Breastfeeding (BF) has been reported to improve long-term maternal metabolic health in observational studies, but not in the randomised controlled PROBIT study. Research also suggests that maternal pre-pregnant metabolic health may affect BF. We aimed to disentangle effects of BF on long-term maternal metabolic health from effects of pre-pregnant metabolic health on BF duration and long-term metabolic health.
Longitudinal population-based cohort study.
Nord-Trøndelag county, Norway.
Women with a first live-born baby (1987-2008) participating in the Nord-Trøndelag Health Study (HUNT).
Odds ratios (ORs) for short BF duration (6 months) on mean values of metabolic health parameters from baseline to follow-up.
Mean change in BMI, WCF, BPs, HR, serum-glucose, and serum-lipids from baseline to follow-up by BF duration categories.
We analysed 1403 women with a median follow-up of 12 years (interquartile range 11-22). Pre-pregnant WCF and HR correlated inversely with BF duration. Pre-pregnant BMI had a u-shaped correlation-pattern with BF duration. We observed similar between-group differences in metabolic health parameters at baseline and at follow-up, which implies that mean change in metabolic health parameters was similar across BF groups. Those women who started out with the best health had the longest BF duration and ended up with the best health, and those women who started out with the poorest health had shortest BF duration and ended up with the poorest health.
Our results do not support a causal relationship between long BF duration and improved metabolic health. It is more likely that pre-pregnant metabolic health affects both BF duration and long-term metabolic health. Reverse causality can explain previously observed improved long-term metabolic health after BF.
Breastfeeding seems not to affect long-term maternal metabolic health, but good pre-pregnant metabolic health does.
Shifts in phenology are a well-documented ecological response to changes in climate, which may or may not be adaptive for a species depending on the climate sensitivity of other ecosystem processes. Furthermore, phenology may be affected by factors in addition to climate, which may accentuate or dampen climate-driven phenological responses. In this study, we investigate how climate and population demographic structure jointly affect spawning phenology of a fish species of major commercial importance: walleye pollock (Gadus chalcogrammus). We use 32 years of data from ichthyoplankton surveys to reconstruct timing of pollock reproduction in the Gulf of Alaska and find that the mean date of spawning has varied by over 3 weeks throughout the last >3 decades. Climate clearly drives variation in spawn timing, with warmer temperatures leading to an earlier and more protracted spawning period, consistent with expectations of advanced spring phenology under warming. However, the effects of temperature were nonlinear, such that additional warming above a threshold value had no additional effect on phenology. Population demographics were equally as important as temperature: An older and more age-diverse spawning stock tended to spawn earlier and over a longer duration than a younger stock. Our models suggest that demographic shifts associated with sustainable harvest rates could shift the mean spawning date 7 days later and shorten the spawning season by 9 days relative to an unfished population, independent of thermal conditions. Projections under climate change suggest that spawn timing will become more stable for walleye pollock in the future, but it is unknown what the consequences of this stabilization will be for the synchrony of first-feeding larvae with production of zooplankton prey in spring. With ongoing warming in the world's oceans, knowledge of the mechanisms underlying reproductive phenology can improve our ability to monitor and manage species under changing climate conditions.
Lifetime number of years of menstruation (LNYM) reflects a woman's cumulative exposure to endogenous estrogen and can be used as a measure of the combined effect of reproductive factors related to endometrial cancer (EC) risk.
We aimed to study the association between LNYM and EC risk among postmenopausal women and calculate the population attributable fraction of EC for different LNYM categories. Our study sample consisted of 117 589 women from the Norwegian Women and Cancer (NOWAC) Study. All women were aged 30-70 years at enrollment and completed a baseline questionnaire between 1991 and 2006. Women were followed up for EC to December 2014 through linkages to national registries. We used Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals (95% CIs), adjusted for potential confounders.
