Postpartum weight retention and the early evolution of cardiovascular risk over the first 5 years after pregnancy.

BACKGROUND: The cumulative effect of postpartum weight retention from each pregnancy in a woman's life may contribute to her risk of ultimately developing type 2 diabetes and cardiovascular disease. However, there is limited direct evidence supporting this hypothesis. Thus, we sought to characterize the impact of postpartum weight retention on the trajectories of cardiovascular risk factors over the first 5-years after pregnancy. METHODS: In this prospective observational cohort study, 330 women (mean age 35.7 ± 4.3 years, mean pre-pregnancy body mass index 25.2 ± 4.8 kg/m2, 50.9% primiparous) underwent serial cardiometabolic characterization (anthropometry, blood pressure, lipids, oral glucose tolerance test, insulin sensitivity/resistance (Matsuda index, HOMA-IR), C-reactive protein (CRP), adiponectin) at 1-year, 3-years, and 5-years postpartum. Based on the magnitude of weight change between pre-pregnancy and 5-years postpartum, they were stratified into the following 3 groups: weight loss (n = 100), weight gain 0-6% (n = 110), and weight gain ≥ 6% (n = 120). RESULTS: At 1-year postpartum, cardiovascular risk factors did not differ between the groups. However, an adverse risk factor profile progressively emerged in the weight retention groups at 3- and 5-years. Indeed, after covariate adjustment, there was stepwise worsening (from the weight loss group to weight gain 0-6% to weight gain ≥ 6% group) of the following cardiovascular risk factors at 5-years: triglycerides (p = 0.001), HDL (p = 0.02), LDL (p = 0.01), apolipoprotein-B (p = 0.003), Matsuda index (p < 0.0001), HOMA-IR (p < 0.0001), fasting glucose (p = 0.07), and CRP (p = 0.01). Moreover, on logistic regression analyses, weight gain ≥ 6% emerged as an independent predictor of pre-diabetes/diabetes at 5-years (adjusted OR = 3.40, 95%CI: 1.63-7.09). CONCLUSION: Postpartum weight retention predicts trajectories of worsening cardiovascular risk factors and glucose intolerance over the first 5-years after delivery, consistent with its postulated contribution to future vascular disease in women.

Impact of the diagnosis of gestational diabetes on maternal physical activity after pregnancy.

AIM: The diagnosis of gestational diabetes (GDM) identifies women who are at future risk of developing type 2 diabetes. However, it is unclear if diagnosing GDM thus motivates women to increase physical activity after pregnancy or if this medicalization has the opposite effect of decreasing activity, possibly reflecting assumption of a sick role. We thus sought to evaluate the impact of diagnosing GDM on changes in maternal physical activity after pregnancy. METHODS: In this prospective cohort study, physical activity patterns were assessed by the Baecke questionnaire for the year before pregnancy and the first year postpartum in 405 white women comprising the following three gestational glucose tolerance groups: (a) those who did not have GDM (non-GDM; n = 247), (b) women with undiagnosed GDM (n = 46) and (c) those diagnosed with GDM (n = 112). RESULTS: In the year before pregnancy, mean adjusted total physical activity progressively decreased from non-GDM to undiagnosed GDM to diagnosed GDM (p = .067). Conversely, at 1 year postpartum, total physical activity was highest in those who had been diagnosed with GDM (p = .02). Compared with non-GDM, diagnosed GDM predicted an increase in total physical activity from pre-pregnancy to 1 year postpartum (t = 2.3, p = .02) whereas undiagnosed GDM predicted a concurrent decrease in leisure-time activity (t = -2.74, p = .006). Accordingly, the mean adjusted increase in body mass index from pre-pregnancy to 1 year postpartum was lowest in those with diagnosed GDM (0.26 ± 0.25 kg/m2 ), highest in undiagnosed GDM (1.23 ± 0.38 kg/m2 ) and intermediate in non-GDM (0.89 ± 0.22 kg/m2 ) (overall p = .04). CONCLUSION: Diagnosis of GDM leads to increased physical activity after pregnancy that may partially attenuate postpartum weight retention.

Infant feeding experiences among Indigenous communities in Canada, the United States, Australia, and Aotearoa: a scoping review of the qualitative literature.

