Insulin-like growth factor-1 and insulin-like growth factor binding protein-3 as early predictors of growth, body composition, and neurodevelopment in preterm infants

OBJECTIVE

To investigate the relationship between insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3) and long-term growth, body composition, and neurodevelopment in preterm infants.

STUDY DESIGN

Prospective data were collected from ≤32 weeks gestational age infant cohort (N = 50). IGF-1 and IGFBP-3 concentrations were measured at 1 week (early) and 35 weeks (late) post-menstrual age (PMA). Growth, body composition, and neurodevelopment outcomes were measured at 4 and 12 months PMA. Relationships were measured by linear regression analysis.

RESULTS

Early IGFBP-3 concentration was positively associated with neurodevelopment at 12 months PMA. Early IGF-1 concentration was positively associated with weight at 4 months PMA, head circumference at 12 months PMA, and body mass index at 12 months PMA. Late IGFBP-3 concentration was positively associated with weight at 4 months PMA.

CONCLUSION

Further investigation of these associations may lead to novel biomarkers and/or treatments to optimize health outcomes in preterm infants.

An exploratory study of clinical factors associated with IGF-1 and IGFBP-3 in preterm infants

BACKGROUND

Despite advances in parenteral nutrition, postnatal growth failure in very low birthweight (VLBW) preterm infants is common and associated with chronic health problems. Insulin-like growth factor 1 (IGF-1) is positively associated with improved infant growth, but factors which promote IGF-1 levels in this population have not been clearly identified. The objective of this study was to explore early factors that influence IGF-1 in VLBW preterm infants.

METHODS

VLBW infants were enrolled into a prospective, randomized controlled nutrition trial (N = 87). Outcome measures included IGF-1 and IGFBP-3 levels measured at 35 weeks PMA. Linear regression analyses tested the relationships between candidate clinical predictors and levels of IGF-1 and IGFBP-3.

RESULTS

Higher protein intake, longer duration of parenteral nutrition, and lower IGFBP-3 levels at 1 week of life were associated with lower IGF-1 levels at 35 weeks PMA. Neither early markers of insulin resistance nor degree of illness were associated with IGF-1 levels at 35 weeks PMA.

CONCLUSION

Optimization of early nutrient intake, and attention to route of delivery, may have a lasting influence on IGF-1/IGFBP-3, and in turn, long-term health outcomes.

IMPACT

In very low birthweight preterm infants, early protein intake, duration of parenteral nutrition, and insulin-like growth factor binding protein 3 (IGFBP-3) levels at 1 week of life are positively associated with insulin-like growth factor 1 (IGF-1) levels at 35 weeks postmenstrual age. Data from this study highlight the influence of early nutrition on components of the endocrine axis in preterm infants. Strategies aimed at early initiation of enteral nutrition, as well as optimizing composition of parenteral nutrition, may bolster hormones involved in promoting preterm infant growth.

Female and male C57BL/6J offspring exposed to maternal obesogenic diet develop altered hypothalamic energy metabolism in adulthood

Maternal obesity is exceedingly common and strongly linked to offspring obesity and metabolic disease. Hypothalamic function is critical to obesity development. Hypothalamic mechanisms causing obesity following exposure to maternal obesity have not been elucidated. Therefore, we studied a cohort of C57BL/6J dams, treated with a control or high-fat-high-sugar diet, and their adult offspring to explore potential hypothalamic mechanisms to explain the link between maternal and offspring obesity. Dams treated with obesogenic diet were heavier with mild insulin resistance, which is reflective of the most common metabolic disease in pregnancy. Adult offspring exposed to maternal obesogenic diet had no change in body weight but significant increase in fat mass, decreased glucose tolerance, decreased insulin sensitivity, elevated plasma leptin, and elevated plasma thyroid-stimulating hormone. In addition, offspring exposed to maternal obesity had decreased energy intake and activity without change in basal metabolic rate. Hypothalamic neurochemical profile and transcriptome demonstrated decreased neuronal activity and inhibition of oxidative phosphorylation. Collectively, these results indicate that maternal obesity without diabetes is associated with adiposity and decreased hypothalamic energy production in offspring. We hypothesize that altered hypothalamic function significantly contributes to obesity development. Future studies focused on neuroprotective strategies aimed to improve hypothalamic function may decrease obesity development.NEW & NOTEWORTHY Offspring exposed to maternal diet-induced obesity demonstrate a phenotype consistent with energy excess. Contrary to previous studies, the observed energy phenotype was not associated with hyperphagia or decreased basal metabolic rate but rather decreased hypothalamic neuronal activity and energy production. This was supported by neurochemical changes in the hypothalamus as well as inhibition of hypothalamic oxidative phosphorylation pathway. These results highlight the potential for neuroprotective interventions in the prevention of obesity with fetal origins.

