Covariation of change in bioavailable testosterone and adiposity in midlife women.
Ontology highlight
ABSTRACT:
SUBMITTER: Janssen I
PROVIDER: S-EPMC4310763 | biostudies-literature | 2015 Feb
REPOSITORIES: biostudies-literature
Publications
Covariation of change in bioavailable testosterone and adiposity in midlife women.
Janssen Imke I Powell Lynda H LH Jasielec Mateusz S MS Kazlauskaite Rasa R
Obesity (Silver Spring, Md.) 20141231 2
<h4>Objective</h4>To determine whether menopause-related changes in reproductive hormones were associated with change in adiposity and whether these relationships were independent of important covariates.<h4>Methods</h4>Annual assessments of adiposity measures [computed tomography-assessed visceral adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAT) and dual-energy X-ray absorptiometry-assessed total body fat (TBF)] over 4 years from an ancillary study at the Chicago site of the ...[more]
Similar Datasets
Project description:OBJECTIVES:Cardiovascular fat (CF) is associated with greater coronary heart disease (CHD) risk. Postmenopausal women have greater CF volumes than premenopausal women, and the association between specific CF depot volumes and CHD risk is more pronounced after menopause. Race, central adiposity, and visceral adiposity are important factors that could impact CF volumes. Whether racial differences in CF volumes and in their associations with central (visceral fat [VAT]) and general adiposity (body mass index [BMI]) exist in midlife women have not been addressed before. METHODS:In all, 524 participants from the Study of Women's Health Across the Nation (mean age: 50.9?±?2.9 years; 62% White and 38% Black) who had data on CF volumes (epicardial fat [EAT], paracardial fat [PAT], total heart fat, and aortic perivascular fat), VAT, and BMI were studied. RESULTS:In models adjusted for age, study site, menopausal status, comorbid conditions, alcohol consumption, and physical activity, Black women had 19.8% less EAT, 24.5% less PAT, 20.4% less total heart fat, and 13.2% less perivascular fat than White women (all P?<?0.001). These racial differences remained significant after additional adjustment for BMI or VAT. Race significantly modified associations between adiposity measures and CF volumes. Every 1-SD higher BMI was associated with 66.7% greater PAT volume in White compared with 42.4% greater PAT volume in Black women (P?=?0.004), whereas every 1-SD higher VAT was associated with 32.3% greater EAT volume in Black compared with 25.3% greater EAT volume in White women (P?=?0.039). CONCLUSIONS:Racial differences were found in CF volumes and in their associations with adiposity measures among midlife women. Future research should determine how race-specific changes in CF volumes impact CHD risk in women.
| S-EPMC5735027 | biostudies-literature
Project description:ObjectiveRegulators of adipose tissue hormones remain incompletely understood, but may include sex hormones. As adipose tissue hormones have been shown to contribute to numerous metabolic and cardiovascular disorders, understanding their regulation in midlife women is of clinical importance. Therefore, we assessed the associations between testosterone (T) and sex hormone binding globulin (SHBG) with leptin, high molecular weight (HMW) adiponectin, and the soluble form of the leptin receptor (sOB-R) in healthy midlife women.Design and methodsCross-sectional analyses were performed using data from 1,881 midlife women (average age 52.6 (±2.7) years) attending the sixth Annual follow-up visit of the multiethnic Study of Women's Health Across the Nation.ResultsT was weakly negatively associated with both HMW adiponectin and sOB-R (r = -0.12 and r = -0.10, respectively; P < 0.001 for both), and positively associated with leptin (r = 0.17; P < 0.001). SHBG was more strongly and positively associated with both HMW adiponectin and sOB-R (r = 0.29 and r = 0.24, respectively; P < 0.001 for both), and more strongly and negatively associated with leptin (r = -0.27; P < 0.001). Adjustment for fat mass, insulin resistance, or waist circumference only partially diminished associations with HMW adiponectin and sOB-R, but attenuated associations with leptin. In conclusion, in these midlife women, lower SHBG values, and to a lesser extent, higher T levels, were associated with lower, or less favorable, levels of adiponectin and sOB-R, independent of fat mass.ConclusionsThese data suggest that variation in these adipose hormones resulting from lower SHBG levels, and possibly, though less likely, greater androgenicity, may contribute to susceptibility for metabolic and cardiovascular outcomes during midlife in women.
