Science Says

Objectives: To investigate the role of body mass index (BMI), systolic blood pressure, and smoking behaviour in explaining the effect of education on the risk of cardiovascular disease outcomes.

Design: Mendelian randomisation study.

Setting: UK Biobank and international genome-wide association study data.

Participants: Predominantly participants of European ancestry.

Exposure: Educational attainment, BMI, systolic blood pressure, and smoking behaviour in observational analysis, and randomly allocated genetic variants to instrument these traits in mendelian randomisation.

Main outcomes measure: The risk of coronary heart disease, stroke, myocardial infarction, and cardiovascular disease (all subtypes; all measured in odds ratio), and the degree to which this is mediated through BMI, systolic blood pressure, and smoking behaviour respectively.

Results: Each additional standard deviation of education (3.6 years) was associated with a 13% lower risk of coronary heart disease (odds ratio 0.86, 95% confidence interval 0.84 to 0.89) in observational analysis and a 37% lower risk (0.63, 0.60 to 0.67) in mendelian randomisation analysis. As a proportion of the total risk reduction, BMI was estimated to mediate 15% (95% confidence interval 13% to 17%) and 18% (14% to 23%) in the observational and mendelian randomisation estimates, respectively. Corresponding estimates were 11% (9% to 13%) and 21% (15% to 27%) for systolic blood pressure and 19% (15% to 22%) and 34% (17% to 50%) for smoking behaviour. All three risk factors combined were estimated to mediate 42% (36% to 48%) and 36% (5% to 68%) of the effect of education on coronary heart disease in observational and mendelian randomisation analyses, respectively. Similar results were obtained when investigating the risk of stroke, myocardial infarction, and cardiovascular disease.

Conclusions: BMI, systolic blood pressure, and smoking behaviour mediate a substantial proportion of the protective effect of education on the risk of cardiovascular outcomes and intervening on these would lead to reductions in cases of cardiovascular disease attributable to lower levels of education. However, more than half of the protective effect of education remains unexplained and requires further investigation.

Carter AR, Gill D, Davies NM, et al. Understanding the consequences of education inequality on cardiovascular disease: mendelian randomisation study. BMJ. 2019;365:l1855. Published 2019 May 22. doi:10.1136/bmj.l1855

This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/.

Sections of the Abstract, Introduction, and Discussion are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6529852/

Linking human behavior to resting-state brain function is a central question in systems neuroscience. In particular, the functional timescales at which different types of behavioral factors are encoded remain largely unexplored. The behavioral counterparts of static functional connectivity (FC), at the resolution of several minutes, have been studied but behavioral correlates of dynamic measures of FC at the resolution of a few seconds remain unclear. Here, using resting-state fMRI and 58 phenotypic measures from the Human Connectome Project, we find that dynamic FC captures task-based phenotypes (e.g., processing speed or fluid intelligence scores), whereas self-reported measures (e.g., loneliness or life satisfaction) are equally well explained by static and dynamic FC. Furthermore, behaviorally relevant dynamic FC emerges from the interconnections across all resting-state networks, rather than within or between pairs of networks. Our findings shed new light on the timescales of cognitive processes involved in distinct facets of behavior.

Liégeois R, Li J, Kong R, et al. Resting brain dynamics at different timescales capture distinct aspects of human behavior. Nat Commun. 2019;10(1):2317. Published 2019 May 24. doi:10.1038/s41467-019-10317-7.

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Sections of the Abstract, Introduction, and Discussion are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6534566/

Aging is the progressive decline of physiological functions necessary for survival and reproduction. In gaining a better understanding of the inevitable aging process, the hope is to preserve, promote, or delay healthy aging through the treatment of common age-associated diseases. Although there are theories that try to explain the aging process, none of them seem to fully satisfy. Microcirculation describes blood flow through the capillaries in the circulatory system. The main functions of the microcirculation are the delivery of oxgen and nutrients and the removal of CO2, metabolic debris, and toxins. The microcirculatory impairment or dysfunction over time will result in the accumulation of toxic products and CO2 and loss of nutrition supplementation and O2 in corresponding tissue systems or internal organs, which eventually affect normal tissue and organ functions, leading to aging. Therefore, I propose a microcirculatory theory of aging: aging is the process of continuous impairment of microcirculation in the body.

