Abide with me: religious group identification among older adults promotes health and well-being by maintaining multiple group memberships

Objectives: Aging is associated with deterioration in health and well-being, but previous research suggests that this can be attenuated by maintaining group memberships and the valued social identities associated with them. In this regard, religious identification may be especially beneficial in helping individuals withstand the challenges of aging, partly because religious identity serves as a basis for a wider social network of other group memberships. This paper aims to examine relationships between religion (identification and group membership) and well-being among older adults. The contribution of having and maintaining multiple group memberships in mediating these relationships is assessed, and also compared to patterns associated with other group memberships (social and exercise).

Method: Study 1 (N = 42) surveyed older adults living in residential care homes in Canada, who completed measures of religious identity, other group memberships, and depression. Study 2 (N = 7021) longitudinally assessed older adults in the UK on similar measures, but with the addition of perceived physical health.

Results: In Study 1, religious identification was associated with fewer depressive symptoms, and membership in multiple groups mediated that relationship. However, no relationships between social or exercise groups and mental health were evident. Study 2 replicated these patterns, but additionally, maintaining multiple group memberships over time partially mediated the relationship between religious group membership and physical health.

Conclusion: Together these findings suggest that religious social networks are an especially valuable source of social capital among older adults, supporting well-being directly and by promoting additional group memberships (including those that are non-religious).     

Skeletal Muscle Triacylglycerol Hydrolysis Does Not Influence Metabolic Complications of Obesity

Intramyocellular triacylglycerol (IMTG) accumulation is highly associated with insulin resistance and metabolic complications of obesity (lipotoxicity), whereas comparable IMTG accumulation in endurance-trained athletes is associated with insulin sensitivity (the athlete’s paradox). Despite these findings, it remains unclear whether changes in IMTG accumulation and metabolism per se influence muscle-specific and systemic metabolic homeostasis and insulin responsiveness. By mediating the rate-limiting step in triacylglycerol hydrolysis, adipose triglyceride lipase (ATGL) has been proposed to influence the storage/production of deleterious as well as essential lipid metabolites. However, the physiological relevance of ATGL-mediated triacylglycerol hydrolysis in skeletal muscle remains unknown. To determine the contribution of IMTG hydrolysis to tissue-specific and systemic metabolic phenotypes in the context of obesity, we generated mice with targeted deletion or transgenic overexpression of ATGL exclusively in skeletal muscle. Despite dramatic changes in IMTG content on both chow and high-fat diets, modulation of ATGL-mediated IMTG hydrolysis did not significantly influence systemic energy, lipid, or glucose homeostasis, nor did it influence insulin responsiveness or mitochondrial function. These data argue against a role for altered IMTG accumulation and lipolysis in muscle insulin resistance and metabolic complications of obesity.Obesity is a global public health problem and a major risk factor for insulin resistance and type 2 diabetes. These disorders are characterized by excess lipid accumulation in multiple tissues, primarily as triacylglycerols (TAGs). The lipotoxicity hypothesis suggests that this lipid excess promotes cellular dysfunction and cell death, which ultimately contribute to insulin resistance and metabolic disease (1). However, intracellular TAG accumulation is not always associated with adverse metabolic outcomes, suggesting that TAGs themselves are not pathogenic (2). In contrast, other non-TAG lipid metabolites such as fatty acids (FAs), diacylglycerols (DAGs), and ceramides have been shown to influence glucose homeostasis and insulin action by interfering with insulin signaling and glucose transport, promoting endoplasmic reticulum stress and mitochondrial dysfunction, and activating inflammatory and apoptotic pathways (reviewed in ref. 3). Nevertheless, the precise identities and sources of these bioactive lipid intermediates remain elusive (4,5). Furthermore, whether intracellular TAGs serve as a protective sink or a toxic source of deleterious lipid metabolites that contribute to insulin resistance remains unclear (6).Since skeletal muscle is the major contributor to insulin-mediated glucose disposal, lipid excess in this tissue could have serious implications for systemic glucose homeostasis and insulin responsiveness (7). Indeed, numerous studies have demonstrated a strong association between intramyocellular triacylglycerol (IMTG) accumulation and insulin resistance (reviewed in ref. 8). In contrast, endurance exercise training is characterized by IMTG accumulation and insulin sensitivity (the athlete’s paradox) (2). This variable association between IMTG accumulation and insulin responsiveness has largely been attributed to differences in the balance between lipid delivery and muscle oxidative capacity (8–10). Not surprisingly then, most studies have focused on the impact of muscle FA uptake and/or oxidation on glucose homeostasis and insulin action (11). However, experimental manipulations of these parameters cannot distinguish among the effects of IMTGs, IMTG metabolism, and other lipid intermediates. Furthermore, accumulating evidence suggests that muscle oxidative capacity cannot entirely explain differences in IMTGs or insulin responsiveness (12). These findings have led to speculation that dynamic IMTG metabolism (i.e., TAG synthesis or hydrolysis) may be critically involved in lipid-induced insulin resistance (6). However, few studies have specifically addressed the contribution of IMTG metabolism per se to this process.The regulated storage and release of IMTGs remain poorly understood, but require the coordinated action of synthetic enzymes (i.e., diacylglycerol acyltransferases [DGATs]), hydrolytic enzymes (i.e., adipose triglyceride lipase [ATGL] and hormone sensitive lipase [HSL]), and other lipid droplet proteins (6). Specifically, modulating IMTG synthesis in murine skeletal muscle alters IMTG content and systemic glucose homeostasis, supporting a role for IMTG metabolism in metabolic disease (13–15). However, the metabolic impact of modulating IMTG hydrolysis in vivo remains unclear. Global deletion of either ATGL (16–19) or HSL (20) has produced variable results. The former, but not the latter, results in massive IMTG accumulation with improvement in systemic glucose homeostasis, suggesting that inhibition of ATGL-mediated TAG hydrolysis protects against insulin resistance. In contrast, recent studies in cardiac muscle (21) and other tissues (22,23) indicate that ATGL-mediated TAG hydrolysis is required for mitochondrial function such that enhancing, rather than inhibiting, ATGL action may improve metabolic outcomes. Nevertheless, the autonomous role of skeletal muscle TAG catabolism in influencing muscle-specific and systemic metabolic phenotypes remains unknown.The goal of the current study was to understand the contribution of IMTG hydrolysis to tissue-specific and systemic metabolic phenotypes, particularly glucose homeostasis and insulin action, in the context of obesity. We therefore generated animal models with decreased (skeletal muscle-specific ATGL knockout [SMAKO] mice) and increased (muscle creatine kinase [Ckm]-ATGL transgenic [Tg] mice) ATGL action exclusively in skeletal muscle, and assessed the metabolic consequences at baseline and in response to chronic high-fat feeding. Interestingly, modulation of IMTG hydrolysis via ATGL action did not significantly influence glucose homeostasis, insulin action, or other metabolic phenotypes in the context of obesity despite dramatic changes in IMTG content.     