BACKGROUND: Although exclusive breastfeeding is recommended for the first six months of life, research suggests that breastfeeding initiation rates and duration among Indigenous communities differ from this recommendation. Qualitative studies point to a variety of factors influencing infant feeding decisions; however, there has been no collective review of this literature published to date. Therefore, the objective of this scoping review was to identify and summarize the qualitative literature regarding Indigenous infant feeding experiences within Canada, the United States, Australia, and Aotearoa. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses- Scoping Reviews and the Joanna Briggs Institute Guidelines, in October 2020, Medline, Embase, CINAHL, PsycINFO, and Scopus were searched for relevant papers focusing on Indigenous infant feeding experiences. Screening and full-text review was completed by two independent reviewers. A grey literature search was also conducted using country-specific Google searches and targeted website searching. The protocol is registered with the Open Science Framework and published in BMJ Open. RESULTS: Forty-six papers from the five databases and grey literature searches were included in the final review and extraction. There were 18 papers from Canada, 11 papers in the US, 9 studies in Australia and 8 studies conducted in Aotearoa. We identified the following themes describing infant feeding experiences through qualitative analysis: colonization, culture and traditionality, social perceptions, family, professional influences, environment, cultural safety, survivance, establishing breastfeeding, autonomy, infant feeding knowledge, and milk substitutes, with family and culture having the most influence on infant feeding experiences based on frequency of themes. CONCLUSIONS: This review highlights key influencers of Indigenous caregivers' infant feeding experiences, which are often situated within complex social and environmental contexts with the role of family and culture as essential in supporting caregivers. There is a need for long-term follow-up studies that partner with communities to support sustainable policy and program changes that support infant and maternal health.

Deteriorating beta cell function is the dominant determinant of progression from normal glucose tolerance to prediabetes/diabetes in young women following pregnancy.

AIMS/HYPOTHESIS: Excess adiposity, insulin resistance and beta cell dysfunction each contribute to the development of prediabetes (impaired glucose tolerance and/or impaired fasting glucose)/diabetes but their comparative impact in relation to one another remains uncertain. We thus ranked their contributions to incident dysglycaemia over the first 5 years postpartum in women reflecting the full spectrum of gestational glucose tolerance (spanning normoglycaemia to gestational diabetes) and hence a range of future diabetic risk. METHODS: In this study, 302 women with normal glucose tolerance (NGT) on OGTT at 3 months postpartum underwent repeat OGTT at 1 year, 3 years and 5 years, enabling serial assessment of glucose tolerance, insulin sensitivity/resistance (Matsuda index, HOMA-IR) and beta cell function (insulin secretion-sensitivity index-2 [ISSI-2], insulinogenic index [IGI]/HOMA-IR). Determinants of prediabetes/diabetes were ranked by change in concordance index (CCI) of Cox proportional hazard regression models. RESULTS: Over 5 years of follow-up, 89 women progressed from NGT to prediabetes/diabetes (progressors). At 3 months postpartum, though all women were normoglycaemic, future progressors had higher fasting glucose (p=0.03) and 2 h glucose (p<0.0001) than non-progressors, coupled with higher BMI (p=0.001), greater insulin resistance (both Matsuda index and HOMA-IR, p≤0.02) and poorer beta cell function (both ISSI-2 and IGI/HOMA-IR, p≤0.006). Unlike their peers, progressors exhibited deteriorating beta cell function from 1 year to 5 years (both p<0.0001). On regression analyses, the dominant determinants of progression to prediabetes/diabetes were time-varying ISSI-2 (change in CCI 25.2%) and IGI/HOMA-IR (13.0%), in contrast to time-varying Matsuda index (2.9%) and HOMA-IR (0.5%). Neither time-varying BMI nor waist were significant predictors after adjustment for beta cell function and insulin sensitivity/resistance. CONCLUSION/INTERPRETATION: Declining beta cell function is the dominant determinant of incident prediabetes/diabetes in young women following pregnancy.

The Environmental Sustainability of Plant-Based Dietary Patterns: A Scoping Review.

BACKGROUND: A large part of the existential threat associated with climate change is the result of current human feeding patterns. Over the last decade, research evaluating the diet-related environmental impacts of plant-based diets has emerged, and a synthesis of the available data is now due. OBJECTIVES: The objectives of the study were as follows: 1) to compile and summarize the literature on diet-related environmental impacts of plant-based dietary patterns; 2) to assess the nature of the data on impacts of plant-based dietary patterns on both environmental parameters and health (e.g., if land use is reduced for a particular diet, is cancer risk also reduced?); and 3) to determine where sufficient data exist for meta-analyses, in addition to identifying gaps within the literature. METHODS: Global peer-reviewed studies on the environmental impacts of plant-based diets were searched in Ovid MEDLINE, EMBASE, and Web of Science. After removing duplicates, the screening identified 1553 records. After 2 stages of independent review by 2 reviewers, 65 records met the inclusion criteria and were eligible to be used in synthesis. RESULTS: Evidence suggests that plant-based diets may offer lower greenhouse gas emissions (GHGEs), land use, and biodiversity loss than offered by standard diets; however, the impact on water and energy use may depend on the types of plant-based foods consumed. Further, the studies were consistent in demonstrating that plant-based dietary patterns that reduce diet-related mortality also promote environmental sustainability. CONCLUSIONS: Overall, there was agreement across the studies regarding the impact of plant-based dietary patterns on GHGE, land used, and biodiversity loss despite varied plant-based diets assessed.

