Catch-up growth

Growth of Brahman cross heifers to 2 years of age in the dry tropics

Growth of 1368 Brahman cross heifers from 6 year cohorts was monitored over the 2 years post-weaning in Australia’s northern forest, a low-animal-growth dry tropical environment. Heifers weighing 47–266 kg at weaning were managed in groups weighing <100 kg, 100–149 kg, 150–199 kg, and >199 kg during the post-weaning dry season. Weaner heifers were allocated to receive 300 g/day of a protein meal during the dry season or to basic nutritional management to sustain health. Heifers in three cohorts were allocated to first mating at 1 or 2 years of age, in four cohorts to vaccination against androstenedione, and in a small proportion of two cohorts to ovariectomy post-weaning. Growth was highly variable between seasons and years; average cohort liveweight by the start of 2-year-old mating was 256–319 kg. Heifer groups not receiving protein supplementation gained –16 to 21 kg (2 kg average) during 6-month dry seasons, and 49–131 kg (101 kg average) during wet seasons to reach an average of two-thirds of mature liveweight (445 kg) and 95% of mature hip height (1350 mm) by the start of mating at 2 years. Average body condition score (1–5) fluctuated by 1–2 units between seasons. Hip height gain continued, irrespective of season, commencing at ~0.60 mm/day at 6 months of age, and decelerating by ~0.00075 mm/day through to 2.5 years of age. Standard errors of predicted means across analyses were ~0.015 for average daily weight gains, 0.4 mm for average monthly height gain and 0.06 score units for average seasonal body condition score change. Post-weaning dry-season supplementation increased gains in liveweight, height and body condition score by an average of 0.1 kg/day, 0.1 mm/day and 0.5 units, respectively, during the supplementation period. Periods of poor nutrition or high nutritional demand secondary to reproduction suppressed daily gains in liveweight and hip height, at which times body condition score was also reduced. Subsequent to this, partial to full compensation occurred for all measures. Ovariectomy had negative effects on growth. Androstenedione vaccination had no effect on growth. The main conclusion is that heifer growth in Australia’s dry tropical northern forest region is highly variable between seasons and years, thus limiting significant proportions of some cohorts from reaching target weights for mating at 2 years of age, even after compensatory growth.

How Much Nutrition for How Much Growth?

BACKGROUND/AIMS

Increasing agreement exists about the use of length-for-age as the indicator of choice in monitoring the long-term impact of chronic nutritional deficiency. Yet, already shortly after World War I, a causal link between nutrition and growth was questioned. Also, modern meta-analyses of controlled nutrition intervention studies show that the net effect of nutrition on body height is small. Broad evidence obtained from historic observations on human starvation made since the 19th century questions an obligatory association between nutrition and growth. Many additional explanations for the apparent shortness of people from developing countries have been published since, focusing on genetic factors, environment, economy, epigenetics, and, recently, psychosocial factors, such as strategic growth adjustments suggesting stature to be a social signal.

CONCLUSION

The marked variability in average population height of up to 20 cm within a few generations complicates the use of normative growth charts, even though they have been widely propagated. We support the concept of local growth references, for example using the "Synthetic Growth References" methodology. These references combine local growth information obtained from a given population of interest and common features of human population growth, with LMS values for height, weight, and BMI from birth to maturity.
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Short children born small for gestational age outcomes in the era of growth hormone therapy

Small-for-gestational age (SGA) infants are at risk for short and long term medical and metabolic complications. Most SGA infants (85-90%) demonstrate spontaneous catch-up growth, typically in the first year after birth. Although catch-up growth (CUG) is a desired goal, it is important to note if CUG is too rapid the infants are at increased risk for insulin resistance and type 2 diabetes mellitus as they become adults. On the flip side, infants who do not exhibit CUG are also at increased risk of adverse adult outcomes including those for cardiovascular disease, insulin resistance and type 2 diabetes mellitus, neurodevelopmental and cognitive impairments, in addition to adult short stature. Treatment with growth hormone is safe and effective not only in increasing adult height, but also in improving body composition and decreasing metabolic complications. The aims of this review are to summarize the current knowledge on what constitutes "healthy" catch-up growth in children born SGA as well as provide an update on the role of growth hormone treatment for short children born SGA.

Excess maternal and postnatal thyroxine alters chondrocyte numbers and the composition of the extracellular matrix of growth cartilage in rats

Purpose/Aim: The aim of this study was to evaluate the effects of excess maternal and postnatal thyroxine on chondrocytes and the extracellular matrix (ECM) of growth cartilage.

MATERIALS AND METHODS

We used 16 adult female Wistar rats divided into two groups: thyroxine treatment and control. From weaning to 40 days of age, offspring of the treated group (n = 8) received L-thyroxine. Plasma free T4 was measured. Histomorphometric analysis was performed on thyroids and femurs of all offspring. Alcian blue histochemical staining and real-time reverse transcription polymerase chain reaction measurements of gene expression levels of Sox9, Runx2, Aggrecan, Col I, Col II, Alkaline phosphatase, Mmp2, Mmp9, and Bmp2 were performed. Data were analyzed for statistical significance by student's t-test.

RESULTS

Excess maternal and postnatal thyroxine reduced the intensity of Alcian blue staining, altered the number of chondrocytes in proliferative and hypertrophic zones in growth cartilage, and reduced the gene expression of Sox9, Mmp2, Mmp9, Col II, and Bmp2 in the growth cartilage of all offspring. Additionally, excess thyroxine altered the gene expression of Runx2, Aggrecan and Col I, and this effect was dependent on age.

CONCLUSIONS

Excess thyroxine in neonates suppresses chondrocyte proliferation, stimulates chondrocyte hypertrophy and changes the ECM composition by reducing the amount of proteoglycans and glycosaminoglycans (GAGs). Prolonged exposure to excess thyroxine suppresses chondrocyte activity in general, with a severe reduction in the proteoglycan content of cartilage and the expression of gene transcripts essential for endochondral growth and characteristics of the chondrocyte phenotype.

DO IN UTERO SHOCKS HAVE ADVERSE EFFECTS ON CHILD HEALTH OUTCOMES AND CAN WELFARE SCHEMES AMELIORATE SUCH EFFECTS? EVIDENCE FROM ANDHRA PRADESH, INDIA

This study aimed to assess whether shocks experienced by children in the mother's womb can have an adverse effect on their future health, and whether these effects can be ameliorated by government welfare schemes. Data were taken from three phases of the Young Lives Survey carried out in the Indian state of Andhra Pradesh in 2002, 2007 and 2009-2010. Different types of in utero shock were distinguished from the data. Using ordinary least squares (OLS) estimation, it was observed that multiple in utero shocks reduced children's weight-for-age and height-for-age z-scores by 0.07-0.08 and 0.08-0.15 units respectively. The roles of two Indian government welfare schemes - the Midday Meal Scheme (MDMS) and the National Rural Employment Guarantee Scheme (NREGS) - in mitigating the adverse effects of in utero shocks were examined. While the effect of the MDMS was statistically insignificant, that of the NREGS was significant. Although not designed to protect child health, the NREGS has been playing a more effective role than the MDMS in acting as a buffer against the damaging effects of in utero shocks on child health. The study points to the need for greater co-ordination between the two welfare schemes.

