Socio-economic differences in body mass index: the contribution of genetic factors

BACKGROUND

Higher mean body mass index (BMI) among lower socioeconomic position (SEP) groups is well established in Western societies, but the influence of genetic factors on these differences is not well characterized.

METHODS

We analyzed these associations using Finnish health surveys conducted between 1992 and 2017 (N = 33 523; 53% women) with information on measured weight and height, polygenic risk scores of BMI (PGS-BMI) and linked data from administrative registers to measure educational attainment, occupation-based social class and personal income.

RESULTS

In linear regressions, largest adjusted BMI differences were found between basic and tertiary educated men (1.4 kg/m2, 95% confidence interval [CI] 1.2; 1.6) and women (2.5 kg/m2, 95% CI 2.3; 2.8), and inverse BMI gradients were also found for social class and income. These SEP differences arose partly because mean PGS-BMI was higher and partly because PGS-BMI predicted BMI more strongly in lower SEP groups. The inverse SEP gradients of BMI were steeper in women than in men, but sex differences were not found in the genetic contributions to these differences.

CONCLUSIONS

Better understanding of the interplay between genes and environment provides insight into the mechanisms explaining SEP differences in BMI.

Hypertensive disorders of pregnancy and midlife maternal cognition in a prospective cohort study

Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of cardiovascular disorders, with recent evidence linking pre-eclampsia with vascular dementia. We examined associations of HDP with cognitive performance measured in midlife, in a prospective cohort study, the Avon Longitudinal Study of Parents and Children. Six cognitive function domains were measured 20 years after pregnancy at a mean age of 51 years. The cognition tests were repeated at clinics in the following two years. Cognitive function domains measured were immediate and delayed verbal episodic memory, working memory, processing speed, verbal intelligence, and verbal fluency. Exposures were pre-eclampsia, gestational hypertension (GH), and a combined category of any HDP, all compared to normotensive pregnancy. Of 3393 pregnancies included in the analysis, GH was experienced by 417 (12.3%) and pre-eclampsia by 57 (1.7%). GH was associated with lower verbal episodic memory, in the delayed logic memory test (-0.16 SDs; 95% CI -0.30, -0.03; p = .015) and there was weak evidence of an association with the immediate logic memory test (-0.13 SDs; -0.27, 0.001; p = .058). However, we did not see steeper declines by age for women with GH and there was no evidence of associations with other cognitive domains or for pre-eclampsia with any domains. Results were not substantially changed after controlling for midlife blood pressure. Our findings suggest that a history of GH is associated with slightly reduced episodic memory 20 years after pregnancy, but we found no evidence of a quicker age-related decline compared to women with normotensive pregnancies.

Integrating multiple lines of evidence to assess the effects of maternal BMI on pregnancy and perinatal outcomes

BACKGROUND

Higher maternal pre-pregnancy body mass index (BMI) is associated with adverse pregnancy and perinatal outcomes. However, whether these associations are causal remains unclear.

METHODS

We explored the relation of maternal pre-/early-pregnancy BMI with 20 pregnancy and perinatal outcomes by integrating evidence from three different approaches (i.e. multivariable regression, Mendelian randomisation, and paternal negative control analyses), including data from over 400,000 women.

RESULTS

All three analytical approaches supported associations of higher maternal BMI with lower odds of maternal anaemia, delivering a small-for-gestational-age baby and initiating breastfeeding, but higher odds of hypertensive disorders of pregnancy, gestational hypertension, preeclampsia, gestational diabetes, pre-labour membrane rupture, induction of labour, caesarean section, large-for-gestational age, high birthweight, low Apgar score at 1 min, and neonatal intensive care unit admission. For example, higher maternal BMI was associated with higher risk of gestational hypertension in multivariable regression (OR = 1.67; 95% CI = 1.63, 1.70 per standard unit in BMI) and Mendelian randomisation (OR = 1.59; 95% CI = 1.38, 1.83), which was not seen for paternal BMI (OR = 1.01; 95% CI = 0.98, 1.04). Findings did not support a relation between maternal BMI and perinatal depression. For other outcomes, evidence was inconclusive due to inconsistencies across the applied approaches or substantial imprecision in effect estimates from Mendelian randomisation.