Determinants of Anishinabeck infant and early childhood growth trajectories in Northwestern Ontario, Canada: a cohort study.

BACKGROUND: The Developmental Origins of Health and Disease (DOHaD) paradigm emphasizes the significance of early life factors for the prevention of chronic health conditions, like type 2 diabetes (T2DM) and obesity, which disproportionately affect First Nations communities in Canada. Despite increasing DOHaD research related to maternal health during pregnancy, early childhood growth patterns, and infant feeding practices with many populations, data from First Nations communities in Canada are limited. In partnership with Sandy Lake First Nation, the aims of this project were to characterize birthweights and growth patterns of First Nations infants/children over the first 6 years of life and to study the impact of maternal and infant social and behavioral factors on birthweight and growth trajectories. METHODS: We recruited 194 families through community announcements and clinic visits. Infant/child length/height and weight were measured at 1 and 2 weeks; 1, 2, 6, 12, and 18 months; and 2, 3, 4, 5 and 6 years. Maternal and infant/child questionnaires captured data about health, nutrition, and social support. Weight-for-Age z-score (WAZ), Height-for-Age z-score (HAZ), and BMI-for-Age z-score (BAZ) were calculated using WHO reference standards and trajectories were analyzed using generalized additive models. Generalized estimating equations and logistic regression were used to determine associations between exposures and outcomes. RESULTS: WAZ and BAZ were above the WHO mean and increased with age until age 6 years. Generalized estimating equations indicated that WAZ was positively associated with age (0.152; 95% CI 0.014, 0.29), HAZ was positively associated with birthweight (0.155; 95% CI 0.035, 0.275), and BAZ was positively associated with caregiver's BMI (0.049; 95% CI 0.004, 0.090). There was an increased odds of rapid weight gain (RWG) with exposure to gestational diabetes (OR: 7.47, 95% CI 1.68, 46.22). Almost 70% of parents initiated breastfeeding, and breastfeeding initiation was modestly associated with lower WAZ (-0.18; 95% CI -0.64, 0.28) and BAZ (-0.23; 95% CI -0.79, 0.34). CONCLUSIONS: This work highlights early life factors that may contribute to T2DM etiology and can be used to support community and Indigenous-led prevention strategies.

Metabolomic profile of combined healthy lifestyle behaviours in humans: A systematic review.

A combination of healthy lifestyle behaviours (i.e., regular physical activity, nutritious diet, no smoking, moderate alcohol, and healthy body mass) has been consistently associated with beneficial health outcomes including reduced risk of cardiometabolic diseases. Metabolomic profiles, characterized by distinct sets of biomarkers, have been described for healthy lifestyle behaviours individually and in combination. However, recent literature calls for systematic evaluation of these heterogenous data to identify potential clinical biomarkers relating to a combined healthy lifestyle. The objective was to systematically review existing literature on the metabolomic profile of combined healthy lifestyle behaviours. MEDLINE, EMBASE and Cochrane databases were searched through March 2022. Studies in humans outlining the metabolomic profile of a combination of two or more healthy lifestyle behaviours were included. Collectively, the metabolomic profile following regular adherence to combined healthy lifestyle behaviours points to a positive association with beneficial fatty acids and phosphocreatine, and inverse associations with triglycerides, trimethylamine N-oxide, and acylcarnitines. The findings suggest that a unique metabolomic profile is associated with combined healthy lifestyle behaviours. Additional research is warranted to further describe this metabolomic profile using targeted and untargeted metabolomic approaches along with uniform definitions of combined healthy lifestyle variables across populations.

Metabolomic profiling of the Dietary Approaches to Stop Hypertension diet provides novel insights for the nutritional epidemiology of type 2 diabetes mellitus.

Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is inversely associated with type 2 diabetes mellitus (T2DM) risk. Metabolic changes due to DASH adherence and their potential relationship with incident T2DM have not been described. The objective is to determine metabolite clusters associated with adherence to a DASH-like diet in the Insulin Resistance Atherosclerosis Study cohort and explore if the clusters predicted 5-year incidence of T2DM. The current study included 570 non-diabetic multi-ethnic participants aged 40­69 years. Adherence to a DASH-like diet was determined a priori through an eighty-point scale for absolute intakes of the eight DASH food groups. Quantitative measurements of eighty-seven metabolites (acylcarnitines, amino acids, bile acids, sterols and fatty acids) were obtained at baseline. Metabolite clusters related to DASH adherence were determined through partial least squares (PLS) analysis using R. Multivariable-adjusted logistic regression was used to explore the associations between metabolite clusters and incident T2DM. A group of acylcarnitines and fatty acids loaded strongly on the two components retained under PLS. Among strongly loading metabolites, a select group of acylcarnitines had over 50 % of their individual variance explained by the PLS model. Component 2 was inversely associated with incident T2DM (OR: 0·89; (95 % CI 0·80, 0·99), P-value = 0·043) after adjustment for demographic and metabolic covariates. Component 1 was not associated with T2DM risk (OR: 1·02; (95 % CI 0·88, 1·19), P-value = 0·74). Adherence to a DASH-type diet may contribute to reduced T2DM risk in part through modulations in acylcarnitine and fatty acid physiology.