Prenatal stress accelerates offspring growth to compensate for reduced maternal investment across mammals

Across mammals, prenatal maternal stress (PREMS) affects many aspects of offspring development, including offspring growth. However, how PREMS translates to offspring growth is inconsistent, even within species. To explain the full range of reported effects of prenatal adversity on offspring growth, we propose an integrative hypothesis: developmental constraints and a counteracting adaptive growth plasticity work in opposition to drive PREMS effects on growth. Mothers experiencing adversity reduce maternal investment leading to stunted growth (developmental constraints). Concomitantly, the pace of offspring life history is recalibrated to partly compensate for these developmental constraints (adaptive growth plasticity). Moreover, the relative importance of each process changes across ontogeny with increasing offspring independence. Thus, offspring exposed to PREMS may grow at the same rate as controls during gestation and lactation, but faster after weaning when direct maternal investment has ceased. We tested these predictions with a comparative analysis on the outcomes of 719 studies across 21 mammal species. First, the observed growth changes in response to PREMS varied across offspring developmental periods as predicted. We argue that the observed growth acceleration after weaning is not "catch-up growth," because offspring that were small for age grew slower. Second, only PREMS exposure early during gestation produced adaptive growth plasticity. Our results suggest that PREMS effects benefit the mother's future reproduction and at the same time accelerate offspring growth and possibly maturation and reproductive rate. In this sense, PREMS effects on offspring growth allow mother and offspring to make the best of a bad start.

Cerebellar granule cell replenishment postinjury by adaptive reprogramming of Nestin+ progenitors

Regeneration of several organs involves adaptive reprogramming of progenitors, however, the intrinsic capacity of the developing brain to replenish lost cells remains largely unknown. In this study, we discovered that the developing cerebellum has unappreciated progenitor plasticity, since it undergoes near full growth and functional recovery following acute depletion of granule cells, the most plentiful neuron population in the brain. We demonstrate that following postnatal ablation of granule cell progenitors, Nestin-expressing progenitors (NEPs) specified during mid-embryogenesis to produce astroglia and interneurons, switch their fate and generate granule neurons in mice. Moreover, Hedgehog-signaling in two NEP populations is crucial not only for the compensatory replenishment of granule neurons but also to scale interneuron and astrocyte numbers. Thus we provide insights into the mechanisms underlying robustness of circuit formation in the cerebellum, and speculate that adaptive reprogramming of progenitors in other brain regions plays a greater role than appreciated in developmental regeneration.

Prenatal Food Restriction with Postweaning High-fat Diet Alters Glucose Metabolic Function in Adult Rat Offspring

BACKGROUND AND AIMS

The present study was designed to investigate the effects of prenatal food restriction (PFR) with postweaning high-fat diet (HFD) on glucose metabolic function in adult offspring.

METHODS

Pregnant Wistar rats were given PFR treatment from gestational day 11 to spontaneous delivery. All pups were fed by HFD after weaning. Oral glucose tolerance test (OGTT) was conducted at postnatal week (PW) 20. Rats were decapitated in PW24 to collect liver and pancreas, and expression of hepatic insulin signaling genes were then quantified.

RESULTS

Body weight from PW4 to PW24 in PFR males was lower than those in control males, whereas there was no distinct difference between females. However, body weight gain rates were higher from PW16 to PW24 in PFR males and females. Fasting serum glucose presented no changes, whereas fasting serum insulin decreased in PW20 in PFR pups. Moreover, glucose intolerance only appeared in PFR males, whereas no changes were shown in PFR females in relative values. Serum insulin increased in both PFR groups after OGTT. Remarkable pathological changes were also found in islets from PFR rats. There was an increase in the hepatic mRNA expression of IR in PFR females and of Glut2 in PFR males.

CONCLUSION

PFR with postweaning HFD induced a catch-up growth in body weight, especially in PFR females. Serum insulin decreased in both PFR groups in fasting status. Insulin resistance after OGTT only existed in PFR males, whereas PFR females showed no obvious changes in glucose metabolism.

Conditions of gestation, childbirth and childhood associated with C-peptide in young adults in the 1982 Birth Cohort in Pelotas-RS; Brazil

BACKGROUND

The connecting peptide in insulin has been associated with cardiovascular risk and overall mortality in the adult population. However, its early determinants are unknown. Assess the association of exposures during pregnancy, delivery, and childhood with C-peptide among 22-23 years old individuals prospectively followed since birth, in a southern Brazilian city.

METHODS

In 1982, all hospital births in the city were identified and those livebirths whose families lived in the urban area were evaluated (n = 5914). The 1982 Pelotas Birth Cohort has prospectively followed these subjects at different moments. In this study, we evaluated the association of C-peptide with exposures occurring during pregnancy, delivery and childhood. In the 22-23 years follow-up visit, we tried to follow the whole cohort and the subjects were interviewed, examined and donated a blood sample. C-peptide was measured using the chemiluminescence immunoassay technique (Immulite®-Siemens, Germany).

RESULTS

In the 22-23 years visit, 4297 subjects were interviewed and the C-peptide was measured in 3807. The geometric mean of C-peptide was 0.83 ng/mL and the mean was higher among women. In the adjusted analysis, C-peptide was positively associated with family income at birth, lower among children of non-white mothers (0.90; CI95% 0.84-0.96), higher among females (1.22; CI95% 1.16-1.28), and positively associated with rapid weight gain between two and four years of age (1.18; CI95% 1.05-1.32).

CONCLUSION

Family income at birth, non-white maternal skin color, and rapid weight gain between two and four years of age were associated with high levels of C-peptide.

Mice with infectious colitis exhibit linear growth failure and subsequent catch-up growth related to systemic inflammation and IGF-1

In developing communities, intestinal infection is associated with poor weight gain and linear-growth failure. Prior translational animal models have focused on weight gain investigations into key contributors to linear growth failure have been lacking. We hypothesized that murine intestinal infection with Citrobacter rodentium would induce linear-growth failure associated with systemic inflammation and suppressed serum levels of insulin-like growth factor-1 (IGF-1). We evaluated 4 groups of mice infected or sham-infected on day-of-life 28: uninfected-controls, wild-type C rodentium-infected, partially-attenuated C rodentium-infected (with deletion of 3 serine protease genes involved in colonization), and pair-fed (given the amount of daily food consumed by the wild-type C rodentium group). Relative to the uninfected group, mice infected with wild-type C rodentium exhibited temporal associations of lower food intake, weight loss, linear-growth failure, higher IL-6 and TNF-α and lower IGF-1. However, relative to the pair-fed group, the C rodentium-infected group only differed significantly by linear growth and systemic inflammatory cytokines. Between post-infection days 15-20, the infected group exhibited resolution of systemic inflammation. Between days 16-20, both wild-type C rodentium and pair-fed groups exhibited rapid linear-growth velocities exceeding the uninfected and mutant C rodentium groups; during this time levels of IGF-1 increased to match the uninfected group. We submit this as a model providing important opportunities to study mechanisms of catch-up growth related to intestinal inflammation. We conclude that in addition to known effects of weight loss, infection with C rodentium induces linear-growth failure potentially related to systemic inflammation and low levels of IGF-1, with catch-up of linear growth following resolution of inflammation.

