Duration of lactation and maternal adipokines at 3 years postpartum

Reproductive risk factors across the female lifecourse and later metabolic health

Metabolic health is characterized by optimal blood glucose, lipids, cholesterol, blood pressure, and adiposity. Alterations in these characteristics may lead to the development of type 2 diabetes mellitus or dyslipidemia. Recent evidence suggests that female reproductive characteristics may be overlooked as risk factors that contribute to later metabolic dysfunction. These reproductive traits include the age at menarche, menstrual irregularity, the development of polycystic ovary syndrome, gestational weight change, gestational dysglycemia and dyslipidemia, and the severity and timing of menopausal symptoms. These risk factors may themselves be markers of future dysfunction or may be explained by shared underlying etiologies that promote long-term disease development. Disentangling underlying relationships and identifying potentially modifiable characteristics have an important bearing on therapeutic lifestyle modifications that could ease long-term metabolic burden. Further research that better characterizes associations between reproductive characteristics and metabolic health, clarifies underlying etiologies, and identifies indicators for clinical application is warranted in the prevention and management of metabolic dysfunction.

The Effects of Breastfeeding and Gestational Diabetes Mellitus on Body Mass Composition and the Levels of Selected Hormones after Childbirth

Breastfeeding may have a positive effect on glucose metabolism and insulin sensitivity, which may reduce the risk of developing diabetes following gestational diabetes mellitus (GDM). This study aimed to evaluate the effect of breastfeeding and GDM on the body mass composition of the studied women, the levels of leptin, ghrelin, adiponectin, resistin, and insulin, and weight loss during the 6-8-week postpartum period and 1 year after childbirth.

MATERIALS AND METHODS

The study group included 42 women with a singleton pregnancy, diagnosed with GDM between the 24th and 28th week of gestation. The control group consisted of 28 non-diabetic women with a singleton pregnancy. This study was carried out at 6-8 weeks as well as at 1 year postpartum. The women were subjected to body weight measurements and body composition analysis performed using a professional body composition analyzer TANITA DC-430 S MA. Waist circumference and subcutaneous fat was measured. Blood for laboratory tests was taken in the morning, on an empty stomach.

RESULTS

It was shown that, regardless of diabetes, exclusive breastfeeding had a significant impact on weight loss at 6-8 weeks postpartum (p = 0.014785) and lower insulin levels (p = 0.047). However, there was no effect of breastfeeding on the women's anthropometric measurements or hormone levels one year after delivery, except for the thickness of subcutaneous adipose tissue, which was significantly lower in breastfeeding women (p = 0.03). One year after delivery, breastfeeding women had a lower BMI (p = 0.0014), less-thick subcutaneous adipose tissue (p < 0.001), and a lower risk of obesity (p = 0.016). There were also higher insulin and ghrelin levels in both breastfeeding and non-breastfeeding women (p < 0.001), and lower resistin levels in non-breastfeeding women (p = 0.004). Women who had diabetes during pregnancy had a significantly reduced waist circumference and subcutaneous fat thickness after one year (p < 0.001 and p = 0.05, respectively).

CONCLUSIONS

Having diabetes during pregnancy did not significantly affect the results of anthropometric measurements and hormone levels noted at 6-8 weeks after delivery (the only exception was the thickness of subcutaneous fat tissue, which was greater in women without GDM). This may indicate normalization of carbohydrate metabolism after childbirth; however, the observation period is too short to elucidate long-term metabolic effects. This suggests the need for further research related to GDM and breastfeeding.

Prolactin does not seem to mediate the improvement on insulin resistance markers and blood glucose levels related to breastfeeding

Introduction

The prevalence of type 2 diabetes mellitus (T2DM) is increasing worldwide. Strategies to decrease this risk should be strongly encouraged. Lactation has been associated, for the mother, with reduction in future T2DM risk in several studies. The mechanisms behind this phenomenon, however, are poorly understood. The aims of this study were, first, to compare blood glucose levels and markers of insulin resistance (MIR) in early postpartum women with overweight/obesity according to their breastfeeding status and, second, to evaluate whether prolactin (PRL) levels could mediate improvements in these parameters.

Methods

The prospective study followed 95 women older than 18 years from early pregnancy for up to 60 to 180 days postpartum. All participants had a BMI > 25 kg/m2 and a singleton pregnancy. At each visit, questionnaires and clinical and biochemical evaluations were performed. Participants were divided into two groups according to the breastfeeding status as "yes" for exclusive or predominant breastfeeding, and "no" for not breastfeeding.

Results

Breastfeeding women (n = 44) had significantly higher PRL levels [47.8 (29.6-88.2) vs. 20.0 (12.0-33.8), p< 0.001]. They also had significantly lower fasting blood glucose levels [89.0 (8.0) vs. 93.9 (12.6) mg/dl, p = 0.04], triglycerides (TG) [92.2 (37.9) vs. 122.4 (64.4) mg/dl, p = 0.01], TG/HDL ratio [1.8 (0.8) vs. 2.4 (1.6) mg/dl, p = 0.02], TyG index [8.24 (0.4) vs. 8.52 (0.53), p = 0.005], fasting serum insulin [8.9 (6.3-11.6) vs. 11.4 (7.7-17.0), p = 0.048], and HOMA-IR [2.0 (1.3-2.7) vs. 2.6 (1.6-3.9), p = 0.025] in the postpartum period compared to the non-breastfeeding group. Groups were homogeneous in relation to prevalence of GDM, pre-gestational BMI, as well as daily caloric intake, physical activity, and weight loss at postpartum. Linear regression analysis with adjustments for confounders showed a statistically significant association of breastfeeding with fasting blood glucose [-6.37 (-10.91 to -1.83), p = 0.006], HOMA-IR [-0.27 (-0.51 to -0.04), p = 0.024], TyG index [-0.04 (-0.06 to -0.02), p = 0.001], and TG/HDL ratio [-0.25 (-0.48 to -0.01), p = 0.038]. Mediation analysis showed that PRL did not mediate these effects. Sensitivity analyses considering different cutoffs for PRL levels also did not show modification effect in the mediation analyses.

Conclusion

Breastfeeding was associated with improvement in glucose metabolism and MIR 60 to 180 days after birth in overweight and obese women, even when adjusted for confounders. PRL levels were not found to mediate the association between breastfeeding and improvement in MIR.

Lactation duration and lifetime progression to metabolic syndrome in women according to their history of gestational diabetes: a prospective longitudinal community-based cohort study

BACKGROUND

Despite the many signs of progress in pharmacotherapies, metabolic syndrome (MetS) is one of the main public-health burdens worldwide. Our study aimed to compare the effect of breastfeeding (BF) in women with and without gestational diabetes mellitus (GDM) on MetS incidence.

METHODS

Of females who participated in the Tehran Lipid and glucose study, women who met our inclusion criteria were selected. The Cox proportional hazards regression model, with adjustment of potential confounders, was done to evaluate the relationship between duration of BF and incident of MetS in women with a GDM history compared to non-GDM.

RESULTS

Out of 1176 women, there were 1001 non-GDM and 175 GDM. The median follow-up was 16.3 (11.9, 19.3) years. Results of the adjusted model illustrated that the total BF duration was negatively associated with MetS incidence risk (hazard ratio (HR) 0.98, 95% CI 0.98-0.99) in total participants indicating that per one-month increase of BF duration, the hazard of MetS reduced by 2%. The HR of MetS in Comparison between GDM and non-GDM women demonstrated significantly more reduced MetS incidence with a longer duration of exclusive BF (HR 0.93, 95% CI 0.88-0.98).

