Influence of Maternal Body Fat on Levels of Insulin, Insulin-Like Growth Factor-1, and Obestatin

BACKGROUND

Insulin, insulin-like Growth Factor-1 (IGF-1), and obestatin in human milk originate from the circulation. There is also limited knowledge about the influence of body fat on the levels of these hormones in human milk.

RESEARCH AIM

To determine (1) the influence of body fat on levels of insulin, IGF-1, and obestatin in human milk and serum/plasma during the postpartum period; (2) the changes in the levels of these hormones in human milk and serum/plasma postpartum; and (3) the presence of IGF-1 mRNA in human milk.

METHODS

In this prospective, longitudinal, observational cohort study, levels of insulin, IGF-1, and obestatin were measured up to 30 days postpartum in milk and serum/plasma of 58 participants with adequate (≤ 32%) or excess (> 32%) total body fat determined by electrical bioimpedance. Student's t test and repeated-measures analysis of variance were used to evaluate the differences between groups. Pearson's test was used to analyze the associations.

RESULTS

The milk from participants with excess body fat had higher insulin and IGF-1 levels and lower obestatin levels than that of participants with adequate body fat at 3-7, 14-15, and 30 days postpartum (adjusted p < .001). The levels of insulin, IGF-1, and obestatin were significantly higher in human milk than in serum/plasma (p < .05) and correlated with maternal body fat (p < .001).

CONCLUSIONS

Maternal body fat was associated with elevated insulin and IGF-1 levels and decreased obestatin levels in human milk up to 30 days postpartum.

Efficacy of Docosahexaenoic Acid for the Prevention of Necrotizing Enterocolitis in Preterm Infants: A Randomized Clinical Trial

Necrotizing enterocolitis (NEC) is an inflammatory bowel disease and a leading cause of morbidity and mortality in preterm infants. In this study, a randomized double-blind parallel-group (1:1) trial was carried out in two neonatal intensive care units of two tertiary hospitals. Two hundred and twenty-five preterm newborns with an expected functional gastrointestinal tract were recruited and received an enteral dose of 75 mg of docosahexaenoic acid (DHA)/kg body weight or high-oleic sunflower oil daily for 14 days from the first enteral feed after birth. Confirmed NEC was evaluated with Bell’s scale from stage ≥ IIa. Two hundred and fourteen randomized infants were analyzed in terms of the intent-to-treat (DHA-group: n = 105; control-group: n = 109); data for two hundred infants were analysed per protocol. Confirmed NEC was lower in infants from the DHA-group compared with the control-group (0/100 vs. 7/100; p = 0.007), with RR = 0.93 (95% CI 0.881 to 0.981), risk difference = −7%, (95% CI −12.00 to −1.99), and number needed-to-treat = 15 (95% CI 8.3 to 50). Intent-to-treat analysis showed a lower level of treatment failure in the DHA-group compared with the control-group (6/105 (6%) vs. 16/109 (15%); p = 0.03, RR = 0.905, (95% CI 0.826 to 0.991)). The results after multivariate-regression analysis remained significant. Adverse events (apart from the incidence of NEC) were not different between groups. A daily dose of DHA for 14 days starting with the first enteral feed may prevent NEC in preterm infants.

Enteral Docosahexaenoic Acid and Retinopathy of Prematurity: A Randomized Clinical Trial

BACKGROUND

Retinopathy of prematurity (ROP) is a disorder of the retina of low-birth-weight preterm infants that potentially leads to blindness. Docosahexaenoic acid (DHA), is protective in experimental models, but its administration as part of parenteral nutrition has shown inconsistent results. We test the effect of enteral DHA to prevent ROP and/or severity and to reduce hospital stay.

METHODS

This was a double-blind parallel clinical trial. Preterm infants (n = 110; 55 per group) with birth weight <1500 g but ≥1000 g were recruited in a neonatal intensive care unit. Infants were randomized to receive 75 mg of DHA/kg/d (DHA group) or high oleic sunflower oil (control group) for 14 days by enteral feeding. The effect of DHA was evaluated on any stage of ROP, severe ROP (stage ≥3) incidence, and hospital stay. Groups were compared with relative risk (RR) and 95% confidence interval (CI), Fisher's exact test, Student's t-test, or Mann-Whitney U-test, as appropriate. Logistic regression was applied to adjust for confounders.

RESULTS

There was no difference between the DHA and control groups in ROP risk (RR for DHA = 0.79; 95% CI, 0.49-1.27; P = 0.33). However, patients who received DHA showed lower risk for stage 3 ROP (RR for DHA = 0.66; 95% CI, 0.44-0.99; P = 0.03). After adjusting for confounders, this decreased risk remained significant (adjusted odds ratio = 0.10; 95% CI, 0.011-0.886; P = 0.04). Hospital stay was similar between groups.

CONCLUSION

Enteral DHA may reduce the incidence of stage 3 ROP.