Is there Catch-Up Growth? Evidence from Three Continents

The ability to correct deficiencies in early childhood malnutrition, what is known as catch-up growth, has widespread consequences for economic and social development. While clinical evidence of catch-up has been observed, less clear is the ability to correct for chronic malnutrition found in impoverished environments in the absence of extensive and focused interventions. This paper investigates whether nutritional status at early age affects nutritional status a few years later among children using panel data from China, South Africa and Nicaragua. The key research question is the extent to which state dependence in linear growth exists among young children, and what family and community level factors mediate state dependency. The answer to this question is crucial for public policy due to the long term economic consequences of poor childhood nutrition. Results show strong but not perfect persistence in nutritional status across all countries, indicating that catch-up growth is possible though unobserved household behaviors tend to worsen the possibility of catch-up growth. Public policy that can influence these behaviors, especially when children are under 24 months old, can significantly alter nutrition outcomes in South Africa and Nicaragua.

Recombinant IGF-I: Past, present and future

Normal linear growth in humans requires GH and IGF-I. Diminished GH action resulting in reduced availability of IGF-I and IGF-binding proteins is the hallmarks of GH Insensitivity Syndromes (GHIS). The deficiencies are the perceived mechanisms for the growth failure of affected patients and the therapeutic targets for the restoration of normal growth. Early treatment attempts with pituitary-derived GH had limited effects in GHIS patients. Recombinant human insulin-like growth factor-I (rhIGF-I) treatment initially provides accelerated growth to GHIS children and provides substantial benefit. But, in general, catch up growth is less substantial with rhIGF-I treatment of GHIS than with rhGH treatment of GH Deficiency. Few classic GHIS patients have reached heights in the normal range (height SD score between -2.0 SD and +2.0 SD) with rhIGF-I monotherapy. A potential explanation is that while rhIGF-I treatment increases circulating concentrations of IGF-1 and IGFBP-3, such treatment reduces endogenous GH levels by negative feedback inhibition of pituitary GH release. In as much as both GH and IGF-I are required for good catch up growth, the loss of any residual GH signaling during IGF-I monotherapy in GHIS patients may attenuate possible catch up growth. Consistent with this explanation is the finding that, as predicted by the preclinical studies by Ross Clark, combination of rhGH & rhIGF-1 provides better growth responses than rhIGF-1 monotherapy in prepubertal children with short stature and low IGF-I levels despite normal stimulated GH responses. In the future, rhGH and rhIGF-I combination therapy can potentially improve growth outcomes over that seen with rhIGF-I monotherapy in all GHIS patients except in those with a total lack of functional GH signaling. Future alternative treatments for GHIS subjects may also include the use of post-growth hormone receptor signaling agonists which restore both GH signaling and IGF-I exposures or the addition of long-acting rhGH species to rhIGF-I. Additional etiologic factors for the growth failure in GHIS should be considered if the growth deficits of GHIS do not resolve with treatment.

Fetal programming and early identification of newborns at high risk of free radical-mediated diseases

Nowadays metabolic syndrome represents a real outbreak affecting society. Paradoxically, pediatricians must feel involved in fighting this condition because of the latest evidences of developmental origins of adult diseases. Fetal programming occurs when the normal fetal development is disrupted by an abnormal insult applied to a critical point in intrauterine life. Placenta assumes a pivotal role in programming the fetal experience in utero due to the adaptive changes in structure and function. Pregnancy complications such as diabetes, intrauterine growth restriction, pre-eclampsia, and hypoxia are associated with placental dysfunction and programming. Many experimental studies have been conducted to explain the phenotypic consequences of fetal-placental perturbations that predispose to the genesis of metabolic syndrome, obesity, diabetes, hyperinsulinemia, hypertension, and cardiovascular disease in adulthood. In recent years, elucidating the mechanisms involved in such kind of process has become the challenge of scientific research. Oxidative stress may be the general underlying mechanism that links altered placental function to fetal programming. Maternal diabetes, prenatal hypoxic/ischaemic events, inflammatory/infective insults are specific triggers for an acute increase in free radicals generation. Early identification of fetuses and newborns at high risk of oxidative damage may be crucial to decrease infant and adult morbidity.

Effect of chronic undernutrition on body mass and mechanical bone quality under normoxic and altitude hypoxic conditions

Both undernutrition and hypoxia exert a negative influence on both growth pattern and bone mechanical properties in developing rats. The present study explored the effects of chronic food restriction on both variables in growing rats exposed to simulated high-altitude hypoxia. Male rats (n 80) aged 28 d were divided into normoxic (Nx) and hypoxic (Hx) groups. Hx rats were exposed to hypobaric air (380 mmHg) in decompression chambers. At T0, Nx and Hx rats were subdivided into four equal subgroups: normoxic control and hypoxic controls, and normoxic growth-restricted and hypoxic growth-restricted received 80 % of the amount of food consumed freely by their respective controls for a 4-week period. Half of these animals were studied at the end of this period (T4). The remaining rats in each group continued under the same environmental conditions, but food was offered ad libitum to explore the type of catch-up growth during 8 weeks. Structural bone properties (strength and stiffness) were evaluated in the right femur midshaft by the mechanical three-point bending test; geometric properties (length, cross-sectional area, cortical mass, bending cross-sectional moment of inertia) and intrinsic properties of the bone tissue (elastic modulus) were measured or derived from appropriate equations. Bone mineralisation was assessed by ash measurement of the left femur. These data indicate that the growth-retarded effects of diminished food intake, induced either by food restriction or hypoxia-related inhibition of appetite, generated the formation of corresponding smaller bones in which subnormal structural and geometric properties were observed. However, they seemed to be appropriate to the body mass of the animals and suggest, therefore, that the bones were not osteopenic. When food restriction was imposed in Hx rats, the combined effects of both variables were additive, inducing a further reduction of bone mass and bone load-carrying capacity. In all cases, the mechanical properties of the mineralised tissue were unaffected. This and the capacity of the treated bones to undergone complete catch-up growth with full restoration of the biomechanical properties suggest that undernutrition, under either Nx or Hx conditions, does not affect bone behaviour because it remains appropriate to its mechanical functions.

