Circulating visfatin levels in healthy preterm infants are independently associated with high-density lipoprotein cholesterol levels and dietary long-chain polyunsaturated fatty acids.

The adipokine visfatin has been proposed to exert insulin-mimicking effects and to play a role in the development of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance and, possibly, for other components of metabolic syndrome. Dietary long-chain polyunsaturated fatty acids (LCPUFAs) during the perinatal period may reduce the risk of metabolic syndrome. The authors' objective was to study the circulating concentrations of visfatin in preterm infants and to examine associations of visfatin with anthropometric measurements, metabolic indices, and dietary LCPUFAs. Serum visfatin concentrations were determined by enzyme-linked immunosorbent assay at mean (SD) 33.8 (11.7) days of life in 60 healthy preterm infants (gestational age, 32.7 [1.9] weeks) randomly assigned to be fed since birth either a formula containing LCPUFA (arachidonic and docosahexaenoic acid) (+LCPUFA group) or the same formula without LCPUFA (-LCPUFA group). Associations of visfatin with anthropometric parameters, serum glucose, insulin, homeostasis model assessment index of insulin resistance, blood lipids, and adiponectin levels were examined. Serum visfatin levels were significantly higher in the +LCPUFA than in the -LCPUFA group (P < .001) and correlated positively with body weight z score (ß = 0.31, P = .02), total cholesterol (ß = 0.34, P = .01), high-density lipoprotein cholesterol (HDL-C) (ß = 0.47, P < .001), and adiponectin levels (ß = 0.29, P = .03), but not with indices of insulin sensitivity. In multiple regression analysis, HDL-C and dietary LCPUFAs correlated independently with serum visfatin levels. Circulating visfatin levels in preterm infants are independently associated with HDL-C levels and dietary LCPUFAs. Whether the higher visfatin levels in the +LCPUFA preterm infant group are beneficial for the later health of these infants remains to be determined.

Circulating adipocyte fatty acid binding protein levels in healthy preterm infants: Positive correlation with weight gain and total-cholesterol levels.

BACKGROUND: Adipocyte fatty acid binding protein (a-FABP) has been suggested to play an important role in the pathogenesis of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance, and, possibly, other components of metabolic syndrome. AIM: To determine circulating levels of a-FABP in preterm infants and examine possible associations of a-FABP with metabolic indices (serum lipids, glucose, and insulin levels, and homeostasis model assessment index of insulin resistance [HOMA-IR]), levels of leptin and adiponectin, anthropometric parameters and weight gain. STUDY DESIGN: Prospective cohort study. SUBJECTS: 55 healthy preterm (mean [SD] gestational age 32.8 [1.8] weeks) and 23 fullterm infants (reference group). OUTCOME MEASURES: Serum a-FABP, lipids, glucose, insulin, leptin and adiponectin levels at 31.9 [10.4] days of life. RESULTS: Serum a-FABP levels did not differ significantly between preterm and fullterm infants. A-FABP levels correlated positively with total-cholesterol [total-C] in both preterm and fullterm infants (beta=0.33; p=0.01 and beta=0.33; p=0.04, respectively). In addition to total-C, weight gain correlated independently with a-FABP levels in preterm infants (beta=0.36, p=0.01). CONCLUSIONS: An association between a-FABP levels and indices of insulin resistance was not present in infants studied. As the development of insulin resistance in children born prematurely is possibly associated with weight gain in early postnatal life, follow-up of our study population is necessary to demonstrate whether a-FABP levels, shown to correlate with weight gain in preterm infants, are a predictive marker for the later development of insulin resistance in these infants.

Disparity in circulating adiponectin multimers between term and preterm infants.

