Sleep, mental health and physical health in new shift workers transitioning to shift work: Systematic review and meta-analysis.

This systematic review and meta-analysis (PROSPERO registration CRD42022309827) aimed to describe how shift work impacts new workers' sleep, mental health, and physical health during the transition to shift work and to consolidate information regarding predictors of shift work tolerance (SWT) during this transition period. Inclusion criteria included: new shift workers; sleep, mental health, or physical health outcomes; prospective study design with the first timepoint assessing workers within three months of starting shift work; and written in English. Searches from six databases returned 12,172 articles as of August 2023. The final sample included 48 papers. Publication quality and risk of bias was assessed using the critical appraisal skills program. Forty-five studies investigated longitudinal changes in sleep, mental health, or physical health outcomes and 29 studies investigated predictors of SWT (i.e., better sleep, mental and physical health). Sleep and mental health outcomes worsened following the onset of shift work, while physical health did not significantly change. Pre-shift work mental health, sleep, and work characteristics predicted SWT later in workers' careers. Shift work adversely impacts new workers' sleep and mental health early in their career, and interventions before beginning shift work are needed to promote better SWT.

Cognitive reappraisal moderates the protective effect of body satisfaction on mental health and wellbeing in adults: A prospective study during COVID-19 lockdown.

BACKGROUND: Body satisfaction is associated with mental health and well-being in adults. However, prospective studies are needed to better understand its protective effects, and in whom these are most beneficial. This study investigated body satisfaction as a predictor of depressive symptoms, generalised anxiety, and well-being in a representative Australian sample collected during the initial COVID-19 lockdown. Two emotion regulation strategies - cognitive reappraisal and expressive suppression - were also tested as moderating variables. METHODS: The sample comprised 684 adults aged 19 to 87 years who completed three primary waves of data spanning two months [Wave 3 (W3), W4 and W7] from the Australian National COVID-19 Mental Health, Behaviour and Risk Communication Survey. RESULTS: Hierarchical multiple regression models controlling for demographic and COVID-19 risk factors, as well as W3 for each outcome variable, indicated that W3 body satisfaction predicted greater W7 well-being, and fewer W7 depressive symptoms and greater W7 well-being in participants reporting low levels of W4 cognitive reappraisal. No moderation for W4 expressive suppression was observed, nor predictive relationships between W3 body satisfaction and W7 anxiety. LIMITATIONS: The two-month follow-up period precludes conclusions relating to the longer-term protective effects of body satisfaction within and beyond the pandemic context. Examination of focal relationships in clinical samples, and inclusion of broader indices of body image, emotion regulation and mental health, is needed in future studies. CONCLUSIONS: Findings suggest body satisfaction warrants attention in community well-being promotion in adults, and may be particularly beneficial for those lack adaptive emotion regulation strategies.

Predictors of individual mental health and psychological resilience after Australia's 2019-2020 bushfires.

AIMS: We assessed the mental health effects of Australia's 2019-2020 bushfires 12-18 months later, predicting psychological distress and positive psychological outcomes from bushfire exposure and a range of demographic variables, and seeking insights to enhance disaster preparedness and resilience planning for different profiles of people. METHODS: We surveyed 3083 bushfire-affected and non-affected Australian residents about their experiences of bushfire, COVID-19, psychological distress (depression, anxiety, stress, post-traumatic stress disorder) and positive psychological outcomes (resilient coping, wellbeing). RESULTS: We found high rates of distress across all participants, exacerbated by severity of bushfire exposure. For people who were bushfire-affected, being older, having less financial stress, and having no or fewer pre-existing mental disorders predicted both lower distress and higher positive outcomes. Being male or having less income loss also predicted positive outcomes. Severity of exposure, higher education and higher COVID-19-related stressors predicted both higher distress and higher positive outcomes. Pre-existing physical health diagnosis and previous bushfire experience did not significantly predict distress or positive outcomes. RECOMMENDATIONS: To promote disaster resilience, we recommend investment in mental health, particularly for younger adults and for those in rural and remote areas. We also recommend investment in mechanisms to protect against financial distress and the development of a broader definition of bushfire-related impacts than is currently used to capture brushfires' far-reaching effects.