Maternal Diet and Infant Feeding Practices Are Associated with Variation in the Human Milk Microbiota at 3 Months Postpartum in a Cohort of Women with High Rates of Gestational Glucose Intolerance.

BACKGROUND: Human milk contains a diverse community of bacteria believed to play a role in breast health and inoculation of the infant's gastrointestinal tract. The role of maternal nutrition and infant feeding practices on the human milk microbiota remains poorly understood. OBJECTIVE: Our aim was to explore the associations between maternal diet (delivery to 3 mo postpartum), infant feeding practices, and the microbial composition and predicted function in milk from women with varied metabolic status. METHODS: This was an exploratory analysis of a previously completed prospective cohort study of women with varying degrees of gestational glucose intolerance (NCT01405547). Milk samples (n = 93 mothers) were collected at 3 mo postpartum. Maternal dietary information (validated food-frequency questionnaire) and infant feeding practices (human milk exclusivity, frequency of direct breastfeeding per day) were collected. V4-16S ribosomal RNA gene sequencing (Illumina MiSeq) was conducted to determine microbiota composition. RESULTS: Intake of polyunsaturated fat [ß estimate (SE): 0.036 (0.018), P = 0.047] and fiber from grains [0.027 (0.013), P = 0.048] were positively associated with ɑ-diversity (Shannon index) of human milk. Overall microbial composition of human milk clustered based on human milk exclusivity (weighted UniFrac R2 = 0.034, P = 0.015; Bray-Curtis R2 = 0.041, P = 0.007), frequency of direct breastfeeding per day (Bray-Curtis R2 = 0.057, P = 0.026), and maternal fiber intake from grains (Bray-Curtis R2 = 0.055, P = 0.040). Total fiber, fiber from grains, dietary fat, and infant feeding practices were also associated with a number of differentially abundant taxa. The overall composition of predicted microbial functions was associated with total fiber consumption (Bray-Curtis R2 = 0.067, P = 0.036) and human milk exclusivity (Bray-Curtis R2 = 0.041, P = 0.013). CONCLUSIONS: Maternal consumption of fiber and fat, as well as mother's infant feeding practices, are important determinants of the human milk microbiota. Understanding whether these microbial changes impact an infant's overall health and development requires future study.

Oligosaccharides and Microbiota in Human Milk Are Interrelated at 3 Months Postpartum in a Cohort of Women with a High Prevalence of Gestational Impaired Glucose Tolerance.

BACKGROUND: Human milk is a rich source of human milk oligosaccharides (HMOs) and bacteria. It is unclear how these components interact within the breast microenvironment. OBJECTIVES: The objectives were first, to investigate the association between maternal characteristics and HMOs, and second, to assess the association between HMOs and microbial community composition and predicted function in milk from women with high rates of gestational glucose intolerance. METHODS: This was an exploratory analysis of a previously completed prospective cohort study (NCT01405547) where milk samples (n = 107) were collected at 3 mo postpartum. Milk microbiota composition was analyzed by V4-16S ribosomal RNA gene sequencing and HMOs by rapid high-throughput HPLC. Data were stratified and analyzed by maternal secretor status phenotype and associations between HMOs and microbiota were determined using linear regression models (ɑ-diversity), Adonis (B-diversity), Poisson regression models (differential abundance), and general linear models (predicted microbial function). RESULTS: Prepregnancy BMI, race, and frequency of direct breastfeeding, but not gestational glucose intolerance, were found to be significantly associated with a number of HMOs among secretors and non-secretors. Fucosyllacto-N-hexaose was negatively associated with microbial richness (Chao1) among secretors [B-estimate (SE): -9.3 × 102 (3.4 × 102); P = 0.0082] and difucosyllacto-N-hexaose was negatively associated with microbiota diversity (Shannon index) [-1.7 (0.78); P = 0.029] among secretors. Lacto-N-neotetraose (LNnT) was associated with both microbial B-diversity (weighted UniFrac R2 = 0.040, P = 0.036) and KEGG ortholog B-diversity (Bray-Curtis R2 = 0.039, P = 0.043) in secretors. Additionally, difucosyllactose in secretors and disialyllacto-N-hexaose and LNnT in non-secretors were associated with enrichment of predicted microbial genes encoding for metabolism- and infection-related pathways (P-false discovery rate < 0.1). CONCLUSIONS: HMOs are associated with the microbial composition and predicted microbial functions in human milk at 3 mo postpartum. Further research is needed to investigate the role these relations play in maternal and infant health.

Changes in adiposity mediate the associations of diet quality with insulin sensitivity and beta-cell function.