Growth and the Growth Hormone-Insulin Like Growth Factor 1 Axis in Children With Chronic Inflammation: Current Evidence, Gaps in Knowledge, and Future Directions

Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt are often seen during adolescence. The underlying inflammatory state mediated by proinflammatory cytokines, prolonged use of glucocorticoid, and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the GH-IGF axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biological therapy may lead to improvement of growth in some of these children, but approximately one-third continue to grow slowly. There is increasing evidence that the use of relatively high-dose recombinant human GH may lead to partial catch-up growth in chronic inflammatory conditions, although long-term follow-up data are currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis, systemic abnormalities of the GH-IGF axis, and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human GH in these conditions and discussed the role of recombinant human IGF-1.

Bone growth resumption following in vivo static and dynamic compression removals on rats

Mechanical loadings influence bone growth and are used in pediatric treatments of musculoskeletal deformities. This in vivo study aimed at evaluating the effects of static and dynamic compression application and subsequent removal on bone growth, mineralization and neuropathic pain markers in growing rats. Forty-eight immature rats (28 days old) were assigned in two groups (2- and 4 weeks experiment duration) and four subgroups: control, sham, static, and dynamic. Controls had no surgery. A micro-loading device was implanted on the 6th and 8th caudal vertebrae of shams without loading, static loading at 0.2 MPa or dynamic loading at 0.2 MPa ± 30% and 0.1 Hz. In 2-week subgroups, compression was maintained for 15 days prior to euthanasia, while in 4- week subgroups, compression was removed for 10 additional days. Growth rates, histomorphometric parameters and mineralization intensity were quantified and compared. At 2 weeks, growth rates and growth plate heights of loaded groups (static/dynamic)were significantly lower than shams (p b 0.01).However, at 4 weeks, both growth rates and growth plate heights of loaded groups were similar to shams. At 4 weeks, alizarin red intensity was significantly higher in dynamics compared to shams (p b 0.05) and controls (p b 0.01). Both static and dynamic compressions enable growth resumption after loading removal, while preserving growth plate histomorphometric integrity. However, mineralization was enhanced after dynamic loading removal only. Dynamic loading showed promising results for fusionless treatment approaches for musculoskeletal deformities.

Stature in 19th and early 20th century Copenhagen. A comparative study based on skeletal remains

Individual stature depends on multifactorial causes and is often used as a proxy for investigating the biological standard of living. While the majority of European studies on 19th and 20th century populations are based on conscript heights, stature derived from skeletal remains are scarce. For the first time in Denmark this study makes a comparison between skeletal stature and contemporary Danish conscript heights and investigates stature of males and females temporally and between socially distinct individuals and populations in 19th and early 20th century Copenhagen. A total of 357 individuals (181 males, 176 females) excavated at the Assistens cemetery in Copenhagen is analyzed. Two stature regression formulae (Trotter, 1970; Boldsen, 1990) are applied using femur measurements and evaluated compared to conscript heights. The results indicate that mean male stature using Boldsen follows a similar trend as the Danish conscript heights and that Trotter overestimate stature by ca. 6cm over Boldsen. At an inter population level statistically significant differences in male stature are observed between first and second half of the 19th century towards a slight stature decrease and larger variation while there are no significant changes observed in female stature. There are insignificant differences in stature between middle and high class individuals, but male stature differs statistically between cemeteries (p=0.000) representing middle/high class, paupers and navy employees, respectively. Female stature had no significant wealth gradient (p=0.516). This study provides new evidence of stature among males and females during the 19th century and suggests that males may have been more sensitive to changes in environmental living and nutrition than females.

Regulation of Long Bone Growth in Vertebrates; It Is Time to Catch Up

The regulation of organ size is essential to human health and has fascinated biologists for centuries. Key to the growth process is the ability of most organs to integrate organ-extrinsic cues (eg, nutritional status, inflammatory processes) with organ-intrinsic information (eg, genetic programs, local signals) into a growth response that adapts to changing environmental conditions and ensures that the size of an organ is coordinated with the rest of the body. Paired organs such as the vertebrate limbs and the long bones within them are excellent models for studying this type of regulation because it is possible to manipulate one member of the pair and leave the other as an internal control. During development, growth plates at the end of each long bone produce a transient cartilage model that is progressively replaced by bone. Here, we review how proliferation and differentiation of cells within each growth plate are tightly controlled mainly by growth plate-intrinsic mechanisms that are additionally modulated by extrinsic signals. We also discuss the involvement of several signaling hubs in the integration and modulation of growth-related signals and how they could confer remarkable plasticity to the growth plate. Indeed, long bones have a significant ability for "catch-up growth" to attain normal size after a transient growth delay. We propose that the characterization of catch-up growth, in light of recent advances in physiology and cell biology, will provide long sought clues into the molecular mechanisms that underlie organ growth regulation. Importantly, catch-up growth early in life is commonly associated with metabolic disorders in adulthood, and this association is not completely understood. Further elucidation of the molecules and cellular interactions that influence organ size coordination should allow development of novel therapies for human growth disorders that are noninvasive and have minimal side effects.

Using height-for-age differences (HAD) instead of height-for-age z-scores (HAZ) for the meaningful measurement of population-level catch-up in linear growth in children less than 5 years of age

BACKGROUND

Evidence from studies conducted in nutritionally deprived children in low- and middle-income countries (LIMC) in past decades showed little or no population-level catch-up in linear growth (mostly defined as reductions in the absolute height deficit) after 2 years of age. Recent studies, however, have reported population-level catch-up growth in children, defined as positive changes in mean height-for-age z-scores (HAZ). The aim of this paper was to assess whether population-level catch-up in linear growth is found when height-for-age difference (HAD: child's height compared to standard, expressed in centimeters) is used instead of HAZ. Our premise is that HAZ is inappropriate to measure changes in linear growth over time because they are constructed using standard deviations from cross-sectional data.

METHODS

We compare changes in growth in populations of children between 2 and 5 years using HAD vs. HAZ using cross-sectional data from 6 Demographic and Health Surveys (DHS) and longitudinal data from the Young Lives and the Consortium on Health-Orientated Research in Transitional Societies (COHORTS) studies.

RESULTS

Using HAD, we find not only an absence of population-level catch-up in linear growth, but a continued deterioration reflected in a decrease in mean HAD between 2 and 5 years; by contrast, HAZ shows either no change (DHS surveys) or an improvement in mean HAZ (some of the longitudinal data). Population-level growth velocity was also lower than expected (based on standards) in all four Young Lives data sets, confirming the absence of catch-up growth in height.

DISCUSSION

We show no evidence of population-level catch-up in linear growth in children between 2 to 5 years of age when using HAD (a measure more appropriate than HAZ to document changes as populations of children age), but a continued deterioration reflected in a decrease in mean HAD.

CONCLUSIONS

The continued widening of the absolute height deficit after 2 years of age does not challenge the critical importance of investing in improving nutrition during the first 1000 days (i.e., from conception to 2 years of age), but raises a number of research questions including how to prevent continued deterioration and what is the potential of children to benefit from nutrition interventions after 2 years of age. Preventing, rather than reversing linear growth retardation remains the priority for reducing the global burden of malnutritionworldwide.

