Lactation and changes in maternal metabolic risk factors

Lipoprotein Metabolism, Dyslipidemia, and Lipid-Lowering Therapy in Women: A Comprehensive Review

Lipid-lowering therapy (LLT) is a cornerstone of atherosclerotic cardiovascular disease prevention. Although LLT might lead to different reductions in low-density lipoprotein cholesterol (LDL-C) levels in women and men, LLT diminishes cardiovascular risk equally effectively in both sexes. Despite similar LLT efficacy, the use of high-intensity statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors is lower in women compared to men. Women achieve the guideline-recommended LDL-C levels less often than men. Greater cholesterol burden is particularly prominent in women with familial hypercholesterolemia. In clinical practice, women and men with dyslipidemia present with different cardiovascular risk profiles and disease manifestations. The concentrations of LDL-C, lipoprotein(a), and other blood lipids differ between women and men over a lifetime. Dissimilar levels of LLT target molecules partially result from sex-specific hormonal and genetic determinants of lipoprotein metabolism. Hence, to evaluate a potential need for sex-specific LLT, this comprehensive review (i) describes the impact of sex on lipoprotein metabolism and lipid profile, (ii) highlights sex differences in cardiovascular risk among patients with dyslipidemia, (iii) presents recent, up-to-date clinical trial and real-world data on LLT efficacy and safety in women, and (iv) discusses the diverse medical needs of women and men with dyslipidemia and increased cardiovascular risk.

Association between breastfeeding duration and diabetes mellitus in menopausal women: a machine-learning analysis using population-based retrospective study

BACKGROUND

Breastfeeding resets insulin resistance caused by pregnancy however, studies on the association between breastfeeding and diabetes mellitus (DM) have reported inconsistent results. Therefore, we aimed to investigate the risk of DM according to breastfeeding duration in large-scale population-based retrospective study. In addition, machine-learning prediction models for DM and hemoglobin A1c (HbA1c) were developed to further evaluate this association.

METHODS

We used the Korean National Health and Nutrition Examination Surveys database, a nationwide and population-based health survey from 2010 to 2020. We included 15,946 postmenopausal women with a history of delivery, whom we divided into three groups according to the average breastfeeding duration: (1) no breastfeeding, (2) < 12 months breastfeeding, and (3) ≥ 12 months breastfeeding. Prediction models for DM and HbA1c were developed using an artificial neural network, decision tree, logistic regression, Naïve Bayes, random forest, and support vector machine.

RESULTS

In total, 2248 (14.1%) women had DM and 14,402 (90.3%) had a history of breastfeeding. The prevalence of DM was the lowest in the < 12 breastfeeding group (no breastfeeding vs. < 12 months breastfeeding vs. ≥ 12 months breastfeeding; 161 [10.4%] vs. 362 [9.0%] vs. 1,725 [16.7%], p < 0.001). HbA1c levels were also the lowest in the < 12 breastfeeding group (HbA1c: no breastfeeding vs. < 12 months breastfeeding vs. ≥ 12 months breastfeeding; 5.9% vs. 5.9% vs. 6.1%, respectively, p < 0.001). After adjustment for covariates, the risk of DM was significantly increased in both, the no breastfeeding (adjusted odds ratio [aOR] 1.29; 95% CI 1.29, 1.62]) and ≥ 12 months of breastfeeding groups (aOR 1.18; 95% CI 1.01, 1.37) compared to that in the < 12 months breastfeeding group. The accuracy and the area under the receiver-operating-characteristic curve of the DM prediction model were 0.93 and 0.95, respectively. The average breastfeeding duration was ranked among the top 15 determinants of DM, which supported the strong association between breastfeeding duration and DM. This association was also observed in a prediction model for HbA1c.

CONCLUSIONS

Women who did not breasted had a higher risk of developing DM than those who breastfed for up to 12 months.

The Fit After Baby randomized controlled trial: An mHealth postpartum lifestyle intervention for women with elevated cardiometabolic risk

BACKGROUND

Postpartum women with overweight/obesity and a history of adverse pregnancy outcomes are at elevated risk for cardiometabolic disease. Postpartum weight loss and lifestyle changes can decrease these risks, yet traditional face-to-face interventions often fail. We adapted the Diabetes Prevention Program into a theory-based mobile health (mHealth) program called Fit After Baby (FAB) and tested FAB in a randomized controlled trial.

METHODS

The FAB program provided 12 weeks of daily evidence-based content, facilitated tracking of weight, diet, and activity, and included weekly coaching and gamification with points and rewards. We randomized women at 6 weeks postpartum 2:1 to FAB or to the publicly available Text4baby (T4B) app (active control). We measured weight and administered behavioral questionnaires at 6 weeks, and 6 and 12 months postpartum, and collected app user data.

RESULTS

81 eligible women participated (77% White, 2% Asian, 15% Black, with 23% Hispanic), mean baseline BMI 32±5 kg/m2 and age 31±5 years. FAB participants logged into the app a median of 51/84 (IQR 25,71) days, wore activity trackers 66/84 (IQR 43,84) days, logged weight 17 times (IQR 11,24), and did coach check-ins 5.5/12 (IQR 4,9) weeks. The COVID-19 pandemic interrupted data collection for the primary 12-month endpoint, and impacted diet, physical activity, and body weight for many participants. At 12 months postpartum women in the FAB group lost 2.8 kg [95% CI -4.2,-1.4] from baseline compared to a loss of 1.8 kg [95% CI -3.8,+0.3] in the T4B group (p = 0.42 for the difference between groups). In 60 women who reached 12 months postpartum before the onset of the COVID-19 pandemic, women randomized to FAB lost 4.3 kg [95% CI -6.0,-2.6] compared to loss in the control group of 1.3 kg [95% CI -3.7,+1.1] (p = 0.0451 for the difference between groups).

CONCLUSIONS

There were no significant differences between groups for postpartum weight loss for the entire study population. Among those unaffected by the COVID pandemic, women randomized to the FAB program lost significantly more weight than those randomized to the T4B program. The mHealth FAB program demonstrated a substantial level of engagement. Given the scalability and potential public health impact of the FAB program, the efficacy for decreasing cardiometabolic risk by increasing postpartum weight loss should be tested in a larger trial.

Breastfeeding Associated with Lower Prevalence of Metabolic Syndrome in Women with Gestational Diabetes in the Very Early Postpartum Period

OBJECTIVE

The aim of this study is to examine the association of breastfeeding with metabolic syndrome (MetS) in women with recent gestational diabetes mellitus (GDM) in the very early postpartum (PP) period.

STUDY DESIGN

We performed a secondary analysis of the Balance After Baby Intervention (BABI) study which enrolled women with recent GDM. Data collected during an early (~8 weeks) PP visit were used in this analysis. At this visit, weight, height, waist circumference (WC), blood pressure (BP), fasting plasma glucose (FPG), and lipids were obtained. MetS was classified per National Cholesterol Education Program Adult Treatment Program III (NCEP-ATP III) criteria. We defined breastfeeding as currently breastfeeding or not currently breastfeeding for the main analysis.

RESULTS

Of 181 women enrolled in BABI, 178 were included in this analysis (3 excluded for missing lipids). Thirty-four percent were Hispanic. Of non-Hispanics, 31.5% were White, 18.5% Asian, and 12.9% Black/African American. The prevalence of MetS was 42.9% in women not breastfeeding versus 17.1% in women breastfeeding (p < 0.001; adjusted odds ratio [aOR] = 0.16 [95% confidence interval (CI): 0.06-0.41]). Breastfeeding women had significantly lower odds of FPG ≥100 mg/dL (aOR = 0.36 [95% CI: 0.14-0.95], p = 0.039), HDL < 50 mg/dL (aOR = 0.19 [95% CI: 0.08-0.46], p < 0.001), and triglycerides (TG) ≥ 150 mg/dL (aOR = 0.26 [95% CI: 0.10-0.66], p = 0.005). When evaluated as continuous variables, WC, FPG, and TG were significantly lower and HDL significantly higher in women breastfeeding in the very early PP period (vs. not breastfeeding).

CONCLUSION

In a diverse population of women with recent GDM, there was lower prevalence of MetS in women breastfeeding compared with those not breastfeeding in the very early PP period. This study extends the findings of an association of breastfeeding with MetS previously reported at time points more remote from pregnancy to the very early PP period and to an ethnically and racially diverse population.

KEY POINTS

· MetS prevalence in women with recent GDM was lower in breastfeeding than not breastfeeding women.. · FPG, HDL, WC, and TG were improved in the breastfeeding group.. · This study extends prior findings to the very early PP period and to a diverse population..

Adverse pregnancy outcomes and risk of type 2 diabetes in postmenopausal women

BACKGROUND

Although gestational diabetes mellitus and delivering high-birthweight infants are known to predict a higher risk of future type 2 diabetes mellitus, the association of hypertensive disorders of pregnancy and other adverse pregnancy outcomes with type 2 diabetes mellitus is not well established.

OBJECTIVE

This study aimed to examine the associations between different types of adverse pregnancy outcomes and incident type 2 diabetes mellitus among postmenopausal women.