Cerebral Effects of Neonatal Dysglycemia

This article summarizes the available evidence reporting the relationship between perinatal dysglycemia and long-term neurodevelopment. We review the physiology of perinatal glucose metabolism and discuss the controversies surrounding definitions of perinatal dysglycemia. We briefly review the epidemiology of hypoglycemia and hyperglycemia in fetal, preterm, and term infants. We discuss potential pathophysiologic mechanisms contributing to dysglycemia and its effect on neurodevelopment. We highlight current strategies to prevent and treat dysglycemia in the context of neurodevelopmental outcomes. Finally, we discuss areas of future research and the potential role of continuous glucose monitoring.

Long-Term Outcomes after Early Neonatal Hyperglycemia in VLBW Infants: A Systematic Review

INTRODUCTION

Long-term effects of early hyperglycemia in VLBW infants are poorly characterized. The objective of this study was to systematically review the effect of early hyperglycemia on growth, metabolic health, and neurodevelopment after neonatal intensive care unit discharge in VLBW infants.

METHODS

The systematic review was conducted in accordance with the PRISMA guidelines. A study protocol was registered in PROSPERO (CRD42019123335). Data sources included Ovid MEDLINE, Embase, Cochrane Library, CINAHL, and Scopus. Selected studies included infants with a blood glucose concentration >150 mg/dL (8.3 mmol/L) during the first 28 days of life, a gestational age (GA) <32 weeks, and/or a birth weight <1,500 g and longitudinal data on growth, metabolic health, or neurodevelopment outcomes. The GRADE system was used to assess quality of evidence.

RESULTS

Eight studies (n = 987 infants) reported long-term outcomes from 4-month corrected GA to 7 years old. Most studies compared long-term outcomes of preterm infants with and without hyperglycemia. Two studies addressed outcomes related to interventions following early hyperglycemia. Some studies found differences in growth, metabolic health, and neurodevelopment outcomes between VLBW preterm infants with hyperglycemia and without hyperglycemia, while other studies found no differences between groups. The overall graded quality of evidence was low.

CONCLUSIONS

Well-designed randomized controlled and prospective studies are necessary to determine the effect of early hyperglycemia and its treatment on later metabolic and neurodevelopmental outcomes in VLBW infants. Authors propose a potential study design for standardizing the assessment of long-term metabolic and neurodevelopmental outcomes following early hyperglycemia in preterm infants.

Excess sucrose intake during pregnancy programs fetal brain glucocorticoid receptor expression in female but not male C57Bl/6J mice

BACKGROUND

Sex-specific mechanisms explaining the association between mothers with obesity and the development of obesity in children are poorly characterized. Permanent changes in fetal brain glucocorticoid receptor (GR) expression caused by exposure to overnutrition in utero may program aberrant energy homeostasis, thereby predisposing the offspring to obesity. This study explores sex differences in brain GR expression using an established mouse model of overnutrition during pregnancy.

METHODS

Female C57Bl/6J mice were fed control (CON) or high-fat-high-sucrose (HFHS) diets. Dam cholesterol, insulin, and triglycerides were measured by colorimetric assays. Fetal corticosterone exposure was measured by placental Abca1, Hsd11β1, Hsd11β2, and brain Nr3c1 (GR); Pomc expression measured by RT-qPCR.

RESULTS

Female, but not male, HFHS fetuses had 46% decreased brain GR and twofold increased Pomc expression. There was decreased Abca1 and Hsd11β1 but not Hsd11β2 expression in HFHS placentas. Caloric and sucrose intake, but not fat intake, in dams inversely correlated with fetal GR expression in both sexes. Excess sucrose consumption by dams inversely correlated with female fetal GR and directly correlated with female fetal Pomc expression.

CONCLUSIONS

Excess sucrose consumption in pregnant dams caused lower GR and higher Pomc expression in the female fetal brain. Clinical investigation of excess sucrose intake during pregnancy and its subsequent effect on hypothalamic-pituitary-adrenal axis activity and appetite in offspring may lead to novel, sex-specific obesity prevention strategies in the development of obesity in children.