In all, 720 women developed EC. We found a statistically significant, positive dose-response relationship between LNYM and EC, with a 9.1% higher risk for each additional year of LNYM (P for trend
APPLE Schools is a Comprehensive School Health (CSH) project, started in schools in socioeconomically disadvantaged areas where dietary habits are poor, physical activity (PA) levels are low, and obesity rates are high. Earlier research showed program effects whereby energy intake, PA and weight status of students in APPLE Schools had reached similar levels as that of students in other schools. However, it is unknown whether the effects of CSH are sustained when children grow into adolescents. Effects of APPLE Schools on health-related knowledge, attitudes, self-efficacy, diet, PA, and weight status, seven years after the start of the project, when students were in junior high and high school were assessed. We hypothesised that APPLE School graduates and comparison school graduates will remain at similar levels for these indicators.
In the 2015/16 school year, junior high and high school graduates (grades 7-12) in Northern Alberta, Canada participated in a Youth Health Survey. Participants included graduates from APPLE elementary schools (n?=?202) and comparison elementary schools (n?=?338). Health-related knowledge, attitudes, self-efficacy, diet (24-h dietary recall), PA (pedometer step count) and weight status were assessed. Mixed effects regression was employed to assess differences in these outcomes between APPLE School graduates and comparison school graduates. Comparisons between elementary school (2008/09) and junior high/high school (2015/16) of self-efficacy, PA and weight status were also conducted.
APPLE School graduates did not significantly differ from comparison school graduates on any outcomes (i.e. knowledge, attitudes, self-efficacy, diet, PA, and weight status). Additionally, no significant differences existed in the comparisons between 2008/09 and 2015/16.
Our findings of no difference between the APPLE School graduates and comparison school graduates suggest that the effects of APPLE Schools may continue into adolescence or the new school environment may have an equalizing effect on the students. Since lifestyle practices are adopted throughout childhood and adolescence, and the school environment has an important influence on development, an extension of CSH initiatives into junior high/high schools should be considered. This will help to consolidate and support the continuance of healthy lifestyle messages and practices throughout childhood and adolescence.
Swedish snus is a smokeless tobacco product that contains reduced levels of harmful compounds compared with cigarette smoke. In Sweden, where snus use exceeds smoking among men, relatively low rates of major smoking-related diseases have been recorded. To better understand how snus use could align with current tobacco harm reduction strategies, its potential mechanisms of toxicity must be investigated. This study aimed to determine, via a systems toxicology approach, the biological impact of repeated 72-hour exposure of human gingival epithelial organotypic cultures to extracts from both a commercial and a reference snus and the total particulate matter (TPM) from cigarette smoke. At concentrations relevant for human use, cultures treated with snus extracts induced mild, generally reversible biological changes, while TPM treatment induced substantial morphological and inflammatory alterations. Network enrichment analysis and integrative analysis of the global mRNA and miRNA expression profiles indicated a limited and mostly transient impact of the snus extracts, in particular on xenobiotic metabolism, while the effects of TPM were marked and sustained over time. High-confidence miRNAs that might be related to pathological conditions in vivo were identified. This study highlights the limited biological impact of Swedish snus extract on human organotypic gingival cultures.
Vitreoretinal (VR) surgery is the third most common intraocular surgery after refractive and cataract surgery. The impact of statin therapy on VR surgery outcomes remains unclear, despite a potentially beneficial effect. We explored the association of preoperative statin therapy and the need for revitrectomy after primary vitrectomy.
Our historical, population-based, register-based, VR surgery cohort consisted of 5709 patients operated in a tertiary, academic referral hospital in Finland, during 2008-2014, covering 6.5 years. Subgroup analysis was performed as follows: eyes operated due to (i) rhegmatogenous retinal detachment (RRD), (ii) VR interface diseases (macular pucker/hole), (iii) diabetic maculopathy or proliferative retinopathy, (iv) vitreous haemorrhage, (v) lens subluxation, (vi) vitreous opacities or (vii) other VR indication. The primary end-point event was revitrectomy during a postoperative follow-up period of 1 year due to retinal redetachment, vitreous rehaemorrhage, postoperative endophthalmitis, recurrent pucker or unclosed macular hole.
Rhegmatogenous retinal detachment (RRD) was the second most frequent indication of VR surgery, including 1916 patients, with 305 re-operations with rate 0.20 (95% CI 0.18-0.23) per person-year. Statin treatment in time of operation was associated with lower risk of re-operation according to relative scale (incidence rate ratio 0.72, 95% CI 0.53-0.97), but not in absolute scale (incidence rate difference -0.58, 95% CI -4.30 to 3.15 for 100 person-years). No association with statin therapy and vitrectomy outcome was observed in the other VR subgroups.