CONCLUSIONS

Our findings support a causal role for maternal pre-/early-pregnancy BMI on 14 out of 20 adverse pregnancy and perinatal outcomes. Pre-conception interventions to support women maintaining a healthy BMI may reduce the burden of obstetric and neonatal complications.

FUNDING

Medical Research Council, British Heart Foundation, European Research Council, National Institutes of Health, National Institute for Health Research, Research Council of Norway, Wellcome Trust.

Early-life socioeconomic circumstances and the comorbidity of depression and overweight in adolescence and young adulthood: A prospective study

Depression and overweight both often emerge early in life and have been found to be associated, but few studies examine depression-overweight comorbidity and its social patterning early in the life course. Drawing on data from 4,948 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort from the UK (2,798 female, 2,150 male), we investigated how different aspects of early-life socioeconomic circumstances are associated with depression-overweight comorbidity from adolescence to young adulthood exploring any differences by age and sex. We estimated how parental education, social class and financial difficulties reported in pregnancy were associated with depression and overweight, and their comorbidity at approximately the ages 17 and 24 in males and females. The results from multinomial logistic regression models showed that all three socioeconomic markers were associated with depression-overweight comorbidity and results were similar across age. Lower parental education (relative risk ratio (RRR) and 95% confidence interval (CI) of low education v high education: 3.61 (2.30-5.67) in females and 1.54 (1.14-2.07) in males) and social class (class IV/V v class I: 5.67 (2.48-12.94) in females and 3.11 (0.70-13.91) in males) had strong associations with comorbidity at age 17 relative to having neither depression or overweight. Financial difficulties were also a risk factor in females, with less clear results in males. These findings highlight how early socioeconomic circumstances are linked with the accumulation of mental and physical health problems already in adolescence, which has implications for life-long health inequalities.

Association between perinatal mortality and morbidity and customised and non-customised birthweight centiles in Denmark, Finland, Norway, Wales, and England: comparative, population based, record linkage study

Objectives

To compare the risk of adverse perinatal outcomes according to infants who are born small for gestational age (SGA; <10th centile) or large for gestational age (LGA; >90th centile), as defined by birthweight centiles that are non-customised (ie, standardised by sex and gestational age only) and customised (by sex, gestational age, maternal weight, height, parity, and ethnic group).

Design

Comparative, population based, record linkage study with meta-analysis of results.

Setting

Denmark, Finland, Norway, Wales, and England (city of Bradford), 1986-2019.

Participants

2 129 782 infants born at term in birth registries.

Main outcome measures

Stillbirth, neonatal death, infant death, admission to neonatal intensive care unit, and low Apgar score (<7) at 5 minutes.

Results

Relative to those infants born average for gestational age (AGA), both SGA and LGA births were at increased risk of all five outcomes, but observed relative risks were similar irrespective of whether non-customised or customised charts were used. For example, for SGA versus AGA births, when non-customised and customised charts were used, relative risks pooled over countries were 3.60 (95% confidence interval 3.29 to 3.93) versus 3.58 (3.02 to 4.24) for stillbirth, 2.83 (2.18 to 3.67) versus 3.32 (2.05 to 5.36) for neonatal death, 2.82 (2.07 to 3.83) versus 3.17 (2.20 to 4.56) for infant death, 1.66 (1.49 to 1.86) versus 1.54 (1.30 to 1.81) for low Apgar score at 5 minutes, and (based on Bradford data only) 1.97 (1.74 to 2.22) versus 1.94 (1.70 to 2.21) for admission to the neonatal intensive care unit. The estimated sensitivity of combined SGA or LGA births to identify the three mortality outcomes ranged from 31% to 34% for non-customised charts and from 34% to 38% for customised charts, with a specificity of 82% and 80% with non-customised and customised charts, respectively.

Conclusions

These results suggest an increased risk of adverse perinatal outcomes of a similar magnitude among SGA or LGA term infants when customised and non-customised centiles are used. Use of customised charts for SGA/LGA births-over and above use of non-customised charts for SGA/LGA births-is unlikely to provide benefits in terms of identifying term births at risk of these outcomes.

Evaluating causal associations of chronotype with pregnancy and perinatal outcomes and its interactions with insomnia and sleep duration: a Mendelian randomization study

IMPORTANCE

Observational studies suggest that chronotype is associated with pregnancy and perinatal outcomes. Whether these associations are causal is unclear.

