Adiposity and hepatic lipid in healthy full-term, breastfed, and formula-fed human infants: a prospective short-term longitudinal cohort study

Concise review: Breastfeeding, lactation, and NAFLD. An updated view of cross-generational disease transmission and prevention

Evidence suggests that breastfeeding protects the mother-infant dyad against the development and progression of nonalcoholic fatty liver disease (NAFLD). In this context, we aim to provide insight into the most notable and representative epidemiological studies published in the literature. Furthermore, we will delve into the potential underlying pathomechanisms that might be involved in this relationship. The current definitions of breastfeeding, lactation, mother-infant dyad, and nonalcoholic fatty liver disease (NAFLD) are provided. Next, the epidemiological evidence supporting potential benefits for the (long-term) lactating mother in terms of protection from the development and progression of NAFLD is reviewed. The putative mechanisms underlying this protection are also analyzed. Similarly, clinical and epidemiological studies evaluating the benefits of breastfeeding for the offspring are examined, together with a discussion of the putative underlying mechanisms. In conclusion, our understanding of breastfeeding (for the offspring) and lactation (for the mother) as protective factors from NAFLD development and fibrotic progression will provide further insight into unprecedented disease mechanisms shared by the mother-infant dyad promising to interrupt the vicious cycle of NAFLD transmission across generations.

Maternal and Perinatal Risk Factors for Pediatric Nonalcoholic Fatty Liver Disease: A Systematic Review

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) has become the most common pediatric liver disease. The intrauterine and early life environment can have an important impact on long-term metabolic health. We investigated the impact of maternal prepregnancy obesity, (pre)gestational diabetes, breastfeeding, and birth anthropometrics/preterm birth on the development of NAFLD in children and adolescents.

METHODS

A comprehensive search was performed in MEDLINE, PubMed Central, EMBASE, and grey literature databases through August 2020. The primary outcome was the prevalence of pediatric NAFLD, whereas the histologic severity of steatohepatitis and/or fibrosis were secondary outcomes. Study selection, data extraction, and quality assessment were performed by 2 independent reviewers.

RESULTS

Our systematic review included 33 articles. Study heterogeneity regarding patient populations, diagnostic tools, and overall quality was considerable. Eight studies determined the impact of maternal prepregnancy overweight/obesity and identified this as a possible modifiable risk factor for pediatric NAFLD. Conversely, 8 studies investigated (pre)gestational diabetes, yet the evidence on its impact is conflicting. Breastfeeding was associated with a reduced risk for NAFLD, steatohepatitis, and fibrosis, especially in studies that evaluated longer periods of breastfeeding. Being born preterm or small for gestational age has an unclear impact on the development of NAFLD, although an early catch-up growth might drive NAFLD.

CONCLUSIONS

In a systematic review, we found that maternal prepregnancy overweight and obesity were associated with an increased risk of pediatric NAFLD. Breastfeeding might be protective against the development of NAFLD when the duration of breastfeeding is sufficiently long (≥6 months).

Non-alcoholic fatty liver disease in pregnancy is associated with adverse maternal and perinatal outcomes

BACKGROUND & AIMS

The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising in young adults, with potential implications for reproductive-aged women. Whether NAFLD during pregnancy confers more serious risks for maternal or perinatal health is unclear.

METHODS

Using weighted discharge data from the US national inpatient sample, we evaluated temporal trends of NAFLD in pregnancies after 20 weeks gestation, and compared outcomes to pregnancies with other chronic liver diseases (CLDs) or no CLD. Study outcomes included preterm birth, postpartum hemorrhage, hypertensive complications (pre-eclampsia, eclampsia, and/or hemolysis, elevated liver enzymes, and low platelets syndrome), and maternal or fetal death. NAFLD prevalence was estimated by calendar year and temporal trends tested by linear regression. Outcomes were analyzed by logistic regression adjusted for age, race, multiple gestation, and pre-pregnancy diabetes, obesity, dyslipidemia and hypertension.

RESULTS

Among 18,574,225 pregnancies, 5,640 had NAFLD and 115,210 had other, non-NAFLD CLD. Pregnancies with NAFLD nearly tripled from 10.5/100,000 pregnancies in 2007 to 28.9/100,000 in 2015 (p <0.001). Compared to the other groups, patients with NAFLD during pregnancy more frequently experienced gestational diabetes (7-8% vs. 23%), hypertensive complications (4% vs. 16%), postpartum hemorrhage (3-5% vs. 6%), and preterm birth (5-7% vs. 9%), all p values ≤0.01. On adjusted analysis, compared to no CLD, NAFLD was associated with hypertensive complications, preterm birth, postpartum hemorrhage and possibly maternal (but not fetal) death.

