Danielle A. J. M. Schoenaker

Socioeconomic position, lifestyle factors and age at natural menopause: a systematic review and meta-analyses of studies across six continents

Background: Age at natural menopause (ANM) is considered a marker of biological ageing and is increasingly recognized as a sentinel for chronic disease risk in later life. Socioeconomic position (SEP) and lifestyle factors are thought to be associated with ANM. Methods: We performed a systematic review and meta-analyses to determine the overall mean ANM, and the effect of SEP and lifestyle factors on ANM by calculating the weighted mean difference (WMD) and pooling adjusted hazard ratios. We explored heterogeneity using meta-regression and also included unpublished findings from the Australian Longitudinal Study on Women’s Health. Results: We identified 46 studies across 24 countries. Mean ANM was 48.8 years [95% confidence interval (CI): 48.3, 49.2], with between-study heterogeneity partly explained by geographical region. ANM was lowest among African, Latin American, Asian and Middle Eastern countries and highest in Europe and Australia, followed by the USA. Education was associated with later ANM (WMD middle vs low education 0.30, 95% CI: 0.10, 0.51; high vs low education 0.64, 95% CI 0.26, 1.02). A similar dose-response relationship was also observed for occupation. Smoking was associated with a 1-year reduction of ANM (WMD: -0.91, 95% CI: –1.34, –0.48). Being overweight and moderate/high physical activity were modestly associated with later ANM, but findings were less conclusive. Conclusions: ANM varies across populations, partly due to differences across geographical regions. SEP and some lifestyle factors are associated with ANM, but further research is needed to examine the impact of the associations between risk factors and ANM on future health outcomes.

The Role of Energy, Nutrients, Foods, and Dietary Patterns in the Development of Gestational Diabetes Mellitus: A Systematic Review of Observational Studies

OBJECTIVE Diet may influence the risk of gestational diabetes mellitus (GDM), but inconsistent findings have been reported. The purpose of this study was to synthesize evidence from observational studies on the associations between dietary factors and GDM. RESEARCH DESIGN AND METHODS Medline and Embase were searched for articles published until January 2015. We included observational studies of reproductive-aged women that reported on associations of maternal dietary intake before or during pregnancy, including energy, nutrients, foods, and dietary patterns, with GDM. All relevant results were extracted from each article. The number of comparable studies that adjusted for confounders was insufficient to perform a meta-analysis. RESULTS The systematic review included 34 articles comprising 21 individual studies (10 prospective cohort, 6 cross-sectional, and 5 case-control). A limited number of prospective cohort studies adjusting for confounders indicated associations with a higher risk of GDM for replacing 1–5% of energy from carbohydrates with fat and for high consumption of cholesterol (≥300 mg/day), heme iron (≥1.1 mg/day), red and processed meat (increment of 1 serving/day), and eggs (≥7 per week). A dietary pattern rich in fruit, vegetables, whole grains, and fish and low in red and processed meat, refined grains, and high-fat dairy was found to be beneficial. The current evidence is based on a limited number of studies that are heterogeneous in design, exposure, and outcome measures. CONCLUSIONS The findings support current dietary guidelines to limit consumption of foods containing saturated fat and cholesterol, such as processed meat and eggs, as part of an overall balanced diet. Further large prospective studies are warranted.

The association between dietary factors and gestational hypertension and pre-eclampsia: a systematic review and meta-analysis of observational studies