OBJECTIVE

To explore associations of a lifetime genetic predisposition to an evening preference chronotype with pregnancy and perinatal outcomes, and explore differences in associations of insomnia and sleep duration with those outcomes between chronotype.

DESIGN SETTING AND PARTICIPANTS

We conducted two-sample Mendelian randomization (MR) using 105 genetic variants reported in a genome-wide association study (N=248 100) to instrument for lifelong predisposition to evening-versus morning-preference chronotypes. We generated variant-outcome associations in European ancestry women from UK Biobank (UKB, N=176 897), Avon Longitudinal Study of Parents and Children (ALSPAC, N=6826), Born in Bradford (BiB, N=2940) and Norwegian Mother, Father and Child Cohort Study (MoBa, with linked data from the Medical Birth Registry of Norway (MBRN), N=57 430), and extracted equivalent associations from FinnGen (N=190 879). We used inverse variance weighted (IVW) as main analysis, with weighted median and MR-Egger as sensitivity analyses. We also conducted IVW analyses of insomnia and sleep duration on the outcomes stratified by genetically predicted chronotype.

EXPOSURES

Self-reported and genetically predicted chronotype, insomnia and sleep duration.

MAIN OUTCOMES AND MEASURES

Stillbirth, miscarriage, preterm birth, gestational diabetes, hypertensive disorders of pregnancy, perinatal depression, low birthweight and macrosomia.

RESULTS

In IVW and sensitivity analyses we did not find robust evidence of effects of chronotype on the outcomes. Insomnia was associated with a higher risk of preterm birth among evening preference women (odds ratio 1.61, 95% confidence interval: 1.17, 2.21), but not among morning preference women (odds ratio 0.87, 95% confidence interval: 0.64, 1.18), with an interaction P-value=0.01. There was no evidence of interactions between insomnia and chronotype on other outcomes, or between sleep duration and chronotype on any outcomes.

CONCLUSIONS AND RELEVANCE

This study raises the possibility of a higher risk of preterm birth among women with insomnia who also have an evening preference chronotype. Our findings warrant replications due to imprecision of the estimates.

Key points

Question: Does an evening preference chronotype adversely affect pregnancy and perinatal outcomes? Is there an interaction between chronotype and either insomnia or sleep duration in relation to those outcomes?Findings: There was no evidence that evening preference was associated with pregnancy or perinatal outcomes. Women with a genetically predicted insomnia had a higher risk of preterm birth, if they also had a genetically predicted preference for evening chronotype.Meaning: The suggestive interaction between insomnia and evening preference on preterm birth, if replicated, supports targeting insomnia prevention in women of reproductive age with an evening chronotype.

Changes in women's physical function in mid-life by reproductive age and hormones: a longitudinal study

BACKGROUND

Whether women's physical function in mid-life is related to their reproductive age is not known. The objectives of this study were to examine and compare changes in physical function in women by reproductive age, measured as time since final menstrual period (FMP), and chronological age, and to explore associations with repeatedly assessed levels of reproductive hormones.

METHODS

We used data from 2319 UK women with up to three repeated measurements of physical function (median length of follow up: 2 years), focusing on changes occurring in women experiencing a natural menopausal transition. The main outcome was a composite physical function score that incorporated assessments of strength (grip strength), balance (one-leg stand) and cardiorespiratory fitness (timed chair rises). Associations with time since FMP, age, and time-updated measures of anti-Müllerian hormone, follicle-stimulating hormone and luteinizing hormone were assessed by multilevel models and generalised estimating equations models adjusted for the underlying effects of chronological age and confounding by education, age at first birth and smoking.

RESULTS

The results showed that, adjusted for these confounders, time since FMP (- 0.21 SD per 10 years, 95% CI - 0.37, - 0.06) and chronological age (- 0.31 SD per 10 years, 95% CI - 0.46, - 0.15) were inversely associated with the physical function composite score. Grip strength seemed to be the main contributor to the decline in the composite score by time since FMP. There was no strong evidence of associations between any of the three reproductive hormones and the composite score.

CONCLUSIONS

Physical function in women in mid-life declined with both chronological and reproductive age. The decline with reproductive age was independent of chronological age but did not seem to be driven by changes in reproductive hormones.

