Cause specific mortality, social position, and obesity among women who had never smoked: 28 year cohort study

Health behavior interventions among people with lower socio-economic position: a scoping review of behavior change techniques and effectiveness

Background

Behavior change interventions can unintendedly widen existing socio-economic health inequalities. Understanding why interventions are (in)effective among people with lower socio-economic position (SEP) is essential. Therefore, this scoping review aims to describe what is reported about the behavior change techniques (BCTs) applied within interventions and their effectiveness in encouraging physical activity and healthy eating, and reducing smoking and alcohol consumption according to SEP.

Methods

A systematic search was conducted in 12 electronic databases, and 151 studies meeting the eligibility criteria were included and coded for health behavioral outcomes, SEP-operationalization, BCTs (type and number) and effectiveness.

Results

Findings suggest that approaches for measuring, defining and substantiating lower SEP vary. Current studies of behavior change interventions for people of different SEP do not systematically identify BCTs, making systematic evaluation of BCT effectiveness impossible. The effectiveness of interventions is mainly evaluated by overall intervention outcomes and SEP-moderation effects are mostly not assessed.

Conclusion

Using different SEP-operationalizations and not specifying BCTs hampers systematic evidence accumulation regarding effective (combinations of) BCTs for the low SEP population. To learn which BCTs effectively improve health behaviors among people with lower SEP, future intervention developers should justify how SEP is operationalized and must systematically describe and examine BCTs.

Dietary xenobiotics, (poly)phenols and fibers: Exploring associations with gut microbiota in socially vulnerable individuals

Objectives

Although xenobiotics derived from food processing may cause modifications in the composition of the gut microbiota (GM) evidence is scarce. The aim of this study is to evaluate the impact of potential dietary carcinogens as heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), nitrates, nitrites, nitroso compounds and acrylamide, in combination to fibers (poly)phenols on the GM composition in a group of materially deprived subjects.

Study design

Transversal observational study in a sample of 19 subjects recipients of Red Cross food aid. Dietary information was recorded by means of 3 non-consecutive 24 h recalls. Questions focused on the type of cooking and the extent of cooking and roasting were included. Information on potential carcinogens was mainly obtained from the European Prospective Investigation into Cancer and Nutrition (EPIC) and Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) Carcinogen Databases. Microbial composition was determined by 16S ribosomal RNA gene sequencing in fecal samples.

Results

Higher levels of Lachnospiraceae and Eggerthellaceae families were found in individuals consuming less than 50 ng/day of 2-amino-3,8 dimethylimidazo (4,5,f) quinoxaline (MeIQx) (considered as lower risk dose for colorectal adenoma) while those consuming more than 40 ng/day of 2-amino-1-methyl-6-phenylimidazo (4,5,b) pyridine (PhIP) (higher risk for colorectal adenoma) showed lower relative abundance of Muribaculaceae and greater presence of Streptococcaceae and Eubacterium coprostanoligenes group.

Conclusion

The associations identified between diet and processing by-products on GM in this study could be used as potential targets for the designing of dietary interventions tailored to this collective.

Obesity is a chronic disease. Positioning statement of the Diabetes, Obesity and Nutrition Workgroup of the Spanish Society of Internal Medicine (SEMI) for an approach centred on individuals with obesity

BACKGROUND

Obesity is a chronic, complex and multifactorial metabolic disease involved in the development of chronic noncommunicable diseases such as type 2 diabetes mellitus, cardiovascular disease and cancer. The care of individuals with obesity is an essential part of the holistic approach provided by internal medicine to patients.

MATERIAL AND METHODS

Between September 2019 and January 2020, we distributed an online survey to the members of the Spanish Society of Internal Medicine. We prepared a Strengths, Weaknesses, Opportunities, and Threats analysis using the responses and, using the nominal group technique, developed the recommendations.

