Change in lifestyle behaviors and diabetes risk: evidence from a population-based cohort study with 10 year follow-up

Abstract Background Promoting positive changes in lifestyle behavior in the whole population may be a feasible and effective approach to reducing type 2 diabetes burden, but the impact of population shifts of modifiable risk factors remains unclear. Currently most of the evidence on modifiable lifestyle behavior and type 2 diabetes risk on a population level comes from studies of between-individual differences. The objective of the study was to investigate the association and potential impact on disease burden for within-individual change in lifestyle behavior and diabetes risk. Methods Population-based prospective cohort study of 35,680 participants aged 30–50 at baseline in 1990–2003 in Västerbotten County, Sweden (follow-up until 2013). Five self-reported modifiable lifestyle behaviors (tobacco use, physical activity, alcohol intake, dietary fiber intake and dietary fat intake) were measured at baseline and 10 year follow-up. Lifestyle behaviors were studied separately, and combined in a score. Incident diabetes was detected by oral glucose tolerance tests. Multivariate logistic regression models and population attributable fractions (PAF) were used to analyze the association between change in lifestyle behavior between baseline and 10 year follow-up, and risk of incident diabetes. Results Incident diabetes was detected in 1,184 (3.3%) participants at 10 year follow-up. There was a reduced diabetes risk associated with increase in dietary fiber intake, odds ratio (OR) 0.79 (95% confidence interval (CI) 0.66, 0.96) for increase of at least one unit standard deviation (3.0 g/1,000 kcal) of the baseline distribution, PAF 16.0% (95% CI 4.2, 26.4%). Increase in the lifestyle behavior score was associated with reduced diabetes risk, OR 0.92 (95% CI 0.85, 0.99) per unit increase of the score. Conclusions These results support a causal link between lifestyle behavior and type 2 diabetes incidence. A small shift in lifestyle behaviors, in particular intake of dietary fiber, has the potential to reduce diabetes burden in the population and might be a suitable target for public health intervention

All You Can Eat: High Performance Capacity and Plasticity in the Common Big-Eared Bat, Micronycteris microtis (Chiroptera: Phyllostomidae)

Ecological specialization and resource partitioning are expected to be particularly high in the species-rich communities of tropical vertebrates, yet many species have broader ecological niches than expected. In Neotropical ecosystems, Neotropical leaf-nosed bats (Phyllostomidae) are one of the most ecologically and functionally diverse vertebrate clades. Resource partitioning in phyllostomids might be achieved through differences in the ability to find and process food. We selected Micronycteris microtis, a very small (5–7 g) animalivorous phyllostomid, to explore whether broad resource use is associated with specific morphological, behavioral and performance traits within the phyllostomid radiation. We documented processing of natural prey and measured bite force in free-ranging M. microtis and other sympatric phyllostomids. We found that M. microtis had a remarkably broad diet for prey size and hardness. For the first time, we also report the consumption of vertebrates (lizards), which makes M. microtis the smallest carnivorous bat reported to date. Compared to other phyllostomids, M. microtis had the highest bite force for its size and cranial shape and high performance plasticity. Bite force and cranial shape appear to have evolved rapidly in the M. microtis lineage. High performance capacity and high efficiency in finding motionless prey might be key traits that allow M. microtis, and perhaps other species, to successfully co-exist with other gleaning bats

Estimating dose—response relationships for vitamin D with coronary heart disease, stroke, and all-cause mortality: observational and revised Mendelian randomization analyses