Investigating causal relations between sleep duration and risks of adverse pregnancy and perinatal outcomes: linear and nonlinear Mendelian randomization analyses

BACKGROUND

Observational studies have reported maternal short/long sleep duration to be associated with adverse pregnancy and perinatal outcomes. However, it remains unclear whether there are nonlinear causal effects. Our aim was to use Mendelian randomization (MR) and multivariable regression to examine nonlinear effects of sleep duration on stillbirth (MR only), miscarriage (MR only), gestational diabetes, hypertensive disorders of pregnancy, perinatal depression, preterm birth and low/high offspring birthweight.

METHODS

We used data from European women in UK Biobank (N=176,897), FinnGen (N=~123,579), Avon Longitudinal Study of Parents and Children (N=6826), Born in Bradford (N=2940) and Norwegian Mother, Father and Child Cohort Study (MoBa, N=14,584). We used 78 previously identified genetic variants as instruments for sleep duration and investigated its effects using two-sample, and one-sample nonlinear (UK Biobank only), MR. We compared MR findings with multivariable regression in MoBa (N=76,669), where maternal sleep duration was measured at 30 weeks.

RESULTS

In UK Biobank, MR provided evidence of nonlinear effects of sleep duration on stillbirth, perinatal depression and low offspring birthweight. Shorter and longer duration increased stillbirth and low offspring birthweight; shorter duration increased perinatal depression. For example, longer sleep duration was related to lower risk of low offspring birthweight (odds ratio 0.79 per 1 h/day (95% confidence interval: 0.67, 0.93)) in the shortest duration group and higher risk (odds ratio 1.40 (95% confidence interval: 1.06, 1.84)) in the longest duration group, suggesting shorter and longer duration increased the risk. These were supported by the lack of evidence of a linear effect of sleep duration on any outcome using two-sample MR. In multivariable regression, risks of all outcomes were higher in the women reporting <5 and ≥10 h/day sleep compared with the reference category of 8-9 h/day, despite some wide confidence intervals. Nonlinear models fitted the data better than linear models for most outcomes (likelihood ratio P-value=0.02 to 3.2×10-52), except for gestational diabetes.

CONCLUSIONS

Our results show shorter and longer sleep duration potentially causing higher risks of stillbirth, perinatal depression and low offspring birthweight. Larger studies with more cases are needed to detect potential nonlinear effects on hypertensive disorders of pregnancy, preterm birth and high offspring birthweight.

Associations between insomnia and pregnancy and perinatal outcomes: Evidence from mendelian randomization and multivariable regression analyses

BACKGROUND

Insomnia is common and associated with adverse pregnancy and perinatal outcomes in observational studies. However, those associations could be vulnerable to residual confounding or reverse causality. Our aim was to estimate the association of insomnia with stillbirth, miscarriage, gestational diabetes (GD), hypertensive disorders of pregnancy (HDP), perinatal depression, preterm birth (PTB), and low/high offspring birthweight (LBW/HBW).

METHODS AND FINDINGS

We used 2-sample mendelian randomization (MR) with 81 single-nucleotide polymorphisms (SNPs) instrumenting for a lifelong predisposition to insomnia. Our outcomes included ever experiencing stillbirth, ever experiencing miscarriage, GD, HDP, perinatal depression, PTB (gestational age <37 completed weeks), LBW (<2,500 grams), and HBW (>4,500 grams). We used data from women of European descent (N = 356,069, mean ages at delivery 25.5 to 30.0 years) from UK Biobank (UKB), FinnGen, Avon Longitudinal Study of Parents and Children (ALSPAC), Born in Bradford (BiB), and the Norwegian Mother, Father and Child Cohort (MoBa). Main MR analyses used inverse variance weighting (IVW), with weighted median and MR-Egger as sensitivity analyses. We compared MR estimates with multivariable regression of insomnia in pregnancy on outcomes in ALSPAC (N = 11,745). IVW showed evidence of an association of genetic susceptibility to insomnia with miscarriage (odds ratio (OR): 1.60, 95% confidence interval (CI): 1.18, 2.17, p = 0.002), perinatal depression (OR 3.56, 95% CI: 1.49, 8.54, p = 0.004), and LBW (OR 3.17, 95% CI: 1.69, 5.96, p < 0.001). IVW results did not support associations of insomnia with stillbirth, GD, HDP, PTB, and HBW, with wide CIs including the null. Associations of genetic susceptibility to insomnia with miscarriage, perinatal depression, and LBW were not observed in weighted median or MR-Egger analyses. Results from these sensitivity analyses were directionally consistent with IVW results for all outcomes, with the exception of GD, perinatal depression, and PTB in MR-Egger. Multivariable regression showed associations of insomnia at 18 weeks of gestation with perinatal depression (OR 2.96, 95% CI: 2.42, 3.63, p < 0.001), but not with LBW (OR 0.92, 95% CI: 0.69, 1.24, p = 0.60). Multivariable regression with miscarriage and stillbirth was not possible due to small numbers in index pregnancies. Key limitations are potential horizontal pleiotropy (particularly for perinatal depression) and low statistical power in MR, and residual confounding in multivariable regression.

