Early postnatal alteration of body composition in preterm and small-for-gestational-age infants: implications of catch-up fat.

The concept of the developmental origins of health and disease is based on studies by Barker et al. They proposed a hypothesis that undernutrition in utero permanently changes the body's structure, function, and metabolism in ways that lead to atherosclerosis and insulin resistance in later life. In addition, profound effects on the extent of body fatness and insulin sensitivity are demonstrated, if there is a "mismatch" between prenatal and postnatal environments. In previous studies, undernutrition in utero has been evaluated simply by birth weight itself or birth weight for gestational age, and the degree of mismatch has been estimated by postnatal rapid weight gain. Recently, we investigated subcutaneous fat accumulation in small-for-gestational-age infants and found that a rapid catch-up in skinfold thickness developed prior to the body weight catch-up. Furthermore, insulin-like growth factor-I and lipoprotein lipase mass concentrations also demonstrate rapid increase during the neonatal period with fat accumulation. Investigating the precise mechanisms of developmental origins of health and disease including mediating metabolic and hormonal factors may provide a new approach to prevent atherosclerosis and insulin resistance. Better management of undernutrition during gestation and neonatal growth during the early postnatal period is an important theme for future health.

Gray matter volumetric MRI differences late-preterm and term infants.

Gray matter develops rapidly during the third trimester of pregnancy, which is a critical period for lipid deposition. We measured brain volume in term and late-preterm infants to determine if it is related to disabilities in late-preterm infants. In addition, we measured serum lipid concentrations to investigate the relationship between brain volume and lipid nutrition. Magnetic resonance imaging scans were obtained in 16 late-preterm and 13 term infants. We measured cerebrum, gray matter, and white matter volumes. We performed serum cholesterol, triglyceride (TG), and lipoprotein analyses in cord blood by high-performance liquid chromatography using gel permeation columns to assess lipid nutritional levels. The gray matter volume and percent cerebrum volume of gray matter were significantly smaller in late-preterm infants (p<0.001). Head circumference and cerebrum and white matter volume did not differ between the two groups. Gray matter volume correlated positively with gestational age (r=0.647, p<0.001), head circumference (r=0.688, p<0.001), and high-density lipoprotein (HDL)-TG levels (r=0.496, p=0.006). Late-preterm infants had a normal head circumference and a lower gray matter volume than term infants. Gestational age and head circumference were significantly associated with gray matter volume. Only HDL-TG levels were significantly associated with gray matter volume. HDL-TG might contribute to the transport of fatty acids and gray matter development during the postnatal period. Thus, delayed gray matter development may partly contribute to neurodevelopmental disabilities in late-preterm infants.

Early postnatal changes of lipoprotein subclass profile in late preterm infants.

BACKGROUND: Late preterm infants (LPIs; 34-37 gestational weeks at birth) have higher risk for several morbidities than do term infants (TIs). It has been suggested that a cholesterol and fatty acid supply may improve their outcomes. We investigated the lipoprotein subclass profile in LPIs to evaluate their early postnatal lipid metabolism. METHODS: Eighty-one infants (25 LPIs, 56 TIs) were included. Cholesterol and triglyceride (TG) concentrations in 12 lipoprotein subclasses were measured at birth and at 1 month using HPLC. RESULTS: In LPIs, the cord blood exhibited higher cholesterol concentrations in medium and large subclasses of very low-density lipoprotein (VLDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) compared to the values in TIs. During the first month of life, LPIs had greater increases in cholesterol concentrations of medium and large subclasses of VLDL than TIs, whereas postnatal increases in cholesterol concentrations of medium and large subclasses of LDL and HDL were smaller. TG concentrations were not different in each VLDL subclass at birth and at 1 month. CONCLUSIONS: In LPIs, cord blood lipoprotein subclass profiles and the early postnatal change exhibited different, especially in cholesterol concentrations.

Examination of severe, hospital acquired infections affecting extremely low birthweight (ELBW) infants.

PURPOSE: A nationwide questionnaire survey was carried out in 77 major neonatal intensive care unit (NICU) facilities in Japan. The survey investigated severe, hospital acquired infections occurring in extremely low birthweight (ELBW) infants at each institution. METHODS: The nationwide questionnaire survey involved 77 major NICU facilities and ELBW infants born in 1996. The actual status of severe infection in these infants was investigated. RESULTS: Replies were obtained from 57 of the 77 facilities that were sent a questionnaire (74% recovery). During the survey period, the total number of patients hospitalized in 57 facilities was 13697, of which there were 836 ELBW infants. During this period, severe infection occurred in 126 of the ELBW infants. Of those, 98 who developed delayed infection (72 h or more after birth) on the basis of the date of onset were investigated. Methicillin-resistant staphylococcus aureus (MRSA) was the most common organism found, (38 infants, 38.8%), followed by Pseudomonas (10 infants, 10.2%) and Candida (8 infants, 8.2%). Septicemia was present in 67 patients (68.4%), while pneumonia and gastrointestinal complications were found in 15 patients (15.3%). With respect to therapy, the selection of antibiotics varied between facilities. Vancomycin (VCM) was used in 31 cases (31.6%) because MRSA was the most common organism. VCM was used from the early stage of treatment in as many as 20 infants (20.4%). Fifty-eight infants survived (59.2%), 28 infants died (28.6%), and 12 subsequentially had obvious complications (12.2%). CONCLUSION: It was confirmed that severe, hospital acquired infections caused by MRSA are still a significant problem in many institutions. Despite active prevention and treatment, the incidence of severe, hospital acquired infection has not decreased and the prognosis has not improved. Considering the inadequacy of the medical care environment in Japan, it seems impossible to solve these problems at present.