falls among females but was associated with lower risk among males (0.91 [95%CI: 0.81–1.02]). Furthermore, achievement of glycemic control (0.85 [95%CI: 0.73–0.98]) and BP control (0.89 [95%CI: 0.79–1.01]) were associated with lower risk but cholesterol control (1.15 [95%CI: 0.99, 1.34]) was associated with higher risk of falls among males. ConclusionsJoint achievement of glycemic, BP and cholesterol targets may prevent falls among older males. Future studies among people with diabetes should consider biomarker control as a preventive factor for falls.

The yin and yang of two opponent processes of sleep-wake regulation: Sex-associated differences in the spectral EEG markers of the drives for sleep and wake

ABSTRACT Although objectively measured characteristics of sleep efficiency and quality were found to be better in women than men, women more frequently than men suffer from poor or insufficient or non-restorative sleep. We explored this apparent paradox by testing the sex-associated differences in electroencephalographic (EEG) indicators of two opponent processes of sleep-wake regulation, the drives for sleep and wake. We tried to provide empirical support for the hypothesis that a stronger women’s sleep drive can explain better objective characteristics of sleep quality in women than men, while a stronger women’s wake drive can be an explanation of a higher frequency of sleep-related complaints in women than men. To our knowledge, this was the first attempt to examine the associations of sex with scores on the 1st and 2nd principal components of the EEG spectrum that can serve as objective spectral EEG markers of the opponent drives for sleep and wake, respectively. The particular prediction was that, in women compared to men, not only the 1st principal component score but also the 2nd principal component score could be higher (i.e. both drives could be stronger). In a sample of 80 university students (40 females), the EEG signals were recorded during 160 afternoon napping attempts (50 min or longer). The difference between male and female students in sleep latencies did not reach a statistically significant level. In accordance with our prediction, both principal component scores were found to be higher in female than in male students irrespective of sleep stage. It is likely that the influence of the wake drive is entirely overlooked in the polysomnographic studies due to the predominant contribution of the indicators of the sleep drive to the conventional objective characteristics of sleep quality. Therefore, a stronger women’s sleep drive can be an explanation of women’s better sleep quality in the results of polysomnographic studies. On the other hand, if a stronger women’s wake drive can influence the perception of their sleep quality, this can explain their more frequent sleep-related complaints.

Sex-associated differences in neuroinflammation reactions in the cerebral cortex during the manifestation of alzheimer’s disease in an experiment

Sex-associated differences in neuroinflammation reactions in the cerebral cortex during the manifestation of alzheimer’s disease in an experiment

Clinical Characteristics and Patterns of Immune Responses in COVID-19 Patients From a Rural Community Hospital.

Background Although demographic and clinical factors such as age, certain comorbidities, and sex have been associated with COVID-19 outcomes, these studies were largely conducted in urban populations affiliated with large academic medical centers. There have been very few studies focusing on rural populations that also characterize broader changes in inflammatory cytokines and chemokines. Methodology A single-center study was conducted between June 2020 and March 2021 in Abilene, Texas, USA.Patients were included if they presented to the hospital for treatment of COVID-19, had extra biological materials from routine care available, and were between the ages of 0 to 110 years. There were no exclusion criteria. Patient characteristics, symptom presentation, and clinical laboratory results were extracted from electronic health records. Blood specimens were analyzed by protein microarray to quantitate 40 immunological biomarkers. Results A total of 122 patients were enrolled, of whom 81 (66%) were admitted to the general non-critical inpatient unit, 37 (30%) were admitted to the intensive or critical care units, and four (3.2%) were treated outpatient. Most hospitalized COVID-19 patients in this rural population were elderly, male, obese, and retired individuals. Predominant symptoms for non-critical patients were shortness of breath, fever, and fatigue. Ferritin levels for outpatient patients were lower on average than those in an inpatient setting and lactate dehydrogenase (LDH) levels were noted to be lower in non-critical and outpatient than those in the intensive care unit setting. Inflammatory biomarkers were positively correlated and consistent with inflammatory cascade. Interleukin (IL)-10 was positively correlated while platelet-derived growth factor was negatively correlated with inflammatory biomarkers. Patients ≥65 years had significantly higher levels of LDH and seven cytokines/chemokines (granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin IL-1b, IL-6, IL-10, IL-11, macrophage inflammatory protein (MIP)-1d, and IL-8) while levels of five other immune molecules (intercellular adhesion molecule 1 (ICAM-1), monocyte chemoattractant protein 1 (MCP-1), tissue inhibitor of metalloproteinase 2 (TIMP-2), IL-2, and IL-4) were significantly lower compared to those <65 years. Females had significantly higher levels of LDH and 10 cytokines/chemokines (GM-CSF, IL-1b, IL-6, IL-10, IL-11, IL-15, IL-16, MIP-1a, MIP-1d, and IL-8) while levels of TIMP-2 and IL-4 were significantly lower than male patients. Conclusions The clinical characteristics of this rural cohort of hospitalized patients differed somewhat from nationally reported data. The contributions of social, environmental, and healthcare access factors should be investigated. We identified age and sex-associated differences in immunological response markers that warrant further investigation to identify the underlying molecular mechanisms and impact on COVID-19 pathogenesis.