BackgroundDietary factors have been suggested to play a role in the prevention of hypertensive disorders of pregnancy (HDP), including gestational hypertension and pre-eclampsia, but inconsistent findings have been reported. A systematic review and meta-analyses were performed to synthesize evidence from observational studies of reproductive-aged women on the association between dietary factors and HDP.MethodsMEDLINE and EMBASE were searched to identify studies published until the end of May 2014. Studies were included if they were observational studies of reproductive-age women and reported results on dietary factors (energy, nutrients, foods or overall dietary patterns, alone or in combination with dietary supplements) and gestational hypertension and/or pre-eclampsia. Studies were excluded if they reported on supplements not in combination with dietary intake, or examined a biomarker of dietary intake. Random effects meta-analyses were performed on calculated weighted mean differences (WMD) of dietary intake between cases and non-cases, and effect estimates were pooled.ResultsIn total, 23 cohort and 15 case-control studies were identified for systematic review, of which 16 could be included in the meta-analyses. Based on meta-analyses of cohort studies, unadjusted energy intake was higher for pre-eclampsia cases (WMD 46 kcal/day, 95% confidence interval (CI) -13.80 to 106.23; I2 = 23.9%, P = 0.26), although this was not statistically significant. Unadjusted intakes of magnesium (WMD 8 mg/day, 95% CI -13.99 to -1.38; I2 = 0.0%, P = 0.41) and calcium (WMD 44 mg/day, 95% CI -84.31 to -3.62, I2 = 51.1%, P = 0.03) were lower for the HDP cases, compared with pregnant women without HDP. Higher calcium intake consistently showed lower odds for HDP after adjustment for confounding factors (OR = 0.76, 95% CI 0.57 to 1.01, I2 = 0.0%, P = 0.79). A few studies examining foods and dietary patterns suggested a beneficial effect of a diet rich in fruit and vegetables on pre-eclampsia, although not all the results were statistically significant.ConclusionsBased on a limited number of studies, higher total energy and lower magnesium and calcium intake measured during pregnancy were identified as related to HDP. Further prospective studies are required to provide an evidence base for development of preventive health strategies, particularly focusing on dietary factors during pre-pregnancy and early pregnancy.Please see related article: http://www.biomedcentral.com/1741-7015/12/176/abstract.

Glycemic control and all-cause mortality risk in type 1 diabetes patients: the EURODIAB prospective complications study.

CONTEXT Glycemic targets and the benefit of intensive glucose control are currently under debate because intensive glycemic control has been suggested to have negative effects on mortality risk in type 2 diabetes patients. OBJECTIVE We examined the association between glycated hemoglobin (HbA1c) and all-cause mortality in patients with type 1 diabetes mellitus. DESIGN, SETTING, AND PATIENTS A clinic-based prospective cohort study was performed in 2764 European patients with type 1 diabetes aged 15-60 years enrolled in the EURODIAB Prospective Complications Study. OUTCOME MEASURE Possible nonlinearity of the association between HbA1c and all-cause mortality was examined using multivariable restricted cubic spline regression using three (at HbA1c 5.6%, 8.1%, and 11.8%) and five knots (additionally at HbA1c 7.1% and 9.5%). Mortality data were collected approximately 7 years after baseline examination. RESULTS HbA1c was related to all-cause mortality in a nonlinear manner after adjustment for age and sex. All-cause mortality risk was increased at both low (5.6%) and high (11.8%) HbA1c compared with the reference (median HbA1c: 8.1%) following a U-shaped association [P overall effect = .008 and .04, P nonlinearity = .03 and .11 (three and five knots, respectively)]. CONCLUSIONS Results from our study in type 1 diabetes patients suggest that target HbA1c below a certain threshold may not be appropriate in this population. We recognize that these low HbA1c levels may be related to anemia, renal insufficiency, infection, or other factors not available in our database. If our data are confirmed, the potential mechanisms underlying this increased mortality risk among those with low HbA1c will need further study.

Association between inflammatory potential of diet and risk of depression in middle-aged women: the Australian longitudinal study on women's health

Dietary factors and inflammation markers have been shown to play a role in the development of depression. However, there are very few studies that have explored the association between inflammatory potential of diet and risk of depression. In this study, we examined the association between the dietary inflammatory index (DII), which was developed specifically to measure the inflammatory potential of diet, and risk of depression in the middle-aged cohort of the Australian Longitudinal Study on Womens Health. A total of 6438 women with a mean age of 52·0 (sd 1·4) years at baseline were followed-up at five surveys over 12 years (2001-2013). Depression was defined as a score of ≥10 on the Center for Epidemiologic Studies Depression-10 scale. The DII score, a literature-derived, population-based dietary index that has been validated against several inflammatory markers, was computed on the basis of dietary intake assessed using a validated FFQ. Generalised estimating equations were used to estimate relative risk (RR) of depression according to DII score. Models were adjusted for energy intake, highest education completed, marital status, menopause status and symptoms, personal illness or injury, smoking status, physical activity, BMI and depression diagnosis or treatment. In total, 1156 women (18 %) had scores≥10 on the CESD scale over the course of 9 years. Women with the most anti-inflammatory diet had an approximately 20 % lower risk of developing depression compared with women with the most pro-inflammatory diet (RRDII quartile 1 v. 4: 0·81; 95 % CI 0·69, 0·96; P trend=0·03). These results suggest that an anti-inflammatory diet is associated with lower risk of depression in middle-aged Australian women.