STUDY DESIGN

The Women's Health Initiative, a nationwide cohort of postmenopausal women, collected self-reported history of adverse pregnancy outcomes, including gestational diabetes mellitus, hypertensive disorders of pregnancy, preterm birth, and delivering low- birthweight (<2500 g) or high-birthweight (>4500 g) infants. Participants were followed up annually for self-reported incident type 2 diabetes mellitus treated with medication from baseline (1993-1998) to March 2021. This study used logistic regression to examine the associations of any and individual adverse pregnancy outcomes with diabetes mellitus. Stratified analyses were performed to assess effect modification by body mass index, race and ethnicity, education, parity, breastfeeding, and age at first birth.

RESULTS

This analysis included 49,717 women without a history of diabetes mellitus at enrollment who had a least 1 pregnancy and responded to the questionnaire about adverse pregnancy outcomes. After adjusting for body mass index, demographic, lifestyle, and reproductive factors, gestational diabetes mellitus (odds ratio, 2.26; 95% confidence interval, 1.94-2.63), high birthweight (odds ratio, 1.30; 95% confidence interval, 1.18-1.44), and hypertensive disorders of pregnancy (odds ratio, 1.18; 95% confidence interval, 1.08-1.30) were independently associated with higher odds of type 2 diabetes mellitus, whereas preterm birth and low birthweight were not associated with diabetes mellitus risk. A history of ≥2 adverse pregnancy outcomes was associated with higher odds of type 2 diabetes mellitus (odds ratio, 1.55; 95% confidence interval, 1.28-1.88). This study further observed higher odds of type 2 diabetes mellitus (odds ratio, 3.69; 95% confidence interval, 2.38-5.70) among women with a history of both gestational diabetes mellitus and hypertensive disorders of pregnancy than those without any adverse pregnancy outcomes.

CONCLUSION

Postmenopausal women with a history of gestational diabetes mellitus, those delivering high-birthweight infants, or those with hypertensive disorders of pregnancy are at risk of future type 2 diabetes mellitus. In addition, women with ≥2 conditions had an augmented risk and might be prioritized for screening and prevention efforts for type 2 diabetes mellitus.

Sex differences in lipids: A life course approach

Differences between men and women in lipids and lipoproteins are observed in distribution and trajectory from infancy to adulthood in the general population. However, these differences are more pronounced in hereditary lipid disorders such as familial hypercholesterolemia (FH) when absolute cholesterol levels are higher from birth onwards. In the early life course, girls compared to boys have higher low-density lipoprotein cholesterol (LDL-C) levels and total cholesterol, while high-density lipoprotein cholesterol (HDL-C) levels are similar. In early adulthood to middle-age, women have lower LDL-C and higher HDL-C levels, as LDL-C levels increase and HDLC levels decrease in men. In the elderly, all lipids - total cholesterol, LDL-C, HDL-C and triglyceride levels decrease but are more pronounced in men. Lipid levels are also affected by specific transitions in girls/women such as the menstrual cycle, pregnancy, breastfeeding and menopause. Lipid levels fluctuate during the menstrual cycle. During pregnancy a physiological increase of LDL-C and even a larger increase in triglyceride levels are observed. Pregnancy has a double impact on LDL-C accumulation in women with FH as they have to stop statins, and the absolute increase in LDL-C is higher than in women without FH. In the menopausal transition, women develop a more adverse lipid profile. Therefore, it is important to take into account both sex and the life course when assessing a lipid profile.

Sex Differences in Familial Hypercholesterolemia

PURPOSE OF REVIEW

This review aims to summarize the existing research on sex differences in familial hypercholesterolemia (FH) across the lifespan.

RECENT FINDINGS

From childhood onward, total- and low-density lipoprotein cholesterol (LDL-C) levels in girls are higher than those in boys with FH. By the age of 30 years, women with FH have a higher LDL-C burden than men. In adulthood, women are diagnosed later than men, receive less lipid-lowering treatment, and consequently have higher LDL-C levels. An excessive atherosclerotic cardiovascular disease risk is reported in young female compared to male FH patients. The periods of pregnancy and breastfeeding contribute to treatment loss and increased cholesterol burden. Earlier initiation of treatment, especially in girls with FH, and lifelong treatment during all life stages are important. Future research should aim to recruit both women and men, report sex-specific data, and investigate the impact of the female life course on cardiovascular outcomes. Future guidelines should include sex-specific aspects.

The relationship between pregnancy count and duration of breast-feeding with metabolic syndrome (Fasa Persian cohort study)

BACKGROUND

Changes that occur during pregnancy and after that during breastfeeding induce some symptoms similar to metabolic syndrome (MetS) risk factors. This study aims to determine the relationship between pregnancy, as well as the duration of breastfeeding and MetS controlling the effect of other risk factors like hypertension, glucose intolerance, triglyceride, central obesity, and reduction of high-density lipoprotein in women of Fasa Persian Cohort Study.

MATERIALS AND METHODS

In this cross-sectional study, 5015 women aged 35-70 years were investigated in the Sheshdeh region from 2016 to 2021, and the information related to the disease symptoms was collected through questionnaires, examinations, and laboratory tests. MetS was calculated based on two guidelines according to adult treatment panel III (ATP III) and international diabetes federation (IDF) methods. For reporting the data, the odds ratio with its 95% confidence interval was used. In order to eliminate the effect of confounders, logistic regression was used.

RESULTS

Prevalence of MetS showed a descending trend in women with up to two pregnancies and it reached 22.6% and 22.4% using ATPIII and IDF methods respectively, while with an increase in the number of pregnancies of more than two, MetS prevalence was ascending. The prevalence of MetS did not have any specific trend across various breastfeeding duration groups. Multivariate analysis approved that the odds ratio of developing MetS in comparison with women who had two pregnancies was significantly increasing trend when the pregnancy counts increased.

CONCLUSION

The chance of developing MetS based on both IDF and ATP III methods after adjustment for confounding effects would grow with an increase in the number of pregnancies to more than two and breast-feeding of more than seven years. It is recommended that women with more than two pregnancies or the long duration of breast-feeding women undergo a specialized examination to investigate and control MetS problems so that future diseases could be prevented.

Associations of Physical Activity and Lactation Duration With Cardiometabolic Risk Factors: The CARDIA Study

BACKGROUND

Physical activity (PA) and lactation benefit cardiometabolic health.

OBJECTIVES

The purpose of this study was to describe the joint associations of PA and lactation with cardiometabolic risk.

METHODS

We averaged PA across exams and summed lifetime lactation in Black and White parous women in the Coronary Artery Risk Development in Young Adults Study. Categories were created for PA (-PA:

RESULTS

The median PA was 256 exercise units and 54% reported lactation duration of ≥3 months. Of 1,068 participants, 303 were in the -PA/-L category, 231 in -PA/+L, 184 in +PA/-L, and 350 in +PA/+L. +PA/+L participants were older, had more years of education, lower body mass index, gained less weight, and less likely to be Black vs -PA/-L participants. Risk scores differed between categories except -PA/+L and +PA/-L (P = 0.08): -PA/-L: 0.23+/-0.04, -PA/+L: 0.08+/-0.04, +PA/-L: -0.02+/-0.05, and +PA/+L: -0.23+/-0.03. After adjustment, +PA/+L was associated with a lower/better risk score (β = -0.15, 95% CI: -0.25 to -0.04).

CONCLUSIONS

Above average PA throughout adulthood combined with ≥3 months of lactation was associated with lower risk scores. Participants with either behavior had lower risk vs those with neither behavior. Attaining these levels of behaviors may reduce cardiometabolic risk in parous women.

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Key Words

• cardiometabolic risk
• lactation
• physical activity

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MESH Headings Collapse

Grants

• R01 DK090047 NIDDK NIH HHS
• R01 DK106201 NIDDK NIH HHS

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Affiliation(s)

Abbi Lane Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
Kara M. Whitaker Department of Health and Human Physiology, Department of Epidemiology, University of Iowa, Iowa City, Iowa, USA
Muna Tahir ICON plc, San Francisco, California, USA
Bethany Barone Gibbs Department of Epidemiology and Biostatistics, School of Public Health, University of West Virginia, Morgantown, West Virginia, USA
Janet Catov Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Department of Obstetrics and Gynecology, Magee-Women’s Research Center, Pittsburgh, Pennsylvania, USA
Mercedes Carnethon Department of Preventive Medicine, Feinberg School of Medicine, Chicago, Illinois, USA
Erica P. Gunderson Division of Research, Kaiser Permanente of Northern California, Oakland, California, USA

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Number of prior live births is associated with higher arterial stiffness but not its change in older women: the atherosclerosis risk in communities study

Introduction

Although studies have demonstrated a J-shaped association between parity and cardiovascular disease (CVD), the association with arterial stiffness is not fully understood.

Methods

We examined the association between parity and carotid-femoral pulse wave velocity (cfPWV), a measure of central arterial stiffness. We conducted a longitudinal analysis of 1220 women (mean age 73.7 years) who attended the Atherosclerosis Risk in Communities Study visit 5 (2011-2013). At visit 2 (1990-1992), women self-reported parity (number of prior live births), which we categorized as: 0 (never pregnant or pregnant with no live births); 1-2 (referent); 3-4; and 5+ live births. Technicians measured cfPWV at visit 5 (2011-2013) and visit 6 or 7 (2016-2019). Multivariable linear regression modeled the associations of parity with visit 5 cfPWV and cfPWV change between visit 5 and 6/7 adjusted for demographics and potential confounding factors.

Results

Participants reported 0 (7.7%), 1-2 (38.7%), 3-4 (40.0%), or 5+ (13.6%) prior live births. In adjusted analyses, women with 5+ live births had a higher visit 5 cfPWV (β=50.6 cm/s, 95% confidence interval: 3.6, 97.7 cm/s) than those with 1-2 live births. No statistically significant associations were observed for other parity groups with visit 5 cfPWV or with cfPWV change.