Growth reconstitution following antiretroviral therapy and nutritional supplementation: systematic review and meta-analysis

OBJECTIVE

As antiretroviral therapy (ART) expands for HIV-infected children, it is important to determine its impact on growth. We quantified growth and its determinants following ART in resource-limited (RLS) and developed settings.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched publications reporting growth [weight-for-age (WAZ), height-for-age (HAZ), and weight-for-height (WHZ) z scores] in HIV-infected children following ART through August 2014. Inclusion criteria were as follows: younger than 18 years; ART; at least 20 patients; growth at ART; and post-ART growth. Standardized and overall weighted mean differences were calculated using random-effects models.

RESULTS

A total of 67 articles were eligible (RLS = 54; developed settings = 13). Mean age was 5.8 years, and comparable between settings (P = 0.90). Baseline growth was substantially lower in RLS vs. developed settings (WAZ -2.1 vs. -0.5; HAZ -2.2 vs. -0.9; both P < 0.01). Rate of weight but not height reconstitution during 12 and 24 months was higher in RLS (12-month WAZ change 0.84 vs. 0.17, P < 0.01). Growth deficits persisted in RLS after 2 years ART (P = 0.04). Younger cohort age was associated with greater growth reconstitution. Protease inhibitor and nonnucleoside reverse-transcriptase inhibitor regimens yielded comparable growth. Adjusting for age and setting, cohorts with nutritional supplements had greater growth gains (24-month rate difference: WAZ 0.55, P = 0.03; HAZ 0.60, P = 0.007). Supplement benefits were attenuated after adjusting for baseline cohort growth.

CONCLUSION

RLS children had substantial growth deficits compared with developed settings counterparts at ART; growth shortfalls in RLS persisted despite reconstitution. Earlier age and nutritional supplementation at ART may improve growth outcomes. Scant data on supplementation limit evaluation of impact and underscores need for systematic data collection regarding supplementation in pediatric ART programmes/cohorts.

Recovery from stunting and cognitive outcomes in young children: evidence from the South African Birth to Twenty Cohort Study

In this study we analyse the implications for cognitive function of recovery from stunting in early childhood. More specifically, we test whether children who met the definition for stunted at age 2, but not at age 5, perform better in cognitive tests than children who remain stunted over this period. The sample is drawn from the Birth to Twenty Cohort Study, a prospective data set of children born in 1990 in urban South Africa. The measure of cognitive function that we use is based on the Revised Denver Prescreening Developmental Questionnaire implemented when the children were age 5. We employ multivariate regression in the analysis to control for child-specific characteristics, socio-economic status, the home environment and caregiver inputs. We find that recovery from stunting is not uncommon among young children in our sample. However, children who recover from stunting by age 5 still perform significantly worse on cognitive tests than children who do not experience early malnutrition, and almost as poorly as children who remain stunted. These findings suggest that the timing of nutritional inputs in the early years is key in a child's cognitive development, with implications for school readiness and achievement.

Ontogeny of the male femur: Geometric morphometric analysis applied to a contemporary Spanish population

OBJECTIVE

To describe the morphological changes of the male femur during the adolescent growth spurt and to compare the pattern obtained with that reported previously for females.

MATERIAL AND METHODS

Two hundred and forty males from a Spanish population aged between 9 and 16 years were analysed, based on telemetries. Size and shape variation of the femur was quantified by 22 2D-landmarks and analysed using geometric morphometric methods. Likewise, the variation of neck-shaft and bicondylar angles were also determined and evaluated by Student's t-test. Sexual differences were analysed by comparing results here obtained on boys with those corresponding to girls reported in a previous study.

RESULTS

In males, both size and shape varied significantly with age, with males having larger dimensions than females. In general terms, these changes are generally characterised by an increase in robustness of the femur and shape modifications in the epiphyses. During growth, the neck-shaft angle decreases and the size of the greater and lesser trochanters increase. A significant increase of distal epiphyseal dimensions was recorded, mainly in the medial condyle. The angular remodeling of both the neck and the bicondylar regions of the male femur continues until 16 and 15 years, respectively. Female and male femur each followed divergent growth trajectories. Males showed a greater variability in neck-shaft and bicondylar angles than females.

DISCUSSION

The timing, morphology and growth trajectories provided on the femur during development can be very helpful in anthropological, paleoanthropological and evolution studies.

Preweaning GH Treatment Normalizes Body Growth Trajectory and Reverses Metabolic Dysregulation in Adult Offspring After Maternal Undernutrition

Maternal undernutrition (UN) results in growth disorders and metabolic dysfunction in offspring. Although dysregulation of the GH-IGF axis in offspring is a known consequence of maternal UN, little is known about the efficacy of GH treatment during the period of developmental plasticity on later growth and metabolic outcomes. The present study investigated the effect of preweaning GH treatment on growth, glucose metabolism, and the GH-IGF axis in adult male and female offspring after maternal UN. Female Sprague Dawley rats were fed either a chow diet ad libitum (control [CON]) or 50% of ad libitum (UN) throughout pregnancy. From postnatal day 3, CON and UN pups received either saline (CON-S and UN-S) or GH (2.5 μg/g·d CON-GH and UN-GH) daily throughout lactation. At weaning, male and female offspring were randomly selected from each litter and fed a standard chow diet for the remainder of the study. Preweaning GH treatment normalized maternal UN-induced alterations in postweaning growth trajectory and concomitant adiposity in offspring. Plasma leptin concentrations were increased in UN-S offspring and normalized in the UN-GH group. Hepatic GH receptor expression was significantly elevated in UN-S offspring and normalized with GH treatment. Hepatic IGF binding protein-2 gene expression and plasma IGF-1 to IGF binding protein-3 ratio was reduced in UN-S offspring and elevated with GH treatment. GH treatment during a critical developmental window prevented maternal UN-induced changes in postnatal growth patterns and related adiposity, suggesting that manipulation of the GH-IGF-1 axis in early development may represent a promising avenue to prevent adverse developmental programming effects in adulthood.

[Low birth weight and obesity: causal or casual association?]

Objective:

To present the conceptual foundations that explain how events occurring during intrauterine life may influence body development, emphasizing the interrelation between low birth weight and risk of obesity throughout life.

Data sources:

Google Scholar, Library Scientific Electronic Online (SciELO), EBSCO, Scopus, and PubMed were the databases. “Catch-up growth”, “life course health”, “disease”, “child”, “development”, “early life”, “perinatal programming”, “epigenetics”, “breastfeeding”, “small baby syndrome”, “phenotype”, “micronutrients”, “maternal nutrition”, “obesity”, and “adolescence” were isolated or associated keywords for locating reviews and epidemiological, intervention and experimental studies published between 1934 and 2014, with complete texts in Portuguese and English. Duplicate articles, editorials and reviews were excluded, as well as approaches of diseases different from obesity.