Normalizing adiponectin levels in obese pregnant mice prevents adverse metabolic outcomes in offspring

Infants of obese mothers have an increased risk of developing obesity, insulin resistance, and type 2 diabetes. The underlying mechanisms remain elusive, and no effective interventions to limit the transmission of metabolic disease from the obese mother to her infant are currently available. Obese pregnant women have decreased circulating levels of adiponectin, which is associated with increased placental nutrient transport and fetal overgrowth. We have reported that normalization of adiponectin levels during late gestation reversed placental dysfunction and fetal overgrowth in a mouse model of maternal obesity in pregnancy. In the current study, we hypothesized that adiponectin supplementation during pregnancy in obese mice attenuates the adverse metabolic outcomes in adult offspring. Adult male offspring of obese mice developed obesity, fatty liver, and insulin resistance, with adult female offspring of obese mice having a less pronounced metabolic phenotype. These metabolic abnormalities in offspring born to obese mice were largely prevented by normalization of maternal adiponectin levels in late pregnancy. We provide evidence that low circulating maternal adiponectin is a critical mechanistic link between maternal obesity and the development of metabolic disease in offspring. Strategies aimed at improving maternal adiponectin levels may prevent long-term metabolic dysfunction in offspring of obese mothers.-Paulsen, M. E., Rosario, F. J., Wesolowski, S. R., Powell, T. L., Jansson, T. Normalizing adiponectin levels in obese pregnant mice prevents adverse metabolic outcomes in offspring.

Bilateral chorioretinitis, centripetal optic neuritis, and encephalitis in a llama

Blindness characterized by dilated, unresponsive pupils and ophthalmoscopic evidence of optic nerve atrophy and retinal degeneration developed in a 5-year-old llama. Lesions were not progressive during 2 months of observation. The llama was euthanatized and necropsied. Histopathologic findings included chorioretinitis, optic neuritis, and encephalitis characterized by mononuclear perivascular infiltration. Attempts to prove an infectious cause were unsuccessful.

Blindness and sexual dimorphism associated with vitamin A deficiency in feedlot cattle

Clinical, ophthalmoscopic, and histopathologic findings of vitamin A deficiency in a group of 535 feedlot cattle are described. Liver vitamin A content and results of histologic examination of ocular and osseous (optic canal) tissue confirmed the diagnosis. Blindness was the only clinical sign observed. Even though the steers and heifers in this feedlot were approximately the same age and were fed the same ration for an equal period, none of the heifers had overt clinical signs of hypovitaminosis A. Production of vitamin A by the bovine corpus luteum may account for the sexual dimorphism observed in vitamin A-deficient cattle.

Monitoring the progression of renal failure in a horse with polycystic kidney disease: use of the reciprocal of serum creatinine concentration and sodium sulfanilate clearance half-time

Sequential reciprocals of serum creatinine concentration and sodium sulfanilate clearance half-times were used to monitor a horse with chronic renal failure. The horse was diagnosed as having polycystic kidney disease; at least one cyst was of distal tubular origin. Using the plots of the sequential data, a reasonably accurate prediction was made for complete renal decompensation to develop.

Nodular granulomatous episclerokeratitis in dogs: 19 cases (1973-1985)

We examined the age and breed prevalence and the response to treatment of 19 dogs with nodular granulomatous episclerokeratitis. Biopsy specimens were evaluated to determine the histologic characteristics of the lesions. In these dogs, this disorder was an idiopathic, bilateral disease characterized histologically by the presence of chronic granulomatous inflammation and reticulin fiber formation. The onset of clinical signs developed predominantly in young to middle-aged Collies, with a slow progression and benign clinical course. With treatment, the condition rarely threatened vision and was controlled easily with azathioprine (2 mg/kg) and/or corticosteroid. The dose of immunosuppressive drug was tapered to allow for minimal systemic effects and continued remission of clinical signs. The response to treatment was highly variable.

Immunohistochemical staining patterns of canine eyes affected with chronic superficial keratitis

Fourteen limbal biopsy specimens from 11 dogs with chronic superficial keratitis (CSK) were examined histologically and immunohistochemically. Ten of the 14 specimens had corneal epithelial hyperplasia and/or atrophy. Eleven of the 14 specimens had thickened epithelial basement membranes. Each specimen had cellular infiltration and lamellar disruption of the stroma. An avidin-biotin immunoperoxidase complex stain was used to detect immunoglobulin (Ig) deposition. Twelve of the 14 specimens stained positive for Ig. The staining pattern was consistent and characterized by diffuse deposition of stain in the superficial conjunctival stroma near the limbus. Four of the 12 Ig-positive specimens also stained positive in the superficial corneal stroma with 1 of these 4 also staining positive along the epithelial cell basement membrane. The diffuse pattern of stain deposition and the absence of staining of specific epithelial structures indicated that CSK is not a classical autoimmune disease similar to any disease in the pemphigus group or similar to systemic lupus erythematosus. Although the results may implicate CSK as an immune-mediated disease, nonspecific factors could not be ruled out.