Discussion

In later life, women with 5+ live births had higher arterial stiffness than those with 1-2 live births, but cfPWV change did not differ by parity, suggesting women with 5+ live births should be targeted for early primary prevention of CVD given their higher arterial stiffness at later-life.

Breastfeeding and Later-Life Cardiometabolic Health in Women With and Without Hypertensive Disorders of Pregnancy

Background Breastfeeding is associated with improved cardiometabolic profiles decades after pregnancy. Whether this association exists for women who experience hypertensive disorders of pregnancy (HDP) is unknown. The authors examined whether breastfeeding duration or exclusivity are associated with long-term cardiometabolic health, and whether this relationship differs by HDP status. Methods and Results Participants (N=3598) were from the UK ALSPAC (Avon Longitudinal Study of Parents and Children) cohort. HDP status was assessed by medical record review. Breastfeeding behaviors were assessed by contemporaneous questionnaires. Breastfeeding duration was categorized as never, <1, 1 to <3, 3 to <6, 6 to <9, and 9+ months. Breastfeeding exclusivity was categorized as never, <1, 1 to <3, and 3 to 6 months. Measures of cardiometabolic health (body mass index, waist circumference, C-reactive protein, insulin, proinsulin, glucose, lipids, blood pressure, mean arterial pressure, carotid intima-media thickness, and arterial distensibility) were measured 18 years after pregnancy. Analyses were conducted using linear regression adjusting for relevant covariates. Breastfeeding was associated with improved cardiometabolic health (lower body mass index, waist circumference, C-reactive protein, triglycerides, insulin, and proinsulin) in all women, but not for every breastfeeding duration. Interaction tests revealed additional benefits in women with a history of HDP, with the strongest benefit observed in the 6- to 9-month breastfeeding category (diastolic blood pressure, -4.87 mm Hg [95% CI, -7.86 to -1.88], mean arterial pressure -4.61 [95% CI, -7.45 to -1.77], and low-density lipoprotein cholesterol, -0.40 mmol/L [95% CI, -0.62 to -0.17 mmol/L]). Differences in C-reactive protein and low-density lipoprotein "survived" Bonferroni correction (P<0.001). Similar results were observed in the exclusive breastfeeding analyses. Conclusions Breastfeeding may be a mechanism to reduce the cardiovascular disease sequela associated with HDP; however, there is a need to establish whether associations reflect a causal effect.

Women's Reproductive Milestones and Cardiovascular Disease Risk: A Review of Reports and Opportunities From the CARDIA Study

In 1985 to 1986, the CARDIA (Coronary Artery Risk Development in Young Adults) study enrolled 5115 Black or White participants, including 2788 women, aged 18 to 30 years. Over the following 35 years, the CARDIA study amassed extensive longitudinal data on women's reproductive milestones, spanning menarche to menopause. Although not initially conceived as a study of women's health, >75 CARDIA study publications address relationships between reproductive factors and events with cardiovascular and metabolic risk factors, subclinical and clinical cardiovascular disease, and social determinants of health. The CARDIA study was one of the earliest population-based reports to note Black-White differences in age at menarche and associations with cardiovascular risk factors. Adverse pregnancy outcomes, particularly gestational diabetes and preterm birth, have been assessed along with postpartum behaviors, such as lactation. Existing studies have examined risk factors for adverse pregnancy outcomes and lactation, as well as their relationship to future cardiovascular and metabolic risk factors, diagnoses, and subclinical atherosclerosis. Ancillary studies examining components of polycystic ovary syndrome and ovarian biomarkers, such as anti-Müllerian hormone, have facilitated examination of reproductive health in a population-based cohort of young adult women. As the cohort transitioned through menopause, examination of the importance of premenopausal cardiovascular risk factors along with menopause has improved our understanding of shared mechanisms. The cohort is now aged in the 50s to mid-60s, and women will begin to experience a greater number of cardiovascular events as well as other conditions, such as cognitive impairment. Thus, in the next decade, the CARDIA study will provide a unique resource for understanding how the women's reproductive life course epidemiology informs cardiovascular risk, as well as reproductive and chronological aging.

Pregnancy-related factors may signal additional protection or risk of future cardiovascular diseases

BACKGROUND

Cardiovascular disease (CVD) guidelines recommend using the Pooled Cohort Equation (PCE) to assess 10-year CVD risk based on traditional risk factors. Pregnancy-related factors have been associated with future CVD. We examined the contribution of two pregnancy-related factors, (1) history of a low birthweight (LBW) infant and (2) breastfeeding to CVD risk accounting for traditional risk factors as assessed by the PCE.

METHODS

A nationally representative sample of women, ages 40-79, with a history of pregnancy, but no prior CVD, was identified using NHANES 1999-2006. Outcomes included (1) CVD death and (2) CVD death plus CVD surrogates. We used Cox proportional hazards models to adjust for PCE risk score.

RESULTS

Among 3,758 women, 479 had a LBW infant and 1,926 reported breastfeeding. Mean follow-up time was 12.1 years. Survival models showed a consistent reduction in CVD outcomes among women with a history of breastfeeding. In cause-specific survival models, breastfeeding was associated with a 24% reduction in risk of CVD deaths (HR 0.76; 95% CI 0.45─1.27, p = 0.30) and a 33% reduction in risk of CVD deaths + surrogate CVD, though not statistically significant. (HR 0.77; 95% CI 0.52─1.14, p = 0.19). Survival models yielded inconclusive results for LBW with wide confidence intervals (CVD death: HR 0.98; 95% CI 0.47─2.05; p = 0.96 and CVD death + surrogate CVD: HR 1.29; 95% CI 0.74─2.25; p = 0.38).

CONCLUSION

Pregnancy-related factors may provide important, relevant information about CVD risk beyond traditional risk factors. While further research with more robust datasets is needed, it may be helpful for clinicians to counsel women about the potential impact of pregnancy-related factors, particularly the positive impact of breastfeeding, on cardiovascular health.

Effects of dietary and exercise treatments on HDL subclasses in lactating women with overweight and obesity: a secondary analysis of a randomised controlled trial

Childbearing decreases HDL-cholesterol, potentially contributing to the increased risk of CVD in parous women. Large HDL particles (HDL-P) are associated with lower risk of CVD. In this secondary analysis of a randomised controlled trial, we investigated the effects of 12-week dietary and exercise treatments on HDL-P subclass concentration, size and apoA1 in lactating women with overweight/obesity. At 10-14 weeks postpartum, 68 women with pre-pregnant BMI 25-35 kg/m² were randomised to four groups using 2 × 2 factorial design: (1) dietary treatment for weight loss; (2) exercise treatment; (3) both treatments and (4) no treatment. Lipoprotein subclass profiling by NMR spectroscopy was performed in serum at randomisation and after 3 and 12 months, and the results analysed with two-way ANCOVA. Lipid concentrations decline naturally postpartum. At 3 months (5-6 months postpartum), both diet (P = 0·003) and exercise (P = 0·008) reduced small HDL-P concentration. Concurrently, exercise limited the decline in very large HDL-P (P = 0·002) and the effect was still significant at 12 months (15 months postpartum) (P = 0·041). At 12 months, diet limited the decline in very large HDL-P (P = 0·005), large HDL-P (P = 0·001) and apoA1 (P = 0·002) as well as HDL size (P = 0·002). The dietary treatment for weight loss and the exercise treatment both showed effects on HDL-P subclasses in lactating women with overweight and obesity possibly associated with lower CVD risk. The dietary treatment had more effects than the exercise treatment at 12 months, likely associated with a 10 % weight loss.

Breastfeeding duration and subsequent risk of mortality among US women: A prospective cohort study

BACKGROUND

Breastfeeding has been associated with a reduced maternal long-term risk of chronic diseases, but its association with mortality is poorly known.

METHODS

We included 166,708 female United States (US) nurses from the Nurses' Health Study (1986-2016) and the Nurses' Health Study II (1989-2019) who experienced at least one pregnancy lasting at least six months across their reproductive lifespan. Hazard ratios and 95% confidence intervals (CI) for mortality according to lifetime breastfeeding duration were estimated with time-dependent Cox proportional hazards regression models.

FINDINGS

During 4,705,160 person-years of follow-up, 36,634 deaths were documented in both cohorts, including 9880 from cancer and 7709 from cardiovascular disease (CVD). Lifetime total breastfeeding duration was associated with a lower subsequent risk of all-cause mortality in a non-linear manner (p-value for non-linearity=0.0007). The pooled multivariable-adjusted hazard ratios of all-cause mortality were 0.95 (95% CI: 0.92 to 0.98), 0.94 (95% CI: 0.91 to 0.98), 0.93 (95% CI: 0.90 to 0.97), and 0.93 (95% CI: 0.89 to 0.97), respectively, for women reporting lifetime total breastfeeding duration of 4-6, 7-11, 12-23, and ≥24 months, compared to women who breastfed for ≤3 months over their reproductive lifespan. Cause-specific analysis showed a similar pattern of non-linear inverse associations between lifetime total breastfeeding duration and CVD and cancer mortality (both p-values for non-linearity <0.01). There was no evidence of interactions between breastfeeding duration and pre-pregnancy lifestyle factors on mortality risk.