RESULTS

We obtained 599 responses. The respondents mean age was 44.4 ± 11 years, and 52.1% were women. Some 91.8% of the internists evaluate their patients to rule out the comorbidities associated with obesity, mainly type 2 diabetes mellitus (96.2%), cardiovascular disease (88.9%) and obesity-associated hypoventilation syndrome (73%), among others. Some 79.9% provided indications on lifestyle changes. Some 64.1% and 74.9% of the respondents knew the indications for the drugs and bariatric surgery, respectively. Some 93.8% and 83% of the respondents considered obesity and excess weight a chronic disease, and 88.7% considered it a disease of specific interest to internists, who should take an active and leading role in its treatment (85.3%).

CONCLUSIONS

The objective of the present document is to determine the degree of understanding and sensitivity of internists regarding the management of obesity and to develop a consensus of recommendations for the Spanish Society of Internal Medicine based on the scientific evidence and the opinion of its members.

The role of the Mediterranean diet on weight loss and obesity-related diseases

Pandemic obesity is a major public health problem because of its association with non-communicable diseases and all-cause mortality, which can be improved/delayed with weight loss. Thus, several scientific societies and governments have launched guidelines to reduce body weight and adiposity or, at least, to avoid weight gain. In spite of the abundant literature on the topic, there is still controversy on the relative roles of fat and carbohydrate in the diet on weight gain. Present recommendations to avoid weight gain and obesity are directed to reduce intake of total energy variably and of total fat to <30% of energy, in spite on the lack of evidence of protection against cardiovascular disease (CVD) and mortality. By contrast, both high and low carbohydrate diets are associated with CVD and all-cause mortality in prospective studies, with a safe intake level at ≈50% of energy. Many popular diets with widely different macronutrient composition, including the Mediterranean diet, have been used in obesity; when energy-restricted, all result in similar modest weight loss at 6 months, but the effects are largely lost at 12 months. The Mediterranean diet is a plant-based, high-fat, high-unsaturated fat dietary pattern that has been consistently associated with lower rates on non-communicable diseases and total mortality in prospective studies and with reduced CVD in the PREDIMED trial. For this merits above other diets, this dietary pattern might also be used advantageously for weight loss. The results of the PREDIMED and PREDIMED-Plus randomized controlled trials on adiposity variables in high-risk populations are discussed.

Obesity is a chronic disease. Positioning statement of the Diabetes, Obesity and Nutrition Workgroup of the Spanish Society of Internal Medicine (SEMI) for an approach centred on individuals with obesity

INTRODUCTION

Obesity is a chronic, complex and multifactorial metabolic disease involved in the development of chronic noncommunicable diseases such as type 2 diabetes mellitus, cardiovascular disease and cancer. The care of individuals with obesity is an essential part of the holistic approach provided by internal medicine to patients.

MATERIAL AND METHODS

Between September 2019 and January 2020, we distributed an online survey to the members of the Spanish Society of Internal Medicine. We prepared a Strengths, Weaknesses, Opportunities, and Threats analysis using the responses and, using the nominal group technique, developed the recommendations.

RESULTS

We obtained 599 responses. The respondents mean age was 44.4±11 years, and 52.1% were women. Some 91.8% of the internists evaluate their patients to rule out the comorbidities associated with obesity, mainly type 2 diabetes mellitus (96.2%), cardiovascular disease (88.9%) and obesity-associated hypoventilation syndrome (73%), among others. Some 79.9% provided indications on lifestyle changes. Some 64.1% and 74.9% of the respondents knew the indications for the drugs and bariatric surgery, respectively. Some 93.8% and 83% of the respondents considered obesity and excess weight a chronic disease, and 88.7% considered it a disease of specific interest to internists, who should take an active and leading role in its treatment (85.3%).

CONCLUSIONS

The objective of the present document is to determine the degree of understanding and sensitivity of internists regarding the management of obesity and to develop a consensus of recommendations for the Spanish Society of Internal Medicine based on the scientific evidence and the opinion of its members.

Association of BMI with overall and cause-specific mortality: a population-based cohort study of 3·6 million adults in the UK

BACKGROUND

BMI is known to be strongly associated with all-cause mortality, but few studies have been large enough to reliably examine associations between BMI and a comprehensive range of cause-specific mortality outcomes.