Sleep and mental health in recruit paramedics: a 6-month longitudinal study.

STUDY OBJECTIVES: To explore potential relationships and longitudinal changes in sleep and mental health in recruit paramedics over the first 6 months of work, and whether sleep disturbances pre-emergency work predict future mental health outcomes. METHODS: Participants (N = 101, 52% female, Mage = 26 years) completed questionnaires prior to (baseline), and after 6 months of emergency work to assess for symptoms of insomnia, obstructive sleep apnea, post-traumatic stress disorder (PTSD), depression, anxiety, and trauma exposure. At each timepoint, participants also completed a sleep diary and wore an actigraph for 14 days to assess sleep patterns. Correlations between baseline sleep and mental health were conducted and changes in these variables across timepoints were examined using linear mixed models. Hierarchical regressions assessed whether sleep at baseline predicted mental health at follow-up. RESULTS: Insomnia and depression symptoms, and total sleep time increased while sleep onset latency decreased across the first 6 months of emergency work. Participants experienced an average of 1 potentially traumatic event during the 6-month period. Baseline insomnia predicted increased depression symptoms at the 6-month follow-up, while baseline wake after sleep onset predicted follow-up PTSD symptoms. CONCLUSION: Results highlight an increase in insomnia and depression across the initial months of emergency work, while sleep disturbances before emergency work were identified as potential risk factors for the development of depression and PTSD among paramedics in their early career. Screening and early interventions targeting poor sleep at the beginning of emergency employment may assist in reducing the risk of future mental health outcomes in this high-risk occupation.

Mental health risk factors for shift work disorder in paramedics: A longitudinal study.

OBJECTIVES: Depression and anxiety are prominent in paramedics, as is the prevalence of shift work disorder (SWD), a circadian sleep condition comorbid with mental health disorders. However, the role of mental health risk factors for SWD is largely unknown. This study investigated whether mental health levels in recruit paramedics before shift work predicted greater risk of SWD at 6-months into their career and explored whether shift and sleep factors mediated this relationship. DESIGN: A longitudinal study. SETTING: Victoria, Australia. PARTICIPANTS: Recruit paramedics were assessed at baseline (n = 101; ie, pre-shift work) and after 6-months (n = 93) of shift and emergency work. MEASUREMENTS: At both time points, participants completed self-reported measures of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder Questionnaire-7), and SWD (SWD-Screening Questionnaire). Participants also filled a sleep and work diary for 14-days at each timepoint. RESULTS: After 6-months of emergency work 21.5% of paramedics had a high SWD risk. Logistic regression models showed baseline depression predicted 1.24-times greater odds for SWD at 6-months. Through Lavaan path analysis we found shift and sleep variables did not mediate the relationship between baseline mental health and SWD risk. Baseline depression was associated with increased sleepiness levels following paramedics' major sleep periods at 6-months. Pre-existing depression levels also predicted greater perceived nightshift workload. CONCLUSIONS: Our results highlight depression symptoms before emergency work are a risk factor for SWD within 6-months of work. Depression represents a modifiable risk factor amenable to early interventions to reduce paramedics' risk of SWD.

The impact of break duration, time of break onset, and prior shift duration on the amount of sleep between shifts in heavy vehicle drivers.

This study aimed to examine the impact of break duration between consecutive shifts, time of break onset, and prior shift duration on total sleep time (TST) between shifts in heavy vehicle drivers (HVDs), and to assess the interaction between break duration and time of break onset. The sleep (actigraphy and sleep diaries) and work shifts (work diaries) of 27 HVDs were monitored during their usual work schedule for up to 9 weeks. Differences in TST between consecutive shifts and days off were assessed. Linear mixed models (followed by pairwise comparisons) assessed whether break duration, prior shift duration, time of break onset, and the interaction between break duration and break onset were related to TST between shifts. Investigators found TST between consecutive shifts (mean [SD] 6.38 [1.38] h) was significantly less than on days off (mean [SD] 7.63 [1.93] h; p < 0.001). Breaks starting between 12:01 and 8:00 a.m. led to shorter sleep (p < 0.05) compared to breaks starting between 4:01 and 8:00 p.m. Break durations up to 7, 9, and 11 h (Australian and European minimum break durations) resulted in a mean (SD) of 4.76 (1.06), 5.66 (0.77), and 6.41 (1.06) h of sleep, respectively. The impact of shift duration prior to the break and the interaction between break duration and time of break were not significant. HVDs' sleep between workdays is influenced independently by break duration and time of break onset. This naturalistic study provides evidence that current break regulations prevent sufficient sleep duration in this industry. Work regulations should evaluate appropriate break durations and break onset times to allow longer sleep opportunities for HVDs.