INTERPRETATION

Parous women with longer lifetime breastfeeding duration had a modestly lower risk of mortality.

FUNDING

The National Institutes of Health grants.

Considerations for treatment of lipid disorders during pregnancy and breastfeeding

Adequate management of lipid disorders during pregnancy is essential given the association of dyslipidemia with adverse pregnancy outcomes. While there are physiologic changes in lipid levels that occur with normal pregnancy, abnormal alterations in lipids can lead to increased future risk of atherosclerotic cardiovascular disease. There are inherent challenges in the treatment of dyslipidemias during pregnancy and the postpartum period given the lack of adequate data in this population and the contraindication of traditional therapeutic agents. However, it remains of utmost importance to optimize screening and identification of patients at high-risk for atherosclerotic cardiovascular disease so that proper counseling can be provided and the risk for pregnancy complications and downstream cardiovascular complications can be addressed. In this review, we summarize the literature on the association of dyslipidemia in pregnancy with adverse outcomes and discuss considerations for the management of lipid disorders during both pregnancy and breastfeeding.

Prolactin and Maternal Metabolism in Women With a Recent GDM Pregnancy and Links to Future T2D: The SWIFT Study

CONTEXT

Prolactin is a multifaceted hormone known to regulate lactation. In women with gestational diabetes mellitus (GDM) history, intensive lactation has been associated with lower relative risk of future type 2 diabetes (T2D). However, the role of prolactin in T2D development and maternal metabolism in women with a recent GDM pregnancy has not been ascertained.

OBJECTIVE

We examined the relationships among prolactin, future T2D risk, and key clinical and metabolic parameters.

METHODS

We utilized a prospective GDM research cohort (the SWIFT study) and followed T2D onset by performing 2-hour 75-g research oral glucose tolerance test (OGTT) at study baseline (6-9 weeks postpartum) and again annually for 2 years, and also by retrieving clinical diagnoses of T2D from 2 years through 10 years of follow up from electronic medical records. Targeted metabolomics and lipidomics were applied on fasting plasma samples collected at study baseline from 2-hour 75-g research OGTTs in a nested case-control study (100 future incident T2D cases vs 100 no T2D controls).

RESULTS

Decreasing prolactin quartiles were associated with increased future T2D risk (adjusted odds ratio 2.48; 95% CI, 0.81-7.58; P = 0.05). In women who maintained normoglycemia during the 10-year follow-up period, higher prolactin at baseline was associated with higher insulin sensitivity (P = 0.038) and HDL-cholesterol (P = 0.01), but lower BMI (P = 0.001) and leptin (P = 0.002). Remarkably, among women who developed future T2D, prolactin was not correlated with a favorable metabolic status (all P > 0.05). Metabolomics and lipidomics showed that lower circulating prolactin strongly correlated with a T2D-high risk lipid profile, with elevated circulating neutral lipids and lower concentrations of specific phospholipids/sphingolipids.

CONCLUSION

In women with recent GDM pregnancy, low circulating prolactin is associated with specific clinical and metabolic parameters and lipid metabolites linked to a high risk of developing T2D.

Protective Influence of Breastfeeding on Cardiovascular Risk Factors in Women With Previous Gestational Diabetes Mellitus and Their Children: A Systematic Review and Meta-Analysis

BACKGROUND

There is evidence that breastfeeding may provide protection against cardiovascular risk factors in mothers with a history of gestational diabetes mellitus and their children who were exposed in utero.

RESEARCH AIM

To perform a systematic review and meta-analysis of observational studies to ascertain the effects of breastfeeding on cardiovascular risk factors in women with previous gestational diabetes mellitus and their children exposed in utero.

METHODS

Studies assessing conventional cardiovascular risk factors in women with previous gestational diabetes mellitus and children exposed in utero stratified by breastfeeding/no breastfeeding or breastfed/not breastfed were included. Gestational diabetes mellitus was defined based on the International Association of Diabetes in Pregnancy Study Group definition or previous accepted definitions. Breastfeeding was defined as reported in each study.

RESULTS

The literature search yielded 260 titles, of which 17 studies were selected to be in the review. Women with previous gestational diabetes mellitus who did not breastfeed had higher blood glucose (SMD: 0.32, 95% CI [0.12, 0.53]) and a greater risk of developing Type 2 diabetes mellitus (RR: 2.08 95% CI [1.44, 3.00]) compared to women with no history. There were not enough studies to conduct a meta-analysis on the effects of breastfeeding on risk factors for cardiovascular disease among children exposed to gestational diabetes mellitus in utero.

CONCLUSION

Breastfeeding appears to be protective against cardiovascular risk factors among women who experience gestational diabetes mellitus.

Association of Breastfeeding Duration with 12-Month Postpartum Blood Lipids in a Predominately Lower-Income Hispanic Pregnancy Cohort in Los Angeles

Breastfeeding may protect women’s long-term cardiovascular health; however, breastfeeding-related postpartum lipid changes remain unclear. We aim to examine associations of breastfeeding duration with maternal lipids at 12 months postpartum. In a subsample (n = 79) of the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort, breastfeeding status and duration at 3, 6, and 12 months postpartum were self-reported. Serum levels of lipids, including total cholesterol, triglycerides (TG), high-, low-, and very low-density lipoprotein cholesterol (HDL-C, LDL-C, VLDL-C), were measured from blood samples collected at 12 months postpartum. We used linear regression models to compare lipids by breastfeeding duration, adjusting for potential confounders. Women who were breastfeeding at 12 months had higher HDL-C (mean: 41.74 mg/dL, 95% CI: 37.27−46.74 vs. 35.11 mg/dL, 95% CI: 31.42−39.24), lower TG (80.45 mg/dL, 95% CI: 66.20−97.77 vs. 119.11 mg/dL, 95% CI: 98.36−144.25), and lower VLDL-C (16.31 mg/dL, 95% CI: 13.23, 20.12 vs. 23.09 mg/dL, 95% CI: 18.61−28.65) compared to women who breastfed for <6 months. No lipids were significantly different between women who breastfed for 6−11 months and for <6 months. Each month’s increase in breastfeeding duration was significantly, inversely associated with TG and VLDL-C and positively with HDL-C. Adjusting for fasting status, demographics, pre-pregnancy body mass index, breastfeeding frequency, and pregnancy complications did not appreciably change effect estimates. Breastfeeding at 12 months postpartum and a longer duration of breastfeeding in the first year postpartum were both associated with increased HDL-C and decreased TG and VLDL-C at 12 months postpartum.

Cumulative Lactation and Clinical Metabolic Outcomes at Mid-Life among Women with a History of Gestational Diabetes

Lactation is associated with a lower risk of subsequent cardiometabolic disease among parous women; however, the underlying mechanisms are unknown. Further, the potential protective effects of lactation on cardiometabolic risk markers at mid-life among high-risk women with past gestational diabetes (GDM) are not established. Using data from the Diabetes & Women’s Health Study (2012−2014; n = 577), a longitudinal cohort of women with past GDM from the Danish National Birth Cohort (1996−2002), we assessed associations of cumulative lactation duration (none, <6 months, 6−12 months, ≥12−24 months, and ≥24 months) with clinical metabolic outcomes (including type 2 diabetes [T2D], prediabetes, and obesity) and cardiometabolic biomarkers (including biomarkers of glucose/insulin metabolism, fasting lipids, inflammation, and anthropometrics) 9−16 years after enrollment when women were at mid-life. At follow-up, women were 43.9 years old (SD 4.6) with a BMI of 28.7 kg/m2 (IQR 24.6, 33.0); 28.6% of participants had T2D, 39.7% had prediabetes, and 41.2% had obesity. Relative risks (95% CI) of T2D for 0−6, 6−12, 12−24, and ≥24 months of cumulative lactation duration compared to none were 0.94 (0.62,1.44), 0.88 (0.59,1.32), 0.73 (0.46,1.17), and 0.71 (0.40,1.27), respectively. Cumulative lactation duration was not significantly associated with any other clinical outcome or continuous biomarker. In this high-risk cohort of middle-aged women with past GDM, T2D, prediabetes, and obesity were common at follow-up, but not associated with history of cumulative lactation duration 9−16 years after the index pregnancy. Further studies in diverse populations among women at mid-age are needed to understand associations of breastfeeding with T2D.

Breastfeeding Is Inversely Associated with Allostatic Load in Postpartum Women: Cross-Sectional Data from Nationally Representative US Women

BACKGROUND

The postpartum period is a critical transition period when exposures to protective factors such as breastfeeding can have long-lasting health impact. Studies have suggested downregulating effects of breastfeeding on stress biomarkers such as cortisol but have not explored the way breastfeeding interacts with allostatic load, a multisystem indicator of chronic stress.

OBJECTIVE

We aimed to examine the association between breastfeeding and maternal allostatic load among women within 2 y postpartum using nationally representative data.

METHODS

A cross-sectional analysis of 10 waves of data from the NHANES (1999-2018) was conducted in a sample of 1302 women aged ≥18 y who provided information on breastfeeding through the reproductive health questionnaire. Clinical and empirical allostatic load scores (range: 0-10; higher numbers associated with increased risk) were derived for each participant based on 10 biomarkers reflecting metabolic, cardiovascular, and immune health. Multiple linear regression tested associations between breastfeeding and allostatic load, adjusting for maternal age, race and ethnicity, education, poverty level, and survey wave.