CONCLUSIONS

In this study, we observed some evidence in support of a possible causal relationship between genetically predicted insomnia and miscarriage, perinatal depression, and LBW. Our study also found observational evidence in support of an association between insomnia in pregnancy and perinatal depression, with no clear multivariable evidence of an association with LBW. Our findings highlight the importance of healthy sleep in women of reproductive age, though replication in larger studies, including with genetic instruments specific to insomnia in pregnancy are important.

Cardiovascular health in the menopause transition: a longitudinal study of up to 3892 women with up to four repeated measures of risk factors

BACKGROUND

Women experience adverse changes in cardiovascular health in mid-life; whether the menopausal transition influences these remains strongly debated. The aim of this study was to examine associations of reproductive age (time since final menstrual period (FMP)) with change in carotid intima media thickness (CIMT) and cardiovascular risk factors and determine the role of chronological and reproductive age.

METHODS

We used data from 1702 women from a pregnancy-based UK cohort who had up to four repeat cardiovascular health measures between mean age 51 (SD = 4.0) and 56 (SD = 3.6) years and experienced a natural menopause. Multilevel models were used to assess the relationship between cardiovascular measures and time since FMP (reproductive age), whilst adjusting for the underlying effects of chronological age and confounders (socioeconomic factors, body mass index, smoking, alcohol, parity, age at menarche). In addition, we looked at the relationship between cardiovascular measures by chronological age according to menopausal stages (pre-menopause, peri-menopause and post-menopause) using information from women who had and had not experienced menopause (N = 3892).

RESULTS

There was no strong evidence that reproductive age was associated with CIMT (difference in mean 0.8 μm/year, 95% CI - 0.4, 2.1), whereas there was a strong positive association of chronological age (7.6 μm/year, 95% CI 6.3, 8.9). Consistent with this, we found weaker linear associations of reproductive compared with chronological age for atherosclerotic risk factors, such as with systolic blood pressure (- 0.1 mmHg/year, 95% CI - 0.3, 0.1, and 0.4 mmHg/year, 95% CI 0.2, 0.5, respectively) and non-HDL-cholesterol (0.02 mmol/l/year, 95% CI 0.005, 0.03, and 0.06, 95% CI 0.04, 0.07, respectively). In contrast, associations with fat mass (0.06 kg/m2/year, 95% CI 0.03, 0.10, and 0 kg/m2/year, 95% CI - 0.04, 0.04, respectively) and C-reactive protein (0.01, 95% CI 0.001, 0.02, and 0.01, 95% CI - 0.001, 0.02 natural logged mg/l/year, respectively) were stronger for reproductive compared with chronological age. Both reproductive and chronological age were (weakly) positively associated with glucose (0.002, 95% CI 0.0001, 0.003, and 0.002, 95% CI 0.0001, 0.003 natural logged mmol/l/year, respectively).

CONCLUSIONS

Our results suggest that going through the menopausal transition does not further increase women's risk of atherosclerosis (measured by CIMT) beyond effects of ageing. Menopausal transition may, in additional to ageing, modestly increase adiposity and glucose levels and therefore a possible associated diabetes risk.