Risk tolerance and changes in coronavirus disease (COVID) related health behaviors: A longitudinal study.

OBJECTIVE: The present study examined behavioral responses during the coronavirus disease 2019 (COVID-19) pandemic and the role of dispositional risk tolerance in the Australian context. METHOD: The study involved a six-wave longitudinal investigation with a nationally representative sample of Australians (N = 1,296). Dispositional risk tolerance was measured at Wave 1 and participants' anxiety level and self-report implementation of 10 COVID actions was assessed in each wave. Autoregressive multinomial regression models were estimated to assess the unique contribution of risk tolerance to the longitudinal change of participants' implementation of COVID actions. RESULTS: The results revealed a high implementation rate for protective actions when Australia had a peak in the severity of the COVID-19 pandemic and subsequently declined with the easing threat of the pandemic. Individuals' dispositional risk tolerance significantly predicted transition to, and endorsement of, protective actions. Participants who had low risk tolerance were more likely to remain at the state of implementing COVID-19 measures than being in, or transitioning to, other states. CONCLUSIONS: The findings suggest that when encouraging protective actions, governments and public authorities should acknowledge variability in the community in responding to risk and consider measures in addition to risk messaging to encourage protective actions among individuals with a high level of risk tolerance. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Psychosocial impacts of home-schooling on parents and caregivers during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has been highly disruptive, with the closure of schools causing sudden shifts for students, educators and parents/caregivers to remote learning from home (home-schooling). Limited research has focused on home-schooling during the COVID-19 pandemic, with most research to date being descriptive in nature. The aim of the current study was to comprehensively quantify the psychosocial impacts of home-schooling on parents and other caregivers, and identify factors associated with better outcomes. METHODS: A nationally representative sample of 1,296 Australian adults was recruited at the beginning of Australian COVID-19 restrictions in late-March 2020, and followed up every two weeks. Data for the current study were drawn from waves two and three. Surveys assessed psychosocial outcomes of psychological distress, work and social impairment, and wellbeing, as well as a range of home-schooling factors. RESULTS: Parents and caregivers who were home-schooling during the COVID-19 pandemic experienced significantly higher levels of psychological distress and work/social impairment compared to those who were not home-schooling or had no school-aged children. A current mental health diagnosis or lower levels of perceived support from their child's school negatively affected levels of psychological distress, work and social impairment, and wellbeing in parents and caregivers involved in home-schooling. CONCLUSIONS: The mental health impacts of home-schooling were high and may rise as periods of home-schooling increase in frequency and duration. Recognising and acknowledging the challenges of home-schooling is important, and should be included in psychosocial assessments of wellbeing during periods of school closure. Emotional and instrumental support is needed for those involved in home-schooling, as perceived levels of support is associated with improved outcomes. Proactive planning by schools to support parents may promote better outcomes and improved home-schooling experiences for students.

Epidemiology of mumps outbreaks and the impact of an additional dose of MMR vaccine for outbreak control in regional Queensland, Australia, 2017-2018.