METHODS

In this population-based cohort study, we used UK primary care data from the Clinical Practice Research Datalink (CPRD) linked to national mortality registration data and fitted adjusted Cox regression models to examine associations between BMI and all-cause mortality, and between BMI and a comprehensive range of cause-specific mortality outcomes (recorded by International Classification of Diseases, 10th revision [ICD-10] codes). We included all individuals with BMI data collected at age 16 years and older and with subsequent follow-up time available. Follow-up began at whichever was the latest of: start of CPRD research-standard follow up, the 5-year anniversary of the first BMI record, or on Jan 1, 1998 (start date for death registration data); follow-up ended at death or on March 8, 2016. Fully adjusted models were stratified by sex and adjusted for baseline age, smoking, alcohol use, diabetes, index of multiple deprivation, and calendar period. Models were fitted in both never-smokers only and the full study population. We also did an extensive range of sensitivity analyses. The expected age of death for men and women aged 40 years at baseline, by BMI category, was estimated from a Poisson model including BMI, age, and sex.

FINDINGS

3 632 674 people were included in the full study population; the following results are from the analysis of never-smokers, which comprised 1 969 648 people and 188 057 deaths. BMI had a J-shaped association with overall mortality; the estimated hazard ratio per 5 kg/m2 increase in BMI was 0·81 (95% CI 0·80-0·82) below 25 kg/m2 and 1·21 (1·20-1·22) above this point. BMI was associated with all cause of death categories except for transport-related accidents, but the shape of the association varied. Most causes, including cancer, cardiovascular diseases, and respiratory diseases, had a J-shaped association with BMI, with lowest risk occurring in the range 21-25 kg/m2. For mental and behavioural, neurological, and accidental (non-transport-related) causes, BMI was inversely associated with mortality up to 24-27 kg/m2, with little association at higher BMIs; for deaths from self-harm or interpersonal violence, an inverse linear association was observed. Associations between BMI and mortality were stronger at younger ages than at older ages, and the BMI associated with lowest mortality risk was higher in older individuals than in younger individuals. Compared with individuals of healthy weight (BMI 18·5-24·9 kg/m2), life expectancy from age 40 years was 4·2 years shorter in obese (BMI ≥30·0 kg/m2) men and 3·5 years shorter in obese women, and 4·3 years shorter in underweight (BMI <18·5 kg/m2) men and 4·5 years shorter in underweight women. When smokers were included in analyses, results for most causes of death were broadly similar, although marginally stronger associations were seen among people with lower BMI, suggesting slight residual confounding by smoking.

INTERPRETATION

BMI had J-shaped associations with overall mortality and most specific causes of death; for mental and behavioural, neurological, and external causes, lower BMI was associated with increased mortality risk.

FUNDING

Wellcome Trust.

Interventions to Promote Healthy Eating, Physical Activity and Smoking in Low-Income Groups: a Systematic Review with Meta-Analysis of Behavior Change Techniques and Delivery/Context

PURPOSE

Healthy eating, physical activity and smoking interventions for low-income groups may have small, positive effects. Identifying effective intervention components could guide intervention development. This study investigated which content and delivery components of interventions were associated with increased healthy behavior in randomised controlled trials (RCTs) for low-income adults.

METHOD

Data from a review showing intervention effects in 35 RCTs containing 45 interventions with 17,000 participants were analysed to assess associations with behavior change techniques (BCTs) and delivery/context components from the template for intervention description and replication (TIDieR) checklist. The associations of 46 BCTs and 14 delivery/context components with behavior change (measures of healthy eating, physical activity and smoking cessation) were examined using random effects subgroup meta-analyses. Synergistic effects of components were examined using classification and regression trees (meta-CART) analyses based on both fixed and random effects assumptions.

RESULTS

For healthy eating, self-monitoring, delivery through personal contact, and targeting multiple behaviors were associated with increased effectiveness. Providing feedback, information about emotional consequences, or using prompts and cues were associated with reduced effectiveness. In synergistic analyses, interventions were most effective without feedback, or with self-monitoring excluding feedback. More effective physical activity interventions included behavioral practice/rehearsal or instruction, focussed solely on physical activity or took place in home/community settings. Information about antecedents was associated with reduced effectiveness. In synergistic analyses, interventions were most effective in home/community settings with instruction. No associations were identified for smoking.