| S-EPMC4109046 | biostudies-literature
Project description:ObjectivesYoung women with hyperandrogenism have high risk of metabolic co-morbidities, including increased risk of nonalcoholic fatty liver disease (NAFLD). Whether testosterone (the predominant androgen) is associated with NAFLD independent of metabolic co-factors is unclear. Additionally, whether testosterone confers increased risk of NAFLD in women without hyperandrogenism is unknown.MethodsAmong women in the prospective population-based multicenter Coronary Artery Risk Development in Young Adults (CARDIA) study, we assessed whether free testosterone levels measured at Year 2 (1987-1988) were associated with prevalent NAFLD at Year 25 (2010-2011) (n=1052). NAFLD was defined using noncontrast abdominal CT scan with liver attenuation≤40 Hounsfield units after excluding other causes of hepatic fat. The association of free testosterone with prevalent NAFLD was assessed by logistic regression.ResultsIncreasing quintiles of free testosterone were associated with prevalent NAFLD at Year 25 (adjusted odds ratio (AOR) 1.25, 95% confidence interval (CI) 1.04-1.50, P=0.015), independent of insulin resistance, body mass index, waist circumference, and serum lipids. Importantly, the association persisted among n=955 women without androgen excess (AOR 1.27, 95% CI 1.05-1.53, P=0.016). Visceral adipose tissue (VAT) volume partially mediated the association of free testosterone with NAFLD (mediating effect 41.0%, 95% CI 22-119%).ConclusionsIncreasing free testosterone is associated with prevalent NAFLD in middle age, even in women without androgen excess. Visceral adiposity appears to play an important role in the relationship between testosterone and NAFLD in women. Testosterone may provide a potential novel target for NAFLD therapeutics, and future studies in pre-menopausal women should consider the importance of testosterone as a risk factor for NAFLD.
| S-EPMC5664187 | biostudies-literature
Project description:BackgroundDigital health interventions are efficacious in health-promoting behaviors (eg, healthy eating and regular physical activity) that mitigate health risks and menopausal symptoms in midlife. However, integrated evidence-based knowledge about the mechanisms of change in these interventions is unclear.ObjectiveThis systematic review aimed to evaluate studies on behavior change techniques (BCTs) and mechanisms of change in digital health interventions aimed at promoting health-enhancing behaviors in midlife women (aged 40-65 years).MethodsA systematic literature search of the electronic databases PubMed, Web of Science, PsycINFO, and Cochrane Central Register of Controlled Trials in the Cochrane Library was conducted. In total, 2 independent reviewers selected the studies for inclusion, extracted data, and completed BCT mapping of eligible studies. The mechanism of action and intervention functions of eligible studies were evaluated using the behavior change wheel framework. Reporting of psychological theory use within these interventions was explored using the Theory Coding Scheme. Mode of delivery, psychological theory, and BCTs were presented as descriptive statistics.ResultsIn total, 13 interventions (including 1315 women) reviewed used 13 (SD 4.30, range 6-21) BCTs per intervention on average. The "Shaping knowledge" and "Repetition and substitution" behavior change categories were used most frequently, with 92% (12/13) of the interventions implementing at least one of the BCTs from these 2 categories. Only 13.98% (169/1209) of the 93 available BCTs were used, with "Instructions on behaviour" most frequently used (12/13, 92%). The behavior change wheel mapping suggests that half of the intervention content aimed to increase "Capability" (49/98, 50% of the intervention strategies), "Motivation" (41/98, 42%), and "Opportunity" (8/98, 8%). "Behavioural Regulation" was the most frequently used mechanism of action (15/98, 15%), followed by increasing "Knowledge" (13/98, 13%) and "Cognitive and Interpersonal skills" (10/98, 10%). A total of 78% (7/9) of the intervention functions were used in the studies to change behavior, primarily through "Enablement" (60/169, 35.5%), whereas no study used "Restriction" or "Modelling" functions. Although 69% (9/13) of the interventions mentioned a psychological theory or model, most (10/13, 77%) stated or suggested rather than demonstrated the use of a theoretical base, and none reported explicit links between all BCTs within the intervention and the targeted theoretical constructs. Technological components were primarily based on web-based (9/13, 69%) modes of delivery, followed by phone or SMS text message (8/13, 62%) and wearables (7/13, 54%).ConclusionsThe findings of this review indicate an overall weak use of theory, low levels of treatment fidelity, insignificant outcomes, and insufficient description of several interventions to support the assessment of how specific BCTs were activated. Thus, the identified limitations in the current literature provide an opportunity to improve the design of lifestyle health-enhancing interventions for women in midlife.Trial registrationPROSPERO CRD42021259246; https://tinyurl.com/4ph74a9u.