Prevalence of the human papillomavirus (HPV) expression of the inner prepuce in asymptomatic boys and men

Objective

To investigate the prevalence of high-risk (HR) and low-risk (LR) human papillomavirus (HPV) in prepuces of boys and men without any HPV related lesions.

Patients and methods

Between 2009 and 2011, a total collective of 250 boys and men were investigated in this prospective study. The samples were subdivided into 3 groups regarding their age, consisting of 125 (50 %) children (0–10 years), 38 (15.2 %) adolescents (11–20 years) and 87 (34.8 %) adults (>20 years). In situ hybridization (ISH) was performed to detect HR and LR virus types within the epithelium, followed by microscopic interpretation and determination between episomal and integrative signal pattern.

Results

Our results revealed high levels of HPV concentration (HR and LR) in all age groups: HR versus LR positivity was seen in 45.5 versus 35 % (children), 60.6 versus 63.6 % (adolescents) and 58.3 versus 48.6 % (adults). The topmost rate of HR (59.8 %)- and LR (50.6 %)-positive probes was found in the group with high estimated sexual activity (>14 years).

Conclusion

Concerning the high prevalence of male HPV infection even in children, indicating non-sexual transmission pathways, inclusion of boys in the vaccination program seems to be required reducing their burden of HPV related disease.     

Effects of transcranial direct current stimulation on risky decision making are mediated by ‘hot’ and ‘cold’ decisions,personality, and hemisphere

Previous results point towards a lateralization of dorsolateral prefrontal cortex (DLPFC) function in risky decision making. While the right hemisphere seems involved in inhibitory cognitive control of affective impulses, the left DLPFC is crucial in the deliberative processing of information relevant for the decision. However, a lack of empirical evidence precludes definitive conclusions. The aim of our study was to determine whether anodal transcranial direct current stimulation (tDCS) over the right DLPFC with cathodal tDCS over the lDLPFC (anodal right/cathodal left) or vice versa (anodal left/cathodal right) differentially modulates risk‐taking in a task [the Columbia Card Task (CCT)] specifically engaging affect‐charged (Hot CCT) vs. deliberative (Cold CCT) decision making. The facilitating effect of the anodal stimulation on neuronal activity was emphasized by the use of a small anode and a big cathode. To investigate the role of individual differences in risk‐taking, participants were either smokers or non‐smokers. Anodal left/cathodal right stimulation decreased risk‐taking in the ‘cold’ cognition version of the task, in both groups, probably by modulating deliberative processing. In the ‘hot’ version, anodal right/cathodal left stimulation led to opposite effects in smokers and non‐smokers, which might be explained by the engagement of the same inhibitory control mechanism: in smokers, improved controllability of risk‐seeking impulsivity led to more conservative decisions, while inhibition of risk‐aversion in non‐smokers resulted in riskier choices. These results provide evidence for a hemispheric asymmetry and personality‐dependent tDCS effects in risky decision making, and may be important for clinical research on addiction and depression.