CONCLUSION

This study identified BCTs and delivery/context components, individually and synergistically, linked to increased and reduced effectiveness of healthy eating and physical activity interventions. The identified components should be subject to further experimental study to help inform the development effective behavior change interventions for low-income groups to reduce health inequalities.

Socioeconomic status as an effect modifier of alcohol consumption and harm: analysis of linked cohort data

Background

Alcohol-related mortality and morbidity are high in socioeconomically disadvantaged populations compared with individuals from advantaged areas. It is unclear if this increased harm reflects differences in alcohol consumption between these socioeconomic groups, reverse causation (ie, downward social selection for high-risk drinkers), or a greater risk of harm in individuals of low socioeconomic status compared with those of higher status after similar consumption. We aimed to investigate whether the harmful effects of alcohol differ by socioeconomic status, accounting for alcohol consumption and other health-related factors.

Methods

The Scottish Health Surveys are record-linked cross-sectional surveys representative of the adult population of Scotland. We obtained baseline demographics and data for alcohol consumption (units per week and binge drinking) from Scottish Health Surveys done in 1995, 1998, 2003, 2008, 2009, 2010, 2011, and 2012. We matched these data to records for deaths, admissions, and prescriptions. The primary outcome was alcohol-attributable admission or death. The relation between alcohol-attributable harm and socioeconomic status was investigated for four measures (education level, social class, household income, and area-based deprivation) using Cox proportional hazards models. The potential for alcohol consumption and other risk factors (including smoking and body-mass index [BMI]) mediating social patterning was explored in separate regression models. Reverse causation was tested by comparing change in area deprivation over time.

Findings

50 236 participants (21 777 men and 28 459 women) were included in the analytical sample, with 429 986 person-years of follow-up. Low socioeconomic status was associated consistently with strikingly raised alcohol-attributable harms, including after adjustment for weekly consumption, binge drinking, BMI, and smoking. Evidence was noted of effect modification; for example, relative to light drinkers living in advantaged areas, the risk of alcohol-attributable admission or death for excessive drinkers was increased (hazard ratio 6·12, 95% CI 4·45–8·41 in advantaged areas; and 10·22, 7·73–13·53 in deprived areas). We found little support for reverse causation.

Interpretation

Disadvantaged social groups have greater alcohol-attributable harms compared with individuals from advantaged areas for given levels of alcohol consumption, even after accounting for different drinking patterns, obesity, and smoking status at the individual level.

Funding

Medical Research Council, NHS Research Scotland, Scottish Government Chief Scientist Office.

BMI and all cause mortality: systematic review and non-linear dose-response meta-analysis of 230 cohort studies with 3.74 million deaths among 30.3 million participants

OBJECTIVE

To conduct a systematic review and meta-analysis of cohort studies of body mass index (BMI) and the risk of all cause mortality, and to clarify the shape and the nadir of the dose-response curve, and the influence on the results of confounding from smoking, weight loss associated with disease, and preclinical disease.

DATA SOURCES

PubMed and Embase databases searched up to 23 September 2015.

STUDY SELECTION

Cohort studies that reported adjusted risk estimates for at least three categories of BMI in relation to all cause mortality.

DATA SYNTHESIS

Summary relative risks were calculated with random effects models. Non-linear associations were explored with fractional polynomial models.

RESULTS

230 cohort studies (207 publications) were included. The analysis of never smokers included 53 cohort studies (44 risk estimates) with >738 144 deaths and >9 976 077 participants. The analysis of all participants included 228 cohort studies (198 risk estimates) with >3 744 722 deaths among 30 233 329 participants. The summary relative risk for a 5 unit increment in BMI was 1.18 (95% confidence interval 1.15 to 1.21; I(2)=95%, n=44) among never smokers, 1.21 (1.18 to 1.25; I(2)=93%, n=25) among healthy never smokers, 1.27 (1.21 to 1.33; I(2)=89%, n=11) among healthy never smokers with exclusion of early follow-up, and 1.05 (1.04 to 1.07; I(2)=97%, n=198) among all participants. There was a J shaped dose-response relation in never smokers (Pnon-linearity <0.001), and the lowest risk was observed at BMI 23-24 in never smokers, 22-23 in healthy never smokers, and 20-22 in studies of never smokers with ≥20 years' follow-up. In contrast there was a U shaped association between BMI and mortality in analyses with a greater potential for bias including all participants, current, former, or ever smokers, and in studies with a short duration of follow-up (<5 years or <10 years), or with moderate study quality scores.