Longitudinal changes in reproductive hormones through the menopause transition in the Avon Longitudinal Study of Parents and Children (ALSPAC)

We characterised changes in reproductive hormones-LH, FSH, SHBG and AMH-by chronological age and time around the menopause (reproductive age) in mid-life women and explored their associations with lifestyle and reproductive factors. We used data from 1608 women from a UK cohort who had repeat hormone measures and experienced a natural menopause. Multilevel models were used to assess: (i) changes in hormones (outcomes) by reproductive age and chronological age (these age variables being the key exposures) and (ii) associations of body mass index (BMI), smoking, alcohol intake, parity and age at menarche with changes in hormones by reproductive age. Both LH and FSH increased until ~ 5 and 7 years postmenopause, respectively, after which they declined, but not to premenopausal levels. SHBG decreased slightly until ~ 4 years postmenopause and increased thereafter. AMH decreased markedly before menopause and remained low subsequently. For all hormones, the best fitting models included both reproductive and chronological age. BMI, smoking and parity were associated with hormone changes; e.g., higher BMI was associated with slower increase in LH and FSH and decrease in AMH. Reproductive and chronological age contribute to changes in LH, FSH, SHBG and AMH across mid-life in women, and BMI, smoking and parity are associated with these hormone changes.

Changes in six domains of cognitive function with reproductive and chronological ageing and sex hormones: a longitudinal study in 2411 UK mid-life women

BACKGROUND

There may be changes in cognitive function in women going through the menopause. The current evidence remains unclear, however, whether these changes occur over and above those of general ageing. We aimed to evaluate the potential impact of the menopause (assessed by reproductive age and hormone levels) on cognitive function in women in mid-life accounting for the underlying effects of ageing.

METHODS

The study was based on the follow up of women originally enrolled in pregnancy in a birth cohort when resident in the South West of England, UK between 1991 and 1992. Using up to three repeated measurements in 2411 women (mean age 51 at first assessment), we modelled changes in six cognitive function domains: immediate and delayed verbal episodic memory, working memory, processing speed, verbal intelligence and verbal fluency. The exposures of interest were reproductive age measured as years relative to the final menstrual period (FMP), chronological age and reproductive hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH) and anti-Müllerian hormone (AMH)).

RESULTS

Processing speed (- 0.21 (95% CI - 0.36 to - 0.06) standard deviation (SD) difference per 10 years since FMP), immediate verbal episodic memory (- 0.15 (95% CI - 0.35 to 0.06)) and delayed verbal episodic memory (- 0.17 (95% CI - 0.37 to 0.03)) declined with reproductive age. Reproductive hormones were not robustly associated with processing speed, but FSH and LH were both negatively associated with immediate (- 0.08 (95% CI - 0.13 to - 0.02) SD difference per SD difference in hormone level) and delayed verbal episodic memory (- 0.08 (95% CI - 0.13 to - 0.03)). There was little consistent evidence of cognitive function declining with menopause in other cognitive domains.

CONCLUSIONS

Of the cognitive domains tested only verbal episodic memory declined both in relation to age since the menopause and in conjunction with the reproductive hormones that reflect the menopause. This decline was independent of normal ageing and suggests that the menopause is associated with a mild impact on this specific domain of cognitive function.

Partner resources and incidence and survival in two major causes of death

Because people tend to marry social equals - and possibly also because partners affect each other's health - the social position of one partner is associated with the other partner's health and mortality. Although this link is fairly well established, the underlying mechanisms are not fully identified. Analyzing disease incidence and survival separately may help us to assess when in the course of the disease a partner's resources are of most significance. This article addresses the importance of partner's education, income, employment status, and health for incidence and survival in two major causes of death: cancer and cardiovascular diseases (CVD). Based on a sample of Finnish middle-aged and older couples (around 200,000 individuals) we show that a partner's education is more often connected to incidence than to survival, in particular for CVD. Once ill, any direct effect of partner's education seems to decline: The survival chances after being hospitalized for cancer or CVD are rather associated with partner's employment status and/or income level when other individual and partner factors are adjusted for. In addition, a partner's history of poor health predicted higher CVD incidence and, for women, lower cancer survival. The findings suggest that various partner's characteristics may have different implications for disease and survival, respectively. A wider focus on social determinants of health at the household level, including partner's social resources, is needed.

The Spillover Influence of Partner's Education on Myocardial Infarction Incidence and Survival

BACKGROUND

Education is believed to have positive spillover effects across network connections. Partner's education may be an important resource preventing the incidence of disease and helping patients cope with illness. We examined how partner's education predicted myocardial infarction (MI) incidence and survival net of own education and other socioeconomic resources in Finland.