BACKGROUND: In recent years, there have been ongoing outbreaks of mumps reported in Northern and North-Western Queensland, Western Australia and the Northern Territory, Australia. We aimed to define the epidemiology of mumps outbreaks in Central Queensland, Australia between October 2017 and October 2018 and evaluate the effectiveness of an additional dose of measles, mumps, rubella (MMR) vaccine. METHODS: A retrospective case control study was conducted, including outbreak investigations with laboratory-confirmed cases of mumps and subsequent comparison with matched controls. We analysed mandatory notifications from the Queensland Health Notifiable Conditions System database and immunisation information from the Queensland Health Vaccination Information and Admin System (VIVAS) and the Australian Immunisation Register. RESULTS: Between October 2017 and October 2018, there were 93 cases of mumps reported in Central Queensland with three distinct outbreaks: a discrete Indigenous community; a correctional facility; and a boarding school. Among all cases, 74 (79.6%) were fully vaccinated and 14 (15.1%) were partially vaccinated with MMR vaccine. Eighty-six cases (92.5%) were reported among Aboriginal and Torres Strait Islander people. In all outbreaks, an additional dose of MMR vaccine was offered with 35.4%, 73.6% and 35.8% of the target population being immunised in the discrete Indigenous community, the correctional facility and the boarding school, respectively. Prior to this additional dose of MMR, the mumps attack rate was 31.0 (95% confidence interval [95% CI]: 24.2-39.0) per 1000 population, compared to the post-additional dose MMR attack rate of 10.6 (95% CI: 6.7-15.9) per 1000 population. CONCLUSION: An additional or booster dose of MMR should be included as an effective public health intervention strategy, particularly in communal or high-density living conditions to control mumps outbreaks in highly vaccinated populations.

Spin Infrequently Occurs in Abstracts of Systematic Reviews For The Pharmacological Treatment of Type 2 Diabetes Mellitus.

AIMS: Currently, there is a growing body of research demonstrating that spin - the misinterpretation and distortion of a study's findings - is common in different fields of medicine. To our knowledge, no study has investigated its presence in systematic reviews focused on diabetic therapies. METHODS: We performed a cross-sectional study by searching MEDLINE and Embase for systematic reviews focused on pharmacologic treatments for type 2 diabetes mellitus. Our search retrieved 26,490 records, from which 199 studies were extracted in a masked, duplicate fashion. Each study was evaluated for the nine most severe types of spin and other study design parameters. Spin was presented as frequencies and odds ratios to identify associations between study characteristics. RESULTS: Spin was identified in the abstracts of 15 systematic reviews (15/199, 7.5%). Spin type 5 was the most common type identified (7/199, 3.5%). Spin types 1, 2, 4, and 8 were not identified. In the last 5 years (2016-2021), 7 systematic reviews contained spin within their abstract. There was no association between spins presence and any extracted study characteristic . CONCLUSIONS: Our findings show that spin infrequently occurs in abstracts of systematic reviews focused on pharmacologic therapies for type 2 diabetes mellitus. However, any amount of spin can lead to the distortion of a reader's interpretation of the study's findings. Thus, we provide recommendations with rationale to prevent spin in future systematic reviews.

Re-emergence of dengue virus in regional Queensland: 2019 dengue virus outbreak in Rockhampton, Central Queensland, Australia.

OBJECTIVE(S): To describe an autochthonous dengue virus type 2 (DENV-2) outbreak in Central Queensland from May 2019 and subsequent public health actions. DESIGN AND SETTING: Public health outbreak investigation of locally acquired DENV-2 cases in Rockhampton, Central Queensland. This included laboratory investigations, associated mosquito vector surveillance, and control measures implemented in response to the outbreak. RESULTS: Twenty-one locally-acquired DENV-2 cases were identified during the Rockhampton outbreak (from 23 May to 7 October 2019): 13 laboratory-confirmed and eight probable cases. Clinical symptoms included lethargy (100%); fever (95%); headache (95%); and aches and pains (90%). Inspections of premises demonstrated that Aedes aegypti was present in 9.5% of those investigated which was more than half of the premises identified as containing mosquitoes. Nucleotide sequencing of a DENV-2 isolate recovered from the first confirmed case and DENV-2 RNA from an additional 5 patients indicated a single DENV-2 strain was responsible for the outbreak which was most closely related to DENV-2 strains from Southeast Asia. CONCLUSIONS: The 2019 DENV-2 outbreak in Rockhampton, Central Queensland, Australia, likely resulted from the importation of a strain, most closely related to DENV-2 strains from Southeast Asia and is the first reported outbreak in the region specifically implicating DENV-2. Given the presence of Aedes aegypti in Rockhampton, appropriate medical and mosquito avoidance advice; ongoing surveillance; and deployment of mosquito control strategies for the prevention of dengue and other mosquito-borne diseases should be priorities for this region.

