Cardiorespiratory events in infants with gastroesophageal reflux symptoms: Is there any association?

BACKGROUND: Cardiorespiratory (CR) events (apnea, bradycardia, oxygen desaturation) and gastroesophageal reflux (GER) symptoms often coexist in infants admitted to Neonatal Intensive Care Unit, leading to over-prescription of drugs and delayed discharge. We aimed to evaluate the relationships between CR and GER events. METHODS: The temporal associations between CR and GER events were analyzed in symptomatic infants who underwent synchronized CR and pH-impedance monitoring. The symptom association probability (SAP) index was used to identify infants with a significant number of temporal associations. Gastroesophageal reflux characteristics and the chronological sequence of CR and GER events occurring within 30 seconds of each other were evaluated according to SAP index. KEY RESULTS: Of the 66 infants enrolled, aged 29 (18-45) days, 58 had CR events during monitoring. From these 58 patients, a total of 1331 CR events and 5239 GER (24% acidic) were detected. The SAP index was positive in seven (12%) infants. These infants had greater GER frequency, duration, and proximal extent (P < .05). The number of temporal associations was 10 times greater in the positive SAP group. Gastroesophageal reflux events preceded CR events in 83% of these associations. These GER events had a higher proximal extent (P = .004), but showed no differences in pH values. CONCLUSIONS & INFERENCES: The simultaneous evaluation of CR and GER events could be useful to identify infants with severe GER and significant temporal associations between these events. Treatment of GER could be indicated in these infants, but as the GER events involved are mainly non-acidic, empirical treatment with antacids is, often, inappropriate.

Advances on human milk hormones and protection against obesity.

Extensive research shows that breast milk could have positive health effects not limited to infancy, but extend into childhood and adulthood. Recently many studies have provided new evidence on the long—term positive effects of breastfeeding, in particular protection against obesity and type 2 diabetes, suggesting that breast milk may have a role in the programming of later metabolic diseases. The mechanism throughout breastfeeding that exerts these effects has been a major focus of interest for researchers and it is still not completely known. There are some hints for biological plausibility of beneficial effects of breastfeeding including macronutrient intake, hormonal and behavioural mechanisms related to breast milk composition. Breast milk biochemical components, such as protein quantity and quality, polyunsaturated fatty acids, oligosaccharides, cytokines and hormones, in particular leptin, adiponectin and resistin together with the breastfeeding practice itself can influence infants feeding behaviour and regulation of growth and appetite control later in life. Further research is needed to confirm the possibility that hormones present in breast milk exert a metabolic and beneficial effects.

High serum leptin levels in infancy can potentially predict obesity in childhood, especially in formula-fed infants.

AIM: To investigate serum leptin levels in breast-fed and formula-fed infants in infancy and their possible relationship to body mass index (BMI) in childhood. METHODS: We enrolled 237 healthy term infants between September 2000 and April 2004 and tested their serum leptin levels, took anthropometric measurements and calculated BMI. A follow-up study was carried out to evaluate the BMI of 89 of these infants in childhood, in relation to their serum leptin levels in infancy, at a median (interquartile range) age of 8.8 years (7.8-10.2). The statistical significance of this multivariate analysis was set at p < 0.05. RESULTS: Breast-fed infants had significantly higher serum leptin levels than formula-fed ones (p < 0.05). Children who were formula-fed in infancy had a significantly higher BMI, at follow-up, than those who were breast-fed (p < 0.001). Furthermore, we identified a leptin cut-off value of 2.7 ng/mL, below which infants had a higher BMI in childhood. CONCLUSION: A higher leptin level in infancy may be inversely associated with BMI in childhood, suggesting that this hormone in infancy is a potential predictor of obesity in later life. Further investigation is required to be conclusive and to confirm our empirical evidence.

Adiponectin in breast milk: relation to serum adiponectin concentration in lactating mothers and their infants.