CONCLUSIONS

Our findings illustrated the protective effect of BF, especially exclusive BF, on MetS incidence risk. BF is more effective in reducing the risk of MetS among women with a history of GDM than among women without such a history.

The Association Between Multiparity and Adipokine Levels: The Multi-Ethnic Study of Atherosclerosis

Background: Multiparity is a risk factor for cardiovascular disease (CVD). However, the mechanisms of this relationship are unknown. Adipokines may predispose multiparous women to certain cardiometabolic complications that can increase their risk of future CVD. Materials and Methods: We studied 973 female participants of the Multi-Ethnic Study of Atherosclerosis free of CVD, who had complete data on parity and adipokines measured at Examination 2 or 3 (randomly assigned). Parity was categorized as nulliparity, 1-2, 3-4, and ≥5 live births. Multivariable linear regression was used to evaluate the association of parity with leptin, resistin, and adiponectin levels. Results: The women had mean age of 65 ± 9 years. After adjustment for age, race/ethnicity, study site, education, menopause status, smoking, physical activity, use of hormone therapy, and waist circumference, a history of grand multiparity (≥5 live births) was associated with 11% higher resistin levels (95% confidence interval [CI] 0-23) and 3-4 live births was associated with 23% higher leptin levels (95% CI 7-42), compared with nulliparity. After adjustment for computed tomography-measured visceral fat, the association of 3-4 live births with leptin remained significant. There were no significant associations of parity with adipokines after further adjustment for additional CVD risk factors. Multigravidity (but not parity) was inversely associated with adiponectin levels. Conclusions: In a multiethnic cohort of women, greater parity was associated with resistin and leptin; however, this association was attenuated after accounting for CVD risk factors. Dysregulation of adipokines could contribute to the excess CVD risk associated with multiparity. Further studies are needed to determine whether adipokines independently mediate the relationship between multiparity and CVD. Clinical trials registration: The MESA cohort is registered at NCT00005487.

Associations of breastfeeding history with metabolic syndrome and cardiovascular risk factors in community-dwelling parous women: The Japan Multi-Institutional Collaborative Cohort Study

OBJECTIVE

The aim of the present study was to investigate the associations between breastfeeding and the prevalence of metabolic syndrome in community-dwelling parous women and to clarify whether the associations depend on age.

METHODS

The present cross-sectional study included 11,118 women, aged 35-69 years. Participants' longest breastfeeding duration for one child and their number of breastfed children were assessed using a self-administered questionnaire, and their total breastfeeding duration was approximated as a product of the number of breastfed children and the longest breastfeeding duration. The longest and the total breastfeeding durations were categorized into none and tertiles above 0 months. Metabolic syndrome and cardiovascular risk factors (obesity, hypertension, dyslipidemia, and hyperglycemia) were defined as primary and secondary outcomes, respectively. Associations between breastfeeding history and metabolic syndrome or each cardiovascular risk factor were assessed using multivariable unconditional logistic regression analysis.

RESULTS

Among a total of 11,118 women, 10,432 (93.8%) had ever breastfed, and 1,236 (11.1%) had metabolic syndrome. In participants aged <55 years, an inverse dose-response relationship was found between the number of breastfed children and the prevalence of metabolic syndrome; multivariable-adjusted odds ratios for 1, 2, 3, and ≥4 breastfed children were 0.60 (95% confidence interval [CI]: 0.31 to 1.17), 0.50 (95% CI: 0.29 to 0.87), 0.44 (95% CI: 0.24 to 0.84), and 0.35 (95% CI: 0.14 to 0.89), respectively. The longest and total breastfeeding durations of longer than 0 months were also associated with lower odds of metabolic syndrome relative to no breastfeeding history in participants aged <55 years. In contrast, all measures of breastfeeding history were not significantly associated with metabolic syndrome and cardiovascular risk factors in participants aged ≥55 years old.

CONCLUSIONS

Breastfeeding history may be related to lower prevalence of metabolic syndrome in middle-aged parous women.

Adiposity, related biomarkers, and type 2 diabetes after gestational diabetes: The Diabetes Prevention Program

OBJECTIVE

This study investigated associations of adiposity and adiposity-related biomarkers with incident type 2 diabetes (T2D) among parous women.

METHODS

Among women in the Diabetes Prevention Program (DPP) who reported a previous live birth, circulating biomarkers (leptin, adiponectin, sex hormone-binding globulin, and alanine aminotransferase; n = 1,711) were measured at enrollment (average: 12 years post partum). Visceral (VAT) and subcutaneous adipose tissue areas at the L2-L3 region and the L3-L4 region were quantified by computed tomography (n = 477). Overall and stratified (by history of gestational diabetes mellitus [GDM]) adjusted Cox proportional hazards models were fit.

RESULTS

Alanine aminotransferase, L2-L3 VAT, and L3-L4 VAT were positively associated (hazard ratio [HR] for 1-SD increases: 1.073, p = 0.024; 1.251, p = 0.009; 1.272, p = 0.004, respectively), and adiponectin concentration was inversely associated with T2D (HR 0.762, p < 0.001). Whereas leptin concentration was not associated with T2D overall, in GDM-stratified models, a 1-SD higher leptin was positively associated with risk of T2D in women without GDM (HR: 1.126, p = 0.016) and inversely in women with a history of GDM (HR: 0.776, p = 0.013, interaction p = 0.002).

CONCLUSIONS

Among parous women, alanine aminotransferase and VAT are positively associated with incident T2D, whereas adiponectin is inversely associated. Leptin is associated with higher risk of T2D in women with a history of GDM but a lower risk in women without a history of GDM.

Effect of Breastfeeding and Its Duration on Impaired Fasting Glucose and Diabetes in Perimenopausal and Postmenopausal Women: Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2019

BACKGROUND AND OBJECTIVES

To examine the effect of maternal breastfeeding on the subsequent risk of diabetes in parous Korean women aged >50 years.

MATERIALS AND METHODS

A total of 14,433 participants from the Korea National Health and Nutrition Examination Survey (KNHANES) were included. The subjects were divided into three groups: normal, impaired fasting glucose, and diabetes. The adjusted odds ratios (ORs) for impaired fasting glucose (IFG) and diabetes were assessed using multivariate logistic regression.

RESULTS

A total of 2301 (15.94%) women were classified as having diabetes, and 3670 (25.43%) women were classified as having impaired fasting glucose. Breastfeeding was associated with an OR for diabetes of 0.76 (95% confidence interval (CI): 0.61, 0.95) compared with non-breastfeeding after adjustment for possible confounders in the multivariable logistic regression analysis. Breastfeeding for 13-24 months was associated with an OR of 0.68 (95% CI, 0.5, 0.91), and breastfeeding for 25-36 months was associated with an OR of 0.68 (95% CI, 0.52, 0.87) for diabetes compared with breastfeeding for <1 month in the multivariable logistic regression analysis.

CONCLUSIONS

Our results suggest that long-term breastfeeding, particularly breastfeeding for 13-36 months, may be associated with a lower risk for diabetes later in life.