Data synthesis:

Within 47 selected articles among 538 eligible ones, the thrifty phenotype hypothesis, the epigenetic mechanisms and the development plasticity were identified as fundamental factors to explain the mechanisms involved in health and disease throughout life. They admit the possibility that both cardiometabolic events and obesity originate from intrauterine nutritional deficiency, which, associated with a food supply that is excessive to the metabolic needs of the organism in early life stages, causes endocrine changes. However, there may be phenotypic reprogramming for low birth weight newborns from adequate nutritional supply, thus overcoming a restrictive intrauterine environment. Therefore, catch-up growth may indicate recovery from intrauterine constraint, which is associated with short-term benefits or harms in adulthood.

Conclusions:

Depending on the nutritional adequacy in the first years of life, developmental plasticity may lead to phenotype reprogramming and reduce the risk of obesity.

Human growth and body weight dynamics: an integrative systems model

Quantifying human weight and height dynamics due to growth, aging, and energy balance can inform clinical practice and policy analysis. This paper presents the first mechanism-based model spanning full individual life and capturing changes in body weight, composition and height. Integrating previous empirical and modeling findings and validated against several additional empirical studies, the model replicates key trends in human growth including A) Changes in energy requirements from birth to old ages. B) Short and long-term dynamics of body weight and composition. C) Stunted growth with chronic malnutrition and potential for catch up growth. From obesity policy analysis to treating malnutrition and tracking growth trajectories, the model can address diverse policy questions. For example I find that even without further rise in obesity, the gap between healthy and actual Body Mass Indexes (BMIs) has embedded, for different population groups, a surplus of 14%-24% in energy intake which will be a source of significant inertia in obesity trends. In another analysis, energy deficit percentage needed to reduce BMI by one unit is found to be relatively constant across ages. Accompanying documented and freely available simulation model facilitates diverse applications customized to different sub-populations.

Effect of a nutritional supplement on growth in short and lean prepubertal children: a prospective, randomized, double-blind, placebo-controlled study

OBJECTIVE

To determine the effect of nutritional supplementation on height, weight, and body mass index (BMI) in short and lean prepubertal children.

STUDY DESIGN

A prospective, randomized, double-blinded, placebo-controlled trial of nutritional supplementation at the endocrinology department of a tertiary pediatric medical center of healthy, lean, short, prepubertal children 3-9-years-old. Anthropometry measurements were measured at 6 months.

RESULTS

Two hundred participants (149 boys) entered the study and 171 (85.5%) completed the intervention period. Baseline characteristics including age, sex, height-SDS, weight-SDS, BMI-SDS, and dietary caloric and protein intakes were similar in the formula and placebo groups. 'Good' consumers (intake of ≥50% of the recommended dose) in the formula group significantly improved height-SDS (P < .001) and weight-SDS (P = .005) with no change in BMI-SDS compared with 'poor' consumers and the placebo group. In the formula-treated group a positive correlation was found between the amount of formula consumed per body weight and the gain in height-SDS (r = 0.44, P < .001) and weight-SDS (r = 0.35, P = .002); no significant correlations were found in the placebo group. No serious adverse events were reported during the study.

CONCLUSIONS

Nutritional intervention with the formula was found to be a feasible, effective, and safe approach for promoting the physical growth of short and lean prepubertal children.

When early life growth restriction in rats is followed by attenuated postnatal growth: effects on cardiac function in adulthood

PURPOSE

Epidemiological and experimental studies demonstrate that intrauterine growth restriction (IUGR) followed by accelerated postnatal growth leads to increased risk of developing cardiac disease in adulthood. The aim of this study was to examine the effect of early life growth restriction on cardiac structure and function in young adult rats.

METHODS

IUGR was induced in Wistar Kyoto dams through administration of a low protein diet (LPD; 8.7% casein) during pregnancy and lactation; controls received a normal protein diet (NPD; 20% casein). Cardiac function and structure were assessed in female NPD (n = 7) and LPD (n = 7) offspring at 18 weeks of age by echocardiography and pressure-volume techniques, and systolic blood pressure by tail-cuff sphygmomanometry.

RESULTS

LPD offspring remained significantly smaller throughout life compared to controls. There were no differences in the levels of systolic blood pressure, left ventricular cardiac dimensions, heart rate, ejection fraction and fractional shortening of the cardiac muscle between the investigated groups. Aortic peak systolic velocity was significantly reduced in the LPD group (P = 0.02).

CONCLUSION

Our findings support the idea that the programming of adult cardiovascular disease can be prevented or delayed in IUGR offspring when postnatal growth trajectory resembles that of in utero.

Skeletal manifestations of stress in child victims of the Great Irish Famine (1845-1852): prevalence of enamel hypoplasia, Harris lines, and growth retardation

The Great Irish Famine of 1845-1852 is among the worst food crises in human history. While numerous aspects of this period have been studied by generations of scholars, relatively little attention has so far been given to the physiological impact it is likely to have had on the people who suffered and succumbed to it. This study examines the prevalence of enamel hypoplasia, Harris lines, and growth retardation in the nonadult proportion of a skeletal population comprising victims of the Famine who died in the workhouse in the city of Kilkenny between 1847 and 1851. The frequency of enamel hypoplasia in these children does not appear to have increased as a consequence of famine, although this fact is likely to be a reflection of the osteological paradox. Harris lines and growth retardation; however, were very prevalent, and the manifestation and age-specific distribution of these may be indicators of the Famine experience. While there was no clear correlation in the occurrence of the assessed markers, the presence of cribra orbitalia displayed a significant relationship to enamel hypoplasia in 1- to 5-year-old children. While starvation, metabolic disorders and infectious diseases are likely to have greatly contributed to the manifestation of the markers, the psychosocial stress relating to institutionalization in the workhouse should not be underestimated as a substantial causative factor for skeletal stress in this population.

Growth and body composition in Brazilian female rhythmic gymnastics athletes

The aim was to analyse the physical growth and body composition of rhythmic gymnastics athletes relative to their level of somatic maturation. This was a cross-sectional study of 136 athletes on 23 teams from Brazil. Mass, standing height and sitting height were measured. Fat-free and fat masses, body fat percentages and ages of the predicted peak height velocity (PHV) were calculated. The z scores for mass were negative during all ages according to both WHO and Brazilian references, and that for standing height were also negative for all ages according to WHO reference but only until 12 years old according to Brazilian reference. The mean age of the predicted PHV was 12.1 years. The mean mass, standing and sitting heights, body fat percentage, fat-free mass and fat mass increased significantly until 4 to 5 years after the age of the PHV. Menarche was reached in only 26% of these athletes and mean age was 13.2 years. The mass was below the national reference standards, and the standing height was below only for the international reference, but they also had late recovery of mass and standing height during puberty. In conclusion, these athletes had a potential to gain mass and standing height several years after PHV, indicating late maturation.