CONCLUSION

Overweight and obesity is associated with increased risk of all cause mortality and the nadir of the curve was observed at BMI 23-24 among never smokers, 22-23 among healthy never smokers, and 20-22 with longer durations of follow-up. The increased risk of mortality observed in underweight people could at least partly be caused by residual confounding from prediagnostic disease. Lack of exclusion of ever smokers, people with prevalent and preclinical disease, and early follow-up could bias the results towards a more U shaped association.

Increase in socioeconomic inequalities in mortality in a Southern European region: a small-area ecological study

BACKGROUND

This study sought to describe the total mortality trend by socioeconomic deprivation (SED) in the Madrid Autonomous Region, by sex and age group.

METHODS

Cross-sectional ecological study by census tract, in two periods: 1994-2000 (P1) with SED of 1996 census and 2001-07 (P2) with SED of 2001 census. We calculated the relative risks (RRs) and their 95% credibility intervals (95% CIs) by SED quintile (Q), taking the quintile of least deprivation as reference. Besag-York-Mollié ecological regression models and the Integrated Nested Laplace Approximation procedure were applied. The absolute differences in age-standardized rates were compared by SED quintile.

RESULTS

Inequalities decreased in young adults: among men aged 20-39 years, the RR in Q5 versus Q1 ranged from 2.73 (95% CI, 2.51-3.02) in P1 to 1.93 (95% CI, 1.76-2.15) in P2, due to the greater improvement in the most underprivileged groups. In contrast, there was an increase in SED-related mortality in the 40-79 age group. Among men aged 40-59 years, the RR in Q5 versus Q1 rose from 1.88 (95% CI, 1.76-2.02) in P1 to 2.29 (95% CI, 2.17-2.43) in P2; the improvement was greater in the most privileged groups.

CONCLUSION

In a context of an economic boom, inequalities were observed to increase among adults by a greater improvement in the most privileged groups.

After 50 years and 200 papers, what can the Midspan cohort studies tell us about our mortality?

OBJECTIVE

To distil the main findings from published papers on mortality in three cohorts involving over 27,000 adults, recruited in Scotland between 1965 and 1976 and followed up ever since.

METHOD

We read and summarized 48 peer-reviewed papers about all-cause and cause-specific mortality in these cohorts, published between 1978 and 2013.

RESULTS

Mortality rates were substantially higher among cigarette smokers in all social classes and both genders. Exposure to second-hand smoke was also damaging. Exposure to higher levels of black smoke pollution was associated with higher mortality. After smoking, diminished lung function was the risk factor most strongly related to higher mortality, even among never-smokers. On average, female mortality rates were much lower than male but the same risk factors were predictors of mortality. Mortality rates were highest among men whose paternal, own first and most recent jobs were manual. Specific causes of death were associated with different life stages. Upward and downward social mobility conferred intermediate mortality rates. Low childhood cognitive ability was strongly associated with low social class in adulthood and higher mortality before age 65 years. There was no evidence that daily stress contributed to higher mortality among people in lower social positions. Men in manual occupations with fathers in manual occupations, who smoked and drank >14 units of alcohol a week had cardiovascular disease mortality rates 4.5 times higher than non-manual men with non-manual fathers, who neither smoked nor drank >14 units. Men who were obese and drank >14 units of alcohol per day had a mortality rate due to liver disease 19 times that of normal or underweight non-drinkers. Among women who never smoked, mortality rates were highest in severely obese women in the lowest occupational classes.

CONCLUSION

These studies highlight the cumulative effect of adverse exposures throughout life, the complex interplay between social circumstances, culture and individual capabilities, and the damaging effects of smoking, air pollution, alcohol and obesity.