Body composition and body mass index in Duchenne muscular dystrophy: Role of dietary intake

INTRODUCTION

In Duchenne muscular dystrophy (DMD) muscle is replaced by adipose tissue. The role of dietary intake (DI) in DMD has not been evaluated. In this study we examined body composition, body mass index (BMI), and adequacy of DI in patients with DMD and evaluated the influence of DI on body composition.

METHODS

Patients (n = 101; age 3-18 years; BMI 11.8-29.5 kg/m² ) completed a dietary recall to determine DI and then underwent dual-energy X-ray absorptiometry to determine body composition.

RESULTS

Preschool-age and school-age boys with DMD had high total energy intake. Protein intake per kilogram exceeded recommendations. As age increased, the percentage of boys with abnormal BMI and fat mass increased, while lean mass decreased. Dietary intake did not predict body fat or lean mass.

DISCUSSION

Age-dependent changes in BD in boys with DMD may be due to endogenous metabolic factors related to the underlying disease process and to disease-related mobility impairments. Muscle Nerve 59:295-302, 2019.

IL-17-differentiated macrophages secrete pro-inflammatory cytokines in response to oxidized low-density lipoprotein

Background

Cytokines and macrophages play a central role in the development of atherosclerosis. Interleukin (IL)-17 is a pro-inflammatory cytokine with differential effects on innate immune cells. We investigated the effects of IL-17 on macrophage differentiation and foam cell formation and activation in response to oxidized low-density lipoprotein (oxLDL).

Methods

Human monocytes were treated with IL-17 to induce macrophage differentiation. As controls, human monocytes were differentiated into M1 macrophages (M1) or M2 macrophages (M2). Subsequently, we analyzed the expression levels of markers such as CD80, CD36 and Toll-like receptors (TLRs) as well as foam cell formation and cytokines in M1, M2 and macrophages differentiated with IL-17 with or without oxLDL.

Results

The expression of M1 or M2 markers or cytokines was not induced in macrophages differentiated with IL-17. Macrophages differentiated with IL-17 formed few foam cells, with an average proportion of 20%, and expressed 3 times as much TLR2 and 3.8 times as much TLR4 as M0 macrophages. Additionally, macrophages differentiated with IL-17 acquired inflammatory capacity in response to oxLDL through the expression of specific markers, such as CD80, which increased 18-times compared with macrophages differentiated with IL-17 alone, and secreted 1.3 times less tumor necrosis factor (TNF)-α than M1. Additionally, oxLDL increased the levels of CD80, CD86 and IL-6 by 5.7, 2.8 and 1.4 times in M1 compared with M1 in the absence of oxLDL. In M2, oxLDL induced increases in the secretion of IL-6 and TNF-α that were 1.9 times and 1.2 times smaller, respectively, than those observed in M1.

Conclusion

Our study demonstrates that differentiation of macrophages with IL-17 does not induce the expression of markers or cytokines characteristic of M1 or M2 and these macrophages form few foam cells; however, the expression of TLR is increased. Moreover, these macrophages acquire the inflammatory capacity as evidenced by the expression of costimulatory molecules and secretion of pro-inflammatory cytokines in response to oxLDL. These findings suggest that the activation of macrophages differentiated with IL-17 by oxLDL contributes to the inflammatory process of atherosclerosis.

The 13C-Glucose Breath Test for Insulin Resistance Assessment in Adolescents: Comparison with Fasting and Post-Glucose Stimulus Surrogate Markers of Insulin Resistance

OBJECTIVE

To evaluate the use of the 13C-glucose breath test (13C-GBT) for insulin resistance (IR) detection in adolescents through comparison with fasting and post-glucose stimulus surrogates.

METHODS

One hundred thirty-three adolescents aged between 10 and 16 years received an oral glucose load of 1.75 g per kg of body weight dissolved in 150 mL of water followed by an oral dose of 1.5 mg/kg of U-13C-Glucose, without a specific maximum dose. Blood samples were drawn at baseline and 120 minutes, while breath samples were obtained at baseline and at 30, 60, 90, 120, 150, and 180 minutes. The 13C-GBT was compared to homeostasis model assessment (HOMA) IR (≥p95 adjusted by gender and age), fasting plasma insulin (≥p90 adjusted by gender and Tanner stage), results of 2-h oral glucose tolerance test (OGTT), insulin levels (≥65 μU/mL) in order to determine the optimal cut-off point for IR diagnosis.

RESULTS

13C-GBT data, expressed as adjusted cumulative percentage of oxidized dose (A% OD), correlated inversely with fasting and post-load IR surrogates. Sexual development alters A% OD results, therefore individuals were stratified into pubescent and post-pubescent. The optimal cut-off point for the 13C-GBT in pubescent individuals was 16.3% (sensitivity=82.8% & specificity=60.6%) and 13.0% in post-pubescents (sensitivity=87.5% & specificity=63.6%), when compared to fasting plasma insulin. Similar results were observed against HOMA and 2-h OGTT insulin.