BACKGROUND AND AIMS: To examine the mediating role of adiposity on the associations of diet quality with longitudinal changes in insulin sensitivity and beta-cell function. METHODS AND RESULTS: Adults at-risk for type 2 diabetes (T2D) in the PROMISE cohort had 4 assessments over 9 years (n = 442). Alternate Healthy Eating Index (AHEI) scores were used to assess diet quality. Generalized Estimating Equations (GEE) evaluated the associations between the AHEI and longitudinal changes in insulin sensitivity (HOMA2-%S and ISI) and beta-cell function (IGI/HOMA-IR and ISSI-2). The proportion of the mediating effect of waist circumference changes was estimated using the difference method. In the primary longitudinal analysis, AHEI was positively associated with insulin sensitivity and beta-cell function over time (% difference per standard deviation increase of AHEI for HOMA2-%S (ß = 11.0, 95%CI 5.43-17.0), ISI (ß = 10.4, 95%CI 4.35-16.8), IGI/HOMA-IR (ß = 7.12, 95%CI 0.98-13.6) and ISSI-2 (ß = 4.38, 95%CI 1.05-7.80), all p < 0.05). There was no significant association between AHEI and dysglycemia incidence (OR = 0.95, 95%CI 0.77-1.17). Adjustments for longitudinal changes in waist circumference substantially attenuated all associations of AHEI with insulin sensitivity and beta-cell function. Mediation analysis indicated that waist circumference mediated 73%, 70%, 83% and 81% of the association between AHEI and HOMA2-%S, ISI, IGI/HOMA-IR, and ISSI-2, respectively (all p < 0.01). CONCLUSION: In a Canadian population at-risk for T2D, AHEI score was positively associated with changes in insulin sensitivity and beta-cell function. These associations were substantially mediated by waist circumference, suggesting that changes in adiposity may represent an important pathway linking diet quality with risk phenotypes for T2D.

Examining the relationship between maternal body size, gestational glucose tolerance status, mode of delivery and ethnicity on human milk microbiota at three months post-partum.

BACKGROUND: Few studies have examined how maternal body mass index (BMI), mode of delivery and ethnicity affect the microbial composition of human milk and none have examined associations with maternal metabolic status. Given the high prevalence of maternal adiposity and impaired glucose metabolism, we systematically investigated the associations between these maternal factors in women ≥20 years and milk microbial composition and predicted functionality by V4-16S ribosomal RNA gene sequencing (NCT01405547;  https://clinicaltrials.gov/ct2/show/NCT01405547 ). Demographic data, weight, height, and a 3-h oral glucose tolerance test were gathered at 30 (95% CI: 25-33) weeks gestation, and milk samples were collected at 3 months post-partum (n = 113). RESULTS: Multivariable linear regression analyses demonstrated no significant associations between maternal characteristics (maternal BMI [pre-pregnancy, 3 months post-partum], glucose tolerance, mode of delivery and ethnicity) and milk microbiota alpha-diversity; however, pre-pregnancy BMI was associated with human milk microbiota beta-diversity (Bray-Curtis R2 = 0.037). Women with a pre-pregnancy BMI > 30 kg/m2 (obese) had a greater incidence of Bacteroidetes (incidence rate ratio [IRR]: 3.70 [95% CI: 1.61-8.48]) and a reduced incidence of Proteobacteria (0.62 [0.43-0.90]) in their milk, compared to women with an overweight BMI (25.0-29.9 kg/m2) as assessed by multivariable Poisson regression. An increased incidence of Gemella was observed among mothers with gestational diabetes who had an overweight BMI versus healthy range BMI (5.96 [1.85-19.21]). An increased incidence of Gemella was also observed among mothers with impaired glucose tolerance with an obese BMI versus mothers with a healthy range BMI (4.04 [1.63-10.01]). An increased incidence of Brevundimonas (16.70 [5.99-46.57]) was found in the milk of women who underwent an unscheduled C-section versus vaginal delivery. Lastly, functional gene inference demonstrated that pre-pregnancy obesity was associated with an increased abundance of genes encoding for the biosynthesis of secondary metabolites pathway in milk (coefficient = 0.0024, PFDR < 0.1). CONCLUSIONS: Human milk has a diverse microbiota of which its diversity and differential abundance appear associated with maternal BMI, glucose tolerance status, mode of delivery, and ethnicity. Further research is warranted to determine whether this variability in the milk microbiota impacts colonization of the infant gut.

Serum apoA1 (Apolipoprotein A-1), Insulin Resistance, and the Risk of Gestational Diabetes Mellitus in Human Pregnancy-Brief Report.