Metabolic Conditions Including Obesity, Diabetes, and Polycystic Ovary Syndrome: Implications for Breastfeeding and Breastmilk Composition

Breastfeeding is internationally recognized as the recommended standard for infant nutrition, informed by evidence of its multiple benefits for both mother and baby. In the context of common metabolic conditions such as polycystic ovary syndrome, diabetes (type 1, type 2, and gestational), and obesity, breastfeeding may be particularly beneficial for both mother and infant. However, there is evidence of delayed lactogenesis and reduced breastfeeding rates and duration in women with these conditions, and the effects of altered maternal metabolic environments on breastmilk composition (and potentially infant outcomes) are incompletely understood. In this review, we explore the relationships between maternal metabolic conditions, lactogenesis, breastfeeding, and breastmilk composition. We examine relevant potential mechanisms, including the central role of insulin both in lactogenesis and as a milk-borne hormone. We also describe the bioactive and hormonal components of breastmilk and how these may link maternal and infant health.

Duration of Lactation and Maternal Risk of Metabolic Syndrome: A Systematic Review and Meta-Analysis

Cardiovascular disease (CVD) is the leading cause of death of women across all ages, and targeting modifiable risk factors, such as those comprised in metabolic syndrome (MetS) (e.g., waist circumference, lipid profile, blood pressure, and blood glucose), is of great importance. An inverse association between lactation and CVD has been suggested, and lactation may decrease the risk of MetS. This systematic review and meta-analysis examined how lactation may affect the development and prevalence of MetS in women. A literature search was performed using Cinahl, Embase, Web of Science, and PubMed. A total of 1286 citations were identified, and finally, ten studies (two prospective and eight cross-sectional) were included. Seven studies (two prospective and five cross-sectional) revealed associations between lactation and MetS, suggesting that breastfeeding might prevent or improve metabolic health and have a protective role in MetS prevention. This protective role might be related to the duration of lactation; however, a lack of controlling for potential confounders, such as parity, might inflict the results. The pooled effect was non-conclusive. Additional research is required to further explore the duration of lactation and its potential role in improving or reversing MetS and its components.

Pregnancy Per- and Polyfluoroalkyl Substance Concentrations and Postpartum Health in Project Viva: A Prospective Cohort

CONTEXT

Per- and polyfluoroalkyl substances (PFAS) are environmental chemicals linked to weight gain and type 2 diabetes.

OBJECTIVE

We examined the extent to which PFAS plasma concentrations during pregnancy were associated with postpartum anthropometry and biomarkers.

DESIGN, PATIENTS, AND MEASURES

We studied women recruited between 1999 and 2002 in the Project Viva prospective cohort with pregnancy plasma concentrations of PFAS, including perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and 2-(N-ethyl-perfluorooctane sulfonamide) acetic acid (EtFOSAA). Three-year postpartum anthropometry measurements were available from 786 to 801 women, blood pressure from 761 women, and blood biomarkers from 450 to 454 women. We used multivariable regression to evaluate the association of log2-transformed PFAS with postpartum anthropometry, blood pressure, and blood biomarkers (leptin, adiponectin, sex hormone binding globulin [SHBG], hemoglobin A1c, interleukin-6 [IL-6], C-reactive protein), adjusting for age, prepregnancy body mass index, marital status, race/ethnicity, education, income, smoking, parity, and breastfeeding history.

RESULTS

Pregnancy concentrations of certain PFAS were associated with greater adiposity (eg, 0.4 cm [95% confidence interval [95%CI]: -0.1, 0.9] greater waist circumference per doubling in EtFOSAA; 0.2 cm [95%CI: -0.1, 0.5] greater mid-upper arm circumference per doubling in PFOA; 1.2 mm [95%CI: 0.1, 2.2] thicker sum of subscapular and triceps skinfolds per doubling in PFOS) and higher systolic blood pressure (eg, 1.2 mm Hg [95%CI: 0.3, 2.2] per doubling in PFOS) at 3 years postpartum. Higher EtFOSAA concentrations were also associated with 10.8% higher IL-6 (95%CI: 3.3, 18.9) and 6.1% lower SHBG (95%CI: 0.7, 11.2) per doubling.

CONCLUSIONS

Pregnancy concentrations of EtFOSAA, PFOS, and PFOA were associated with adverse postpartum cardiometabolic markers.

Parity, lactation, and long-term weight change in Mexican women

One post-partum behaviour that may be protective against post-partum weight retention and long-term weight gain among women of reproductive age is lactation because of its potential role in resetting maternal metabolism after pregnancy. However, most of the evidence focuses on weight retention at 6, 12, or 24 months post-partum, and data beyond 2 years after birth are sparse, and findings are inconclusive. Therefore, our aim was to assess the association of parity and mean duration of lactation per child with long-term weight change in Mexican women. We assessed the association of parity and mean duration of lactation per child with long-term weight change in 75,421 women from the Mexican Teachers' Cohort. Several multivariable regression models were fit to assess these associations. We also examined the non-linear association between duration of lactation and weight change using restricted cubic splines. We found that parous women (≥4 children) gained 2.81 kg more (95% CI [2.52, 3.10]) than did nulliparous women. The association between mean duration of lactation per child and weight change appeared to be non-linear. Women who breastfed on average 3-6 months per child had lower gain weight (-1.10, 95% CI [-1.58, -0.47 kg]) than had women who did not breastfeed. This association was linear up to 6 months of lactation per child. Our findings suggest that parity alters weight-gain trajectory in women and that lactation could reduce this alteration. These findings are important in the prevention of excessive weight gain through reproductive years and their future health implications.

Longer duration of exclusive breastfeeding reduces maternal weight retention: results from the CLaB study

Abstract Objectives: to evaluate the relation between breastfeeding and postpartum weight reten-tion. Methods: this prospective cohort study involved 641 newborns and their mothers, followed up to twelve months postpartum. Data were collected from June 2015 to February 2017. In the first interview, we investigated data regarding socioeconomic and demographic characteristics, obstetric history, weight, and gestational age of the infant at birth. Maternal weight and breastfeeding status were obtained at 3, 6, 9 and 12 months postpartum at the mother’s home. A descriptive analysis of maternal weight retention according to the lactation status was performed. Multiple linear regression models evaluated the effect on exclusive breastfeeding and total breastfeeding duration on maternal weight retention at 6 and 12 months postpartum, considering potential confounders. Results: 512 and 490 mothers were evaluated at six months and at twelve months post-partum, and the mean weight retention was 1.79 (SD=5.52) and 1.69 (SD=6.69) kg, respectively. Regardless of the confounders, the mean postpartum weight reduction for each day of exclusive breastfeeding was 11 (CI95%= -0.019 to -0.003) and 16 grams (CI95%= -0.026 to -0.007) for 6 and 12 months, respectively. The total maternal breastfeeding duration had the same effect. Conclusions: longer periods of exclusive breastfeeding and total breastfeeding are associated with lower postpartum weight retention.

Associations of appetite sensations and metabolic characteristics with weight retention in postpartum women

Postpartum weight retention (PPWR) is an important risk factor for long-term obesity. Appetite may be a key factor regulating PPWR. The objectives of this study were to determine the associations between (i) PPWR and appetite; and (ii) appetite, lactation, and metabolic characteristics. Data from 49 women at 9 months postpartum contributed to this cross-sectional analysis. Energy expenditure was assessed in a whole-body calorimetry unit for 24 h. Appetite sensations were rated using visual analogue scales. Lactation (min/day) was measured using a 3-day breastfeeding diary. PPWR was negatively associated with fullness (β ± SE; R² = -2.97 ± 0.72; 0.661; P < 0.001), and satiety (-2.75 ± 0.81; 0.617; P = 0.002), and was positively associated with hunger (2.19 ± 1.02; 0.548; P = 0.039), prospective food consumption (PFC; 2.19 ± 0.91; 0.562; P = 0.021), and composite appetite score (CAS; 0.34 ± 0.09; 0.632; P = 0.001). Lactation was associated with higher CAS (39.68 ± 15.56; 0.365; P = 0.015), hunger (3.56 ± 1.61; 0.308; P = 0.033), and PFC (4.22 ± 1.78; 0.314; P = 0.023), and with reduced sensations of fullness (-4.18 ± 1.94; 0.358; P = 0.038) and satiety (-3.83 ± 1.87; 0.295; P = 0.048). Lactation was associated with appetite, which in turn was related to PPWR. Appetite control should be explored to support postpartum weight management strategies. Novelty Postpartum weight retention was associated with appetite sensations, which were assessed throughout the day under conditions in which energy intake and expenditure were precisely matched. Lactation and other maternal metabolic factors, including carbohydrate oxidation and physical activity level may play a role in controlling appetite during the postpartum period.