| S-EPMC9685514 | biostudies-literature
Project description:As they approach a traffic light, drivers and pedestrians monitor the color (instructed stimulus feature) and/or the position of the signal (covarying stimulus feature) for response selection. Many studies have pointed out that instructions can effectively determine the stimulus features used for response selection in a task. This leaves open whether and how practice with a correlating alternative stimulus feature can lead to a strategy change from an instructed to a learned variant of performing the task. To address this question, we instructed participants to respond to the position of a stimulus within a reference frame, at the same time, during task performance, an unmentioned second stimulus feature, the color, covaried with stimulus position and allowed the use of an alternative response strategy. To assess the impact of the non-instructed stimulus feature of color on response selection throughout practice, the spatial position of the stimulus was ambiguous on some trials. Group average increases in color usage were based on a mixture of (1) participants who, despite extended practice on the covariation, exclusively relied on the instructed stimulus feature and (2) those who abruptly started to rely heavily on stimulus color to select responses in ambiguous trials. When the instructed and uninstructed feature predicted different actions, choices were still biased by the uninstructed color feature, albeit more weakly. A second experiment showed that the influence of color generalized across frequently and infrequently presented combinations of position and color. Strategy changes were accompanied by awareness in both experiments. The results suggest that incidental covariation learning can trigger spontaneous voluntary strategy change involving a re-configuration of the instructed task set.
| S-EPMC6345462 | biostudies-literature
Project description:BackgroundAge-related changes in testosterone levels in older persons and especially in women have not been fully explored. The objective of this study was to describe age-related trajectories of total testosterone (TT), ammonium sulfate precipitation-measured bioavailable testosterone (mBT), and sex hormone-binding glycoprotein (SHBG) in men and women from the Baltimore Longitudinal Study of Aging, with special focus on the oldest adults.MethodsParticipants included 788 White men and women aged 30-96 years with excellent representation of old and oldest old, who reported not taking medications known to interfere with testosterone. Longitudinal data were included when available. TT, mBT, and SHBG were assayed. Age-related trajectories of mBT were compared with those obtained using calculated bioavailable testosterone (cBT). Generalized least square models were performed to describe age-related trajectories of TT, mBT, and SHBG in men and women.ResultsmBT linearly declines over the life span and even at older ages in both sexes. In men, TT remains quite stable until the age of 70 years and then declines at older ages, whereas in women TT progressively declines in premenopausal years and slightly increases at older ages. Differences in age-related trajectories between total and bioavailable testosterone are only partially explained by age changes in SHBG, whose levels increases at accelerated rates in old persons. Noteworthy, although mBT and cBT highly correlated with one another, mBT is a much stronger correlate of chronological age than cBT.ConclusionIn both men and women, mBT linearly declines over the life span and even at old ages. Its relationship with age-related phenotypes should be further investigated.
| S-EPMC4978359 | biostudies-literature
Project description:Mammographic breast density is a strong risk factor for breast cancer. We comprehensively investigated the associations of body mass index (BMI) change from ages 10, 18, and 30 to age at mammogram with mammographic breast density in postmenopausal women. We used multivariable linear regression models, adjusted for confounders, to investigate the associations of BMI change with volumetric percent density, dense volume, and nondense volume, assessed using Volpara in 367 women. At the time of mammogram, the mean age was 57.9 years. Compared with women who had a BMI gain of 0.1-5 kg/m2 from age 10, women who had a BMI gain of 5.1-10 kg/m2 had a 24.4% decrease [95% confidence interval (CI), 6.0%-39.2%] in volumetric percent density; women who had a BMI gain of 10.1-15 kg/m2 had a 46.1% decrease (95% CI, 33.0%-56.7%) in volumetric percent density; and women who had a BMI gain of >15 kg/m2 had a 56.5% decrease (95% CI, 46.0%-65.0%) in volumetric percent density. Similar, but slightly attenuated associations were observed for BMI gain from ages 18 and 30 to age at mammogram and volumetric percent density. BMI gain over the life course was positively associated with nondense volume, but not dense volume. We observed strong associations between BMI change over the life course and mammographic breast density. The inverse associations between early-life adiposity change and volumetric percent density suggest that childhood adiposity may confer long-term protection against postmenopausal breast cancer via its effect of mammographic breast density.