Jin K. A Microcirculatory Theory of Aging. Aging Dis. 2019;10(3):676–683. Published 2019 Jun 1. doi:10.14336/AD.2019.0315.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.

Sections of the Abstract, Introduction, and Aging: consequence of microcirculatory impairment are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538209/

Research has shown that individual differences in adult attachment predict several organizational outcomes. However, little is known about the mechanism that underlies these associations. The current study examines whether self-compassion can serve as a potential mediator explaining the associations between individual differences in attachment and organizational outcomes. Four outcome measures were evaluated: job performance (HPQ; Kessler et al., 2003), organizational citizenship behaviors (OCB) (Goodman and Svyantek, 1999), turnover intentions (Abrams et al., 1998), and emotional exhaustion (Schaufeli et al., 1996). In addition, participants (N = 202, response rate 81%) also completed several questionnaires assessing attachment style (ECR; Brennan et al., 1998) and self-compassion (SCS; Neff, 2003). Using structural equation modeling (SEM) for testing the research hypotheses, the hypothesized model was supported, with self-compassion mediating the relationship between attachment styles and all four work-related outcomes. The research findings suggest that self-compassion can provide a solid mechanism for understanding organizational outcomes and for understanding individual differences related to attachment functioning in the workplace.

Reizer A. Bringing Self-Kindness Into the Workplace: Exploring the Mediating Role of Self-Compassion in the Associations Between Attachment and Organizational Outcomes. Front Psychol. 2019;10:1148. Published 2019 May 21. doi:10.3389/fpsyg.2019.01148

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Sections of the Abstract, Introduction, and Conclusion are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6536612/

Background: Positive psychology indicators like well-being and life satisfaction may play a pivotal role in pain-related outcomes. In this study, we aimed to examine the prospective associations of positive well-being and life satisfaction with pain severity.

Methods and Subjects: This longitudinal study, with a follow-up of 2 years, included 9361 participants (4266 males, 5095 females; mean age: 52.5 years; SD: 17.5) without and with chronic pain (CP) at baseline. All analyses were stratified by the two sub-cohorts—participants without CP (sub-cohort 1) and participants with CP (sub-cohort 2) at baseline. The predictive associations, assessed using ordinal regression in a Generalized Linear Model, were adjusted for baseline potential confounders and reported as odds ratios (ORs) with corresponding 95% confidence intervals (CIs).

Results: After adjustments, in sub-cohort 1 positive well-being at baseline was associated with lower severe pain at follow-up compared to participants with severe distress (OR: 0.64; 95% CI 0.49–0.84; p < 0.001). In sub-cohort 2, both positive well-being and life satisfaction at baseline were associated with lower severe pain at follow-up compared to participants with severe distress and not satisfied with life (OR: 0.80; 95% CI 0.65–0.98; p = 0.031 and OR: 0.82; 95% CI 0.69–0.96; p = 0.014, respectively).

Conclusions: Positive well-being is predictive of lower pain severity both among participants without and with CP at baseline, whereas life satisfaction was found predictive of lower pain severity only for subjects with CP. Future research should emphasize implementing treatments associated with promoting and maintaining positive well-being and life satisfaction in patients who suffer from chronic pain and in risk populations.

Larsson B, Dragioti E, Gerdle B, Björk J. Positive psychological well-being predicts lower severe pain in the general population: a 2-year follow-up study of the SwePain cohort. Ann Gen Psychiatry. 2019;18:8. Published 2019 May 31. doi:10.1186/s12991-019-0231-9.

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,unless otherwise stated.

Sections of the Abstract, Background, and Conclusion are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6543656/

Background: Online dating has become increasingly popular over the years. Few research studies have examined the association between dating apps and disordered eating. In this study, we evaluated the association between dating app use and unhealthy weight control behaviors (UWCBs) among a sample of U.S. adults.

Methods: Our sample includes 1769 adults who completed an online survey assessing dating app use and UWCBs in the past year. Survey assessed participants’ self-reported frequency of using dating apps within the past 30 days and engagement in six UWCBs with the purpose of lowering weight or changing their body shape within the past 12 months. UWCBs included vomiting, laxative use, fasting, diet pill use, muscle building supplement use, and use of anabolic steroids.

Results: Results of multivariate logistic regression models suggest dating app users had substantially elevated odds of UWCBs compared with non-users (odds ratios [OR] range = 2.7—16.2). These findings were supported by results of additional gender-stratified multivariate logistic regression analyses among women and men.