Metabolic effects of breastfeed in women with prior gestational diabetes mellitus: A systematic review and meta-analysis

This study was undertaken to provide comprehensive analyses of current research developments in the field of breastfeed (BF) and metabolic-related outcomes among women with prior gestational diabetes mellitus (GDM). Database PubMed, Embase, BIOSIS Previews, Web of Science, and Cochrane Library were searched through December 3, 2017. Odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) were pooled by random-effects model using Stata version 12.0. Twenty-three observational studies were included in quantitative synthesis. Reduced possibility of progression to type 2 diabetes mellitus (T2DM; OR = 0.79; 95% CI, 0.68-0.92) and pre-DM (OR = 0.66; 95% CI, 0.51-0.86) were found among women with longer BF of any intensity after GDM pregnancy. The positive effect of longer BF on progression to T2DM gradually became prominent with the extension of follow-up period. Compared with women with shorter BF, those with longer BF manifested more favourable metabolic parameters, including significant lower body mass index, fasting glucose, triglyceride, and higher insulin sensitivity index. The findings support that BF may play an important role in protection against the development of T2DM-related outcomes in midlife of women with prior GDM. However, further studies are needed to reveal the etiological mechanism.

Lactation and maternal cardiovascular disease risk in later life

Cardiovascular disease is the leading cause of death worldwide. The identification of protective factors against cardiovascular disease is important with regard to public health policies. Lactation has multiple beneficial effects for both mother and child. This review summarizes the evidence on the association between lactation and maternal cardiovascular risk in later life. Lactation may help to reverse the metabolic and cardiovascular changes that take place during pregnancy. Overall, lactation seems to exert a protective effect against the development of hypertension, metabolic syndrome, and diabetes, whilst data on postpartum weight and lipidemic profile are less conclusive. Both subclinical and clinical cardiovascular disease are negatively associated with a history of lactation. Increased energy expenditure and a favorable hormonal and adipokine profile during lactation may explain these associations.

Breastfeeding and Maternal Age-related Cataract

PURPOSE

No studies addressed the influence of breastfeeding on cataract formation. The objective of this study was to address the relationship between breastfeeding and maternal age-related cataract.

DESIGN

A nationwide cross-sectional study.

METHODS

This study analyzed data for 3821 parous women aged 50 years or above in the Korea National Health and Nutrition Examination Survey 2010-2012. Participants were aggregated into quartiles according to the number of breastfed children and duration of breastfeeding. Logistic regression analysis was used to examine the relationships between less or short duration of breastfeeding and increased risks of cataract.

RESULTS

A total of 2197 women (57.5%) were classified as having age-related cataract. Women who breastfed 4-12 children (odds ratio [OR] = 0.56; 95% confidence interval [CI] = 0.35-0.89) had significantly lower risks for cortical cataract, compared to those who breastfed no or 1 child (P for trend across quartiles = .010). Women who breastfed for 36-60 months (OR = 0.61, 95% CI = 0.42-0.90) or 61-324 months (OR = 0.53, 95% CI = 0.33-0.83) had lower risks for cortical cataract compared to those who breastfed 16 months or less (P for trend across tertiles = .003). The population-attributable fractions of cortical cataract induced by number of children breastfed less than 3 and duration of breastfeeding less than 36 months were 9.4% (95% CI = 1.3%-17.6%) and 10.7% (95% CI = 3.0%-18.4%), respectively.

CONCLUSIONS

Breastfeeding more children and long-term breastfeeding were associated with lower risk of cortical cataract formation in parous women.

Breastfeeding and Maternal Hypertension

BACKGROUND

Little is known about the relationship between breastfeeding and hypertension. We performed this study to identify whether breastfeeding itself influenced maternal hypertension and whether degree of obesity or insulin sensitivity would contribute to the relationship between breastfeeding and hypertension in postmenopausal women.

METHODS

Our study population comprised 3,119 nonsmoking postmenopausal women aged 50 years or above in the 2010-2011 Korea National Health and Nutrition Examination Survey. We performed logistic regression analyses to examine the relationship between breastfeeding and hypertension and mediation analyses to examine the contributions of obesity and insulin sensitivity to the breastfeeding-hypertension relationship.

RESULTS

The odds ratios, with 95% confidence intervals, for hypertension among the highest quintile of number of breastfed children (5-11) and the highest quintile of duration of breastfeeding (96-324 months) were 0.49 (0.31-0.75) and 0.55 (0.37-0.82), respectively, compared to each of lowest quintile groups. The population attributable fractions of hypertension caused by breastfeeding 3 or fewer children and breastfeeding for 56 months or less were 10.2% (P < 0.001) and 6.5% (P = 0.017), respectively. In the mediation analysis, unexpectedly, increased insulin resistance significantly attenuated the protective effect on hypertension of having breastfed more children; additionally, greater obesity and insulin resistance significantly attenuated the protective effects on hypertension of having breastfed for longer.

CONCLUSIONS

More children breastfed and longer duration of breastfeeding were associated with lower risk of hypertension in postmenopausal women, and degree of obesity and insulin resistance moderated the breastfeeding-hypertension association.

Breastfeeding and maternal cardiovascular risk factors and outcomes: A systematic review

Background

There is growing evidence that breastfeeding has short- and long-term cardiovascular health benefits for mothers. The objectives of this systematic review were to examine the association between breastfeeding and maternal cardiovascular risk factors and outcomes that have not previously been synthesized systematically, including metabolic syndrome, hypertension and cardiovascular disease.

Methods and findings

This systematic review meets PRISMA guidelines. The MEDLINE, EMBASE and CINAHL databases were systematically searched for relevant publications of any study design from the earliest publication date to March 2016. The reference lists from selected articles were reviewed, and forward and backward referencing were conducted. The methodological quality of reviewed articles was appraised using validated checklists.

Twenty-one studies meeting the inclusion criteria examined the association between self-reported breastfeeding and one or more of the following outcomes: metabolic syndrome/metabolic risk factors (n = 10), inflammatory markers/adipokines (n = 2), hypertension (n = 7), subclinical cardiovascular disease (n = 2), prevalence/incidence of cardiovascular disease (n = 3) and cardiovascular disease mortality (n = 2). Overall, 19 studies (10 cross-sectional/retrospective, 9 prospective) reported significant protective effects of breastfeeding, nine studies (3 cross-sectional/retrospective, 5 prospective, 1 cluster randomized controlled trial) reported non-significant findings and none reported detrimental effects of breastfeeding. In most studies reporting significant associations, breastfeeding remained associated with both short- and long-term maternal cardiovascular health risk factors/outcomes, even after covariate adjustment. Findings from several studies suggested that the effects of breastfeeding may diminish with age and a dose-response association between breastfeeding and several metabolic risk factors. However, further longitudinal studies, including studies that measure exclusive breastfeeding, are needed to confirm these findings.