Differential gene expression identified by RNA-Seq and qPCR in two sizes of pearl oyster (Pinctada fucata)

Differential growth of the pearl oyster Pinctada fucata still exists in the aquaculture production. There is no systematic study of the entire transcriptome of differential gene expression in P. fucata in the literature. In this study, high-throughput Illumina/HiSeq™ 2000 RNA-Seq was used to examine the differences of gene expression in large (L) and small oysters (S). In total, 74,293 and 76,635 unigenes were generated from L and S oysters, respectively. RT quantitative PCR (qPCR) analysis showed that the differential expression pattern of 19 out of 34 selected genes was consistent with the results of RNA-Seq analysis: 14 genes (11 for growth, 1 for reproduction and 2 for shell formation) were expressed more highly in S, 5 genes (1 for growth, 1 for reproduction and 3 for the immune system) were expressed more highly in L; 3 genes associated with the immune system were opposite to it; and no difference was found for the remaining 12 genes. Another 9 shell formation-related genes in L and S were examined by qPCR: 1 gene was expressed more highly in L, 5 genes were expressed more highly in S and no difference was found for the remaining 3 genes. Some genes related to growth and development, shell formation and reproduction were expressed more highly in S compared to L. This phenomenon could be explained by "catch-up growth". The results of this study will help toward a comprehensive understanding of the complexity of differential growth between P. fucata individuals and provide valuable information for future research.

Inflammation in rat pregnancy inhibits spiral artery remodeling leading to fetal growth restriction and features of preeclampsia

Abnormal maternal inflammation leads to TNF-mediated fetal growth restriction and some features of preeclampsia that can be ameliorated with the nitric oxide mimetic nitroglycerin.

Fetal growth restriction (FGR) and preeclampsia (PE) are often associated with abnormal maternal inflammation, deficient spiral artery (SA) remodeling, and altered uteroplacental perfusion. Here, we provide evidence of a novel mechanistic link between abnormal maternal inflammation and the development of FGR with features of PE. Using a model in which pregnant rats are administered low-dose lipopolysaccharide (LPS) on gestational days 13.5–16.5, we show that abnormal inflammation resulted in FGR mediated by tumor necrosis factor-α (TNF). Inflammation was also associated with deficient trophoblast invasion and SA remodeling, as well as with altered uteroplacental hemodynamics and placental nitrosative stress. Moreover, inflammation increased maternal mean arterial pressure (MAP) and was associated with renal structural alterations and proteinuria characteristic of PE. Finally, transdermal administration of the nitric oxide (NO) mimetic glyceryl trinitrate prevented altered uteroplacental perfusion, LPS-induced inflammation, placental nitrosative stress, renal structural and functional alterations, increase in MAP, and FGR. These findings demonstrate that maternal inflammation can lead to severe pregnancy complications via a mechanism that involves increased maternal levels of TNF. Our study provides a rationale for the use of antiinflammatory agents or NO-mimetics in the treatment and/or prevention of inflammation-associated pregnancy complications.

HIV infection, viral load, low birth weight, and nevirapine are independent influences on growth velocity in HIV-exposed South African infants

Data from a prospective multisite cohort study were used to examine the effect of HIV exposure, untreated HIV infection, and single-dose nevirapine on infant growth velocity. The 2009 WHO growth velocity standards constitute a new tool for this type of investigation and are in need of functional validation. In period 1 (3-24 wk), 65 HIV-infected, 502 HIV-exposed uninfected (HEU), and 216 HIV-unexposed infants were included. In period 2 (25-36 wk), 31 infants moved from the HEU group to the HIV-infected group. We compared weight velocity Z-scores (WVZ) and length velocity Z-scores (LVZ) by HIV group and assessed their independent influences. In period 1, mean WVZ (95% CI) was significantly (P < 0.001) lower in infected [-0.87 (-1.77, 0.04)] than HEU [0.81 (0.67, 0.94)] and unexposed [0.55 (0.33, 0.78)] infants. LVZ showed similar associations. In both periods, sick infants and those exposed to higher maternal viral loads had lower WVZ. Higher mean LVZ was associated with low birth weight. Infants that had received nevirapine had higher LVZ. In conclusion, HIV infection and not exposure was associated with low WVZ and LVZ in period 1. Eliminating infant HIV infection is a critical component in averting HIV-related poor growth patterns in infants in the first 6 mo of life.

Prenatal nicotine exposure enhances the susceptibility to metabolic syndrome in adult offspring rats fed high-fat diet via alteration of HPA axis-associated neuroendocrine metabolic programming

AIM

Prenatal nicotine exposure (PNE) alters the hypothalamic-pituitary-adrenocortical (HPA) axis-associated neuroendocrine metabolic programming in intrauterine growth retardation offspring rats. In this study we aimed to clarify the susceptibility to metabolic diseases of PNE offspring rats fed a high-fat diet.

METHODS

Maternal Wistar rats were injected with nicotine (1.0 mg/kg, sc) twice per day from gestational day 11 until full-term delivery, and all pups were fed a high-fat diet after weaning and exposed to unpredictable chronic stress (UCS) during postnatal weeks 18-20. Blood samples were collected before and after chronic stress, and serum ACTH, corticosterone, glucose, insulin, total cholesterol, triglyceride and free fatty acids levels were measured. The hypothalamus, pituitary gland and liver were dissected for histological studies.

RESULTS

UCS significantly increased the serum ACTH, corticosterone and insulin levels as well as the insulin resistant index without changing the serum glucose, total cholesterol, triglyceride and free fatty acids levels in adult offspring rats without PNE. The body weight of PNE offspring rats presented a typical "catch-up" growth pattern. PNE not only aggravated the UCS-induced changes in the HPA axis programmed alteration (caused further increases in the serum ACTH and corticosterone levels), but also significantly changed the glucose and lipid metabolism after UCS (caused further increases in the serum glucose level and insulin resistant index, and decrease in the serum free fatty acids). The effects of PNE on the above indexes after UCS showed gender differences. Pathological studies revealed that PNE led to plenty of lipid droplets in multiple organs.

CONCLUSION

PNE enhances not only the HPA axis, but also the susceptibility to metabolic diseases in adult offspring rats fed a high-fat diet after UCS in a gender-specific manner and enhances the susceptibility to metabolic diseases in adult offspring rats fed a high-fat diet.

Measuring catch-up growth in malnourished populations

BACKGROUND AND AIM

Numerous recent studies measure catch-up growth by regressing adult or pre-adolescent height on early childhood height. Using simple statistical theory and data from a healthy and well-nourished population, this paper shows that these tests are uninformative about the extent of catch-up growth. The study also provides new empirical evidence on pubertal catch-up growth using longitudinal data for rural Tanzania.