Are interventions for low-income groups effective in changing healthy eating, physical activity and smoking behaviours? A systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis examining the effectiveness of behavioural interventions targeting diet, physical activity or smoking in low-income adults.

DESIGN

Systematic review with random effects meta-analyses. Studies before 2006 were identified from a previously published systematic review (searching 1995-2006) with similar but broader inclusion criteria (including non-randomised controlled trials (RCTs)). Studies from 2006 to 2014 were identified from eight electronic databases using a similar search strategy.

DATA SOURCES

MEDLINE, EMBASE, PsycINFO, ASSIA, CINAHL, Cochrane Controlled Trials, Cochrane Systematic Review and DARE.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

RCTs and cluster RCTs published from 1995 to 2014; interventions targeting dietary, physical activity and smoking; low-income adults; reporting of behavioural outcomes.

MAIN OUTCOME MEASURES

Dietary, physical activity and smoking cessation behaviours.

RESULTS

35 studies containing 45 interventions with 17,000 participants met inclusion criteria. At postintervention, effects were positive but small for diet (standardised mean difference (SMD) 0.22, 95% CI 0.14 to 0.29), physical activity (SMD 0.21, 95% CI 0.06 to 0.36) and smoking (relative risk (RR) of 1.59, 95% CI 1.34 to 1.89). Studies reporting follow-up results suggested that effects were maintained over time for diet (SMD 0.16, 95% CI 0.08 to 0.25) but not physical activity (SMD 0.17, 95% CI -0.02 to 0.37) or smoking (RR 1.11, 95% CI 0.93 to 1.34).

CONCLUSIONS

Behaviour change interventions for low-income groups had small positive effects on healthy eating, physical activity and smoking. Further work is needed to improve the effectiveness of behaviour change interventions for deprived populations.

Variations in the relation between education and cause-specific mortality in 19 European populations: a test of the "fundamental causes" theory of social inequalities in health

Link and Phelan have proposed to explain the persistence of health inequalities from the fact that socioeconomic status is a "fundamental cause" which embodies an array of resources that can be used to avoid disease risks no matter what mechanisms are relevant at any given time. To test this theory we compared the magnitude of inequalities in mortality between more and less preventable causes of death in 19 European populations, and assessed whether inequalities in mortality from preventable causes are larger in countries with larger resource inequalities. We collected and harmonized mortality data by educational level on 19 national and regional populations from 16 European countries in the first decade of the 21st century. We calculated age-adjusted Relative Risks of mortality among men and women aged 30-79 for 24 causes of death, which were classified into four groups: amenable to behavior change, amenable to medical intervention, amenable to injury prevention, and non-preventable. Although an overwhelming majority of Relative Risks indicate higher mortality risks among the lower educated, the strength of the education-mortality relation is highly variable between causes of death and populations. Inequalities in mortality are generally larger for causes amenable to behavior change, medical intervention and injury prevention than for non-preventable causes. The contrast between preventable and non-preventable causes is large for causes amenable to behavior change, but absent for causes amenable to injury prevention among women. The contrast between preventable and non-preventable causes is larger in Central & Eastern Europe, where resource inequalities are substantial, than in the Nordic countries and continental Europe, where resource inequalities are relatively small, but they are absent or small in Southern Europe, where resource inequalities are also large. In conclusion, our results provide some further support for the theory of "fundamental causes". However, the absence of larger inequalities for preventable causes in Southern Europe and for injury mortality among women indicate that further empirical and theoretical analysis is necessary to understand when and why the additional resources that a higher socioeconomic status provides, do and do not protect against prevailing health risks.

The mediating role of dietary factors and leisure time physical activity on socioeconomic inequalities in body mass index among Australian adults

BACKGROUND

The relationship between socioeconomic position and obesity has been clearly established, however, the extent to which specific behavioural factors mediate this relationship is less clear. This study aimed to ascertain the contribution of specific dietary elements and leisure-time physical activity (LTPA) to variations in obesity with education in the baseline (1990-1994) Melbourne Collaborative Cohort Study (MCCS).