OBJECTIVE: apoA1 (apolipoprotein A-1) is the main lipoprotein associated with HDL (high-density lipoprotein) cholesterol. It was recently reported that intravenous infusion of apoA1 could lower insulin resistance in pregnant rats, leading to the suggestion that apoA1 could provide a target for reducing pregnancy-induced insulin resistance and the risk of gestational diabetes mellitus (GDM) in humans. However, the effects of apoA1 on insulin resistance and risk of GDM in human pregnancy are not known. Thus, we sought to systematically evaluate the relationships of apoA1 with glucose homeostasis and metabolic function in pregnant women. Approach and Results: In this study, 870 pregnant women were recruited in late second trimester and underwent metabolic characterization, including an oral glucose tolerance test on which 214 were diagnosed with GDM. Metabolic characterization included assessment of glucose tolerance, insulin sensitivity/resistance (Matsuda index, homeostasis model assessment of insulin resistance), pancreatic ß-cell function, lipids (LDL [low-density lipoprotein] cholesterol, HDL cholesterol, triglycerides, apoB [apolipoprotein B], and apoA1), CRP (C-reactive protein), and adiponectin. Serum apoA1 was strongly correlated with HDL (r=0.79, P<0.0001) and weakly so with adiponectin (r=0.12, P=0.0004) but showed no association with measures of insulin sensitivity/resistance, ß-cell function, glycemia, or CRP. There were no significant differences across apoA1 tertiles in mean adjusted Matsuda index (P=0.24), homeostasis model assessment of insulin resistance (P=0.08), or area under the glucose curve on the oral glucose tolerance test (P=0.96). Moreover, there were no differences in risk of GDM across tertiles of apoA1, both before (P=0.67) and after covariate adjustment (P=0.78). CONCLUSIONS: Serum apoA1 is not associated with insulin resistance or the risk of GDM in human pregnancy.

Determinants of insulin resistance in children exposed to gestational diabetes in utero.

BACKGROUND: The evolution of increased adiposity and cardiometabolic risk in offspring exposed to maternal gestational diabetes (GDM) is not well understood. OBJECTIVE: (a) To evaluate the impact of in utero exposure to GDM and maternal weight status on homeostasis model assessment of insulin resistance (HOMA-IR) in the offspring longitudinally from 1 to 3 years of age and (b) to compare body mass index (BMI) and HOMA-IR in GDM and non-GDM exposed offspring at 1 and 3 years of age. METHODS: A prospective cohort of children born to mothers with and without GDM underwent metabolic characterization between birth and 3 years of age. RESULTS: In the overall cohort, weight gain between birth and 3 years of age was positively associated with HOMA-IR (ß = 0.1491, P = .02), independent of maternal weight status. HOMA-IR was not different between GDM and non-GDM exposed children from 1 to 3 years of age; however, BMI z score was greater in GDM exposed children at 3 years of age. Among non-GDM exposed children, male sex predicted a 35.1% lower HOMA-IR (P = .03). In GDM exposed offspring, a 1 unit increase in maternal insulin sensitivity predicted a 20.8% decrease in HOMA-IR (P = .002). CONCLUSIONS: Overall, weight gain in the first 3 years of life was positively associated with HOMA-IR, while insulin sensitivity of mothers with GDM negatively predicted HOMA-IR in the offspring. Our findings indicate the need to target weight trajectories in early life, as well as maternal factors during gestation to improve metabolic outcomes in the offspring, particularly those exposed to GDM.

Association of accelerated body mass index gain with repeated measures of blood pressure in early childhood.

BACKGROUND/OBJECTIVES: We examined the association for rates of age- and sex-standardized body mass index (zBMI) gain between 0-3, 3-18, and 18-36 months with BP in children at 36-72 months of age. METHODS: We collected repeated measures of zBMI and BP in 2502 children. zBMI was calculated using the World Health Organization standards. Each child's zBMI at birth and rates of zBMI gain in each period from birth to 36 months were estimated using linear spline multilevel models. Generalized estimating equations were used to determine whether zBMI at birth and zBMI gain between 0-3, 3-18, and 18-36 months were each associated with repeated measures of BP at 36-72 months of age. We sequentially conditioned on zBMI at birth and zBMI gain in each period prior to each period tested, as covariates, and adjusted for important socio-demographic, familial, and study design covariates. We examined whether these associations were modified by birthweight or maternal obesity, by including interaction terms. RESULTS: After adjusting for all covariates and conditioning on prior zBMI gains, a 1 standard deviation unit faster rate of zBMI gain during 0-3 months, (ß = 0.59 mmHg; 95% CI 0.31, 0.86) and 3-18 months (ß = 0.74 mmHg; 95% CI 0.46, 1.03) were each associated with higher systolic BP at 36-72 months. No significant associations were observed, however, for zBMI at birth or zBMI gain in the 18-36 month growth period. zBMI gains from 0-3 and 3-18 months were also associated with diastolic BP. Birthweight significantly modified the relationship during the 3-18 month period (p = 0.02), with the low birthweight group exhibiting the strongest association for faster rate of zBMI gain with higher systolic BP (ß = 1.31 mmHg; 95% CI 0.14, 2.48). CONCLUSIONS: Given that long-term exposure to small elevations in BP are associated with subclinical cardiovascular disease, promoting interventions targeting healthy growth in infancy may be important.