Trajectories of depression and anxiety symptoms during the COVID-19 pandemic in a representative Australian adult cohort.

OBJECTIVES: To estimate initial levels of symptoms of depression and anxiety, and their changes during the early months of the COVID-19 pandemic in Australia; to identify trajectories of symptoms of depression and anxiety; to identify factors associated with these trajectories. DESIGN, SETTING, PARTICIPANTS: Longitudinal cohort study; seven fortnightly online surveys of a representative sample of 1296 Australian adults from the beginning of COVID-19-related restrictions in late March 2020 to mid-June 2020. MAIN OUTCOME MEASURES: Symptoms of depression and anxiety, measured with the Patient Health Questionnaire (PHQ-9) depression and Generalised Anxiety Disorder (GAD-7) scales; trajectories of symptom change. RESULTS: Younger age, being female, greater COVID-19-related work and social impairment, COVID-19-related financial distress, having a neurological or mental illness diagnosis, and recent adversity were each significantly associated with higher baseline depression and anxiety scores. Growth mixture models identified three latent trajectories for depression symptoms (low throughout the study, 81% of participants; moderate throughout the study, 10%; initially severe then declining, 9%) and four for anxiety symptoms (low throughout the study, 77%; initially moderate then increasing, 10%; initially moderate then declining, 5%; initially mild then increasing before again declining, 8%). Factors statistically associated with not having a low symptom trajectory included mental disorder diagnoses, COVID-19-related financial distress and social and work impairment, and bushfire exposure. CONCLUSION: Our longitudinal data enabled identification of distinct symptom trajectories during the first three months of the COVID-19 pandemic in Australia. Early intervention to ensure that vulnerable people are clinically and socially supported during a pandemic should be a priority.

Predicting deseasonalised serum 25 hydroxy vitamin D concentrations in the D-Health Trial: An analysis using boosted regression trees.

BACKGROUND: The D-Health Trial aims to determine whether monthly high-dose vitamin D supplementation can reduce the mortality rate and prevent cancer. We did not have adequate statistical power for subgroup analyses, so could not justify the high cost of collecting blood samples at baseline. To enable future exploratory analyses stratified by baseline vitamin D status, we developed models to predict baseline serum 25 hydroxy vitamin D [25(OH)D] concentration. METHODS: We used data and serum 25(OH)D concentrations from participants who gave a blood sample during the trial for compliance monitoring and were randomised to placebo. Data were partitioned into training (80%) and validation (20%) datasets. Deseasonalised serum 25(OH)D concentrations were dichotomised using cut-points of 50, 60 and 75 nmol/L. We fitted boosted regression tree models, based on 13 predictors, and evaluated model performance using the validation data. RESULTS: The training and validation datasets had 1788 (10.5% <50 nmol/L, 23.1% <60 nmol, 48.8 <75 nmol/L) and 447 (11.9% <50 nmol/L, 25.7% <60 nmol/L, and 49.2% <75 nmol/L) samples, respectively. Ambient UV radiation and total intake of vitamin D were the strongest predictors of 'low' serum 25(OH)D concentration. The area under the receiver operating characteristic curves were 0.71, 0.70, and 0.66 for cut-points of <50, <60 and <75 nmol/L respectively. CONCLUSIONS: We exploited compliance monitoring data to develop models to predict serum 25(OH)D concentration for D-Health participants at baseline. This approach may prove useful in other trial settings where there is an obstacle to exhaustive data collection.

The Effect of COVID-19 on Mental Health and Wellbeing in a Representative Sample of Australian Adults.