RESULTS

Breastfeeding had a significant inverse association with allostatic load in unadjusted and adjusted models. Controlling for age, race and ethnicity, education, poverty level, and survey wave, breastfeeding women had a 0.36-point lower clinical allostatic load score than nonbreastfeeding women (β = -0.36, SE = 0.11; 95% CI: -0.59, -0.14; P = 0.002) and a 0.44-point lower empirical allostatic load score (β = -0.44, SE = 0.15; 95% CI: -0.74, -0.14; P = 0.005).

CONCLUSIONS

Our study suggests that breastfeeding is protective of maternal stress and provides a more comprehensive picture of breastfeeding's influence on multiple body systems, exemplifying physiological benefits beyond effects on single biomarkers. However, limitations of cross-sectional data and non-classification of breastfeeding duration, mode, and intensity should be considered when interpreting these findings, and further research to address the role of breastfeeding and allostatic load is needed.

The Association Between Breastfeeding and Nonalcoholic Fatty Liver Disease in Parous Women: A Nation-wide Cohort Study

BACKGROUND AND AIMS

Breastfeeding has multiple effects on maternal health outcomes. However, the effect of breastfeeding on NAFLD in parous women remains unclear.

APPROACH AND RESULTS

A total of 6,893 Korean parous women aged 30-50 years who participated in the Korean National Health and Nutrition Examination Survey were assessed for the association between breastfeeding and NAFLD. Duration of lactation was calculated by dividing the total lactation period by the number of breastfed children. NAFLD was defined by the hepatic steatosis index. Of 6,893 women, 1,049 (15.2%) had NAFLD. Prevalence of NAFLD was 18.3%, 14.3%, 12.3%, 14.4%, and 15.8% in women with a breastfeeding period of <1, ≥1-<3, ≥3-<6, ≥6-<12, and ≥12 months, respectively. In a fully adjusted model, breastfeeding (≥1 month) was associated with reduced NAFLD prevalence (OR, 0.67; 95% CI, 0.51-0.89) after adjusting for metabolic, socioeconomic, and maternal risk factors. Fully adjusted ORs (95% CI) decreased with an increase of breastfeeding duration: 0.74 (0.49-1.11), 0.70 (0.47-1.05), 0.67 (0.48-0.94), and 0.64 (0.46-0.89) for women with ≥1-<3, ≥3-<6, ≥6-<12, and ≥12 months of breastfeeding duration, respectively, compared to women with <1 month of breastfeeding duration. Such an association was also observed in all predefined subgroups without interaction.

CONCLUSIONS

Breastfeeding showed a protective effect against NAFLD in later life of parous women, suggesting a maternal benefit of breastfeeding on NAFLD.

Management of familial hypercholesterolemia in pregnancy

PURPOSE OF REVIEW

To highlight quandaries and review options for the management of familial hypercholesterolemia (FH) during pregnancy.

RECENT FINDINGS

Women with FH face barriers to effective care and consequently face significant disease related long term morbidity and mortality.Pregnancy includes major maternal physiological changes resulting in exacerbation of maternal hypercholesterolemia compounded by the current practice of cessation or reduction in the dose of lipid-lowering therapy during pregnancy and lactation that may impact short and long term cardiac morbidity and mortality. Although lipoprotein apheresis is the treatment of choice for high- risk FH patients, reassuring safety evidence for the use of statins during pregnancy is mounting rapidly. However, it will be some time before subtle effects on the development of the offspring can be definitively excluded. Women with homozygous FH or with an established atherosclerotic vessel or aortic disease should be offered therapy with statins during pregnancy if lipoprotein apheresis is not readily available. Pregnancy outcomes tend to be favourable in women with FH. We have reviewed the currently available evidence regarding the risks and benefits of treatment options for FH during pregnancy.

Metabolic Effects of Breastfeeding in Women with Previous Gestational Diabetes Mellitus: A Meta-Analysis

Objective: To investigate the effects of breastfeeding (BF) on metabolic-related outcomes in women with previous gestational diabetes mellitus. Methods: Databases, including PubMed, Embase, Cochrane Library, and Web of Science, were searched until March 5, 2020. Finally, 14 high-quality articles were included. Relative risk (RR) and weighted mean difference (WMD) with 95% confidence interval (CI) were pooled using Stata14.0 Software. Results: Subjects in the BF group had a lower incidence of diabetes (RR: 0.611, 95% CI: 0.452-0.826, p < 0.001) and lower fasting plasma glucose level (WMD: -4.762, 95% CI: -5.552 to -3.973, p < 0.001), fasting insulin level (WMD: -21.513, 95% CI: -37.594 to -5.431, p = 0.009), homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -1.107, 95% CI: -1.683 to -0.532, p < 0.001), and triglyceride level (WMD: -33.951, 95% CI: -50.714 to -17.189, p < 0.001) than those in the non-BF group. The high-density lipoprotein level (WMD: 3.855, 95% CI: 2.629-5.081, p < 0.001), low-density lipoprotein level (WMD: 4.223, 95% CI: 0.6712-7.774, p = 0.020), and insulin sensitivity index (WMD: 1.503, 95% CI: 0.857-2.160, p < 0.001) in the BF group were higher than that in the non-BF group. No difference was found in the 2-hour postprandial blood glucose (WMD: -3.804, 95% CI: -8.237 to 0.630, p = 0.093), incidence of prediabetes mellitus (RR: 0.870, 95% CI: 0.750-1.009, p = 0.065), or cholesterol level (WMD: 1.377, 95% CI: -8.178 to 10.931, p = 0.778) between the two groups. Conclusion: BF may improve several metabolic markers and decrease the risk of developing diabetes.

Women who breastfeed exhibit cognitive benefits after age 50

Background and objectives

Women who breastfeed may experience long-term benefits for their health in addition to the more widely appreciated effects on the breastfed child. Breastfeeding may induce long-term effects on biopsychosocial systems implicated in brain health. Also, due to diminished breastfeeding in the postindustrial era, it is important to understand the lifespan implications of breastfeeding for surmising maternal phenotypes in our species’ collective past. Here, we assess how women’s breastfeeding history relates to postmenopausal cognitive performance.

Methodology

A convenience sample of Southern California women age 50+ was recruited via two clinical trials, completed a comprehensive neuropsychological test battery and answered a questionnaire about reproductive life history. General linear models examined whether cognitive domain scores were associated with breastfeeding in depressed and non-depressed women, controlling for age, education and ethnicity.

Results

Women who breastfed exhibited superior performance in the domains of Learning, Delayed Recall, Executive Functioning and Processing Speed compared to women who did not breastfeed (P-values 0.0003–0.015). These four domains remained significant in analyses limited to non-depressed and parous subsets of the cohort. Among those depressed, only Executive Functioning and Processing Speed were positively associated with breastfeeding.

Conclusions and implications

We add to the growing list of lifespan health correlates of breastfeeding for women’s health, such as the lower risk of type-2 diabetes, cardiovascular disease and breast cancer. We surmise that women’s postmenopausal cognitive competence may have been greater in past environments in which breastfeeding was more prevalent, bolstering the possibility that postmenopausal longevity may have been adaptive across human evolutionary history.

Lay Summary

Breastfeeding may affect women’s cognitive performance. Breastfeeding’s biological effects and psychosocial effects, such as improved stress regulation, could exert long-term benefits for the mother’s brain. We found that women who breastfed performed better on a series of cognitive tests in later life compared to women who did not breastfeed.

Association of maternal pre-pregnancy BMI and breastfeeding with NAFLD in young adults: a parental negative control study

BACKGROUND

The importance of the maternal-infant dyad in the genesis of nonalcoholic fatty liver disease (NAFLD) is of increasing interest. The Avon Longitudinal Study of Parents and Children (ALSPAC) showed that at age 24, 1 in 5 had NAFLD measured by transient elastography and controlled attenuation parameter (CAP). Our aim was to investigate the association between breastfeeding duration and maternal pre-pregnancy BMI on offspring NAFLD in young adulthood.

METHODS

4021 participants attended clinic for FibroScan and CAP measurement using Echosens 502 Touch®. 440 participants with Alcohol Use Disorders were excluded. Offspring of 100 non-singleton pregnancies were excluded. 2961 valid CAP measurements for NAFLD were analysed. Exposures of interest were breastfeeding of any duration, ≥6months exclusive breastfeeding, and maternal pre-pregnancy BMI. Multivariable regression models estimated the odds of NAFLD at 24 years. We performed a paternal negative control test to explore residual confounding in the analyses of pre-pregnancy BMI.

FINDINGS

There was a modest inverse association of exclusive and non-exclusive breastfeeding ≥6 months having a protective effect on NAFLD in offspring (OR 0·92 [95%CI 0·66-1·27] and OR 0·90 [0·67-1·21] respectively).The odds of offspring NAFLD in overweight pre-pregnancy maternal BMI and paternal BMI was OR 2·09 [1·62-2·68] and OR 1·33 [95%CI 1·07-1·65] respectively, with the ratio of effect sizes OR 1·57 [1·11-2·22]. Similarly, odds of offspring NAFLD with obese pre-pregnancy maternal BMI and paternal BMI was OR 2·66 [1·71-4·14] and OR 1·35 [0·91-2·00] respectively, with the ratio of effect sizes OR 1·98 [1·05-3·74].

INTERPRETATION

Higher maternal pre-pregnancy BMI was associated with offspring NAFLD, having accounted for shared parental confounding. We did not replicate previous work that found a strong association between breastfeeding and NAFLD.