CONCLUSION

The prevalence of NAFLD in pregnancy has nearly tripled in the last decade and is independently associated with hypertensive complications, postpartum hemorrhage and preterm birth. NAFLD should be considered a high-risk obstetric condition, with clinical implications for pre-conception counseling and pregnancy care.

LAY SUMMARY

The prevalence of non-alcoholic fatty liver disease (NAFLD) in pregnancy has almost tripled over the past 10 years. Having NAFLD during pregnancy increases risks for both the mother and the baby, including hypertensive complications of pregnancy, bleeding after delivery, and preterm birth. Thus, pre-conception counseling is warranted with consideration of high-risk obstetric management among women with NAFLD in pregnancy.

Growth in exclusively breastfed infants

OBJECTIVE

To address the growth of full-term children in the first 6 months of life in exclusive breastfeeding.

SOURCE OF DATA

A non-systematic review was carried out by searching the MEDLINE/PubMed, Web of Science, and Cochrane Library databases and the World Health Organization website for articles and documents on the growth of exclusively breastfed infants and their monitoring. Those documents considered to be the most relevant by the author were selected.

DATA SYNTHESIS

Exclusively breastfeed infants show differentiated growth when compared to formula-fed infants. Weight loss in the first four days of life is due more to loss of fat mass rather than lean mass, including body water, and is usually lower in exclusively breastfed infants. In turn, the time for recovery of the birth weight may be longer in these infants. Formula-fed infants gain weight and increase their BMI more rapidly in the first three to six months of life than infants in exclusive or predominant breastfeeding due to a progressive increase in lean mass. The World Health Organization growth curves, which use the growth pattern of breastfed children as their standard, are used to monitor growth.

CONCLUSIONS

Exclusively breastfed infants have differentiated growth when compared with formula-fed infants. This should be considered when monitoring the infant's growth. It should be emphasized that the growth pattern currently used as reference is that of the exclusively breastfed infant.

Associations of infant feeding with trajectories of body composition and growth

Background: The extent to which breastfeeding is protective against later-life obesity is controversial. Little is known about differences in infant body composition between breastfed and formula-fed infants, which may reflect future obesity risk.Objective: We aimed to assess associations of infant feeding with trajectories of growth and body composition from birth to 7 mo in healthy infants.Design: We studied 276 participants from a previous study of maternal vitamin D supplementation during lactation. Mothers used monthly feeding diaries to report the extent of breastfeeding. We measured infants' anthropometrics and used dual-energy X-ray absorptiometry to assess body composition at 1, 4, and 7 mo. We compared changes in infant size (z scores for weight, length, and body mass index [BMI (in kg/m²)]) and body composition (fat and lean mass, body fat percentage) between predominantly breastfed and formula-fed infants, adjusting in linear regression for sex, gestational age, race/ethnicity, maternal BMI, study site, and socioeconomic status.Results: In this study, 214 infants (78%) were predominantly breastfed (median duration: 7 mo) and 62 were exclusively formula fed. Formula-fed infants had lower birth-weight z scores than breastfed infants (-0.22 ± 0.86 and 0.16 ± 0.88, respectively; P < 0.01) but gained more in weight and BMI through 7 mo of age (weight z score difference: 0.37; 95% CI: 0.04, 0.71; BMI z score difference: 0.35; 95% CI: 0, 0.69), with no difference in linear growth (z score difference: 0.05; 95% CI: -0.24, 0.34). Formula-fed infants gained more lean mass (difference: 303 g; 95% CI: 137, 469 g) than breastfed infants, but not fat mass (difference: -42 g; 95% CI: -299, 215 g).Conclusions: Formula-fed infants gained weight more rapidly and out of proportion to linear growth than did predominantly breastfed infants. These differences were attributable to greater accretion of lean mass, rather than fat mass. Any later obesity risk associated with infant feeding does not appear to be explained by differential adiposity gains in infancy.