Background Randomised trials of vitamin D supplementation for cardiovascular disease and all-cause mortality have generally reported null findings. However, generalisability of results to individuals with low vitamin D status is unclear. We aimed to characterise dose-response relationships between 25-hydroxyvitamin D (25[OH]D) concentrations and risk of coronary heart disease, stroke, and all-cause mortality in observational and Mendelian randomisation frameworks. Methods Observational analyses were undertaken using data from 33 prospective studies comprising 500 962 individuals with no known history of coronary heart disease or stroke at baseline. Mendelian randomisation analyses were performed in four population-based cohort studies (UK Biobank, EPIC-CVD, and two Copenhagen population-based studies) comprising 386 406 middle-aged individuals of European ancestries, including 33 546 people who developed coronary heart disease, 18 166 people who had a stroke, and 27 885 people who died. Primary outcomes were coronary heart disease, defined as fatal ischaemic heart disease (International Classification of Diseases 10th revision code I20-I25) or non-fatal myocardial infarction (I21-I23); stroke, defined as any cerebrovascular disease (I60-I69); and all-cause mortality. Findings Observational analyses suggested inverse associations between incident coronary heart disease, stroke, and all-cause mortality outcomes with 25(OH)D concentration at low 25(OH)D concentrations. In population-wide genetic analyses, there were no associations of genetically predicted 25(OH)D with coronary heart disease (odds ratio [OR] per 10 nmol/L higher genetically-predicted 25(OH)D concentration 0·98, 95% CI 0·95–1·01), stroke (1·01, [0·97–1·05]), or all-cause mortality (0·99, 0·95–1·02). Null findings were also observed in genetic analyses for cause-specific mortality outcomes, and in stratified genetic analyses for all outcomes at all observed levels of 25(OH)D concentrations. Interpretation Stratified Mendelian randomisation analyses suggest a lack of causal relationship for 25(OH)D concentrations with both cardiovascular and mortality outcomes for individuals at all levels of 25(OH)D. Our findings suggest that substantial reductions in mortality and cardiovascular morbidity due to long-term low-dose vitamin D supplementation are unlikely even if targeted at individuals with low vitamin D status

Identifying risk of type 2 diabetes : epidemiologic perspectives from biomarkers to lifestyle

Type 2 diabetes is a significant health problem because of its high prevalence and strong association with cardiovascular morbidity and mortality. An increase of type 2 diabetes is predicted due to increasing obesity and sedentary lifestyle habits. The development from latent to diagnostic disease spans many years and during this time it is possible to prevent or postpone type 2 diabetes using lifestyle and pharmacological interventions. The objective of this thesis is to investigate and describe early patterns and risk indicators of type 2 diabetes. The focus is on type 2 diabetes as one component in metabolic syndrome, i.e. the clustering of several cardiovascular risk markers. Two studies based on the Västerbotten Intervention Programme (VIP) provided the data; one case-referent study nested within VIP which includes 237 diabetes cases that were clinically diagnosed 5.4 years after the health survey, each with two referents; and one panel study with 5 consecutive annual cohorts including subjects that participated in VIP between1990 and 1994 and returned to a follow-up after 10 years, a total of 16 492 individuals. Associations between risk markers and type 2 diabetes or metabolic syndrome are evaluated by several statistical techniques. A model of metabolic syndrome is hypothesized. A prediction model for developing type 2 diabetes among middle-aged individuals is proposed, where high risk is defined as having at least two out of three risk criteria (fasting plasma glucose ≥6.1 mmol/L, HbA1c ≥4.7% (Swedish Mono-S standard) and BMI ≥27 in men and BMI ≥30 in women). With positive predictive values of 32% in men and 46% in women, this model performs at least as well as other published prediction models. Information on family history of diabetes does not improve the result and the cumbersome oral glucose tolerance test is not needed. Therefore this model should be feasible for use in routine care. A model of metabolic syndrome with five composite factors, based on 14 variables including markers produced by adipose tissue and b-cells, suggest that obesity with insulin resistance and b-cell decompensation are the core perturbations in the early stages of type 2 diabetes, while inflammation and dyslipidemia could not be shown to be independent early risk indicators. The composite factors do not improve the prediction as compared to the single markers of fasting glucose, BMI and proinsulin and, possibly blood pressure values. Stress (measured as passive or tense working conditions) and weak social support (measured as emotional support), are suggested to be strong risk indicators along with high BMI for type 2 diabetes in women. In men BMI is predictive, but the stress variables are not shown to be associated with future type 2 diabetes. A social gap is indicated by double risk of metabolic syndrome among subjects with low (≤ 9 years at school) compared to high education (≥ 13 years). High consumption of Swedish smokeless tobacco, snuff (>4 cans/week), is independently associated with metabolic syndrome, obesity and hypertriglyceridemia, but not with dysregulation of glucose. To conclude, single markers, that are commonly used in daily practice, are useful and sufficient for identification of subjects that are in the early stages of type 2 diabetes. Obesity with insulin resistance and b-cell decompensation are the core perturbations in early development to T2DM. Lifestyle, socioeconomic and psychosocial markers, in addition to biomarkers, are important determinants of future type 2 diabetes and metabolic syndrome, albeit not similarly among men and women