AIMS: To study circulating levels and distribution of adiponectin multimers [low molecular weight (LMW)-, medium molecular weight (MMW)- and high molecular weight (HMW)-adiponectin] in preterm and full-term infants. METHODS: Total serum adiponectin and its multimers were measured in 40 healthy infants at the age of one month and associations with anthropometric parameters [body weight and length, body mass index (BMI)], weight gain and metabolic indices (glucose, insulin) were examined. Twenty of the infants were born preterm (gestational age 33.2+/-1.6 weeks). RESULTS: LMW-adiponectin level and its fractional ratio to total adiponectin were significantly higher in full-term than in preterm infants (P<0.001 and P<0.01, respectively), whereas, MMW-adiponectin level and its ratio were significantly lower (P=0.03 and P=0.01, respectively). HMW-adiponectin did not differ significantly between full-term and preterm infants and accounted for almost 60% of total adiponectin levels in both groups. HMW-adiponectin, but not MMW adiponectin or LMW adiponectin, correlated significantly with anthropometric measurements, similarly to total adiponectin; in addition, HMW adiponectin correlated significantly with weight gain. CONCLUSIONS: HMW adiponectin is the most prevalent form in infants. Circulating levels and distribution of MMW- and LMW-adiponectin differ between full-term and preterm infants, but the role of these adiponectin multimers needs to be studied further.

Circulating adiponectin in preterm infants fed long-chain polyunsaturated fatty acids (LCPUFA)-supplemented formula--a randomized controlled study.

Adiponectin has potent insulin-sensitizing effects, improves lipid metabolism, and potentially protects against the development of metabolic syndrome. Thus, increasing adiponectin levels in preterm infants at risk for developing metabolic syndrome may be of special interest. The aim of this study was to examine the effects of dietary long-chain polyunsaturated fatty acids (LCPUFA) on serum adiponectin and lipid concentrations in preterm infants. Adiponectin and lipid levels of 60 healthy preterm infants [gestational age 32.7 (1.9) wk] randomly assigned to be fed either 1) a formula containing LCPUFA [arachidonic and docosahexanoic] (+LCPUFA group) or 2) the same formula without LCPUFA (-LCPUFA/control group), were determined at mean (SD) 33.8 (11.7) d. Adiponectin and HDL-C concentrations were significantly higher in the +LCPUFA group than in controls (p = 0.002 and p = 0.01, respectively); whereas, triglyceride levels were lower (p = 0.06). Adiponectin correlated positively with HDL-C levels and negatively with triglyceride levels in the +LCPUFA group but not in the controls. In conclusion, circulating adiponectin concentrations were higher in preterm infants fed a formula containing LCPUFA than infants fed an LCPUFA-free formula and they correlated with lipidemic profile.

Oxidative stress in preterm infants fed a formula containing long-chain polyunsaturated fatty acids (LCPUFA).

Our study examined if dietary long-chain polyunsaturated fatty acids (LCPUFA) have an impact on oxidative stress in preterm infants. Serum malonyldialdehyde (MDA), total peroxide concentrations, and total antioxidant capacity were determined at mean (standard deviation [SD]) 34.7 (10.9) days of life in 104 healthy preterm infants (gestational age, 32.6 [2.9] weeks; birthweight; 1605 [285] g) who were randomly assigned to be fed since birth either a formula containing LCPUFA (arachidonic and docosahexaenoic) (group A, n = 50) or a LCPUFA-free formula with identical compositions for other nutrients (group B, n = 54). Clinical and anthropometric characteristics did not differ significantly between the two groups. Mean (SD) serum MDA levels did not differ significantly between groups A (0.23 [0.04] micromol/L) and B (0.22 [0.05] micromol/L). The concentrations of total peroxides were below the detection limits of the assay in 41 of 50 (82%) infants of group A and 43 of 54 (79%) infants of group B and not significantly different between the two infant groups. No difference was observed in serum total antioxidant capacity between groups A (340.0 [46.2] micromol/L) and B (354.7 [46.5] micromol/L). We concluded that supplementation of infant formulas with LCPUFA does not affect lipid peroxidation in healthy preterm infants.

Peptide YY (3-36) represents a high percentage of total PYY immunoreactivity in preterm and full-term infants and correlates independently with markers of adiposity and serum ghrelin concentrations.