Conclusions

The evidence from this review suggests that breastfeeding is associated with cardiovascular health benefits. However, results should be interpreted with caution as the evidence gathered for each individual outcome was limited by the small number of observational studies. Additional prospective studies are needed.

PROSPERO registration number

CRD42016047766.

[Effects of gestational weight gain and breastfeeding on postpartum weight retention among women in the BRISA cohort]

This study analyzed the effects of gestational weight gain and breastfeeding on postpartum weight retention. The study followed 2,607 women from the BRISA cohort. The variables were age, socioeconomic status, parity, pre-gestational body mass index, gestational weight gain, duration of maternal breastfeeding, length of postpartum follow-up, and postpartum weight gain. Structural equation modeling was used to evaluate the total, direct, and indirect effects of the explanatory variables on postpartum weight retention. An increase of one standard deviation in gestational weight gain corresponded to a significant increase of 0.49 standard deviations in postpartum weight retention (p < 0.001). An increase of one standard deviation in duration of breastfeeding corresponded to mean decrease of 0.10 standard deviations in postpartum weight retention (p < 0.001). Independently of pre-gestational BMI, gestational weight gain is a risk factor and duration of breastfeeding is a protective factor against postpartum weight retention.

Association between breastfeeding duration and postpartum weight retention of lactating mothers: A meta-analysis of cohort studies

BACKGROUND & AIMS

To clarify the relationship between different breastfeeding duration and postpartum weight retention through meta-analysis.

METHODS

In this study, all relevant studies that described the effect of breastfeeding duration on postpartum weight retention were identified from Pubmed, Cochrane, and WANGFANG databases and so on (1960-2016). This meta-analysis had been registered in International Prospective Register of Systematic Reviews (CRD42016038409).

RESULTS

Fourteen cohort studies involving 66 comparisons were included. Compared with bottle-feeding mothers, breastfeeding mothers had significantly lower postpartum weight retention of -0.38 kg (95% confidence interval: -0.64, -0.11 kg). Subgroup analysis showed that, mothers who were primipara, less than 30 years old or normal pre-pregnancy body mass index had lower postpartum weight retention. When breastfeeding duration were stratified into <12 weeks, 12 weeks-24 weeks, 24 weeks-48 weeks, and ≥48 weeks, postpartum weight retention in breastfeeding women presented a U-shaped trend: a decline during early breastfeeding duration (year 1) (from 0.23 kg at < 12 weeks to -1.58 kg at 24-48 weeks) and then an increase in the follow-up duration (from -1.58 kg at 24-48 weeks to -0.97 kg at more than 48 weeks).

CONCLUSIONS

Our results indicated that breastfeeding including exclusive breastfeeding and mixed breastfeeding were inversely related to postpartum weight retention. The decreasing influence of breastfeeding was more significant when the lactating mothers were less than 30 years old, primipara, normal pre-pregnant body mass index, or breastfeeding duration for 6-12 months.

Maternal metabolic adaptations to pregnancy among young women in Cebu, Philippines

OBJECTIVES

Evidence that fetal development has long-term impacts on health has increased interest in maternal-fetal nutrient exchange. Although maternal metabolism is known to change during gestation to accommodate fetal nutrient demands, little is known about these modifications outside of a Western, clinical context. This study characterizes maternal metabolic adaptations to pregnancy, and their associations with offspring birth weight (BW), among women living in the Philippines.

METHODS

Fasting glucose, triglycerides, insulin, leptin, and adiponectin were assessed in 808 participants in the Cebu Longitudinal Health and Nutrition Survey (Metropolitan Cebu, Philippines). Cross-sectional relationships between metabolites and hormones and gestational and lactational status were evaluated. Among the subset of currently pregnant women, associations between maternal glucose and triglycerides and offspring BW were also examined.

RESULTS

Women in their second and third trimesters had significantly lower fasting glucose and adiponectin compared to nulliparous women, and leptin levels and triglyceride levels were notably higher late in pregnancy (all P < .05). Among pregnant women, fasting glucose was a positive predictor of offspring BW, but only in males (P = .012, R²  = .28). Hormones and metabolites in post-partum women trend back toward levels found in nulliparous women, with some differences by breastfeeding status.

CONCLUSIONS

We find evidence for marked changes in maternal lipid and carbohydrate metabolism during pregnancy, consistent with known adaptations to support fetal growth. The finding of sex-specific relationships between maternal glucose and offspring BW adds to evidence for greater impacts of the maternal-gestational environment on biology and health in male offspring.

Prior lactation reduces future diabetic risk through sustained postweaning effects on insulin sensitivity

Breastfeeding for ≥12 mo is recommended for optimal infant nutrition but may hold maternal benefits as well. Indeed, lactation has been associated with lower long-term risk of diabetes in the mother, but the mechanism by which it imparts sustained postweaning effects on glucose tolerance remains unclear. In this context, we postulated that lactation could potentially induce postweaning beneficial effects on glucose tolerance by modifying the natural history of insulin sensitivity and/or pancreatic β-cell function over time. Thus, in this study, we evaluated the relationships between duration of lactation [≤3 mo (n = 70), 3-12 mo (n = 140), and ≥12 mo (n = 120)] and trajectories of insulin sensitivity/resistance, β-cell function, and glycemia over the first 3 yr postpartum in a cohort of 330 women comprising the full spectrum of glucose tolerance in pregnancy, who underwent serial metabolic characterization, including oral glucose tolerance tests, at 3 mo, 1 yr, and 3 yr postpartum. The prevalence of dysglycemia (pre-diabetes/diabetes) at 3 yr postpartum was lower in women who breastfed for ≥12 mo (12.5%) than in those who breastfed for ≤3 mo (21.4%) or for 3-12 mo (25.7%)(overall P = 0.028). On logistic regression analysis, lactation for ≥12 mo independently predicted a lower likelihood of prediabetes/diabetes at 3 yr postpartum (OR = 0.37, 95% CI 0.18-0.78, P = 0.009). Notably, lactation for ≥12 mo predicted lesser worsening of insulin sensitivity/resistance (P < 0.0001), fasting glucose (P < 0.0001), and 2-h glucose (P = 0.011) over 3 yr compared with lactation ≤3 mo but no differences in β-cell function (P ≥ 0.37). It has thus emerged that adherence to current breastfeeding recommendations reduces future diabetic risk through sustained postweaning effects on insulin sensitivity/resistance but not β-cell function.

Active ghrelin and the postpartum

Postpartum depression (PPD) occurs in 10-15 % of women. The appetite hormone ghrelin, which fluctuates during pregnancy, is associated with depression in nonpregnant samples. Here, we examine the association between PPD and active ghrelin from pregnancy to postpartum. We additionally examine whether ghrelin changes from pregnancy to postpartum and differs between breastfeeding and non-breastfeeding women. Sixty women who participated in a survey examining PPD and had information in regard to ghrelin concentrations were included in the study. The Edinburgh Postnatal Depression Scale was used to assess symptoms of PPD. Raw ghrelin levels and ghrelin levels adjusted for creatinine were included as outcomes. Women screening positive for PPD at 12 weeks postpartum had higher pregnancy ghrelin concentrations. Ghrelin concentrations significantly decreased from pregnancy to 6 weeks postpartum and this change differed based on pregnancy depression status. Finally, ghrelin levels were lower in women who breastfed compared with women who were bottle-feeding. No significant findings remained once ghrelin levels were adjusted for creatinine. Although results do not suggest an association between PPD and ghrelin after adjusting for creatinine, future research should continue to explore this possibility extending further across the postpartum period with larger sample sizes.