Conclusions: This study’s findings contribute to the limited literature exploring the association between dating app use and adverse health outcomes, particularly UWCBs. While additional longitudinal and representative research is needed, public health professionals ought to explore dating app use as a potential risk factor for UWCBs.

Tran A, Suharlim C, Mattie H, Davison K, Agénor M, Austin SB. Dating app use and unhealthy weight control behaviors among a sample of U.S. adults: a cross-sectional study. J Eat Disord. 2019;7:16. Published 2019 May 31. doi:10.1186/s40337-019-0244-4.

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,unless otherwise stated.

Sections of the Abstract, Background, and Discussion are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6543621/

Background: The energy content of whole, fresh fruit derives primarily from simple sugars, which are currently under heightened scrutiny for their potential contribution to obesity and chronic disease risk. Yet fruit also has a relatively low energy density, moderate palatability/reward value, and high fiber content, which together may limit energy intake. Although reasoned arguments can be made that fruit is fattening or slimming, the question is best resolved empirically.

Methods: Methods were preregistered with PROSPERO (CRD42018111830). The primary outcome is the impact of whole, fresh fruit consumption on measures of adiposity including body weight in randomized controlled trials (RCTs). Secondary outcomes are the impact of whole, fresh fruit consumption on energy intake in RCTs, and the association between whole, fresh fruit consumption and changes in measures of adiposity in prospective observational studies. CENTRAL and PubMed databases were searched through October 2018. Cochrane risk of bias tool was used to assess risk of bias in RCTs, and the GRADE method was used to judge and convey the certainty of conclusions. Reporting follows PRISMA guidelines.

Results: RCTs, and particularly those of higher quality, suggest that increasing whole, fresh fruit consumption promotes weight maintenance or modest weight loss over periods of 3–24 weeks (moderate certainty), with limited evidence suggesting that a high intake of fruit favors weight loss among people with overweight or obesity. Consistent with this, single-meal RCTs suggest that consuming whole, fresh fruit tends to decrease energy intake, particularly when consumed prior to a meal or when displacing more energy-dense foods (moderate certainty). Prospective observational studies suggest that habitually higher fruit intake is not associated with weight change, or is associated with modest protection against weight gain, over five or more years.

Conclusions: Current evidence suggests that whole, fresh fruit consumption is unlikely to contribute to excess energy intake and adiposity, but rather has little effect on these outcomes or constrains them modestly. Single-meal RCTs, RCTs lasting 3–24 weeks, and long-term observational studies are relatively consistent in supporting this conclusion. Whole, fresh fruit probably does not contribute to obesity and may have a place in the prevention and management of excess adiposity.

Guyenet SJ. Impact of Whole, Fresh Fruit Consumption on Energy Intake and Adiposity: A Systematic Review. Front Nutr. 2019;6:66. Published 2019 May 8. doi:10.3389/fnut.2019.00066

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Sections of the Abstract, Introduction, and Conclusion are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6518666/

The core symptoms of psychosis—delusions, hallucinations, and thought disorders—are not unique to the disorder traditionally called schizophrenia. They occur at the early stages of various brain diseases, too. Psychosis seems to be a preformed pattern of response of the human brain. Most schizophrenia onsets are marked by a prodromal stage extending over several years and producing the maximum of social consequences. Schizophrenia incidence shows a steep increase culminating at age 15 to 25 years in males. In females it reaches a first peak at age 15 to 30 years and a second, flatter peak at menopausal age (44-49 years). Thereafter, incidence declines to a plateau at later ages. Unlike what the findings of most large-scale epidemiological studies applying an upper age limit of 45 to 55 years suggest, schizophrenia is a disorder of all ages. The lifetime risk seems to be the same for both sexes. The lower incidence in premenopausal women is accounted for by the downregulating effect of oestrogen on dopamine receptors. This hormonal protective effect is antagonised by the genetic effect of a high familial load. In the long-term illness course, right-censored to 11.2 years following first admission, the number of psychotic relapse episodes ranges from 0 to 29 with a mean of 3. The positive symptom dimension produces the highest number of relapses and the shortest duration of exacerbations with a mean length of two months. The depressive and negative symptom dimensions show exacerbations extending over nearly six months on average. Following the first illness episode symptom scores decline sharply, reaching a plateau five years after first admission. Negative symptoms come to a plateau after 2 to 3 years in females and after 5 years in males. Depression is the most frequent type of symptom in the long-term course. In the light of these results urgent treatment issues will be discussed.