Developmental origins of NAFLD: a womb with a clue

Changes in the maternal environment leading to an altered intrauterine milieu can result in subtle insults to the fetus, promoting increased lifetime disease risk and/or disease acceleration in childhood and later in life. Particularly worrisome is that the prevalence of NAFLD is rapidly increasing among children and adults, and is being diagnosed at increasingly younger ages, pointing towards an early-life origin. A wealth of evidence, in humans and non-human primates, suggests that maternal nutrition affects the placenta and fetal tissues, leading to persistent changes in hepatic metabolism, mitochondrial function, the intestinal microbiota, liver macrophage activation and susceptibility to NASH postnatally. Deleterious exposures in utero include fetal hypoxia, increased nutrient supply, inflammation and altered gut microbiota that might produce metabolic clues, including fatty acids, metabolites, endotoxins, bile acids and cytokines, which prime the infant liver for NAFLD in a persistent manner and increase susceptibility to NASH. Mechanistic links to early disease pathways might involve shifts in lipid metabolism, mitochondrial dysfunction, pioneering gut microorganisms, macrophage programming and epigenetic changes that alter the liver microenvironment, favouring liver injury. In this Review, we discuss how maternal, fetal, neonatal and infant exposures provide developmental clues and mechanisms to help explain NAFLD acceleration and increased disease prevalence. Mechanisms identified in clinical and preclinical models suggest important opportunities for prevention and intervention that could slow down the growing epidemic of NAFLD in the next generation.

Abdominal Fat Distribution Among Breastfed and Formula-Fed Infants

OBJECTIVES

To compare abdominal subcutaneous and preperitoneal fat thickness among breastfed, mixed-fed, and formula-fed infants during the first 6 months of life.

STUDY DESIGN

A cohort study started with 94 healthy newborns and 76 were followed during the whole first semester of life. Breastfeeding status was assessed by a personal interview. Abdominal subcutaneous and preperitoneal fat thickness was measured by ultrasound at the first, third, and sixth month of life.

RESULTS

Subcutaneous and preperitoneal fat thickness showed no differences from the first to the sixth month of life among breastfed, mixed-fed,s and formula-fed infants, respectively; subcutaneous: 26.1 ± 10.2 to 57.4 ± 10.3 cm, 27.7 ± 10.5 to 55.4 ± 1.4, and 28.1 ± 10.9 to 52.7 ± 10.6; p = 0.344; preperitoneal: 10.6 ± 2.0 to 15.2 ± 1.7, 10.3 ± 2.8 to 15.5 ± 1.7, and 9.7 ± 2.6 to 15.6 ± 1.6; p = 0.623). No differences were observed among male and female infants.

CONCLUSION

Abdominal fat distribution measured by ultrasound seems not to be different among breastfed and formula-fed infants during the first semester of life.

Obesity and Gestational Diabetes Mellitus Pathways for Programming in Mouse, Monkey, and Man—Where Do We Go Next? The 2014 Norbert Freinkel Award Lecture

Obesity and gestational diabetes mellitus continue to increase worldwide and span the spectrum of age, race, ethnicity, and socioeconomic status. Alarmingly, 1 in 10 infants and toddlers is obese, and 1 in 5 youths is both obese and at risk for metabolic syndrome prior to puberty. The mechanisms underlying how poor maternal health imparts risk for future metabolic disease in the offspring are beginning to emerge in deeply phenotyped human and nonhuman primate models. Maternal diet and obesity impact fuels, hormones, and inflammation with powerful effects on fetal metabolic systems. These are accompanied by persistent changes in the infant microbiome and epigenome and in offspring behavior. These results suggest that gestational and lactational dietary exposures are driving health risks in the next generation. Whether maternal diet can prevent changes in the womb to alter infant life-course disease risk is still unknown. Controlled, mechanistic studies to identify interventions are sorely needed for a healthier next generation.

Sexual dimorphism in relation to adipose tissue and intrahepatocellular lipid deposition in early infancy

Sexual dimorphism in adiposity is well described in adults, but the age at which differences first manifest is uncertain. Using a prospective cohort, we describe longitudinal changes in directly measured adiposity and intrahepatocellular lipid (IHCL) in relation to sex in healthy term infants. At median ages of 13 and 63 days, infants underwent quantification of adipose tissue depots by whole-body magnetic resonance imaging and measurement of IHCL by in vivo proton magnetic resonance spectroscopy. Longitudinal data were obtained from 70 infants (40 boys and 30 girls). In the neonatal period girls are more adipose in relation to body size than boys. At follow-up (median age 63 days), girls remained significantly more adipose. The greater relative adiposity that characterises girls is explained by more subcutaneous adipose tissue and this becomes increasingly apparent by follow-up. No significant sex differences were seen in IHCL. Sex-specific differences in infant adipose tissue distribution are in keeping with those described in later life, and suggest that sexual dimorphism in adiposity is established in early infancy.