The gut hormone peptide YY 3-36 [PYY (3-36)] has been suggested to posses anorexigenic actions in animals and human adults. However, its circulating concentrations and function have not been studied in neonates. Serum concentrations of PYY (3-36) were determined by RIA (RIA) in 62 healthy preterm infants [mean(SD) gestational age, 32.0(2.1) weeks; postnatal age, 40.9(14.8 d)] and 15 healthy fullterm infants of comparable postnatal age and gender. The correlations between PYY (3-36) levels and anthropometric characteristics, food intake, growth rates and circulating concentrations of total PYY, ghrelin, leptin, insulin and adiponectin were examined. Mean (SD) PYY (3-36) concentrations were higher in preterm [543.7(157.6) ng/L) than full term infants [350.9(114.1) ng/L; p < 0.001) and accounted for 48% and 42% of total PYY basal plasma immunoreactivity in preterm and full term infants, respectively. In multiple regression analysis, PYY (3-36) concentrations correlated negatively with the infants' BMI and positively with serum ghrelin concentrations, but not with caloric intake, weight gain or concentrations of any other hormone studied. In conclusion, PYY (3-36) represents almost half of total PYY immunoreactivity in neonates. It's correlations with ghrelin and BMI suggest a role of this peptide in the regulation of energy homeostasis; however, its specific functions and physiologic significance in neonates remain to be elucidated.

Circulating levels of adiponectin in preterm infants.

OBJECTIVE: To determine circulating levels of adiponectin in preterm infants and examine possible associations with anthropometric measurements, weight gain, and leptin and insulin levels. DESIGN: Prospective study. SETTING: A university hospital neonatal care unit. STUDY POPULATION: 62 preterm (mean (SD) gestational age 32.0 (2.1) weeks) and 15 full-term infants (reference group). INTERVENTIONS: Blood samples taken at discharge (40.9 (14.8) days of life) from the preterm infants and at a comparable postnatal age in full-term infants. All infants were fed the same commercial formula, but in nine preterms the formula contained long-chain polyunsaturated fatty acids (LCPUFAs). MAIN OUTCOME MEASURES: Serum levels of adiponectin, leptin and insulin. Associations of adiponectin levels were tested only in the preterm group. RESULTS: Serum levels of adiponectin were lower in preterm (40.9 (14.8) microg/ml) than full-term infants (53.1 (16.0) microg/ml, p<0.01). However, after adjustment for body weight, the influence of prematurity on adiponectin levels was no longer significant. In preterm infants, adiponectin levels independently correlated with being born small for gestational age (SGA) (beta=-0.35, p=0.01), weight gain (beta=0.28, p=0.03) and LCPUFA-supplemented formula (beta=0.34, p=0.009). Serum adiponectin levels did not correlate with insulin or leptin levels. However, insulin levels were higher in preterm than in full-term infants after adjustment for body weight. CONCLUSIONS: Adiponectin levels are lower in preterm infants at discharge than full-term infants probably due to decreased adiposity. The levels are influenced by being born SGA, weight gain and, possibly, by dietary LCPUFAs. The importance of these findings in the development of insulin or leptin resistance in children born prematurely needs to be further studied.

Neuroendocrine abnormalities in a neonate with congenital toxoplasmosis.

The central nervous system is often affected in patients with congenital toxoplasmosis. However, hypothalamo-pituitary dysfunction has rarely been reported in children with congenital toxoplasmosis, and no case with prolonged fever of central origin has been documented so far. We describe a newborn with congenital toxoplasmosis who presented with fever due to hypothalamo-pituitary dysregulation and combined hypothalamo-pituitary deficiencies consisting of central diabetes insipidus, hypothyroidism and ACTH deficiency.

Circulating peptide YY concentrations are higher in preterm than full-term infants and correlate negatively with body weight and positively with serum ghrelin concentrations.