Häfner H. From Onset and Prodromal Stage to a Life-Long Course of Schizophrenia and Its Symptom Dimensions: How Sex, Age, and Other Risk Factors Influence Incidence and Course of Illness. Psychiatry J. 2019;2019:9804836. Published 2019 Apr 16. doi:10.1155/2019/9804836.

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Sections of the Abstract, Introduction, and Conclusion are presented in the Podcast. Link to the full-text article:

Background/Objectives: Antibiotic use in early life has been associated with weight gain in several populations. However, associations between chronic antibiotic use and weight among adults in the general population are unknown.

Subjects/Methods: The NIEHS Sister Study is a longitudinal cohort of sisters of women with breast cancer. We examined associations between chronic antibiotic use (≥ 3 months) during the fourth decade of life (30–39 years) and subsequent obesity at enrollment (mean age = 55) via logistic regression. We also examined associations between chronic antibiotic use in the 5 years and 12 months prior to enrollment and weight gain after enrollment in linear mixed models. Models were adjusted for race/ethnicity, education, urban/rural status, age, and smoking.

Results: In adjusted analyses (n = 50,237), chronic penicillin use during the 4th decade of life was associated with obesity at enrollment (OR 2.00, 95% CI 1.40, 2.87), and use in the 5 years prior to enrollment was associated with increased BMI change after enrollment (β 1.00 95% CI 0.01, 2.00). Use of bactericidals (OR 1.71, 95% CI 1.29, 2.26) during the 4th decade of life was also associated with obesity at enrollment. Associations for penicillins and bactericidals were consistent across indications for use. Bacteriostatic use in the 5 years prior to enrollment was associated with a reduction in BMI after enrollment (β -0.52, 95% CI -1.04, 0.00), and tetracycline use during the 4th decade of life was associated with reduced odds of obesity at enrollment (OR 0.72, 95% CI 0.56, 0.92). However, these inverse associations were only present for those who reported taking antibiotics for skin purposes. Cephalosporins, macrolides, quinolones, and sulfonamides were not associated with BMI change over time.

Conclusions: Chronic use of antibiotics during adulthood may have long-lasting impacts on BMI. Associations may differ by antibiotic class, and confounding by indication may be important for some antibiotic classes.

Furlong M, Deming-Halverson S, Sandler DP. Chronic antibiotic use during adulthood and weight change in the Sister Study. PLoS One. 2019;14(5):e0216959. Published 2019 May 16. doi:10.1371/journal.pone.0216959.

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Sections of the Abstract and Introduction are presented in the Podcast. Link to the full-text article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6522121/

Objective: Dementia is a common and feared aspect of Parkinson's disease but there are no robust predictors of cognitive outcome. Visuoperceptual deficits are linked to risk of dementia in Parkinson's disease but whether they predict cognitive change is not known, and the neural substrates of visuoperceptual dysfunction in Parkinson's have not yet been identified.

Methods: We compared patients with Parkinson's disease and unaffected controls who underwent BOLD fMRI while performing our previously validated visuoperceptual task and tested how functional connectivity between task‐specific regions and the rest of the brain differed between patients who performed well and poorly in the task.

Results: We show that task performance at baseline predicts change in cognition in Parkinson's disease after 1 year. Our task‐based fMRI study showed that the performance in this task is associated with activity in the posterior cingulate cortex/precuneus. We found that functional connectivity between this region and dorsomedial prefrontal cortex was reduced in poor performers compared with good performers of this task.

Interpretation: Our findings suggest that functional connectivity is reduced between posterior and anterior hubs of the default mode network in Parkinson's patients who are likely to progress to worsening cognitive dysfunction. Our work implicates posterior default mode nodes and their connections as key brain regions in early stages of dementia in Parkinson's disease.

Weil RS, Winston JS, Leyland LA, et al. Neural correlates of early cognitive dysfunction in Parkinson's disease. Ann Clin Transl Neurol. 2019;6(5):902–912. Published 2019 Mar 28. doi:10.1002/acn3.767.

This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Sections of the Abstract and Introduction are presented in the Podcast. Link to the full-text article:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6529983/