Clusters of fatty acids in the serum triacylglyceride fraction associate with the disorders of type 2 diabetes.

Our aim was to examine longitudinal associations of triacylglyceride fatty acid (TGFA) composition with insulin sensitivity (IS) and ß-cell function. Adults at risk for T2D (n = 477) had glucose and insulin measured from a glucose challenge at three time points over 6 years. The outcome variables Matsuda insulin sensitivity index, homeostatic model of assessment 2-percent sensitivity (HOMA2-%S), Insulinogenic Index over HOMA-IR (IGI/IR), and Insulin Secretion-Sensitivity Index-2 were computed from the glucose challenge. Gas chromatography quantified TGFA composition from the baseline. We used adjusted generalized estimating equation (GEE) models and partial least squares (PLS) regression for the analysis. In adjusted GEE models, four TGFAs (14:0, 16:0, 14:1n-7, and 16:1n-7 as mol%) had strong negative associations with IS, whereas others (e.g., 18:1n-7, 18:1n-9, 20:2n-6, and 20:5n-3) had strong positive associations. Few associations were seen for ß-cell function, except for 16:0, 18:1n-7, and 20:2n-6. PLS analysis indicated four TGFAs (14:0, 16:0, 14:1n-7, and 16:1n-7) that clustered together and strongly related with lower IS. These four TGFAs also correlated highly (r > 0.4) with clinically measured triacylglyceride. We found that higher proportions of a cluster of four TGFAs strongly related with lower IS as well as hypertriglyceridemia, suggesting that only a few FAs within the TGFA composition may primarily explain lipids' role in glucose dysregulation.

Impact of daily incremental change in environmental temperature on beta cell function and the risk of gestational diabetes in pregnant women.

AIMS/HYPOTHESIS: The prevalence of gestational diabetes (GDM) is higher in summer months, possibly reflecting an association between ambient temperature and blood glucose levels. However, the specific exposure and mechanism by which temperature may affect glucose metabolism in pregnancy remains unclear. We systematically evaluated the relationships of environmental temperature and changes therein over varying durations of exposure time with beta cell function, insulin sensitivity and glucose tolerance in women undergoing antepartum screening for GDM. METHODS: At a mean gestation of 29 weeks, 1464 women in Toronto (ON, Canada) underwent an OGTT, from which 318 were diagnosed with GDM. Blood glucose, beta cell function and insulin sensitivity were evaluated in relation to 18 temperature variables: mean temperature and change in temperature on the day of the OGTT and over the preceding 7, 14, 21, 28, 35, 42, 49 and 56 days, respectively. RESULTS: Temperature changes in the preceding 14, 21, 28, 35, 42, 49 and 56 days (rather than mean temperatures) emerged as independent predictors of blood glucose. These relationships were evident in months where mean daily temperature was rising (February - July), but not in those where it was falling (August - January). Indeed, in February - July, the temperature changes in the preceding 21, 28 and 35 days emerged as predictors of both poorer beta cell function and higher blood glucose. Moreover, in February - July, the changes in temperature in the preceding 21 days (OR 1.16, 95% CI 1.01, 1.33) and 28 days (OR 1.20, 95% CI 1.03, 1.39) were independent predictors of GDM, while mean temperatures were not. CONCLUSIONS/INTERPRETATION: In pregnant women, rising environmental temperature in the 3-4 weeks prior to glucose tolerance testing may be associated with beta cell dysfunction and an increased risk of GDM.

Association of NEFA composition with insulin sensitivity and beta cell function in the Prospective Metabolism and Islet Cell Evaluation (PROMISE) cohort.

AIMS/HYPOTHESIS: Our aim was to determine the longitudinal associations of individual NEFA with the pathogenesis of diabetes, specifically with differences in insulin sensitivity and beta cell function over 6 years in a cohort of individuals who are at risk for diabetes. METHODS: In the Prospective Metabolism and Islet Cell Evaluation (PROMISE) longitudinal cohort, 477 participants had serum NEFA measured at the baseline visit and completed an OGTT at three time points over 6 years. Outcome variables were calculated using the OGTT values. At each visit, insulin sensitivity was assessed using the HOMA2 of insulin sensitivity (HOMA2-%S) and the Matsuda index, while beta cell function was assessed using the insulinogenic index over HOMA-IR (IGI/IR) and the insulin secretion-sensitivity index-2 (ISSI-2). Generalised estimating equations were used, adjusting for time, waist, sex, ethnicity, baseline age, alanine aminotransferase (ALT) and physical activity. NEFA were analysed as both concentrations (nmol/ml) and proportions (mol%) of the total fraction. RESULTS: Participants' (73% female, 70% with European ancestry) insulin sensitivity and beta cell function declined by 14-21% over 6 years of follow-up. In unadjusted models, several NEFA (e.g. 18:1 n-7, 22:4 n-6) were associated with lower insulin sensitivity, however, nearly all of these associations were attenuated in fully adjusted models. In adjusted models, total NEFA, 16:0, 18:1 n-9 and 18:2 n-6 (as concentrations) were associated with 3.7-8.0% lower IGI/IR and ISSI-2, while only 20:5 n-3 (as mol%) was associated with 7.7% higher HOMA2-%S. CONCLUSIONS/INTERPRETATION: Total NEFA concentration was a strong predictor of lower beta cell function over 6 years. Our results suggest that the association with beta cell function is due to the absolute size of the serum NEFA fraction, rather than the specific fatty acid composition.