| S-EPMC8210631 | biostudies-literature
Project description:Concurrent and retrospective reports correspond for personality, affect, and coping. The present study described how autonomy, competence, and relatedness components of eudaemonic well-being (EWB) change over days and months and tested correspondences of daily and retrospective reports between and within people. Midlife and older (50-75 years) women (N = 200) completed online diaries daily for 1 week for 9 bursts over 2 years and answered questionnaires at the end of each burst (burst n = 1,529). Multilevel models partialed levels of variance and tested correspondence. Women varied in their daily experiences of EWB but did not vary substantially between bursts. Burst-level diary means and questionnaire responses corresponded between people, but changes within people were less strongly related. The daily, but not monthly, time scale of change is important for capturing within-person changes in EWB. Finding EWB change over months to years may depend on measurement designed to capture medium-term change.
| S-EPMC8104436 | biostudies-literature
Project description:Although several studies have shown that pubertal tempo and timing are shaped by genetic and environmental factors, few studies consider to what extent endocrine triggers of puberty are shaped by genetic and environmental factors. Doing so moves the field from examining correlated developmentally-sensitive biomarkers toward understanding what drives those associations. Two puberty related hormones, dehydroepiandrosterone and testosterone, were assayed from salivary samples in 118 MZ (62 % female), 111 same sex DZ (46 % female) and 103 opposite-sex DZ twin pairs, aged 12-16 years (M = 13.1, SD = 1.3). Pubertal status was assessed with a composite of mother- and self-reports. We used biometric models to estimate the genetic and environmental influences on the variance and covariance in testosterone and DHEA, with and without controlling for their association with puberty, and to test for sex differences. In males, the variance in testosterone and pubertal status was due to shared and non-shared environmental factors; variation in DHEA was due to genetic and non-shared environmental factors. In females, variance in testosterone was due to genetic and non-shared environmental factors; genetic, shared, and non-shared environmental factors contributed equally to variation in DHEA. In males, the testosterone-DHEA covariance was primarily due to shared environmental factors that overlapped with puberty as well as shared and non-shared environmental covariation specific to testosterone and DHEA. In females, the testosterone-DHEA covariance was due to genetic factors overlapping with pubertal status, and shared and non-shared environmental covariation specific to testosterone and DHEA.
| S-EPMC4425578 | biostudies-literature
Project description:Women in midlife experience health risks that could be mitigated by regular physical activity and reduced sedentary time, but this population rarely achieves physical activity levels that would protect their health. As a result, many behavioral interventions are designed to promote physical activity in this population, which are purportedly guided by theoretical models of health behavior (change) and activate an associated set of behavior change techniques (BCTs). The efficacy and effectiveness of these interventions appear to be limited, however, raising questions about their design and adaptation for women in midlife. Several aspects of these interventions are currently unclear. Specifically, which women they target (i.e., how "midlife" and "sedentary" or "inactive" are defined), which theoretical models or behavior BCTs are used, and how BCTs are activated in such interventions. A synthesis of this information would be useful as an initial step toward improving physical activity interventions for this at-risk group, and thus, represented the goal of the present scoping review. Eligibility required publication in a peer-reviewed journal in English between 2000 and 2021, inclusion of only women in midlife who did not have any medical or other restrictions on their physical activity (e.g., cancer diagnosis), and free-living physical activity or sedentary behavior as the target outcome (with associated assessment). Of the 4,410 initial results, 51 articles met inclusion criteria, and these described 36 unique interventions. More than half of the articles (59%) named an underlying theoretical model and interventions included an average of 3.76 identifiable BCTs (range 1-11). However, descriptions of many interventions were limited and did not provide enough detail to determine whether or how specific BCTs were activated. Interventions also used a wide range of inclusion criteria for age range and starting activity level, which has implications for targeting/tailoring and effectiveness, and many interventions focused on marginalized populations (e.g., women from racial/ethnic minority backgrounds, those un- or under-insured). The present review identifies some strengths and highlights important limitations of existing literature, as well as key opportunities for advancing the design and potential utility of physical activity interventions for women in midlife.Systematic review registrationhttps://osf.io/g8tuc.
| S-EPMC9534296 | biostudies-literature