Socioeconomic inequalities and body mass index in Västerbotten County, Sweden : a longitudinal study of life course influences over two decades

INTRODUCTION: Life course socioeconomic inequalities in heart disease, stroke and all-cause mortality are well studied in Sweden. However, few studies have sought to explain the mechanism for such associations mainly due to lack of longitudinal data with multiple measures of socioeconomic status (SES) across the life course. Given the population health concern about how socioeconomic inequality is related to poorer health, we aim to tackle obesity as one of the prime suspects that could explain the association between SES inequality and cardiovascular disease and consequently premature death. The aim of this study is to test which life course model best describes the association between socioeconomic disadvantage and obesity among 60 year old inhabitants of Västerbotten County in Northern Sweden. METHODS: A birth cohort consisting of 3340 individuals born between 1930 and 1932 was studied. Body mass index (BMI) at the age of 60 and information on socioeconomic status at three stages of life (ages 40, 50, and 60 years) was collected. Independent samples t-test was used to compare BMI between advantaged and disadvantaged groups and one-way ANOVA was used to compare BMI among eight SES trajectories. We applied a structured modeling approach to examine three different hypothesized life course SES models (accumulation, critical period, and social mobility) in relation to BMI. RESULTS: We found sex differences in the way that late adulthood socioeconomic disadvantage is associated with BMI among inhabitants of Northern Sweden. Our study suggests that social adversity in all stages of late adulthood is a particularly important indicator for addressing the social gradients in BMI among women in Northern Sweden and that unhealthy behaviors in terms of smoking and physical inactivity are insufficient to explain the relationships between social and lifestyle inequalities and BMI. CONCLUSION: In order for local authorities to develop informed preventive efforts, we suggest further research to identify modifiable risk factors across the life course which could explain this health inequality

A sustainable teacher training: approaching more science content and inquiry

How can teachers change the way they teach so students get access to more features of inquiry based science teaching and learning? Four teacher educators and researchers worked with five teachers from two schools, to develop tools to analyze teaching sequences. The teachers’ lessons were video-taped on two occasions at least with several weeks in between. The films were analyzed and various didactic issues discussed in seminars with the researchers and the teachers. After the first lesson feedback, the teachers were given the challenge to make a teaching sequence paying regard to his/her reflections on our seminar and our analysis of the first lesson. We report a case study in which a teacher, Roy, develops his teaching in several respects such as dialogic communicative approaches, writing, and science content. We compare and analyze two of his lessons: the first on Electricity and the other on the Water Cycle. The teacher Roy is able to create interesting lessons in which argumentation and debate are included. With the second lesson Roy showed awareness of the significance of the science content in the dialogue, and he gave a greater subject-matter depth compared to the first lesson, as well as a wider variety of scientific ways including experimental work. The science content was, however, superficial and vague in both lessons. The difficulty of meeting the students in dialogue occurs when the teacher’s own knowledge is insufficient. The teacher’s awareness of the importance of dialogue in the classroom combined with a greater depth of subject focus, lead to learning opportunities for students that are of benefit for both language and science skills

A sustainable teacher training: approaching more science content and inquiry

How can teachers change the way they teach so students get access to more features of inquiry based science teaching and learning? Four teacher educators and researchers worked with five teachers from two schools, to develop tools to analyze teaching sequences. The teachers’ lessons were video-taped on two occasions at least with several weeks in between. The films were analyzed and various didactic issues discussed in seminars with the researchers and the teachers. After the first lesson feedback, the teachers were given the challenge to make a teaching sequence paying regard to his/her reflections on our seminar and our analysis of the first lesson. We report a case study in which a teacher, Roy, develops his teaching in several respects such as dialogic communicative approaches, writing, and science content. We compare and analyze two of his lessons: the first on Electricity and the other on the Water Cycle. The teacher Roy is able to create interesting lessons in which argumentation and debate are included. With the second lesson Roy showed awareness of the significance of the science content in the dialogue, and he gave a greater subject-matter depth compared to the first lesson, as well as a wider variety of scientific ways including experimental work. The science content was, however, superficial and vague in both lessons. The difficulty of meeting the students in dialogue occurs when the teacher’s own knowledge is insufficient. The teacher’s awareness of the importance of dialogue in the classroom combined with a greater depth of subject focus, lead to learning opportunities for students that are of benefit for both language and science skills