CONCLUSION

The 13C-GBT is a practical and non-invasive method to screen for IR in adolescents with reasonable sensitivity and specificity.

Oral administration of docosahexaenoic acid attenuates interleukin-1β response and clinical course of septic neonates

OBJECTIVE

To analyze cytokine responses and the clinical course of septic neonates orally supplemented with docosahexaenoic acid as well as to evaluate fatty acid incorporation into leukocytes.

METHODS

A quasiexperimental study was conducted in neonates who developed sepsis following a surgical procedure. Selected neonates were randomly assigned to receive 100 mg docosahexaenoic acid (G-DHA) daily or olive oil (G-OO) as placebo for 14 d throughout a sepsis episode. At selection (baseline), blood samples were obtained to determine interleukin-1 (IL-1)β, interleukin-6 (IL-6), and tumor necrosis factor-α as well as the leucocyte fatty acid profile. Measurements were repeated at 7 (D7) and 14 d (D14) of follow-up. Within- and between-group comparisons were conducted with parametric statistics after logarithmic transformation. Repeated measurement analyses with a general linear model procedure were used, adjusting according to human milk intake, use of anti-inflammatory drugs, and nutritional status.

RESULTS

Sixty-three neonates were included: 29 in G-DHA group and 34 in G-OO group. Although decreases of cytokines during hospitalization were similar in both groups, there was a greater decrease of IL-1β in the G-DHA group than in the G-OO group after adjusting by confounders (P = 0.028). Leukocyte docosahexaenoic acid increased from 4.96 ± 2.96 at baseline to 5.52 ± 3.05 and 5.92 ± 2.8 at D7 and D14, respectively, in the G-DHA group (P = 0.044). Illness severity was inversely associated with the proportion of docosahexaenoic acid in leukocytes throughout follow-up (P = 0.034).

CONCLUSIONS

Oral supplementation with docosahexaenoic acid to neonates attenuates IL-1β response and the clinical course of sepsis. This may be an additional strategy to further benefit ill neonates even if they are not candidates for parenteral nutrition.

Docosahexaenoic acid administered in the acute phase protects the nutritional status of septic neonates

OBJECTIVE

We tested the hypothesis of whether a pharmacologic, orogastric dose of docosahexaenoic acid (DHA) administered during the acute phase of sepsis protects the nutritional status of neonates.

METHODS

A randomized, placebo-controlled trial was conducted. Neonates who developed sepsis after a surgical procedure were randomly assigned to receive daily 100 mg of DHA or 100 mg of olive oil as placebo for 14 d. At selection, illness severity was evaluated and a blood sample was obtained to measure erythrocyte fatty acid composition. Energy intake and type of feeding were recorded daily. Body composition was also determined at selection and after 14 d of follow-up with the deuterium dilution technique. Body composition differences between d 14 and baseline were calculated and compared between groups. Confounders were analyzed in a multiple regression model.

RESULTS

In all, 16 DHA and 11 placebo cases were followed up. Both groups showed an increase in length and head circumference, but length gain tended to be greater in neonates with DHA (P = 0.07). The DHA group presented increases in body mass (50 g, P = 0.03) and fat mass (70 g, P = 0.03), whereas infants in the placebo group did not show an increase in any body composition components. Gain in fat mass was positively related with the DHA of erythrocytes and whether or not infants received DHA.

CONCLUSIONS

Orogastric DHA administered in the acute phase of infection likely protects the nutritional status of neonates with sepsis.

A fortifier comprising protein, vitamins, and calcium-glycerophosphate for preterm human milk

BACKGROUND

The infant's own mother's milk, fortified with proteins, minerals, and vitamins, is considered the best food for low-birth-weight infants. This paper describes the process to obtain a liquid human milk fortifier.

METHODS

The fortifier comprises a protein concentrate, calcium, phosphate, and zinc salts, as well as vitamins A and D. A powdered whey protein extracted from bovine milk was concentrated from 31.5-76.8 g/100 g using repetitive dialysis. The protein concentrate was dissolved in a 0.2 M phosphate buffer pH 7.4 and mixed with calcium-glycerophosphate and calcium-gluconate, vitamins A and D, folic acid, and zinc. Each 10 mL of this liquid fortifier has 0.78 g protein, 53 mg calcium, 36 mg phosphate, and 0.93 mg zinc.

RESULTS

Repetitive dialysis did not modify the protein structure as demonstrated by electrophoresis. A total of 95% of lactose content was discarded. Enriching human milk using this human milk fortifier increased the concentration per deciliter of all added nutrients; proteins increased from 1.68-2.35 g, calcium from 26-90 mg, and phosphorus, from 15-51 mg.

CONCLUSIONS

A liquid human milk fortifier was successfully manufactured using a noncomplex procedure. An intake of 180-200 mL/kg/day of the fortified human milk by the premature infant would satisfy the infant's nutritional requirements and achieve expected growth and development.