FUNDING

Medical Research Council UK, Alcohol Research UK, David Telling Charitable Trust.

Associations between parity, pregnancy loss, and breastfeeding duration and risk of maternal type 2 diabetes: An observational cohort study

BACKGROUND

Parity, pregnancy loss, and breastfeeding duration were found to be associated with diabetes. However, the results are inconsistent. Also, no epidemiological studies have examined the association of these reproductive factors with diabetes in the same large population. We aim to investigate the associations between parity, pregnancy loss, breastfeeding duration, and the risk of maternal diabetes in middle-aged and elderly Chinese females.

METHODS

We included 131 174 females aged ≥40 years from the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study). Multivariable linear regression and logistic regression were used to assess the association between parity, pregnancy loss, and breastfeeding duration and type 2 diabetes.

RESULTS

The number of parities and breastfeeding duration were positively related to fasting plasma glucose, 2-hour postload glucose, glycosylated hemoglobin, and homeostatic model assessment of insulin resistance. Compared with those with one birth, nulliparous women or women with 2 or ≥3 births had a significantly increased risk of diabetes. The odds ratios (OR) and 95% confidence intervals (CI) were 1.27 (1.10-1.48), 1.17 (1.12-1.22), and 1.28 (1.21-1.35), respectively. Compared with women without pregnancy loss, those who underwent 2 (OR 1.09; 95% CI, 1.04-1.14) or ≥3 pregnancy losses (OR 1.11; 95% CI, 1.04-1.18) had an increased risk of diabetes. Moreover, women with a breastfeeding duration ≥0 to 6 months (OR 0.82; 95% CI, 0.75-0.90) and ≥6 to 12 months (OR 0.94; 95% CI, 0.89-0.99) had a significantly lower risk of diabetes.

CONCLUSIONS

Nulliparous women or women with multiparity or more than one pregnancy loss have an increased risk of diabetes in later life, while women who breastfeed more than 0 to 12 months have a lower risk of diabetes.

Intensive lactation among women with recent gestational diabetes significantly alters the early postpartum circulating lipid profile: the SWIFT study

BACKGROUND

Women with a history of gestational diabetes mellitus (GDM) have a 7-fold higher risk of developing type 2 diabetes (T2D). It is estimated that 20-50% of women with GDM history will progress to T2D within 10 years after delivery. Intensive lactation could be negatively associated with this risk, but the mechanisms behind a protective effect remain unknown.

METHODS

In this study, we utilized a prospective GDM cohort of 1010 women without T2D at 6-9 weeks postpartum (study baseline) and tested for T2D onset up to 8 years post-baseline (n=980). Targeted metabolic profiling was performed on fasting plasma samples collected at both baseline and follow-up (1-2 years post-baseline) during research exams in a subset of 350 women (216 intensive breastfeeding, IBF vs. 134 intensive formula feeding or mixed feeding, IFF/Mixed). The relationship between lactation intensity and circulating metabolites at both baseline and follow-up were evaluated to discover underlying metabolic responses of lactation and to explore the link between these metabolites and T2D risk.

RESULTS

We observed that lactation intensity was strongly associated with decreased glycerolipids (TAGs/DAGs) and increased phospholipids/sphingolipids at baseline. This lipid profile suggested decreased lipogenesis caused by a shift away from the glycerolipid metabolism pathway towards the phospholipid/sphingolipid metabolism pathway as a component of the mechanism underlying the benefits of lactation. Longitudinal analysis demonstrated that this favorable lipid profile was transient and diminished at 1-2 years postpartum, coinciding with the cessation of lactation. Importantly, when stratifying these 350 women by future T2D status during the follow-up (171 future T2D vs. 179 no T2D), we discovered that lactation induced robust lipid changes only in women who did not develop incident T2D. Subsequently, we identified a cluster of metabolites that strongly associated with future T2D risk from which we developed a predictive metabolic signature with a discriminating power (AUC) of 0.78, superior to common clinical variables (i.e., fasting glucose, AUC 0.56 or 2-h glucose, AUC 0.62).

CONCLUSIONS

In this study, we show that intensive lactation significantly alters the circulating lipid profile at early postpartum and that women who do not respond metabolically to lactation are more likely to develop T2D. We also discovered a 10-analyte metabolic signature capable of predicting future onset of T2D in IBF women. Our findings provide novel insight into how lactation affects maternal metabolism and its link to future diabetes onset.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01967030 .

Obesity, not a high fat, high sucrose diet alone, induced glucose intolerance and cardiac dysfunction during pregnancy and postpartum

Cardiovascular disease is the leading cause of death in women during pregnancy and the postpartum period. Obesity is an independent risk factor for cardiovascular diseases. Nearly 60% of women of reproductive age are considered overweight or obese, cardiovascular disease morbidity and mortality continue to be pervasive. The objective of this study was to determine the effects of an obesogenic diet on the cardiometabolic health of dams during pregnancy and postpartum. Female mice were fed either a high-fat, high-sucrose diet (HFHS) or a refined control diet (CON) for 8 weeks before initiation of pregnancy and throughout the study period. Mice in the HFHS showed two distinct phenotypes, obesity-prone (HFHS/OP) and obesity resistance (HFHS/OR). Pre-pregnancy obesity (HFHS/OP) induced glucose intolerance before pregnancy and during postpartum. Systolic function indicated by the percent fractional shortening (%FS) was significantly decreased in the HFHS/OP at late pregnancy (vs. HFHS/OR) and weaning (vs. CON), but no differences were found at 6 weeks of postpartum among groups. No induction of pathological cardiac hypertrophy markers was found during postpartum. Plasma adiponectin was decreased while total cholesterol was increased in the HFHS/OP. Our results suggested that obesity, not the diet alone, negatively affected cardiac adaptation during pregnancy and postpartum.

Association of breastfeeding and risk of metabolic syndrome and its components in postmenopausal parous women: Korea national health and nutrition examination survey (2010 ~ 2016)

Background

Understanding the relationship between breastfeeding (BF) and metabolic syndrome (Mets) is important for maternal long-term health benefits and disease prevention. This study aimed to examine the association between BF and Mets and its components among postmenopausal parous Korean women.

Methods

This cross-sectional study on 10,356 Korean women used nationally representative data from the KNHANES from 2010 to 2016. Anthropometric, laboratory data and manual BP were measured. A multivariate logistic regression analysis was conducted to examine the association of BF with Mets and its components after adjusting for potential confounding variables. A p-value < 0.05 was to be considered statistically significant.

Results

Mets was present in 42% of the study participants. The BF group had low household income and education level. The prevalence of Mets in the BF group was higher than that in the non-BF group (42.69% vs. 34.76%, p <  0.001). BF was associated with increased risk of Mets (odds ratio [OR]: 1.4, 95% confidence interval [CI]: 1.18–1.65, p <  0.001). The BF group was at higher risks for diabetes (OR: 1.5, 95%CI: 1.14–1.98), hypertension (OR: 1.32, 95%CI: 1.03–1.68), hypertriglyceridemia (OR: 1.42, 95%CI: 1.02–1.99) and low high-density lipoprotein cholesterol (OR: 1.32, 95%CI: 1.06–1.65).

Conclusion

In this study, BF did not affect decreasing the prevalence of Mets and its components.

Adverse Pregnancy Outcomes and Cardiovascular Disease Risk: Unique Opportunities for Cardiovascular Disease Prevention in Women: A Scientific Statement From the American Heart Association

This statement summarizes evidence that adverse pregnancy outcomes (APOs) such as hypertensive disorders of pregnancy, preterm delivery, gestational diabetes, small-for-gestational-age delivery, placental abruption, and pregnancy loss increase a woman's risk of developing cardiovascular disease (CVD) risk factors and of developing subsequent CVD (including fatal and nonfatal coronary heart disease, stroke, peripheral vascular disease, and heart failure). This statement highlights the importance of recognizing APOs when CVD risk is evaluated in women, although their value in reclassifying risk may not be established. A history of APOs is a prompt for more vigorous primordial prevention of CVD risk factors and primary prevention of CVD. Adopting a heart-healthy diet and increasing physical activity among women with APOs, starting in the postpartum setting and continuing across the life span, are important lifestyle interventions to decrease CVD risk. Lactation and breastfeeding may lower a woman's later cardiometabolic risk. Black and Asian women experience a higher proportion APOs, with more severe clinical presentation and worse outcomes, than White women. More studies on APOs and CVD in non-White women are needed to better understand and address these health disparities. Future studies of aspirin, statins, and metformin may better inform our recommendations for pharmacotherapy in primary CVD prevention among women who have had an APO. Several opportunities exist for health care systems to improve transitions of care for women with APOs and to implement strategies to reduce their long-term CVD risk. One proposed strategy includes incorporation of the concept of a fourth trimester into clinical recommendations and health care policy.