There is minimal knowledge about the impact of large-scale epidemics on community mental health, particularly during the acute phase. This gap in knowledge means we are critically ill-equipped to support communities as they face the unprecedented COVID-19 pandemic. This study aimed to provide data urgently needed to inform government policy and resource allocation now and in other future crises. The study was the first to survey a representative sample from the Australian population at the early acute phase of the COVID-19 pandemic. Depression, anxiety, and psychological wellbeing were measured with well-validated scales (PHQ-9, GAD-7, WHO-5). Using linear regression, we tested for associations between mental health and exposure to COVID-19, impacts of COVID-19 on work and social functioning, and socio-demographic factors. Depression and anxiety symptoms were substantively elevated relative to usual population data, including for individuals with no existing mental health diagnosis. Exposure to COVID-19 had minimal association with mental health outcomes. Recent exposure to the Australian bushfires was also unrelated to depression and anxiety, although bushfire smoke exposure correlated with reduced psychological wellbeing. In contrast, pandemic-induced impairments in work and social functioning were strongly associated with elevated depression and anxiety symptoms, as well as decreased psychological wellbeing. Financial distress due to the pandemic, rather than job loss per se, was also a key correlate of poorer mental health. These findings suggest that minimizing disruption to work and social functioning, and increasing access to mental health services in the community, are important policy goals to minimize pandemic-related impacts on mental health and wellbeing. Innovative and creative strategies are needed to meet these community needs while continuing to enact vital public health strategies to control the spread of COVID-19.

Factors influencing the uptake of influenza vaccination in African American patients with heart failure: Findings from a large urban public hospital.

BACKGROUND: Evidence suggests that annual influenza vaccination may prevent acute heart failure exacerbation episodes and improve survival. OBJECTIVE: Determine the influenza vaccination rate among African American patients with heart failure and identify predictors of uptake. METHODS: African American patients with heart failure were recruited at Grady Memorial Hospital, Atlanta GA between October 1, 2017 and April 28, 2018 (N = 281). All participants completed a questionnaire. RESULTS: Mean age of the sample was 50.5 ± 11.5 years (58% male). The influenza vaccination rate among the patients was 46% (n = 129/281). Patients who received vaccination information and recommendation from their physician, especially cardiologists, were significantly more likely to be vaccinated than those who did not (P<0.05). Major reasons for declining vaccination included fear of getting sick from influenza vaccine and distrust of the pharmaceutical companies that produce vaccines. CONCLUSIONS: Recommendation of influenza vaccines by physicians during medical consultations and cardiology visits may improve uptake rates in heart failure patients.

Corrigendum: The Effect of COVID-19 on Mental Health and Wellbeing in a Representative Sample of Australian Adults.

[This corrects the article DOI: 10.3389/fpsyt.2020.579985.].

Neutrophil ß-defensin gene expression of postpartum dairy cows is altered by prepartum dietary cation-anion difference.

The objective of this study was to evaluate expression of a cluster of genes encoding ß-defensin antimicrobial peptides in neutrophils of postpartum cows in relation to prepartum dietary cation-anion difference (DCAD), vitamin D, and postpartum disease. Pregnant dry Holstein cows (28 nulliparous and 51 parous) at 255 d gestation were blocked by parity and randomly assigned to 4 prepartum diets of positive (+130 mEq/kg) or negative (-130 mEq/kg) DCAD and either 3 mg vitamin D3 or 3 mg of 25-hydroxyvitamin D3 per 11 kg of dry matter/d. Treatment diets were fed from 255 d of gestation until calving. Peripheral blood neutrophils of 35 parous cows were collected at 0 and 3 d after calving and stimulated with 0 or 100 ng/mL of lipopolysaccharide (LPS). Furthermore, serum Ca and incidences of postpartum diseases were recorded for all cows. The mRNA transcripts of ß-defensin genes were quantified by real-time PCR, and data were analyzed with a general linear mixed model to test for fixed effects and interactions of day, level of DCAD, source of vitamin D, and incidence of disease. Effects of DCAD and vitamin D on neutrophil oxidative burst and phagocytosis were previously reported but were analyzed for effects of disease in the present study. Transcripts for DEFB1, DEFB3, DEFB4, DEFB5, DEFB7, DEFB10, and lingual antimicrobial peptide (LAP) in neutrophils were upregulated by LPS at 0 d but not at 3 d. Transcripts for DEFB4 and DEFB7 in LPS-stimulated neutrophils were greater in cows fed negative DCAD diets compared with positive DCAD. Source of vitamin D (vitamin D3 vs. 25-hydroxyvitamin D3) did not affect expression of ß-defensins in neutrophils. Cows with postpartum subclinical hypocalcemia (serum Ca <2.0 mM) had decreased DEFB3, DEFB4, DEFB6, DEFB7, DEFB10, and LAP expression in LPS-stimulated neutrophils compared with cows that did not experience subclinical hypocalcemia. Likewise, DEFB4, DEFB6, DEFB7, DEFB10, and LAP in LPS-stimulated neutrophils at 3 d postpartum were positively associated with serum Ca at 0 d postpartum. Transcripts for DEFB7, DEFB10 and LAP also were less abundant in neutrophils from cows with metritis compared with healthy cows. In conclusion, feeding a prepartum negative DCAD to improve postpartum serum Ca resulted in greater neutrophil ß-defensin expression, and greater neutrophil ß-defensin expression was positively associated with postpartum health.