METHODS

A sample of adults aged 40-69 years at baseline in Finland in 1990 was followed up for MI incidence and mortality during the period 1991-2007 (n = 354,100).

RESULTS

Lower own and spousal education both contributed independently to a higher risk of MI incidence and fatality when mutually adjusted. Having a partner with basic education was particularly strongly associated with long-term fatality in women with a hazard ratio of 1.53 (95% confidence interval, 1.22-1.92) compared with women with tertiary level educated partners. There was some evidence that the incidence risk associated with basic spousal education was weaker in those with own basic education. The highest risks of MI incidence and fatality were consistently found in those without a partner, whereas the most favorable outcomes were in households where both partners had a tertiary level of education.

CONCLUSIONS

Accounting for spousal education demonstrates how health-enhancing resources accumulate to some households. Marriage between people of similar educational levels may therefore contribute to the widening of educational differences in MI incidence and survival.

Disentangling the relative importance of different socioeconomic resources for myocardial infarction incidence and survival: a longitudinal study of over 300,000 Finnish adults

BACKGROUND

Lower socioeconomic position (SEP) is associated with an increased risk of myocardial infarction (MI) incidence and mortality, but the relative importance of different socioeconomic resources at different stages of the disease remains unclear.

METHODS

A nationally representative register-based sample of 40- to 60-year-old Finnish men and women in 1995 (n= 302 885) were followed up for MI incidence and mortality in 1996-2007. We compared the effects of education, occupation, income and wealth on first MI incidence, first-day and long-term fatality. Cox's proportional hazards regression and logistic regression models were estimated adjusting for SEP covariates simultaneously to assess independent effects.

RESULTS

Fully adjusted models showed greatest relative inequalities of MI incidence by wealth in both sexes, with an increased risk also associated with manual occupations. Education was a significant predictor of incidence in men. Low income was associated with a greater risk of death on the day of MI incidence [odds ratio (OR) = 1.40 in men and 1.95 in women when comparing lowest and highest income quintiles], and in men, with long-term fatality [hazard ratio (HR) = 1.74]. Wealth contributed to inequalities in first-day fatality in men and in long-term fatality in both sexes.

CONCLUSION

The results show that different socioeconomic resources have diverse effects on the disease process and add new evidence on the significant association of wealth with heart disease onset and fatality. Targeting those with the least resources could improve survival in MI patients and help reduce social inequalities in coronary heart disease mortality.

Alarming predictions for obesity and non-communicable diseases in the Middle East

OBJECTIVE

The present study aimed to model obesity trends and future obesity-related disease for nine countries in the Middle East; in addition, to explore how hypothetical reductions in population obesity levels could ameliorate anticipated disease burdens.

DESIGN

A regression analysis of cross-sectional data v. BMI showed age- and sex-specific BMI trends, which fed into a micro simulation with a million Monte Carlo trials for each country. We also examined two alternative scenarios where population BMI was reduced by 1 % and 5 %.

SETTING

Statistical modelling of obesity trends was carried out in nine Middle East countries (Bahrain, Egypt, Iran, Jordan, Kuwait, Lebanon, Oman, Saudi Arabia and Turkey).

SUBJECTS

BMI data along with disease incidence, mortality and survival data from national and sub-national data sets were used for the modelling process.

RESULTS

High rates of overweight and obesity increased in both men and women in most countries. The burden of incident type 2 diabetes, CHD and stroke would be moderated with even small reductions in obesity levels.

CONCLUSIONS

Obesity is a growing problem in the Middle East which requires government action on the primary prevention of obesity. The present results are important for policy makers to know the effectiveness of obesity interventions on future disease burden.

Obesity prevalence in Mexico: impact on health and economic burden

OBJECTIVE

Along with other countries having high and low-to-middle income, Mexico has experienced a substantial change in obesity rates. This rapid growth in obesity prevalence has led to high rates of obesity-related diseases and associated health-care costs.

DESIGN

Micro-simulation is used to project future BMI trends. Additionally thirteen BMI-related diseases and health-care costs are estimated. The results are simulated for three hypothetical scenarios: no BMI reduction and BMI reductions of 1 % and 5 % across the population.