Host-plant sex and phenology of Buddleja cordata Kunth interact to influence arthropod communities.

Intraspecific variation in plants is expected to have profound impacts on the arthropod communities associated with them. Because sexual dimorphism in plants is expected to provide consistent variation among individuals of the same species, researchers have often studied the effect it has on associated arthropods. Nevertheless, most studies have focused on the effect of sexual dimorphism in a single or a few herbivores, thus overlooking the potential effects on the whole arthropod community. Our main objective was to evaluate effects of Buddleja cordata's plant-sex on its associated arthropod community. We surveyed 13 pairs of male and female plants every 2 months during a year (June 2010 to April 2011). Every sampling date, we measured plant traits (water content and leaf thickness), herbivory, and the arthropod community. We did not find differences in herbivory between plant sex or through time. However, we found differences in water content through time, with leaf water-content matching the environmental seasonality. For arthropod richness, we found 68 morphospecies associated with female and 72 with male plants, from which 53 were shared by both sexes. We did not observe differences in morphospecies richness; however, we found sex-associated differences in the diversity of all species and differences on the diversity of the most abundant species with an interesting temporal component. During peak flowering season, male plants showed higher values on both parameters, but during the peak fructification season female plants showed the higher values on both diversity parameters. Our research exemplifies the interaction between plant-phenology and plant-sex as drivers of arthropod communities' diversity, even when plant sexual-dimorphism is inconspicuous, and highlighting the importance of accounting for seasonal variation. We stress the need of conducting more studies that test this time-dependent framework in other dioecious systems, as it has the potential to reconcile previous contrasting observations reported in the literature.

Acute pharmacodynamic responses to sitagliptin: Drug-induced increase in early insulin secretion in oral glucose tolerance test.

DPP4 inhibitors are widely prescribed as treatments for type 2 diabetes. Because drug responses vary among individuals, we initiated investigations to identify genetic variants associated with the magnitude of drug responses. Sitagliptin (100 mg) was administered to 47 healthy volunteers. Several endpoints were measured to assess clinically relevant responses - including the effect of sitagliptin on glucose and insulin levels during an oral glucose tolerance test (OGTT). This pilot study confirmed that sitagliptin (100 mg) decreased the area under the curve for glucose during an OGTT (p = 0.0003). Furthermore, sitagliptin promoted insulin secretion during the early portion of the OGTT as reflected by an increase in the ratio of plasma insulin at 30 min divided by plasma insulin at 60 min (T30:T60) from mean ± SEM 0.87 ± 0.05 to 1.62 ± 0.36 mU/L (p = 0.04). The magnitude of sitagliptin's effect on insulin secretion (as judged by the increase in the T30:T60 ratio for insulin) was correlated with the magnitude of sitagliptin-induced increase in the area under the curve for intact plasma GLP1 levels during the first hour of the OGTT. This study confirmed previously reported sex differences in glucose and insulin levels during an OGTT. Specifically, females exhibited higher levels of glucose and insulin at the 90-180 min time points. However, we did not detect significant sex-associated differences in the magnitude of sitagliptin-induced changes in T30:T60 ratios for either glucose or insulin. In conclusion, T30:T60 ratios for insulin and glucose during an OGTT provide useful indices to assess pharmacodynamic responses to DPP4 inhibitors.