BACKGROUND: Peptide YY (PYY) and ghrelin are gastrointestinal tract-derived hormones that play roles in the regulation of food intake and energy balance. Negative energy balance often occurs in hospitalized preterm infants. METHODS: To measure serum concentrations of PYY in preterm and full-term infants and to investigate their correlations with anthropometric characteristics, food intake, and serum ghrelin concentrations, we measured serum PYY and ghrelin concentrations by RIA in 62 healthy preterm infants [mean (SD) gestational age, 32.0 (2.1) weeks; postnatal age, 40.9 (14.8) days] and 15 healthy full-term infants of comparable postnatal age. All of the infants were formula-fed every 3 h. RESULTS: PYY concentrations were significantly higher in preterm [1126.2 (215.4) ng/L] than in full-term infants [825.3 (234.4) ng/L; P < 0.001]. In the entire study population, serum PYY concentrations correlated negatively with gestational age and anthropometric measurements (birth weight, body weight, body length, body mass index, and head circumference) and positively with serum ghrelin concentrations, whereas there was no significant correlation between PYY concentration and caloric intake or weight gain. Multiple regression analysis, after correction for prematurity, revealed that serum PYY concentrations correlated independently with serum ghrelin concentrations and infant body weight or body mass index. CONCLUSIONS: Circulating concentrations of PYY may increase in preterm infants to compensate for the negative body-weight balance. The physiologic mechanisms behind the correlation between PYY and ghrelin remain to be elucidated.

Hyperglycaemia and insulinopenia in a neonate with cystic fibrosis.

UNLABELLED: Abnormal glucose tolerance is a frequent late complication of cystic fibrosis (CF), but the prevalence of CF-related diabetes mellitus (CFRD) in children less than 10 y old is less than 2%. The youngest child with CFRD reported to date was 6 mo of age. Insulinopenia is the primary cause of abnormal glucose tolerance/CFRD, but it is unknown whether it may begin in the neonatal period. We describe a case of a neonate with CF who presented with hyperglycaemia in the diabetic range and marked insulinopenia. Insulinopenia and impaired glucose tolerance were permanent findings at 6 and 15 mo of age. CONCLUSION: This case suggests that abnormal glucose tolerance/diabetes may occur much earlier in the course of CF, even during neonatal age. Careful follow-up and further studies in CF infants could reveal that the real incidence of glucose intolerance and diabetes in this age group has been underestimated.

Serum lipids in preterm infants fed a formula supplemented with nucleotides.

BACKGROUND: The effect of dietary nucleotides on lipid metabolism has been the subject of clinical studies with conflicting results. We measured serum triglycerides, total cholesterol (total-C), and lipoprotein cholesterol levels (HDL-C, LDL-C, and VLDL-C) in preterm neonates fed formula with and without nucleotide supplements. METHODS: This prospective, randomized, controlled study included 150 healthy preterm neonates (gestational age, 33.0 +/- 1.9 weeks) matched for gestational age, birth weight, and gender. Subjects were assigned at birth to receive either a standard milk formula supplemented with nucleotides (group F-NT) or the same formula without nucleotides (group F). Serum was obtained before discharge (29.1 +/- 10.0 days of life) and triglycerides, total-C, and HDL-C were determined enzymatically. LDL-C and VLDL-C were estimated by the Friedewald formula. For statistical analysis t test, Mann Whitney-U test, two-way ANOVA, and chi2 test were used, as appropriate. The influence of several factors on serum lipid levels was evaluated by linear regression analysis. RESULTS: Serum triglycerides, total-C, and VLDL-C levels did not differ between groups. HDL-C levels (median; 25th-75th percentiles) were significantly higher (P < 0.001) in group F-NT (48.0 mg/dL; 40.5-57.0 mg/dL) than in group F (34.5 mg/dL; 27.2-44.0 mg/dL). On the contrary, LDL-C levels (median; 25th-75th percentiles) were significantly lower (P < 0.001) in group F-NT (39.0 mg/dL; 26.0-54.0 mg/dL) than in group F (65.0 mg/dL; 41.0-73.0 mg/dL). In the multiple regression analysis, nucleotide supplementation was identified as one of the controlled independent factors influencing serum HDL-C and LDL-C levels. CONCLUSIONS: Preterm neonates fed from birth with formula supplemented with nucleotides have significantly higher HDL-C and lower LDL-C serum levels than do neonates fed unsupplemented formula. The clinical relevance of these results remains to be elucidated.