InterLACE: A new International Collaboration for a Life Course Approach to Women's Reproductive Health and Chronic Disease Events

Evidence from population-based studies of women increasingly points to the inter-related nature of reproductive health, lifestyle, and chronic disease risk. This paper describes the recently established International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease. InterLACE aims to advance the evidence base for womens health policy beyond associations from disparate studies by means of systematic and culturally sensitive synthesis of longitudinal data. Currently InterLACE draws on individual level data for reproductive health and chronic disease among 200,000 women from over thirteen studies of womens health in seven countries. The rationale for this multi-study research programme is set out in terms of a life course perspective to reproductive health. The research programme will build a comprehensive picture of reproductive health through life in relation to chronic disease risk. Although combining multiple international studies poses methodological challenges, InterLACE represents an invaluable opportunity to strength evidence to guide the development of timely and tailored preventive health strategies.

Before the beginning: nutrition and lifestyle in the preconception period and its importance for future health

A woman who is healthy at the time of conception is more likely to have a successful pregnancy and a healthy child. We reviewed published evidence and present new data from low-income, middle-income, and high-income countries on the timing and importance of preconception health for subsequent maternal and child health. We describe the extent to which pregnancy is planned, and whether planning is linked to preconception health behaviours. Observational studies show strong links between health before pregnancy and maternal and child health outcomes, with consequences that can extend across generations, but awareness of these links is not widespread. Poor nutrition and obesity are rife among women of reproductive age, and differences between high-income and low-income countries have become less distinct, with typical diets falling far short of nutritional recommendations in both settings and especially among adolescents. Several studies show that micronutrient supplementation starting in pregnancy can correct important maternal nutrient deficiencies, but effects on child health outcomes are disappointing. Other interventions to improve diet during pregnancy have had little effect on maternal and newborn health outcomes. Comparatively few interventions have been made for preconception diet and lifestyle. Improvements in the measurement of pregnancy planning have quantified the degree of pregnancy planning and suggest that it is more common than previously recognised. Planning for pregnancy is associated with a mixed pattern of health behaviours before conception. We propose novel definitions of the preconception period relating to embryo development and actions at individual or population level. A sharper focus on intervention before conception is needed to improve maternal and child health and reduce the growing burden of non-communicable diseases. Alongside continued efforts to reduce smoking, alcohol consumption, and obesity in the population, we call for heightened awareness of preconception health, particularly regarding diet and nutrition. Importantly, health professionals should be alerted to ways of identifying women who are planning a pregnancy.

The relationship between the dietary inflammatory index and risk of total cardiovascular disease, ischemic heart disease and cerebrovascular disease: Findings from an Australian population-based prospective cohort study of women

BACKGROUND AND AIMS Recently, a pro-inflammatory diet based on a dietary inflammatory index (DII) has been related to higher CVD risk in general population, but this has not been investigated among women. METHODS We investigated the relationship between DII and risk of total CVD and CVD subgroups (myocardial infarction, ischemic heart disease, stroke and cerebrovascular disease) in a prospective cohort of 6972 Australian women aged 50-55 years at baseline in 2001. We used clinical and procedure information from inpatient hospital separation registries, information on use of health care services, and from the causes-of-death registry to ascertain CVD outcomes during 11-year follow up. The association between baseline DII score and cardiovascular endpoints was analysed through cox-regression, with correction for demographic and cardiovascular risk factors. RESULTS We identified 335 incident cases of CVD and 191 cases of ischaemic heart disease (including 69 myocardial infarctions) and 59 cases of cerebrovascular disease (including 40 cases of stroke). A statistically significant higher risk of myocardial infarction was observed in analyses using DII scores as a continuous variable with a hazard ratio of 1.46 (95% confidence interval 1.12-1.89), but this was attenuated by further adjustment for other known cardiovascular risk factors. No association was found for total CVD, ischaemic heart diseases, or cerebrovascular disease. CONCLUSIONS There was no statistically significant association between the dietary inflammatory index and risk of total cardiovascular disease, ischemic heart disease, myocardial infarction, cerebrovascular disease or stroke in this population of mid-aged Australian women. Associations were not different for postmenopausal women.

