From the α to the ω-3: Breaking the link between impaired fetal growth and adult cardiovascular disease

Increased α-Linolenic Acid Intake during Pregnancy is Associated with Higher Offspring Birth Weight

BACKGROUND

The amount and type of fat in the maternal diet during pregnancy are important contributors to fetal growth. The importance of plant-based omega-3 fatty acid (α-linolenic acid, ALA) intake in fetal growth has not been previously examined.

OBJECTIVE

We sought to determine the association of maternal ALA intake during pregnancy with birth weight and body composition of the offspring.

METHODS

Mothers and their newborn infants (n = 224) were recruited from the Royal Prince Alfred Hospital, Australia. Maternal diet during pregnancy was assessed using a validated food frequency questionnaire. Plasma fatty acid composition was analyzed in a subset of mothers (n = 41). Newborn body composition was assessed using air-displacement plethysmography. All analyses were adjusted for gestational age, sex, physical activity, and total energy intake.

RESULTS

Dietary fatty acid intakes were positively associated with plasma phospholipid fatty acids for total omega-3 fatty acids (β = 0.452, P = 0.003), ALA (β = 0.339, P = 0.03), linoleic acid (β = 0.353, P = 0.03), eicosapentaenoic acid (β = 0.407, P = 0.009), and docosahexaenoic acid (β = 0.388, P = 0.01). Higher maternal intake of ALA (% total fat) was associated with higher offspring birth weight [189.7-g increase per 1% higher ALA (95% CI: 14, 365 g); P = .04], although individually neither newborn fat mass nor fat-free mass was significant. Birth weight increased across tertiles of maternal ALA intake (P ANOVA = 0.05), with birth weight being 221 g (95% CI: 12, 429 g) higher in those with the highest maternal ALA intake compared with those with the lowest intake (P = 0.04). Mothers of infants born small for gestational age (n = 32) had a lower ALA intake than those born appropriate for gestational age (n = 162) or large for gestational age [(n = 21); P = 0.05].

CONCLUSIONS

In otherwise healthy women giving birth at a major tertiary hospital in Australia, intake of ALA during pregnancy is associated with higher offspring birth weight. This may have implications for dietary strategies aimed at optimizing fetal growth via modification of maternal diet.

Marine Omega-3 Fatty Acids, Complications of Pregnancy and Maternal Risk Factors for Offspring Cardio-Metabolic Disease

Marine omega-3 polyunsaturated fatty acids (n-3 PUFA) are important nutrients during periods of rapid growth and development in utero and infancy. Maternal health and risk factors play a crucial role in birth outcomes and subsequently offspring cardio-metabolic health. Evidence from observational studies and randomized trials have suggested a potential association of maternal intake of marine n-3 PUFAs during pregnancy with pregnancy and birth outcomes. However, there is inconsistency in the literature on whether marine n-3 PUFA supplementation during pregnancy can prevent maternal complications of pregnancy. This narrative literature review summarizes recent evidence on observational and clinical trials of marine n-3 PUFA intake on maternal risk factors and effects on offspring cardio-metabolic health. The current evidence generally does not support a role of maternal n-3 PUFA supplementation in altering the incidence of gestational diabetes, pregnancy-induced hypertension, or pre-eclampsia. It may be that benefits from marine n-3 PUFA supplementation are more pronounced in high-risk populations, such as women with a history of complications of pregnancy, or women with low marine n-3 PUFA intake. Discrepancies between studies may be related to differences in study design, dosage, fatty acid interplay, and length of treatment. Further prospective double-blind studies are needed to clarify the impact of long-chain marine n-3 PUFAs on risk factors for cardio-metabolic disease in the offspring.

Postnatal undernutrition in mice causes cardiac arrhythmogenesis which is exacerbated when pharmacologically stressed

Growth restriction caused by postnatal undernutrition increases risk for cardiovascular disease in adulthood with the potential to induce arrhythmogenesis. Thus, the purpose was to determine if undernutrition during development produced arrhythmias at rest and when stressed with dobutamine in adulthood. Mouse dams were fed (CON: 20% protein), or low-protein (LP: 8%) diet before mating. A cross-fostering model was used where pups nursed by dams fed LP diet in early [EUN; postnatal day (PN) 1–10], late (LUN; PN11–21) and whole (PUN; 1–21) phases of postnatal life. Weaned pups were switched to CON diets for the remainder of the study (PN80). At PN80, body composition (magnetic resonance imaging), and quantitative electrocardiogram (ECG) measurements were obtained under 1% isoflurane anesthesia. After baseline ECG, an IP injection (1.5 µg/g body weight) of dobutamine was administered and ECG repeated. Undernutrition significantly (P<0.05) reduced body weight in LUN (22.68±0.88 g) and PUN (19.96±0.32 g) but not in CON (25.05±0.96 g) and EUN (25.28±0.9207 g). Fat mass decreased in all groups compared with controls (CON: 8.00±1.2 g, EUN: 6.32±0.65 g, LUN: 5.11±1.1 g, PUN: 3.90±0.25 g). Lean mass was only significantly reduced in PUN (CON: 17.99±0.26 g, EUN: 17.78±0.39 g, LUN: 17.34±0.33 g, PUN: 15.85±0.28 g). Absolute heart weights were significantly less from CON, with PUN having the smallest. ECG showed LUN had occurrences of atrial fibrillation; EUN had increases of 1st degree atrioventricular block upon stimulation, and PUN had increased risk for ventricular depolarization arrhythmias. CON did not display arrhythmias. Undernutrition in early life resulted in ventricular arrhythmias under stressed conditions, but undernutrition occurring in later postnatal life there is an increased incidence of atrial arrhythmias.

Metabolic signatures of birthweight in 18 288 adolescents and adults

BACKGROUND

Lower birthweight is associated with increased susceptibility to cardiometabolic diseases in adulthood, but the underlying molecular pathways are incompletely understood. We examined associations of birthweight with a comprehensive metabolic profile measured in adolescents and adults.

METHODS

High-throughput nuclear magnetic resonance metabolomics and biochemical assays were used to quantify 87 circulating metabolic measures in seven cohorts from Finland and the UK, comprising altogether 18 288 individuals (mean age 26 years, range 15-75). Metabolic associations with birthweight were assessed by linear regression models adjusted for sex, gestational age and age at blood sampling. The metabolic associations with birthweight were compared with the corresponding associations with adult body mass index (BMI).

RESULTS

Lower birthweight adjusted for gestational age was adversely associated with cardiometabolic biomarkers, including lipoprotein subclasses, fatty acids, amino acids and markers of inflammation and impaired liver function (P < 0.0015 for 46 measures). Associations were consistent across cohorts with different ages at metabolic profiling, but the magnitudes were weak. The pattern of metabolic deviations associated with lower birthweight resembled the metabolic signature of higher adult BMI (R² = 0.77) assessed at the same time as the metabolic profiling. The resemblance indicated that 1 kg lower birthweight is associated with similar metabolic aberrations as caused by 0.92 units higher BMI in adulthood.

CONCLUSIONS

Lower birthweight adjusted for gestational age is associated with adverse biomarker aberrations across multiple metabolic pathways. Coherent metabolic signatures between lower birthweight and higher adult adiposity suggest that shared molecular pathways may potentially underpin the metabolic deviations. However, the magnitudes of metabolic associations with birthweight are modest in comparison to the effects of adiposity, implying that birthweight is only a weak indicator of the metabolic risk profile in adulthood.