METHODS

18, 489 women and 12, 141 men were included in this cross-sectional analysis. A series of linear regression models were used in accordance with the products of coefficients method to examine the mediating role of alcohol, soft drink (regular and diet), snacks (healthy and sweet), savoury items (healthy and unhealthy), meeting fruit and vegetable guidelines and LTPA on the relationship between education and body mass index (BMI).

RESULTS

Compared to those with lowest educational attainment, those with the highest educational attainment had a 1 kg/m2 lower BMI. Among men and women, 27% and 48%, respectively, of this disparity was attributable to differences in LTPA and diet. Unhealthy savoury item consumption and LTPA contributed most to the mediated effects for men and women. Alcohol and diet soft drink were additionally important mediators for women.

CONCLUSIONS

Diet and LTPA are potentially modifiable behavioural risk factors for the development of obesity that contribute substantially to inequalities in BMI. Our findings highlight the importance of specific behaviours which may be useful to the implementation of effective, targeted public policy to reduce socioeconomic inequalities in obesity.

What (or who) causes health inequalities: theories, evidence and implications?

Health inequalities are the unjust differences in health between groups of people occupying different positions in society. Since the Black Report of 1980 there has been considerable effort to understand what causes them, so as to be able to identify actions to reduce them. This paper revisits and updates the proposed theories, evaluates the evidence in light of subsequent epidemiological research, and underlines the political and policy ramifications. The Black Report suggested four theories (artefact, selection, behavioural/cultural and structural) as to the root causes of health inequalities and suggested that structural theory provided the best explanation. These theories have since been elaborated to include intelligence and meritocracy as part of selection theory. However, the epidemiological evidence relating to the proposed causal pathways does not support these newer elaborations. They may provide partial explanations or insights into the mechanisms between cause and effect, but structural theory remains the best explanation as to the fundamental causes of health inequalities. The paper draws out the vitally important political and policy implications of this assessment. Health inequalities cannot be expected to reduce substantially as a result of policy aimed at changing health behaviours, particularly in the face of wider public policy that militates against reducing underlying social inequalities. Furthermore, political rhetoric about the need for 'cultural change', without the required changes in the distribution of power, income, wealth, or in the regulatory frameworks in society, is likely to divert from necessary action.

Impact of smoking and smoking cessation on overweight and obesity: Scotland-wide, cross-sectional study on 40,036 participants

BACKGROUND

Weight control is cited by some people, especially adolescent girls, as a reason for commencing smoking or not quitting. The aim of this study was to explore the relationship between smoking behaviour and being overweight or obese, overall and by age and sex sub-groups.

METHODS

We used data from the six Scottish Health Surveys conducted to date (1995-2010) to undertake a population-based, cross-sectional study on 40,036 participants representative of the adult (≥16 years) Scottish population. Height and weight were measured by a trained interviewer, not self-reported.

RESULTS

24,459 (63.3%) participants were overweight (BMI ≥25 kg/m²) and 9,818 (25.4%) were obese (BMI ≥30 kg/m²). Overall, current smokers were less likely to be overweight than never smokers. However, those who had smoked for more than 20 years (adjusted OR 1.54, 95% CI 1.41-1.69, p < 0.001) and ex-smokers (adjusted OR 1.18, 95% CI 1.11-1.25, p < 0.001) were more likely to be overweight. There were significant interactions with age. Participants 16-24 years of age, were no more likely to be overweight if they were current (adjusted OR 1.01, 95% CI 0.84-1.20, p = 0.944) or ex (adjusted OR 0.88, 95% CI 0.67-1.14, p = 0.319) smokers. The same patterns pertained to obesity.

CONCLUSIONS

Whilst active smoking may be associated with reduced risk of being overweight among some older adults, there was no evidence to support the belief among young people that smoking protects them from weight gain. Making this point in educational campaigns targeted at young people may help to discourage them from starting to smoke.

Smoking-related disease risk, area deprivation and health behaviours

BACKGROUND

Smokers and ex-smokers are at risk of many chronic diseases. However, never smokers and never smokers exposed to environmental tobacco smoke (ETS) are also at risk. Additionally, smoking behaviours and their associated disease risk are socially patterned and positively associated with health inequalities. However, other lifestyle choices also contribute to health inequalities. We aim to assess the contribution of other lifestyle behaviours pertaining to alcohol, physical inactivity and weight to smoking-related disease risk across (i) the socioeconomic spectrum and (ii) smoking status.