Does Insulin Explain the Relation between Maternal Obesity and Poor Lactation Outcomes? An Overview of the Literature

It is well established that obese women are at increased risk of delayed lactogenesis and short breastfeeding duration, but the underlying causal contributors remain unclear. This review summarizes the literature examining the role of insulin in lactation outcomes. Maternal obesity is a strong risk factor for insulin resistance and prediabetes, but until recently a direct role for insulin in milk production had not been elucidated. Over the past 6 y, studies in both animal models and humans have shown insulin-sensitive gene expression to be dramatically upregulated specifically during the lactation cycle. Insulin is now considered to play a direct role in lactation, including essential roles in secretory differentiation, secretory activation, and mature milk production. At the same time, emerging clinical research suggests an important association between suboptimal glucose tolerance and lactation difficulty. To develop effective interventions to support lactation success in obese women further research is needed to identify how, when, and for whom maternal insulin secretion and sensitivity affect lactation ability.

Do Lactation-Induced Changes in Ghrelin, Glucagon-Like Peptide-1, and Peptide YY Influence Appetite and Body Weight Regulation during the First Postpartum Year?

To determine whether fasting and meal-induced appetite-regulating hormones are altered during lactation and associated with body weight retention after childbearing, we studied 24 exclusively breastfeeding women (BMI = 25.2 ± 3.6 kg/m(2)) at 4-5 weeks postpartum and 20 never-pregnant controls (BMI = 24.0 ± 3.1 kg/m(2)). Ghrelin, PYY, GLP-1, and appetite ratings were measured before/and 150 minutes after a standardized breakfast and 60 minutes after an ad libitum lunch. Body weight/composition were measured at 6 and 12 months. Fasting and area under-the-curve responses for appetite-regulating hormones did not differ between lactating and control groups; ghrelinacyl, however, tended to track higher after the standardized breakfast in lactating women and was higher (p < 0.05) after the ad libitum lunch despite a 24% higher energy intake (p < 0.05). By 12 months, lactating women lost 5.3 ± 2.2 kg (n = 18), whereas control women (n = 15) remained weight stable (p = 0.019); fifteen of the lactating women returned to within ±2.0 kg of prepregnancy weight but three retained >6.0 kg. The retainers had greater (p < 0.05) postmeal ghrelin rebound responses following breakfast. Overall these studies do not support the hypothesis that appetite-regulating hormones are altered during lactation and associated with postpartum weight retention. Altered ghrelin responses, however, deserve further exploration.

Lactation and Progression to Type 2 Diabetes Mellitus After Gestational Diabetes Mellitus: A Prospective Cohort Study

BACKGROUND

Lactation improves glucose metabolism, but its role in preventing type 2 diabetes mellitus (DM) after gestational diabetes mellitus (GDM) remains uncertain.

OBJECTIVE

To evaluate lactation and the 2-year incidence of DM after GDM pregnancy.

DESIGN

Prospective, observational cohort of women with recent GDM. (ClinicalTrials.gov: NCT01967030).

SETTING

Integrated health care system.

PARTICIPANTS

1035 women diagnosed with GDM who delivered singletons at 35 weeks' gestation or later and enrolled in the Study of Women, Infant Feeding and Type 2 Diabetes After GDM Pregnancy from 2008 to 2011.

MEASUREMENTS

Three in-person research examinations from 6 to 9 weeks after delivery (baseline) and annual follow-up for 2 years that included 2-hour, 75-g oral glucose tolerance testing; anthropometry; and interviews. Multivariable Weibull regression models evaluated independent associations of lactation measures with incident DM adjusted for potential confounders.

RESULTS

Of 1010 women without diabetes at baseline, 959 (95%) were evaluated up to 2 years later; 113 (11.8%) developed incident DM. There were graded inverse associations for lactation intensity at baseline with incident DM and adjusted hazard ratios of 0.64, 0.54, and 0.46 for mostly formula or mixed/inconsistent, mostly lactation, and exclusive lactation versus exclusive formula feeding, respectively (P trend = 0.016). Time-dependent lactation duration showed graded inverse associations with incident DM and adjusted hazard ratios of 0.55, 0.50, and 0.43 for greater than 2 to 5 months, greater than 5 to 10 months, and greater than 10 months, respectively, versus 0 to 2 months (P trend = 0.007). Weight change slightly attenuated hazard ratios.

LIMITATION

Randomized design is not feasible or desirable for clinical studies of lactation.

CONCLUSION

Higher lactation intensity and longer duration were independently associated with lower 2-year incidences of DM after GDM pregnancy. Lactation may prevent DM after GDM delivery.

PRIMARY FUNDING SOURCE

National Institute of Child Health and Human Development.

Lactation and appetite-regulating hormones: increased maternal plasma peptide YY concentrations 3-6 months postpartum

Breast-feeding is associated with maternal hormonal and metabolic changes ensuring adequate milk production. In this study, we investigate the impact of breast-feeding on the profile of changes in maternal appetite-regulating hormones 3-6 months postpartum. Study participants were age- and BMI-matched lactating mothers (n 10), non-lactating mothers (n 9) and women without any history of pregnancy or breast-feeding in the previous 12 months (control group, n 10). During study sessions, young mothers breast-fed or bottle-fed their babies, and maternal blood samples were collected at five time points during 90 min: before, during and after feeding the babies. Outcome parameters were plasma concentrations of ghrelin, peptide YY (PYY), leptin, adiponectin, prolactin, cortisol, insulin, glucose and lipid values. At baseline, circulating PYY concentrations were significantly increased in lactating mothers (100·3 (se 6·7) pg/ml) v. non-lactating mothers (73·6 (se 4·9) pg/ml, P=0·008) and v. the control group (70·2 (se 9) pg/ml, P=0·021). We found no differences in ghrelin, leptin and adiponectin values. Baseline prolactin concentrations were over 4-fold higher in lactating mothers (P<0·001). Lactating women had reduced TAG levels and LDL-cholesterol:HDL-cholesterol ratio, but increased waist circumference, when compared with non-lactating women. Breast-feeding sessions further elevated circulating prolactin (P<0·001), but induced no acute effects on appetite-regulating hormones. In summary, one single breast-feeding session did not acutely modulate circulating appetite-regulating hormones, but increased baseline PYY concentrations are associated with prolonged lactation. PYY might play a role in the coordination of energy balance during lactation, increasing fat mobilisation from maternal depots and ensuring adequate milk production for the demands of the growing infant.

Lactation in Relation to Long-Term Maternal Weight Gain in African-American Women

We assessed the relationship of lactation to long-term maternal weight gain among African-American women, who have a lower prevalence of lactation and a higher prevalence of obesity than other US women. A pregnancy cohort of 3,147 African-American women from the Black Women's Health Study who gave birth for the first time between 1995 and 2003 was followed for 8 years postpartum. Participants provided data on weight, lactation, gestational weight gain, education, diet, and exercise. Mean differences in weight gain were estimated in multivariable models. Overall, lactation was not associated with mean weight gain. However, the association was modified by prepregnancy body mass index (BMI; weight (kg)/height (m)2) (P for interaction=0.03): Among women with BMI<30 prior to the pregnancy, mean weight gain decreased with increasing months of lactation (P for trend<0.01), whereas among obese women (BMI≥30), mean weight gain increased with increasing duration of lactation (P for trend=0.04). Adjusted mean differences for ≥12 months of lactation relative to no lactation were -1.56 kg (95% confidence interval: -2.50, -0.61) among nonobese women and 2.33 kg (95% confidence interval: -0.35, 5.01) among obese women. The differences in postpartum mean weight gain persisted over the 8-year study period. Residual confounding by factors more common in women who breastfeed longer may have influenced the results.