Circulating B-type natriuretic peptide in women with and without recent gestational diabetes: The impact of current glucose intolerance.

CONTEXT: Circulating B-type natriuretic peptide, as measured by the N-terminal fragment of its prohormone (NT-proBNP), is inversely associated with incident type 2 diabetes (T2DM) but positively related to future cardiovascular disease (CVD). Recognizing that gestational diabetes (GDM) identifies women at future risk for both T2DM and CVD, we sought to determine whether gestational glucose tolerance relates to NT-proBNP in the years after delivery. DESIGN/PATIENTS/MEASUREMENTS: Three hundred and forty women underwent a glucose challenge test (GCT) and an oral glucose tolerance test (OGTT) in pregnancy, yielding 4 gestational glucose tolerance groups: GDM (n = 105); gestational impaired glucose tolerance (n = 59); abnormal GCT with a normal OGTT (n = 98); and normal GCT with normal OGTT (n = 75). At 3-year postpartum, they underwent cardiometabolic characterization (including measurement of estimated glomerular filtration rate (eGFR), adiponectin and NT-proBNP) and repeated the OGTT, revealing 69 women with glucose intolerance (prediabetes/diabetes). RESULTS: At 3-year postpartum, serum NT-proBNP did not differ between the 4 original gestational glucose tolerance groups (P = .44), but instead progressively decreased across current glucose tolerance strata, from normal to prediabetes to diabetes (P = .006). Indeed, on logistic regression analysis, NT-proBNP emerged as a negative predictor of prediabetes/diabetes (OR = 0.903, 95% CI 0.825-0.988, P = .026). On multiple linear regression analyses of NT-proBNP, the significant association with current glucose intolerance was ultimately attenuated in a fully adjusted model, revealing two independent determinants of NT-proBNP: eGFR (t = -2.71, P = .007) and adiponectin (t = 2.44, P = .015). CONCLUSION: Serum NT-proBNP relates to current glucose intolerance, rather than preceding gestational dysglycaemia. Thus, the diabetic (rather than vascular) risk implications of NT-proBNP predominate in young women.

Rising plasminogen activator inhibitor-1 and hypoadiponectinemia characterize the cardiometabolic biomarker profile of women with recent gestational diabetes.

BACKGROUND: Gestational diabetes (GDM) and milder gestational impaired glucose tolerance (GIGT) identify women at risk of developing type 2 diabetes and cardiovascular disease later in life. Accordingly, the postpartum years after gestational dysglycemia can provide insight into early events in the natural history of these disorders. We thus sought to prospectively evaluate the relationship between gestational glucose tolerance and emerging cardiometabolic biomarkers [adiponectin, chemerin, retinol-binding protein-4 (RBP-4), C-reactive protein (CRP), plasminogen activator inhibitor-1 (PAI-1)] at both 1- and 3-years postpartum in a cohort reflecting the full spectrum of gestational dysglycemia (from normal to GIGT to GDM). METHODS: Three-hundred-and-thirty-nine women completed a glucose challenge test (GCT) and oral glucose tolerance test (OGTT) in pregnancy, which identified 4 gestational glucose tolerance groups: GDM (n = 105); GIGT (n = 59); abnormal GCT with normal OGTT (n = 99); and normal GCT with normal OGTT (n = 76). At 1- and 3-years postpartum, the women underwent repeat OGTT with measurement of biomarkers (adiponectin/chemerin/RBP-4/CRP/PAI-1). RESULTS: Serum adiponectin was lower in women with GDM and GIGT at both 1-year and 3-years (both P ≤ 0.002), whereas chemerin, RBP-4, CRP and PAI-1 showed no differences across the 4 groups. Importantly, the change in PAI-1 between 1- and 3-years progressively increased from the normal GCT group to the abnormal GCT group to GIGT to GDM (P = 0.03). Indeed, both GDM (t = 2.98, P = 0.003) and GIGT (t = 2.14, P = 0.03) independently predicted an increase in PAI-1 from 1- to 3-years postpartum. CONCLUSIONS: Hypoadiponectinemia and rising PAI-1 over time are early features of the cardiometabolic biomarker profile of women with recent gestational dysglycemia.