METHODS

Smoking-related disease risk is modelled using probit analysis. The results are used to predict disease risk across the socioeconomic dimension and smoking status for a set of healthy and unhealthy behaviours using the administratively linked Scottish Health Surveys and Scottish Morbidity Records.

RESULTS

The results confirm the deprivation gradient in disease risk regardless of smoking status group. Imposition of healthy (unhealthy) lifestyle behaviours decreases (increases) the predicted risk across the deprivation distribution regardless of smoking status providing evidence of the multifaceted health behavioural determinants of disease risk across the deprivation distribution.

CONCLUSION

The results are of policy interest as they suggest that to reduce inequalities in smoking-related diseases, interventions reducing both smoking and other unhealthy behaviours are required.

Social inequalities and mortality in Europe--results from a large multi-national cohort

BACKGROUND

Socio-economic inequalities in mortality are observed at the country level in both North America and Europe. The purpose of this work is to investigate the contribution of specific risk factors to social inequalities in cause-specific mortality using a large multi-country cohort of Europeans.

METHODS

A total of 3,456,689 person/years follow-up of the European Prospective Investigation into Cancer and Nutrition (EPIC) was analysed. Educational level of subjects coming from 9 European countries was recorded as proxy for socio-economic status (SES). Cox proportional hazard model's with a step-wise inclusion of explanatory variables were used to explore the association between SES and mortality; a Relative Index of Inequality (RII) was calculated as measure of relative inequality.

RESULTS

Total mortality among men with the highest education level is reduced by 43% compared to men with the lowest (HR 0.57, 95% C.I. 0.52-0.61); among women by 29% (HR 0.71, 95% C.I. 0.64-0.78). The risk reduction was attenuated by 7% in men and 3% in women by the introduction of smoking and to a lesser extent (2% in men and 3% in women) by introducing body mass index and additional explanatory variables (alcohol consumption, leisure physical activity, fruit and vegetable intake) (3% in men and 5% in women). Social inequalities were highly statistically significant for all causes of death examined in men. In women, social inequalities were less strong, but statistically significant for all causes of death except for cancer-related mortality and injuries.

DISCUSSION

In this European study, substantial social inequalities in mortality among European men and women which cannot be fully explained away by accounting for known common risk factors for chronic diseases are reported.

Plant-derived polyphenols regulate expression of miRNA paralogs miR-103/107 and miR-122 and prevent diet-induced fatty liver disease in hyperlipidemic mice

BACKGROUND

MicroRNAs have the potential for clinical application. Probable modulation by plant-derived polyphenols might open preventive measures using simple dietary recommendations.

METHODS

We assessed the ability of continuous administration of high-dose polyphenols to modulate hepatic metabolism and microRNA expression in diet-induced fatty liver disease in commercially available hyperlipidemic mice using well-established and accepted procedures that included the development of new antibodies against modified quercetin.

RESULTS

Weight gain, liver steatosis, changes in the composition of liver tissue, and insulin resistance were all attenuated by the continuous administration of polyphenols. We also demonstrated that metabolites of polyphenols accumulate in immune cells and at the surface of hepatic lipid droplets indicating not only bioavailability but a direct likely action on liver cells. The addition of polyphenols also resulted in changes in the expression of miR-103, miR-107 and miR-122.

CONCLUSIONS

Polyphenols prevent fatty liver disease under these conditions. The differential expression of mRNAs and miRNAs was also associated with changes in lipid and glucose metabolism and with the activation of 5'-adenosine monophosphate-activated protein kinase, effects that are not necessarily connected. miRNAs function via different mechanisms and miRNA-mRNA interactions are difficult to ascertain with current knowledge. Further, cell models usually elicit contradictory results with those obtained in animal models.

GENERAL SIGNIFICANCE

Our data indicate that plant-derived polyphenols should be tested in humans as preventive rather than therapeutic agents in the regulation of hepatic fatty acid utilization. A multi-faceted mechanism of action is likely and the regulation of liver miRNA expression blaze new trails in further research.