Use of statin treatment was associated with a 28% lower risk of revitrectomy in patients operated due to RRD. Further randomized clinical trials are highly warranted.
Mosses collected decades ago and stored in herbaria are often used to assess historical nitrogen deposition. This method is effectively based on the assumption that tissue N concentration remains constant during storage. The present study raises serious doubt about the generality of that assumption. We measured tissue N and C concentrations as well as d15N, d13C, Pb and Mg in herbarium and present day samples of seven bryophyte species from six sites across Denmark. While an increase in nitrogen deposition during the last century is well-documented for the study site, we surprisingly found foliar N concentration to be higher in historical samples than in modern samples. Based on d15N values and Pb concentration, we find nitrogen contamination of herbarium specimens during storage to be the most likely cause, possibly in combination with dilution though growth and/or decomposition during storage. We suggest ways to assess contamination and recommend caution to be taken when using herbarium specimens to assess historical pollution if exposure during storage cannot be ruled out.
The aim of this study was to describe physiological load and psychological stress of Finnish firefighters during a 24-hour work shift.
R-R intervals were recorded during 24-hour work shifts. Short-time Fourier transform was used to analyze heart rate variability during shifts.
HRmean, HRpeak, and square root of the mean of the sum of the squares of the differences between adjacent R-to-R peak intervals of the 24-hour shift was 73?±?7?bpm (38?±?4% of HRmax), 156?±?16 bpm (82?±?8% of HRmax), and 42?±?14?ms. Mean VO2 was 11?±?2 (% of VO2max) and VO2peak 72?±?11 (% of VO2max).
Physiological load and psychological stress were temporarily high, even in young, fit firefighters. As the relative work load may increase and recovery processes slow down among aging employees, fatigue may occur unless work arrangements are well-designed.
The aim of this paper was to conduct pilot-scale column tests on an alternative treatment filter designed for the treatment of highway stormwater in cold climates. The study evaluated adsorption performance of the filter with regard to the four most commonly found metals (Cu, Ni, Pb, and Zn) in highway stormwater. An alternative method was used to estimate the operational life of the filter from the adsorption test data without a breakthrough under high hydraulic loads. The potential environmental impact of the filter was assessed by comparing desorption test data with four different environmental quality standards. The proposed filter achieved high adsorption (over 90%) of the target metals. The comparisons of desorption and leaching data with the environmental standards indicated that iron-oxide/bottom ash was non-hazardous, reusable and without serious environmental risks. The operational life and filter dimensions were highly dependent on rainfall depth, which indicated that the filter design would have to be adapted to suit the climate. To fully appreciate the performance and environmental aspects, the filter unit should be tested in the field and the testing should explicitly include ecotoxicological and life cycle impacts.
There have been few studies investigating the association between food security and breast-feeding duration and none have been conducted among Canadian Inuit, a population disproportionately burdened with food insecurity. We evaluated the association between household food security and breast-feeding duration in Canadian Inuit children.
Data were obtained from the Nunavut Inuit Child Health Survey, a population-based cross-sectional survey.
The Canadian Territory of Nunavut in 2007 and 2008.
Caregivers of Inuit children aged 3-5 years. Participating children were randomly sampled from community medical centre lists.
Out of 215 children, 147 lived in food-insecure households (68·4 %). Using restricted mean survival time models, we estimated that children in food-secure households were breast-fed for 16·8 (95 % CI 12·5, 21·2) months and children in food-insecure households were breast-fed for 21·4 (95 % CI 17·9, 24·8) months. In models adjusting for social class, traditional knowledge and child health, household food security was not associated with breast-feeding duration (hazard ratio=0·82, 95 % CI 0·58, 1·14).
Our research does not support the hypothesis that children living in food-insecure households were breast-fed for a longer duration than children living in food-secure households. However, we found that more than 50 % of mothers in food-insecure households continued breast-feeding well beyond 1 year. Many mothers in food-secure households also continued to breast-feed beyond 1 year. Given the high prevalence of food insecurity in Inuit communities, we need to ensure infants and their caregivers are being adequately nourished to support growth and breast-feeding, respectively.