AIMS: The aims of the study were to determine human breast milk adiponectin concentration and to investigate its relationship with serum adiponectin concentration in lactating mothers and their infants and also to evaluate the relationship between serum adiponectin concentration and anthropometric parameters in nurses and infants. METHODS: We enrolled 60 healthy term breastfed (BF) infants and their lactating mothers. Adiponectin was determined by radioimmunoassay test in serum and by enzyme-linked immunosorbent assay test in human milk (HM). Infants' and mothers' anthropometric parameters were measured. RESULTS: Median (25‰, 75‰) adiponectin concentration in HM was 9.99 (3.59, 20.52) ng/mL. Serum adiponectin concentration in infants was 60.49 (45.76, 74.24) µg/mL and in lactating mothers 21.14 (12.61, 29.66) µg/mL. Adiponectin concentration in HM correlated positively with adiponectin in mothers' serum; r = 0.60 (p < 0.001) and in infants' serum r = 0.37 (p = 0.015). Adiponectin in HM correlated negatively with infants' age r = -0.3 (p = 0.04). Infants' serum adiponectin correlated negatively with their weight r = -0.35 (p = 0.005), length r = -0.35 (p = 0.006) and age r = -0.46 (p < 0.001) and mothers' serum adiponectin with their weight r = -0.37 (p = 0.02) and body mass index r = -0.45 (p = 0.004). CONCLUSIONS: The observed correlations between adiponectin in mothers, HM and BF infants may be suggestive for a metabolic link between nurses and infants through milk.

Thrombocytosis in children.

In healthy pediatric subjects normal count platelet ranges between 250,000 µL and 450,000 µL. An elevated platelet count greater than 2 SD defines a condition of thrombocytosis. On a clinical level, thrombocytosis is classified "mild" at a platelet count between >500,000 µL and <700,000 µL; "moderate" at a platelet count between >700,000/µL and <900,000/µL; "severe" at a platelet count >900,000/µL; and "extreme" at a platelet count >1,000,000/µL. Thrombocytosis can be classified as primary or secondary. Primary thrombocytosis is divided into familial and essential. Primary thrombocytosis is an extremely rare clonal disease in childhood with incidence of one per million children, i.e., 60 times lower than in adults. It is classified as a myeloproliferative disorder with polycythemia vera, chronic myeloid leukaemia and myelofibrosis and may be associated with thrombotic or haemorrhagic events. Platelet count is generally above 1,000,000/µL. The median age at diagnosis is about 11 years. On the contrary, secondary or reactive thrombocytosis (RT) is very common in pediatric age, occurring in 3-13% of hospitalized children because of several causes. Generally, it is a reactive process caused by infection, chronic inflammation, iron deficiency, tissue damage, cancer, drugs and surgical or functional splenectomy. Thrombocytosis is mild in 72-86% of children, moderate in about 6-8%, and extreme in 0.5-3%. Consultation with a pediatric hematologist is required if elevation of platelet count persists, is unexplained or symptomatic. In the majority of cases no treatment is necessary, and the patient must be only closely monitored.

Evaluation of leptin in breast milk, lactating mothers and their infants.