Optimal periods of exclusive breastfeeding associated with any breastfeeding duration through one year

OBJECTIVE

To quantify optimal minimum durations of exclusive breastfeeding associated with maintenance of any breastfeeding at 15 time points during the first year of life.

STUDY DESIGN

Mothers (n = 1189) from the prospective Infant Feeding Practices Study II cohort who initiated exclusive breastfeeding with healthy term infants were included. In a 80:20 split-sample validation study, receiver operating characteristic curves estimated optimal minimum durations of exclusive breastfeeding needed to predict maintenance of any breastfeeding at 15 time points during the first year (n = 951). Logistic regression estimated the predictive performance of the identified thresholds adjusted for maternal age, race, education, parity, support system, and return-to-work status. Results were validated in the remaining 20% (n = 238).

RESULTS

Optimal minimum durations ranged from 4.0-17.1 weeks of exclusive breastfeeding associated with maintenance of any breastfeeding at 15 time points. All estimated threshold durations were statistically significant after adjustment.

CONCLUSIONS

Using a methodological approach unique to breastfeeding duration research, the authors report optimal durations of exclusive breastfeeding associated with duration of any breastfeeding at time points throughout the first year. Perinatal clinicians, pediatricians, lactation professionals, policymakers, researchers, and families might apply these findings to achieve desirable collective breastfeeding duration outcomes.

Breastfeeding status and maternal cardiovascular variables across the postpartum

BACKGROUND

There have been recent reports that lactational history is associated with long-term women's health benefits. Most of these studies are epidemiological. If particular cardiometabolic changes that occur during lactation ultimately influence women's health later is unknown.

METHODS

Seventy-one healthy women participated in a prospective postpartum study that provided an opportunity to study anthropometric, endocrine, immune, and behavioral variables across time. Variables studied were heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), C-reactive protein, body mass index (BMI), perceived stress, and hormones. A cohort of women without a change in breastfeeding (N=22) or formula feeding (N=23) group membership for 5 months was used for analysis of effects of feeding status. The data were analyzed using factorial repeated measures analysis of variance and analysis of covariance.

RESULTS

SBP and HR declined across the postpartum and were significantly lower in breastfeeding compared to formula feeding mothers (p<0.05). These differences remained statistically significant when BMI was added to the model. Other covariates of income, stress, marital status, and ethnicity were not significantly associated with these variables over time. DBP was also lower, but the significance was reduced by the addition of BMI as a covariate. Stress also was lower in breastfeeders, but this effect was reduced by the addition of income as a covariate.

CONCLUSIONS

These data suggest that there are important physiological differences in women during months of breastfeeding. These may have roles in influencing or programming later risks for a number of midlife diseases.

Breast-feeding and maternal risk of type 2 diabetes: a prospective study and meta-analysis

AIMS/HYPOTHESIS

We aimed to examine the association between breast-feeding and maternal risk of type 2 diabetes and to investigate whether this association is mediated by anthropometric and biochemical factors.

METHODS

A case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study between 1994 and 2005 including 1,262 childbearing women (1,059 in a random sub-cohort and 203 incident cases) mainly aged between 35 and 64 years at baseline was applied. Self-reported lifetime duration of breast-feeding was assessed by questionnaire. Blood samples were used for biomarker measurement (HDL-cholesterol, triacylglycerols, C-reactive protein, fetuin-A, γ-glutamyltransferase, adiponectin). A systematic literature search and meta-analysis was conducted of prospective cohort studies investigating breast-feeding and risk of type 2 diabetes.

RESULTS

The HR for each additional 6 months of breast-feeding was 0.73 (95% CI 0.56, 0.94) in EPIC-Potsdam. Meta-analysis of three previous prospective studies and the current study revealed an inverse association between breast-feeding duration and risk of diabetes (pooled HR for lifetime breast-feeding duration of 6-11 months compared with no breast-feeding 0.89; 95% CI 0.82, 0.97). Adjustment for BMI and waist circumference attenuated the association (HR per six additional months in EPIC-Potsdam 0.80; 95% CI 0.61, 1.04). Further controlling for potentially mediating biomarkers largely explained this association (HR 0.89; 95% CI 0.68, 1.16).

CONCLUSIONS/INTERPRETATION

Longer duration of breast-feeding may be related to a lower risk of diabetes. This potentially protective effect seems to be reflected by a more favourable metabolic profile; however, the role of body weight as a mediator or confounder remains uncertain.

Lactation intensity and fasting plasma lipids, lipoproteins, non-esterified free fatty acids, leptin and adiponectin in postpartum women with recent gestational diabetes mellitus: the SWIFT cohort

OBJECTIVES

Lactation may influence future progression to type 2 diabetes after gestational diabetes mellitus (GDM). However, biomarkers associated with progression to glucose intolerance have not been examined in relation to lactation intensity among postpartum women with previous GDM. This study investigates whether higher lactation intensity is related to more favorable blood lipids, lipoproteins and adipokines after GDM pregnancy independent of obesity, socio-demographics and insulin resistance.

METHODS

The Study of Women, Infant Feeding, and Type 2 Diabetes (SWIFT) is a prospective cohort study that recruited 1035 women diagnosed with GDM by the 3-h 100g oral glucose tolerance tests (OGTTs) after delivery of a live birth in 2008-2011. Research staff conducted 2-h 75 g OGTTs, and assessed lactation intensity, anthropometry, lifestyle behaviors and socio-demographics at 6-9 weeks postpartum (baseline). We assayed fasting plasma lipids, lipoproteins, non-esterified free fatty acids, leptin and adiponectin from stored samples obtained at 6-9 weeks postpartum in 1007 of the SWIFT participants who were free of diabetes at baseline. Mean biomarker concentrations were compared among lactation intensity groups using multivariable linear regression models.

RESULTS

Increasing lactation intensity showed graded monotonic associations with fully adjusted mean biomarkers: 5%-8% higher high-density lipoprotein cholesterol (HDL-cholesterol), 20%-28% lower fasting triglycerides, 15%-21% lower leptin (all trend P-values < 0.01), and with 6% lower adiponectin, but only after adjustment for insulin resistance (trend P-value = 0.04).

CONCLUSION

Higher lactation intensity was associated with more favorable biomarkers for type 2 diabetes, except for lower plasma adiponectin, after GDM delivery. Long-term follow-up studies are needed to assess whether these effects of lactation persist to predict progression to glucose intolerance.

Prevalence and risk factors for early, undesired weaning attributed to lactation dysfunction

BACKGROUND

Breastfeeding durations in the United States fall short of public health objectives. We sought to quantify the prevalence and identify risk factors for early, undesired weaning that mothers attribute to physiologic difficulties with breastfeeding.

METHODS

We analyzed data from the Infant Feeding Practices Study (IFPS) II, a longitudinal study of US women. We defined disrupted lactation as early, undesired weaning attributed to at least two of the following three problems: breast pain, low milk supply, and difficulty with infant latch. We used logistic regression to estimate the association maternal body mass index (BMI), postpartum depressive symptoms, and disrupted lactation.