Factor Analysis Is More Appropriate to Identify Overall Dietary Patterns Associated with Diabetes When Compared with Treelet Transform Analysis

Treelet transform (TT) is a proposed alternative to factor analysis for deriving dietary patterns. Before applying this method to nutrition data, further analyses are required to assess its validity in nutritional epidemiology. We aimed to compare dietary patterns from factor analysis and TT and their associations with diabetes incidence. Complete data were available for 7349 women (50-55 y at baseline) from the Australian Longitudinal Study on Womens Health. Exploratory factor analysis and TT were performed to obtain patterns by using dietary data collected from an FFQ. Generalized estimating equations analyses were used to examine associations between dietary patterns and diabetes incidence. Two patterns were identified by both methods: a prudent and a Western dietary pattern. Factor analysis factors are a linear combination of all food items, whereas TT factors also include items with zero loading. The Western pattern identified by factor analysis showed a significant positive association with diabetes [highest quintile: OR = 1.94 (95% CI: 1.25, 3.00); P-trend = 0.001). Both factor analysis and TT involve different assumptions and subjective decisions. TT produces clearly interpretable factors accounting for almost as much variance as factors from factor analysis. However, TT patterns include food items with zero loading and therefore do not represent overall dietary patterns. The different dietary pattern loading structures identified by both methods result in different conclusions regarding the relationship with diabetes. Results from this study indicate that factor analysis might be a more appropriate method for identifying overall dietary patterns associated with diabetes compared with TT.

Depressive symptoms across the menopause transition: findings from a large population-based cohort study.

Objective:The aim of the study was to describe the trajectories of depressive symptoms in a large population-based cohort of midaged women, and to examine the associations of current and changing reproductive stage with depressive symptoms over time. Methods:Prospective, population-based cohort study of 13,715 women aged 45 to 50 years followed up for over 15 years (Australian Longitudinal Study on Womens Health). Nearly 6,000 women provided complete data for this study. Menopause status was determined from questionnaires about hysterectomy, oophorectomy, hormone therapy, and menstrual patterns. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression scale (CESD-10). Results:Latent class analysis indicated four distinct profiles of CESD-10 scores over 15 years: stable low (80.0%), increasing (9.0%), decreasing (8.5%), and stable high (2.5%). Those with “increasing” depressive symptoms were more likely to have had bilateral salpingo-oophorectomy or be perimenopausal at baseline compared with women in the “stable low” group. Depressive symptoms were higher in perimenopausal women, (higher CESD-10 score of 0.19, 95% CI 0.02, 0.31), after hysterectomy alone (0.53, 95% CI 0.31, 0.74), bilateral salpingo-oophorectomy with/without hysterectomy (0.85, 95% CI 0.58, 1.12), hormone therapy users (0.19, 95% CI 0.01, 0.36), and after starting or stopping hormone therapy compared with postmenopausal women (adjusted for sociodemographic factors, vasomotor symptoms, health behaviors, and history of depression diagnosis or treatment). Conclusions:Depressive symptoms follow distinct trajectories across the menopause transition. Most women have stable symptoms, but around 9% have increasing symptoms and a similar proportion (8.5%) decreasing symptoms. Increasing depressive symptoms were independent of vasomotor symptoms but were associated with oophorectomy and stopping or starting hormone therapy. A large number of women were excluded due to missing data, and thus the results should be interpreted with caution.