Low Sun Exposure and Vitamin D Deficiency as Risk Factors for Inflammatory Bowel Disease, With a Focus on Childhood Onset.

The incidence and prevalence of inflammatory bowel disease (IBD) are increasing worldwide. Some ecological studies show increasing incidence with increasing latitude. Ambient ultraviolet radiation varies inversely with latitude, and sun exposure of the skin is a major source of vitamin D. Vitamin D deficiency is common in patients with IBD. Sun exposure and vitamin D have immune effects that could plausibly reduce, or be protective for, IBD. One quarter of new IBD cases are diagnosed in childhood or adolescence, but most research is for adult-onset IBD. Here, we review the evidence for low sun exposure and/or vitamin D deficiency as risk factors for IBD, focusing where possible on pediatric IBD, where effects of environmental exposures may be clearer. The literature provides some evidence of a latitude gradient of IBD incidence, and evidence for seasonal patterns of timing of birth or disease onset is inconsistent. High prevalence of vitamin D deficiency occurs in people with IBD, but cannot be interpreted as being a causal risk factor. Evidence of vitamin D supplementation affecting disease activity is limited. Further research on predisease sun exposure and well-designed supplementation studies are required to elucidate whether these potentially modifiable exposures are indeed risk factors for IBD.

On the Nature of Evidence and 'Proving' Causality: Smoking and Lung Cancer vs. Sun Exposure, Vitamin D and Multiple Sclerosis.

If environmental exposures are shown to cause an adverse health outcome, reducing exposure should reduce the disease risk. Links between exposures and outcomes are typically based on 'associations' derived from observational studies, and causality may not be clear. Randomized controlled trials to 'prove' causality are often not feasible or ethical. Here the history of evidence that tobacco smoking causes lung cancer-from observational studies-is compared to that of low sun exposure and/or low vitamin D status as causal risk factors for the autoimmune disease, multiple sclerosis (MS). Evidence derives from in vitro and animal studies, as well as ecological, case-control and cohort studies, in order of increasing strength. For smoking and lung cancer, the associations are strong, consistent, and biologically plausible-the evidence is coherent or 'in harmony'. For low sun exposure/vitamin D as risk factors for MS, the evidence is weaker, with smaller effect sizes, but coherent across a range of sources of evidence, and biologically plausible. The association is less direct-smoking is directly toxic and carcinogenic to the lung, but sun exposure/vitamin D modulate the immune system, which in turn may reduce the risk of immune attack on self-proteins in the central nervous system. Opinion about whether there is sufficient evidence to conclude that low sun exposure/vitamin D increase the risk of multiple sclerosis, is divided. General public health advice to receive sufficient sun exposure to avoid vitamin D deficiency (<50 nmol/L) should also ensure any benefits for multiple sclerosis, but must be tempered against the risk of skin cancers.