RESULTS

Of 4,902 women enrolled in the IFPS II, we analyzed 2,335 women who reported prenatal intention and breastfeeding initiation. The prevalence of disrupted lactation was 12 per 100 women (95% confidence interval [CI] 11, 13) during the first year of life. Women in this group weaned earlier (median 1.2 months, interquartile range [IQR] 0.5-2.8) than women without disrupted lactation (median 7.0 months, IQR 2.8-2.0, p<0.01). In multivariable-adjusted (MV-adj.) models, we found increased odds of disrupted lactation among overweight (odds ratio [OR] 1.6, 95% CI 1.1-2.3) or obese (OR 1.7, 95% CI 1.2-2.6) women, compared with women with a normal pregravid BMI. Maternal depressive symptoms at 2 months, defined as Edinburgh Postnatal Depression Scale ≥13, were also associated with disrupted lactation (MV-adj. OR 1.7, 95% CI 1.1-2.7).

CONCLUSION

In a longitudinal sample of US women, disrupted lactation affected one in eight mothers who initiated breastfeeding. These findings underscore the need for both improved early breastfeeding support and targeted research to define the underlying pathophysiology and to determine management strategies that will enable more mothers to achieve their breastfeeding goals.

Heterogeneity of cardiovascular risk factors profile in non-diabetic women 2-24 months post gestational diabetes mellitus

Previously gestational diabetic (pGDM) women are characterized by high cardiovascular risk (CVR). The aim of this study was to assess the CVR markers levels in non-diabetic pGDM women in relation to time postpartum and to soluble E-selectin (sES) level. We investigated 125 women aged 18-40 years with a history of GDM between 2 and 24 months after their pregnancy. We evaluated age, body mass index (BMI), waist circumference, glucose levels during the oral glucose tolerance test (OGTT), levels of insulin and the parameters of endothelial dysfunction, fibrinolysis activity, low-grade systemic inflammation and lipid profiles. Prediabetes was identified in 38 women (30%), while in the remaining women OGTT results were normal. The tests performed >6 months revealed decreased hs-CRP (p = 0.01), sICAM-1 (p = 0.01), and elevated sES (p = 0.01) >12 months after adjustment for age, BMI, waist circumference and 2 h OGTT glucose. In the subgroup tested ≤12 months after an index pregnancy sES was independently associated with hs-CRP (p < 0.0001) and triglycerides (p = 0.0139). No association was found between sES and remaining parameters in women tested >12 months postpartum. We conclude that the period 2-24 months post GDM is heterogeneous with respect to the CVR markers. The plasma level of hs-CRP could be useful as an important cardiovascular risk marker up to 12 months postpartum in non-diabetic pGDM women.

Breastfeeding and the maternal risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies

BACKGROUND AND AIMS

Breastfeeding has been associated with reduced risk of maternal type 2 diabetes in some cohort studies, but the evidence from published studies have differed with regard to the strength of the association. To clarify this association we conducted a systematic review and dose-response meta-analysis of breastfeeding and maternal risk of type 2 diabetes.

METHODS AND RESULTS

We conducted a systematic review and dose-response meta-analysis of prospective studies of breastfeeding and maternal risk of type 2 diabetes. We searched the PubMed, Embase and Ovid databases up to September 19th 2013. Summary relative risks were estimated using a random effects model. Six cohort studies including 10,842 cases among 273,961 participants were included in the meta-analysis. The summary RR for the highest duration of breastfeeding vs. the lowest was 0.68 (95% CI: 0.57-0.82, I(2) = 75%, p heterogeneity = 0.001, n = 6). The summary RR for a three month increase in the duration of breastfeeding per child was 0.89 (95% CI: 0.77-1.04, I(2) = 93%, p heterogeneity < 0.0001, n = 3) and the summary RR for a one year increase in the total duration of breastfeeding was 0.91 (95% CI: 0.86-0.96, I(2) = 81%, p heterogeneity = 0.001, n = 4). There was little difference in the summary estimates whether or not BMI had been adjusted for. The inverse associations appeared to be nonlinear, p nonlinearity < 0.0001 for both analyses, and in both analyses the reduction in risk was steeper when increasing breastfeeding from low levels.

CONCLUSION

This meta-analysis suggests that there is a statistically significant inverse association between breastfeeding and maternal risk of type 2 diabetes.

Long-term protective effect of lactation on the development of type 2 diabetes in women with recent gestational diabetes mellitus

Women with gestational diabetes mellitus (GDM) have a high risk of developing postpartum type 2 diabetes. Strategies to prevent postpartum type 2 diabetes are important to reduce the epidemic of diabetes and its societal impact. Breastfeeding was reported to improve early postpartum glucose tolerance and reduce the subsequent risk of type 2 diabetes. To investigate whether breastfeeding influences short- and long-term postpartum diabetes outcomes, women with GDM (n = 304) participating in the prospective German GDM study were followed from delivery for up to 19 years postpartum for diabetes development. All participants were recruited between 1989 and 1999. Postpartum diabetes developed in 147 women and was dependent on the treatment received during pregnancy (insulin vs. diet), BMI, and presence/absence of islet autoantibodies. Among islet autoantibody-negative women, breastfeeding was associated with median time to diabetes of 12.3 years compared with 2.3 years in women who did not breastfeed. The lowest postpartum diabetes risk was observed in women who breastfed for >3 months. On the basis of these results, we recommend that breastfeeding should be encouraged among these women because it offers a safe and feasible low-cost intervention to reduce the risk of subsequent diabetes in this high-risk population.

Gestational glucose tolerance and maternal metabolic profile at 3 years postpartum

OBJECTIVE

To estimate the independent effect of gestational impaired glucose tolerance, defined as a single abnormal oral glucose tolerance test value, on metabolic dysfunction at 3 years postpartum.

METHODS

We used multiple linear regression to measure associations between glucose testing during pregnancy and metabolic markers at 3 years postpartum in Project Viva, a prospective cohort study of maternal and infant health. We compared metabolic measures at 3 years postpartum among four groups: normal glucose challenge test (less than 140 mg/dL, n=461); abnormal glucose challenge test but normal glucose tolerance test (n=39); impaired glucose tolerance (a single abnormal glucose tolerance test value, n=21); and gestational diabetes mellitus (n=16).

RESULTS

Adjusting for age, race, parity, parental history of diabetes, and maternal body mass index at 3 years postpartum, we found women with gestational diabetes mellitus had lower adiponectin (11.2 ng/mL compared with 20.7 ng/mL) and higher homeostatic model assessments of insulin resistance (3.1 compared with 1.3) and waist circumference (91.3 cm compared with 86.2 cm) compared with women with impaired glucose tolerance or normal glucose tolerance. Women in both the impaired glucose tolerance and gestational diabetes mellitus groups had lower high-density lipoprotein (gestational diabetes mellitus 44.7 mg/dL; impaired glucose tolerance 45.4/dL compared with normal glucose tolerance 55.8 mg/dL) and higher triglycerides (gestational diabetes mellitus 136.1 mg/dL; impaired glucose tolerance 140.1 mg/dL compared with normal glucose tolerance 78.3) compared with women in the normal glucose tolerance group. We found the highest values for hemoglobin A1c (gestational diabetes mellitus 5.1%, impaired glucose tolerance 5.3%, normal glucose tolerance 5.1%) and high-sensitivity C-reactive protein (gestational diabetes mellitus 1.4 mg/dL, impaired glucose tolerance 2.2 mg/dL, normal glucose tolerance 1.0 mg/dL) among women with impaired glucose tolerance.

CONCLUSION

Gestational diabetes mellitus and impaired glucose tolerance during pregnancy are associated with persistent metabolic dysfunction at 3 years postpartum, independent of other clinical risk factors.