Echocardiographic characterization of age- and sex-associated differences in cardiac function and morphometry in nonhuman primates.

Aging per se is a major risk factor for cardiovascular diseases and is associated with progressive changes in cardiac structure and function. Rodent models are commonly used to study cardiac aging, but do not closely mirror differences as they occur in humans. Therefore, we performed a 2D echocardiographic study in non-human primates (NHP) to establish age- and sex-associated differences in cardiac function and morphometry in this animal model. M mode and 2D echocardiography and Doppler analyses were performed cross-sectionally in 38 healthy rhesus monkeys (20 females and 18 males), both young (age 7-12years; n = 20) and old (age 19-30years; n = 18). The diameters of the cardiac chambers did not differ significantly by age group, but males had larger left ventricular diameters (2.43 vs 2.06cm in diastole and 1.91 vs 1.49cm in systole, p = 0.0004 and p = 0.0001, respectively) and left atrial diameter (1.981 vs 1.732cm; p = 0.0101). Left ventricular mass/body surface area did not vary significantly with age and sex. Ejection fraction did not differ by age and females presented a higher ejection fraction than males (54.0 vs 50.8%, p = 0.0237). Diastolic function, defined by early to late mitral peak flow velocity ratio (E/A), was significantly lower in old rhesus monkeys (2.31 vs 1.43, p = 0.0020) and was lower in females compared to males (1.595 vs 2.230, p = 0.0406). Right ventricular function, evaluated by measuring the Tricuspid Annular Plane Systolic Excursion, did not differ by age or sex, and Right Ventricular Free Wall Longitudinal Strain, did not differ with age but was lower in males than in females (-22.21 vs -17.95%, p = 0.0059). This is the first echocardiographic study to evaluate age- and sex-associated changes of cardiac morphometry and function in young and old NHP. The findings of this work will provide a reference to examine the effect of age and sex on cardiac diseases in NHP.

Traditional Cardiovascular Risk Factors and Coronary Microvascular Dysfunction in Women and Men: A Single-Center Study

Introduction: Coronary microvascular dysfunction (CMD) is common in patients with and without obstructive epicardial coronary artery disease (CAD). Risk factors for the development of CMD have not been fully elucidated, and data regarding sex-associated differences in traditional cardiovascular risk factors for obstructive CAD in patients with CMD are lacking. Methods: In this single-center, prospective registry, we enrolled patients with nonobstructive CAD undergoing clinically indicated invasive assessment of coronary microvascular function between November 2019 and March 2023. Associations between coronary microvascular dysfunction, traditional cardiovascular risk factors, and sex were assessed using univariate and multivariate regression models. Results: Overall, 245 patients with nonobstructive CAD were included in the analysis (62.9% female; median age 68 (interquartile range: 59, 75). Microvascular dysfunction was diagnosed in 141 patients (57.5%). The prevalence of microvascular dysfunction was similar in women and men (59.0% vs. 57.0%; p = 0.77). No association was found between traditional risk factors for coronary atherosclerosis and CMD regardless of whether CMD was structural or functional. In women, but not in men, older age and the presence of previous ischemic heart disease were associated with lower coronary flow reserve (β = −0.29; p < 0.01 and β = −0.15; p = 0.05, respectively) and lower resistive reserve ratio (β = −0.28; p < 0.01 and β = −0.17; p = 0.04, respectively). Conclusion: For the entire population, no association was found between coronary microvascular dysfunction and traditional risk factors for coronary atherosclerosis. In women only, older age and previous ischemic heart disease were associated with coronary microvascular dysfunction. Larger studies are needed to elucidate risk factors for CMD.

Incongruence between Cardiorespiratory Fitness and Subjective Reports of Physical Activity in Multiple Sclerosis: A Focus on Sex Differences.