Full Breastfeeding Modifies Anthropometric and Body Composition Indicators in Nursing Mothers

Background: It has been observed that breastfeeding mobilizes the deposits of fat that accumulate during pregnancy and promotes weight loss through energy expenditure. The purpose of this study was to demonstrate that full breastfeeding (FBF) reduces anthropometric and body composition indicators in women between the 8th and the 16th week postpartum. Methods: In a nonrandom cohort study, 170 mothers at the Hospital Civil de Guadalajara, Guadalajara, México, were enrolled: FBF 74, partial breastfeeding (PBF) 57, and human milk substitutes (HMS) 39. Anthropometric indicators and body composition were measured at the 8th and 16th week postpartum. We performed analysis of variance to compare body composition according to the type of feeding and paired Student's t-test to compare the changes from the 8th to 16th week postpartum. Results: We found that FBF mothers had a trend to lower arm fat area and triceps skinfold than PBF and HMS mothers at 8 and 16 weeks postpartum. We observed a decrease in weight (p = 0.004), weight/age index (p = 0.003), body mass index (p = 0.003), hip circumference (p = 0.037), and lean mass (p = 0.003) from 8 to 16 weeks postpartum in mothers who offered FBF. The mid-upper arm circumference, the arm total area, and their z-score increased in the three feeding groups. Conclusions: Our results show that FBF mothers had some lower adiposity from 8 to 16 weeks postpartum compared with the result observed among PBF mothers and those who utilized HMS.

Effect of breastfeeding on metabolic-related outcomes in women with previous gestational diabetes mellitus: A protocol for systematic review and meta-analysis

BACKGROUND

This meta-analysis was to systematically investigate the effect of breastfeeding on metabolic-related outcomes in women with previous gestational diabetes mellitus (GDM).

METHODS

We will search the online databases of Relevant studies were searched in Pubmed, Embase, Cochrane Library, Web of Science. Relative risk and weighted mean difference with 95% confidence interval will pooled using Stata14.0 software.

CONCLUSION

Our meta-analysis will explore the effect of breastfeeding on metabolic-related outcomes in women with previous GDM and may provide effective treatment options of GDM.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/HA5U8.

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.

Breastfeeding and Maternal Age-Related Cataract in the U.S. Population

PURPOSE

An estimated 38 million and 50 million individuals will have cataract in the U.S. alone by 2030 and 2050, respectively. Breastfeeding is known to improve a number of health outcomes in both breastfed children and breastfeeding mothers. However, little is known about the relationship between breastfeeding and cataract, the leading cause of blindness worldwide, in breastfeeding mothers. This study was conducted to investigate the relationship between breastfeeding and maternal cataract extraction history in a nationally representative sample of the U.S. population.

METHODS

A 10-year multistage, probability-sampling survey data was used to identify parous women aged ≥50 years who provided breastfeeding history and cataract extraction history (n = 4897). Breastfeeding history was considered positive if a participant reported breastfeeding at least one child for ≥1 month. The main outcome was cataract extraction history. Estimates are presented in odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

Approximately half of the studied women breastfed at least one child ≥1 month, and about 18% reported cataract extraction history. Participants with a positive breastfeeding history were less likely to have a positive cataract extraction history in both age-adjusted (OR = 0.814, 95%CI = 0.670-0.989) and multivariable logistic regression (OR = 0.794, 95%CI = 0.639-0.988). Higher number of breastfed children was also associated with a lower risk of cataract extraction history (OR = 0.934, 95%CI = 0.883-0.988).

CONCLUSIONS

The findings suggest that breastfeeding may be associated with a decrease in the likelihood of age-related cataract extraction in parous women from the U.S. population.

Physiologic changes in serotonin concentrations in breast milk during lactation

OBJECTIVES

Serotonin (5-hydroxytryptamine; 5-HT) plays an important role in milk volume homeostasis in the mammary glands during lactation, and 5-HT in milk also may affect infant development. The aim of this study was to investigate changes in 5-HT concentration in breast milk according to the duration of lactation and evaluate whether the 5-HT concentration varied before and after nursing.

METHODS

Healthy nursing Japanese women who had a natural delivery or underwent a cesarean delivery at Iwate Medical University Hospital were included in this study.

RESULTS

The mean 5-HT concentration in milk was obtained from multiparous mothers 6 to 7 d after delivery (colostrum) and was significantly higher compared with primiparous mothers (24.3 ± 2.63 versus 18.5 ± 2.60 ng/mL). Additionally, mean 5-HT concentration increased with increasing lactation duration in primiparous women (colostrum: 18.5 ± 2.60; 1 mo postdelivery: 19.8 ± 2.46; 3 mo postdelivery: 22.7 ± 2.55 ng/mL); in particular, the mean 5-HT concentration in breast milk 3 mo after delivery was significantly higher than in colostrum. The mean 5-HT concentrations in breast milk in primiparous mothers immediately before nursing, 1 to 2 h after nursing, and immediately before the next nursing event were 23.6 ± 1.48, 22.82 ± 1.65, and 21.84 ± 1.31 ng/mL, respectively; mean 5-HT concentrations in multiparous women were 25.4 ± 1.65, 23.6 ± 2.20, or 22.4 ± 2.09 ng/mL, respectively. There was no significant difference in 5-HT concentrations at each time point between the groups.

CONCLUSION

This information may be useful in determining the role of 5-HT in breast milk on infant development and growth.

The effect of breastfeeding on postpartum glucose tolerance and lipid profiles in women with gestational diabetes mellitus

Background

We aimed to investigate the association of breastfeeding on postpartum glucose levels and lipid profiles in women diagnosed with gestational diabetes mellitus (GDM) and women without GDM.

Methods

We performed a secondary analysis of a cohort study of 243 women, 159 women with GDM and 84 normally glucose tolerant women between 2012 and 2017. At approximately 6-10 weeks postpartum, we measured fasting blood glucose and plasma lipid levels. Breastfeeding behaviour was self-defined as exclusive breastfeeding or not exclusive breastfeeding.

Results

The mean (SD) glucose in the group of women who breastfed exclusively was 4.6 (0.49) mmol/L, compared to 4.9 (0.58) mmol/L (95% CI 0.45, 0.15, p <  0.001) among women who did not exclusively breastfeed. Among women with GDM, the reduction in fasting glucose in women who were breastfeeding was 0.22 mmol/L (95% CI 0.39, 0.05, p = 0.004), and in women who were not GDM, the reduction was 0.14 mmol/L (95% CI 0.37, 0.09, p = 0.24,). After adjustment for GDM status in pregnancy, maternal body mass index (BMI), maternal age and ethnicity, and exclusive breastfeeding was associated with a decreased fasting glucose of 0.19 (95% CI 0.318, 0.061, p = 0.004). After similar adjustment, there was no significant difference in triglycerides, high density lipoprotein cholesterol or low-density lipoprotein cholesterol between women who were breastfeeding and women who were not breastfeeding.

Conclusions

Breastfeeding is associated with a reduction in fasting glucose levels postpartum, but not maternal lipid profile. Breastfeeding may play a role in reducing glucose intolerance in women who have had GDM.

Breastfeeding and maternal cardiovascular risk factors: 1982 Pelotas Birth Cohort

This study evaluated the association of breastfeeding duration with maternal metabolic cardiovascular risk factors among women who have been prospectively followed since birth in a southern Brazilian city. In the unadjusted analysis, total cholesterol was higher among women who never breastfed in relation to those who breastfed ≥12 months. Among women with one livebirth, a shorter duration of breastfeeding was associated with lower HDL, while those with two or more livebirths and that breastfed for shorter time presented lower pulse wave velocity, glycaemia and non-HDL measures. After controlling for confounding variables, the magnitude of these associations decreased, and the confidence intervals included the reference. Concerning the duration of breastfeeding of the last child, the analysis was stratified by time since last birth. After controlling for confounders, systolic blood pressure was lower among women who breastfed 3 to <6 months and had a child within the last five years in relation to those who breastfed ≥6, but no clear trend was observed (p = 0.17). In conclusion, our findings suggest that there is no association between lactation and maternal cardiometabolic risk factors.

Cardiovascular and Metabolic Risk in Women in the First Year Postpartum: Allostatic Load as a Function of Race, Ethnicity, and Poverty Status

OBJECTIVE

Allostatic load (AL) represents multisystem physiological "wear-and-tear" reflecting emerging chronic disease risk. We assessed AL during the first year postpartum in a diverse community sample with known health disparities.

STUDY DESIGN

The Eunice Kennedy Shriver National Institute for Child Health and Human Development Community Child Health Network enrolled 2,448 predominantly low-income African-American, Latina, and White women immediately after delivery of liveborn infants at ≥20 weeks' gestation, following them over time with interviews, clinical measures, and biomarkers. AL at 6 and 12 months postpartum was measured by body mass index, waist:hip ratio, blood pressure, pulse, hemoglobin A1c, high-sensitive C-reactive protein, total cholesterol and high-density lipoprotein, and diurnal cortisol slope.

RESULTS

Adverse AL health-risk profiles were significantly more prevalent among African-American women compared with non-Hispanic Whites, with Latinas intermediate. Breastfeeding was protective, particularly for White women. Complications of pregnancy were associated with higher AL, and disparities persisted or worsened through the first year postpartum.

CONCLUSION

Adverse AL profiles occurred in a substantial proportion of postpartum women, and disparities did not improve from birth to 1 year. Breastfeeding was protective for the mother.