BACKGROUND/OBJECTIVES: Leptin is present in human milk, but it is not clear what the relationship between breast milk (BM) leptin levels and maternal and infant serum leptin concentrations is. The objective of this study was to evaluate the leptin concentration in BM and to investigate its relationship with infants' and mothers' anthropometric parameters and with serum leptin concentration in breast-fed (BF) infants and lactating mothers. SUBJECTS/METHODS: We enrolled 36 adequate for gestational age healthy, exclusively BF, term infants aged <6 months. Leptin concentration in serum and BM was determined by radioimmunoassay (RIA) test (human-leptin-RIA-sensitive, Mediagnost). Infants' and mothers' weights, lengths and body mass indexes (BMI) were measured. RESULTS: The median leptin concentration was 3.42 ng/ml (interquartile range (IR): 2.65) in BF infants' serum, 3.02 ng/ml (IR: 2.85) in mothers' serum (n=17) and 0.51 ng/ml (IR: 0.34) in BM (n=24). BM leptin concentrations were significantly lower than serum BF infant (P<0.001) and maternal (P<0.001) leptin levels. Infant serum leptin concentration correlated positively with infant weight (r=0.437, P=0.008) and BMI (r=0.561, P=0.004). Mother serum leptin levels correlated positively with weight (r=0.755, P<0.001) and BMI (r=0.661, P=0.007). No correlations were found between BM leptin and serum leptin concentrations in BF infants and mothers. CONCLUSIONS: We confirmed the presence of leptin in BM at a lower concentration than that found in infant and lactating mother serum. We observed a positive correlation between serum leptin levels in BF infants and their growth parameters.

Ghrelin, motilin, insulin concentration in healthy infants in the first months of life: relation to fasting time and anthropometry.

AIMS: This study aimed to investigate: (i) the relation between fasting time and serum ghrelin, motilin and insulin concentrations and (ii) the correlations between these hormones and anthropometrical parameters of infants in the first 18 months of life. PATIENT AND METHODS: A cross-sectional study on 62 term infants was performed. Blood samples for hormonal assay were obtained at least 1 h after feeding. Weight, length and head circumference were recorded. Plasma ghrelin, motilin and insulin concentrations were determined by radioimmunoassay. RESULTS: Ghrelin and motilin had a significant direct correlation with fasting time (r = 0.447; P < 0.001 and r = 0.36; P = 0.004, respectively). We observed a negative influence of insulin on ghrelin levels (beta = -0.32; P = 0.036). Plasma ghrelin levels correlated significantly with age (r = 0.45, P < 0.001), weight (r = 0.31, P = 0.013), head circumference (r = 0.35, P = 0.006) and length (r = 0.39, P = 0.001). A significant correlation emerged between motilin and age (r = 0.45, P < 0.001), weight (r = 0.43, P = 0.001), head circumference (r = 0.47, P < 0.001) and length (r = 0.48, P < 0.001). CONCLUSIONS: Fasting influence on serum ghrelin concentration confirms the role of this hormone as a physiological meal initiator also in infancy. The correlation between ghrelin, anthropometrical parameters and age supports the hypothesis that this hormone could exert an important influence on growth in the first months of life. Considering motilin, age and weight might play a role in determining its secretion; motilin could be considered one of the numerous factors involved in long-term regulation of energy balance.

Serum ghrelin concentration and weight gain in healthy term infants in the first year of life.

OBJECTIVES: Ghrelin, a recently discovered hormone mainly secreted by the stomach, has several metabolic functions including regulation of food intake, energy homeostasis and body weight. There are few studies on this hormone in healthy infants during the first year of life. The aim of this study was to examine the correlations between ghrelin and weight gain in healthy term infants in the first year of life. METHODS: 104 healthy term infants aged 0 to 12 months were included in a cross-sectional study. Anthropometric measurements were assessed and mean weight gain was calculated. Serum ghrelin concentrations have been determined at least 3 hours after feeding by radioimmunoassay test. RESULTS: Ghrelin concentrations were correlated negatively to weight gain (r=-0.302; P=0.003) and positively to age (r = 0.412; P < 0.001), weight (r = 0.374; P < 0.001) and length (r=0.387; P<0.001). In breastfed infants a statistically significant negative correlation between ghrelin concentration and infant weight gain (r=-0.407; P=0.001) was observed, whereas in formula-fed infants this correlation was not statistically significant (r=-0.067; P=0.719). CONCLUSIONS: The negative correlation observed between ghrelin concentration and infant weight gain suggests that ghrelin might also play a role in the regulation of body weight in healthy infants with a physiologic energy balance. Further studies are needed to clarify how ghrelin might be involved in both short-term and long-term energy balance.