The link between moderate- to vigorous-intensity physical activity (MVPA) and cardiorespiratory fitness in individuals with multiple sclerosis (MS) remains unclear. This study examined the relationship between self-reported MVPA and objectively assessed cardiorespiratory fitness, emphasizing sex differences. 107 adults with MS (77 females), aged (mean ± standard deviation) 47.2 ± 10.2 years, were recruited from a local MS clinic. Fitness was measured as maximal oxygen uptake (V̇O2max) during a graded maximal exercise test using a recumbent stepper. MVPA (24-hour recall) was estimated as the duration of activities ≥ 3 MET (metabolic equivalent of task). MET-minutes were calculated by multiplying MET by duration. We explored sex differences in self-reported MVPA, cardiorespiratory fitness, and disability; examined sex differences in associations between these variables; and investigated whether MET-minutes of MVPA predicted V̇O2max in females and males. Mean V̇O2max was 24.79 mL·kg-1·min-1, indicating poor cardiorespiratory fitness levels, despite high levels of self-reported MVPA (mean = 412.5 MET-minutes). Fifty-three percent of males and 40% of females had V̇O2max levels below the 20th age- and sex-standardized population percentile, indicating poor cardiorespiratory fitness. There were statistically significant associations between MVPA and V̇O2max (Rho = 0.27, p = .01), as well as disability and V̇O2max (Rho = -0.35, p = .02), in females but not males. A regression model using sex, age, body mass, disability, and MVPA to estimate V̇O2max was valid in predicting V̇O2max values that were statistically equivalent to those measured in the laboratory in females but not males. However, the inclusion of MVPA did not add to the predictive value of this equation. Despite reporting high levels of MVPA, people with MS had poor cardiorespiratory fitness. MVPA, fitness, and disability were associated in females only, indicating that sex differences should be considered in fitness appraisal. Self-reported MVPA did not predict fitness, suggesting 24-hour recall may not be representative of true activity or fitness levels in persons with MS. Future work should examine sex differences in associations between MVPA and fitness using objective measures such as accelerometry.

Sex-associated differences in cardiac ageing: Clinical aspects and molecular mechanisms.

Despite the extensive clinical and scientific advances in prevention, diagnostics and treatment, cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality worldwide for people aged 65 and over. Of all ageing-related diseases, CVD are responsible for almost one-third of deaths in the elderly, being above all cancers combined. Age is an independent and unavoidable risk factor contributing to the impairment of heart and blood vessels. As the average age of the population in industrialized countries has doubled in the last century, and almost a fifth of the world's population is predicted to be over 65 in the next decade, we can assume that the burden of CVD will fall primarily on the elderly. Evidence from basic and clinical science has shown that sex significantly influences the onset and severity of CVD. In women, CVD usually develop later than in men and with atypical symptomatology. After menopause, however, the incidence and severity of CVD increase in women, reaching equality in both sexes. Although intrinsic sexual dimorphism in cardiovascular ageing may contribute to the sex differences in CVD progression, the molecular mechanisms associated with cardiovascular ageing and their clinical value are not known in detail. In this review, we discuss the scientific knowledge available, focusing on structural, hormonal, genetic/epigenetic and inflammatory pathways, seeking to transfer these findings to the cardiovascular clinic in terms of prevention, diagnosis, prognosis and management of these pathologies and proposing possible validation of target specifics.

Peripheral Blood Cells From Older Adults Exhibit Sex-Associated Differences in Mitochondrial Function.

Blood-based mitochondrial bioenergetic profiling is a feasible, economical, and minimally invasive approach that can be used to examine mitochondrial function and energy metabolism in human subjects. In this study, we use 2 complementary respirometric techniques to evaluate mitochondrial bioenergetics in both intact and permeabilized peripheral blood mononuclear cells (PBMCs) and platelets to examine sex dimorphism in mitochondrial function among older adults. Employing equal numbers of PBMCs and platelets to assess mitochondrial bioenergetics, we observe significantly higher respiration rates in female compared to male participants. Mitochondrial bioenergetic differences remain significant after controlling for independent parameters including demographic parameters (age, years of education), and cognitive parameters (mPACC5, COGDX). Our study illustrates that circulating blood cells, immune cells in particular, have distinctly different mitochondrial bioenergetic profiles between females and males. These differences should be taken into account as blood-based bioenergetic profiling is now commonly used to understand the role of mitochondrial bioenergetics in human health and aging.