The Association Between Parity and Subsequent Cardiovascular Disease in Women: The Atherosclerosis Risk in Communities Study

Background: Previous studies are inconclusive on the relationship between parity and cardiovascular disease (CVD), with few evaluating multiple cardiovascular outcomes. It is also unclear if any relationship between parity and CVD is independent of breastfeeding. We examined the associations between parity and cardiovascular outcomes, including breastfeeding adjustment. Materials and Methods: Data were from 8,583 White and African American women, 45-64 years of age, in the Atherosclerosis Risk in Communities Study. Coronary heart disease (CHD), myocardial infarction (MI), heart failure, and strokes were ascertained from 1987 to 2016 by annual interviews and hospital surveillance. Parity and breastfeeding were self-reported. Cox proportional hazards regression estimated hazard ratios (HR) for the association between parity and cardiovascular outcomes, adjusting for baseline sociodemographic, clinical and lifestyle factors, and breastfeeding. Results: Women reported no pregnancies (6.0%), or having 0 (1.6%), 1-2 (36.2%), 3-4 (36.4%), or 5+ (19.7%) live births. During 30 years follow-up, there were 1,352 CHDs, 843 MIs, 750 strokes, and 1,618 heart failure events. Compared with women with 1-2 prior births, those with prior pregnancies and no live births had greater incident CHD (HR = 1.64, 95% confidence interval 1.14-2.42) and heart failure risk (1.46, 1.04-2.05), after adjustment for baseline characteristics. Women with 5+ births had greater risk of CHD (1.29, 1.10-1.52) and hospitalized MI (1.38, 1.13-1.69), after adjustment for baseline characteristics and breastfeeding. Conclusions: In a diverse U.S. cohort, a history of 5+ live births is associated with CHD risk, specifically, MI, independent of breastfeeding. Having a prior pregnancy and no live birth is associated with greater CHD and heart failure risk.

Associations between Breastfeeding and Type 2 Diabetes Mellitus and Glycemic Control in Parous Women: A Nationwide, Population-Based Study

We investigated associations between breastfeeding duration and number of children breastfed and type 2 diabetes mellitus (T2DM) and glycemic control among parous women. We performed a cross-sectional analysis of data for 9,960 parous women from the Korea National Health and Nutritional Examination Survey (2010 to 2013). Having ever breastfed was inversely associated with prevalent T2DM (adjusted odds ratio [OR], 0.60; 95% confidence interval [CI], 0.42 to 0.87). All ranges of total and average breastfeeding duration showed inverse associations with T2DM. Even short periods of breastfeeding were inversely associated with T2DM (adjusted OR, 0.61; 95% CI, 0.38 to 0.99 for a total breastfeeding duration ≤12 months; adjusted OR, 0.65; 95% CI, 0.42 to 0.99 for an average breastfeeding duration per child ≤6 months). A longer duration of breastfeeding was associated with better glycemic control in parous women with T2DM (P trend=0.004 for total breastfeeding duration; P trend <0.001 for average breastfeeding duration per child). Breastfeeding may be associated with a lower risk of T2DM and good glycemic control in parous women with T2DM. Breastfeeding may be a feasible method to prevent T2DM and improve glycemic control.

Long-Term Effect of Lactation on Maternal Cardiovascular Function and Adiposity in a Murine Model

OBJECTIVE

Epidemiological studies suggest that lactation is associated with long-term maternal health benefits. To avoid confounders in human studies, we used a previously characterized murine model to investigate the long-term effect of lactation on both cardiovascular function and adiposity.

STUDY DESIGN

After the delivery of the pups, CD-1 female mice were randomly divided into two groups: lactated and nonlactated (NL). Before pregnancy and at 9 months postdelivery, blood pressure was measured using a tail cuff, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by computed tomography (CT), echocardiography was performed using microultrasound, and cholesterol panels and fasting blood glucose were measured. The data were analyzed using Student's t-test (significance at p < 0.05).

RESULTS

There were no differences in baseline parameters between the two groups. At 9 months postdelivery, the NL group weighed significantly more (p = 0.03) and demonstrated a significantly lower cardiac output (p = 0.05) and ejection fraction (p = 0.03). The mice in the NL group also had higher VAT (p < 0.01) and SAT percentiles (p = 0.03). Fasting glucose (p = 0.01) and low-density lipoprotein (p = 0.01) were significantly higher in the NL group at 9 months.

CONCLUSION

Our results show the benefit of lactation is not just limited to the immediate postpartum period but it also extends into midlife in a murine model.

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.

Association of breastfeeding, maternal anthropometry and body composition in women at 30 years of age

This study aimed at assessing the association of breastfeeding with maternal body mass index (BMI), waist circumference, fat mass index, fat free mass index, android/gynoid fat ratio and bone mineral density. In 1982, the maternity hospitals in Pelotas, Rio Grande do Sul State, Brazil, were daily visited and all live births were identified and examined. These subjects underwent follow-up for several times. At 30 years of age, the participants were interviewed and examined. Parous women provided information on parity and duration of breastfeeding. Multiple linear regression was used in the multivariate analysis, controlling for genomic ancestry, family income, schooling and smoking at 2004-2005. After controlling for confounding factors, breastfeeding was inversely associated with BMI and fat mass index, whereas breastfeeding per live birth was negatively associated with BMI, waist circumference and fat mass index. Women who had had a child in the last 5 years and had breastfed, showed lower BMI (β = -2.12, 95%CI: -4.2; -0.1), waist circumference (β = -4.46, 95%CI: -8.3; -0.6) and fat mass index (β = -1.79, 95%CI: -3.3; -0.3), whereas no association was observed among those whose last childbirth was > 5 years, but the p-value for the tests of interaction were > 0.05. Our findings suggest that breastfeeding is associated with lower BMI and other adiposity measures, mostly in the first years after delivery. Besides that, it has no negative impact on bone mineral density.

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.

Longer lactation duration is associated with decreased prevalence of non-alcoholic fatty liver disease in women

BACKGROUND & AIMS

Lactation lowers blood glucose and triglycerides, and increases insulin sensitivity. We hypothesized that a longer duration of lactation would be associated with lower prevalence of non-alcoholic fatty liver disease (NAFLD), which is the leading cause of chronic liver disease in the United States.

METHODS

Participants from the Coronary Artery Risk Development in Young Adults cohort study who delivered ≥ 1 child post-baseline (Y0: 1985-1986), and underwent CT quantification of hepatic steatosis 25 years following cohort entry (Y25: 2010-2011) were included (n = 844). The duration of lactation was summed for all post-baseline births, and NAFLD at Y25 was assessed by central review of CT images and defined by liver attenuation ≤ 40 Hounsfield Units after exclusion of other causes of hepatic steatosis. Unadjusted and multivariable logistic regression analyses were performed using an a priori set of confounding variables; age, race, education, and baseline body mass index.

RESULTS

Of 844 women who delivered after baseline (48% black, 52% white, mean age 49 years at Y25 exam), 32% reported lactation duration of 0 to 1 month, 25% reported >1 to 6 months, 43% reported more than 6 months, while 54 (6%) had NAFLD. Longer lactation duration was inversely associated with NAFLD in unadjusted logistic regression. For women who reported >6 months lactation compared to those reporting 0-1 month, the odds ratio for NAFLD was 0.48 (95% CI 0.25-0.94; p = 0.03) and the association remained after adjustment for confounders (adjusted odds ratio 0.46; 95% CI 0.22-0.97; p = 0.04).

CONCLUSIONS

A longer duration of lactation, particularly greater than 6 months, is associated with lower odds of NAFLD in mid-life and may represent a modifiable risk factor for NAFLD.

LAY SUMMARY

A longer duration of breastfeeding has been associated with multiple potential health benefits for the mother including reduction in heart disease, diabetes and certain cancers. In this study we found that breastfeeding for longer than 6 months was associated with a lower risk of non-alcoholic fatty liver disease in mid-life.

Breastfeeding Duration and the Risk of Coronary Artery Disease

BACKGROUND

Previous studies have suggested that prolonged breastfeeding has beneficial effects on the health of the mother including the reduction of long-term risk of coronary artery disease (CAD). The mechanism of this association remains unclear.

METHODS

We surveyed 643 women aged 40-65 years receiving outpatient care at Stanford University Hospital on their reproductive/lactation history, including 137 women (cases) with clinically confirmed CAD. Survey data were supplemented with traditional risk factor data for CAD obtained from the participant's medical record. We then conducted logistic regression analyses to assess the relationship between breastfeeding duration and case-control status for each of the two separate definitions of duration. The first was based on the participant's single longest duration of breastfeeding considering all live births reported and the second was based on a participant's total duration of breastfeeding summed over all live births. For each of these two definitions, we ran three sequential models each with a different reference group-(1) nulliparous women, (2) parous women that never breastfed, and (3) parous women with a short duration of breastfeeding-successively excluding women in the reference group of the previous model(s).

RESULTS

Just over one-half (51.6%) of the women surveyed reported a history of breastfeeding. We found nominally significant associations (p = 0.04-0.12) for our multivariate analyses that modeled maximum duration of breastfeeding. When compared with nulliparous women, parous women who either never breastfed or always breastfed for <5 months had approximately double the risk of CAD. Among parous women, women who breastfeed for ≥5 months at least once in their lifetime had a ∼30% decrease risk of CAD compared with those who did not initiate breastfeeding. Among parous women who breastfed ≥1 month, women who breastfed ≥5 months had ∼50% decreased risk of CAD. We found similar point estimates of effect for analogous analyses modeling maximum breastfeeding duration but p-values for these analyses were not significant. Unadjusted analyses demonstrated higher valued odds ratios and lower p-values suggesting the presence of some confounding by traditional risk factors.

CONCLUSIONS

Parous women who breastfeed ≥5 months in at least one pregnancy seem to be at decreased risk of CAD later in their life, whereas parous women who either never breastfed or discontinued breastfeeding early seem to be at increased risk. More research is needed to more reliably quantify and determine the nature of the relationship between parity, breastfeeding duration, and risk of CAD.