SETTING

Mexican Health and Nutrition Surveys 1999 and 2000, and Mexican National Health and Nutrition Survey 2006.

SUBJECTS

Mexican adults.

RESULTS

In 2010, 32 % of men and 26 % of women were normal weight. By 2050, the proportion of normal weight will decrease to 12 % and 9 % for males and females respectively, and more people will be obese than overweight. It is projected that by 2050 there will be 12 million cumulative incidence cases of diabetes and 8 million cumulative incidence cases of heart disease alone. For the thirteen diseases considered, costs of $US 806 million are estimated for 2010, projected to increase to $US 1·2 billion and $US 1·7 billion in 2030 and 2050 respectively. A 1 % reduction in BMI prevalence could save $US 43 million in health-care costs in 2030 and $US 85 million in 2050.

CONCLUSIONS

Obesity rates are leading to a large health and economic burden. The projected numbers are high and Mexico should implement strong action to tackle obesity. Results presented here will be very helpful in planning and implementing policy interventions.

Health and economic burden of obesity in Brazil

INTRODUCTION

Higher and lower-middle income countries are increasingly affected by obesity. Obesity-related diseases are placing a substantial health and economic burden on Brazil. Our aim is to measure the future consequences of these trends on the associated disease burden and health care costs.

METHOD

A previously developed micro-simulation model is used to project the extent of obesity, obesity-related diseases and associated healthcare costs to 2050. In total, thirteen diseases were considered: coronary heart disease, stroke, hypertension, diabetes, osteoarthritis, and eight cancers. We simulated three hypothetical intervention scenarios: no intervention, 1% and 5% reduction in body mass index (BMI).

RESULTS

In 2010, nearly 57% of the Brazilian male population was overweight or obese (BMI ≥25 kg/m(2)), but the model projects rates as high as 95% by 2050. A slightly less pessimistic picture is predicted for females, increasing from 43% in 2010 to 52% in 2050. Coronary heart disease, stroke, hypertension, cancers, osteoarthritis and diabetes prevalence cases are projected to at least double by 2050, reaching nearly 34,000 cases of hypertension by 2050 (per 100,000). 1% and 5% reduction in mean BMI will save over 800 prevalence cases and nearly 3,000 cases of hypertension by 2050 respectively (per 100,000). The health care costs will double from 2010 ($5.8 billion) in 2050 alone ($10.1 billion). Over 40 years costs will reach $330 billion. However, with effective interventions the costs can be reduced to $302 billion by 1% and to $273 billion by 5% reduction in mean BMI across the population.

CONCLUSION

Obesity rates are rapidly increasing creating a high burden of disease and associated costs. However, an effective intervention to decrease obesity by just 1% will substantially reduce obesity burden and will have a significant effect on health care expenditure.

High rates of obesity and non-communicable diseases predicted across Latin America

Non-communicable diseases (NCDs) such as cardiovascular disease and stroke are a major public health concern across Latin America. A key modifiable risk factor for NCDs is overweight and obesity highlighting the need for policy to reduce prevalence rates and ameliorate rising levels of NCDs. A cross-sectional regression analysis was used to project BMI and related disease trends to 2050. We tested the extent to which interventions that decrease body mass index (BMI) have an effect upon the number of incidence cases avoided for each disease. Without intervention obesity trends will continue to rise across much of Latin America. Effective interventions are necessary if rates of obesity and related diseases are to be reduced.

Modelling obesity trends and related diseases in Eastern Europe

Obesity has increased at an alarming rate across the world and, in turn, rates of non-communicable diseases have escalated. In Eastern Europe, this epidemic has probably occurred at a later stage than the West due to the economic transition following the demise of communism. Knowing how these trends will change is important. We used a micro-simulation model to project obesity trends and related incidence of coronary heart disease and stroke, cancer and type 2 diabetes 20 and 40 years into the future. Where nationally representative data were available, obesity levels were shown to increase with most prominent increases seen amongst men in Latvia and Estonia, and amongst women in Croatia and Latvia. The exception was Lithuania where a decrease in overweight and obesity was observed in both men and women. We showed that interventions effective in reducing obesity would have a significant impact upon the number of new cases of each disease. It is necessary to improve surveillance of obesity and disease incidence as well as implement policies that are effective in reducing body fat.