SUBJECTS AND METHODS

The 1970 British Cohort Study is used to demonstrate the flaws in the recent literature using regression techniques to study catch-up growth. The data for the empirical analysis come from the Kagera Health and Development survey-a longitudinal study spanning two decades. The final sample includes 540 children whose heights are measured in early childhood and in adulthood. Catch-up growth is measured as the change in height-for-age z-score over time.

RESULTS

The mean HAZ-score in the cohort improves from -1.86 in early childhood to -1.20 in adulthood. Without catch-up growth, children would have been 4.5-5 centimetres shorter adults. Graphical analysis shows that most of this catch-up growth takes place in puberty.

CONCLUSION

Catch-up growth after early childhood is possible. Puberty seems to offer an opportunity window for recovery.

Prenatal food restriction induces a hypothalamic-pituitary-adrenocortical axis-associated neuroendocrine metabolic programmed alteration in adult offspring rats

BACKGROUND AND AIMS

Intrauterine growth restriction produces susceptibility to adult metabolic syndrome, which may be caused by the permanent alteration of the hypothalamic-pituitary-adrenocortical (HPA) axis. We aimed to verify that HPA axis-associated neuroendocrine metabolic programming is altered in food-restricted (FR) offspring.

METHODS

Maternal rats were fed a restricted diet from gestational day 11 until full-term delivery, all pups were fed a high-fat diet after weaning and exposed to unpredictable chronic stress (UCS) during postnatal weeks 17-20.

RESULTS

Serum levels of adrenocorticotrophic hormone and corticosterone in adult offspring of the prenatal FR group were lower than the control (CN) rats before UCS but increased significantly after UCS. Serum glucose levels in the FR group were normal before UCS but increased after UCS. Serum insulin levels were significantly decreased in FR males but showed a slight increase in FR females before UCS; however, insulin levels decreased significantly in the FR male and female rats after UCS. Before UCS, serum lipid levels were higher in the FR males but were normal in the FR females; after UCS, FR males had a slight decrease and FR females had an increasing trend in serum lipids levels. Lipid droplets in the hypothalamus, pituitary gland, and livers of the FR group indicated steatosis.

CONCLUSIONS

These results suggest that prenatal food restriction alters HPA axis-associated neuroendocrine metabolism in adult offspring fed a high-fat diet, which may originate from the intrauterine programming and increase the susceptibility to adult metabolic diseases.

Endocrine regulation of compensatory growth in fish

Compensatory growth (CG) is a period of accelerated growth that occurs following the alleviation of growth-stunting conditions during which an organism can make up for lost growth opportunity and potentially catch up in size with non-stunted cohorts. Fish show a particularly robust capacity for the response and have been the focus of numerous studies that demonstrate their ability to compensate for periods of fasting once food is made available again. CG is characterized by an elevated growth rate resulting from enhanced feed intake, mitogen production, and feed conversion efficiency. Because little is known about the underlying mechanisms that drive the response, this review describes the sequential endocrine adaptations that lead to CG; namely during the precedent catabolic phase (fasting) that taps endogenous energy reserves, and the following hyperanabolic phase (refeeding) when accelerated growth occurs. In order to elicit a CG response, endogenous energy reserves must first be moderately depleted, which alters endocrine profiles that enhance appetite and growth potential. During this catabolic phase, elevated ghrelin and growth hormone (GH) production increase appetite and protein-sparing lipolysis, while insulin-like growth factors (IGFs) are suppressed, primarily due to hepatic GH resistance. During refeeding, temporal hyperphagia provides an influx of energy and metabolic substrates that are then allocated to somatic growth by resumed IGF signaling. Under the right conditions, refeeding results in hyperanabolism and a steepened growth trajectory relative to constantly fed controls. The response wanes as energy reserves are re-accumulated and homeostasis is restored. We ascribe possible roles for select appetite and growth-regulatory hormones in the context of the prerequisite of these catabolic and hyperanabolic phases of the CG response in teleosts, with emphasis on GH, IGFs, cortisol, somatostatin, neuropeptide Y, ghrelin, and leptin.

Effect of breastfeeding on head circumference of children from impoverished communities

OBJECTIVE

This study investigated the effect of exclusive breastfeeding on head circumference (HC) among children living in impoverished communities.

SUBJECTS AND METHODS

A cross-sectional study was conducted among children 12-60 months old from the 39 quilombos located in the State of Alagoas, Brazil. HC deficit was defined by a z-score of less than -2 from the median (based on the 2006 World Health Organization growth standards). Prevalence ratio and 95% confidence interval (95% CI) were estimated using Poisson regression with robust adjustment of the variance, and estimates were adjusted for possible confounders (anthropometric, socioeconomic, demographic, and health-related variables).

RESULTS

We evaluated 725 children (365 boys and 360 girls). The prevalence of HC deficit was 13.3% among those children who were exclusively breastfed for less than 30 days, 10.6% among those exclusively breastfed for 30-119 days, and 5.8% among those who were exclusively breastfed for 120 days or more. Even after controlling for possible confounding variables, exclusive breastfeeding for ≥4 months decreased the risk of HC deficit (prevalence ratio, 0.48; 95% CI 0.24, 0.99).

CONCLUSIONS

Exclusive breastfeeding for ≥4 months was associated with a larger HC in children exposed to great social vulnerability in impoverished communities.

Food insecurity and linear growth of adolescents in Jimma Zone, Southwest Ethiopia

Background

Although many studies showed that adolescent food insecurity is a pervasive phenomenon in Southwest Ethiopia, its effect on the linear growth of adolescents has not been documented so far. This study therefore aimed to longitudinally examine the association between food insecurity and linear growth among adolescents.

Methods

Data for this study were obtained from a longitudinal survey of adolescents conducted in Jimma Zone, which followed an initial sample of 2084 randomly selected adolescents aged 13–17 years. We used linear mixed effects model for 1431 adolescents who were interviewed in three survey rounds one year apart to compare the effect of food insecurity on linear growth of adolescents.

Results

Overall, 15.9% of the girls and 12.2% of the boys (P=0.018) were food insecure both at baseline and on the year 1 survey, while 5.5% of the girls and 4.4% of the boys (P=0.331) were food insecure in all the three rounds of the survey. In general, a significantly higher proportion of girls (40%) experienced food insecurity at least in one of the survey rounds compared with boys (36.6%) (P=0.045).

The trend of food insecurity showed a very sharp increase over the follow period from the baseline 20.5% to 48.4% on the year 1 survey, which again came down to 27.1% during the year 2 survey.

In the linear mixed effects model, after adjusting for other covariates, the mean height of food insecure girls was shorter by 0.87 cm (P<0.001) compared with food secure girls at baseline. However, during the follow up period on average, the heights of food insecure girls increased by 0.38 cm more per year compared with food secure girls (P<0.066). However, the mean height of food insecure boys was not significantly different from food secure boys both at baseline and over the follow up period. Over the follow-up period, adolescents who live in rural and semi-urban areas grew significantly more per year than those who live in the urban areas both for girls (P<0.01) and for boys (P<0.01).

Conclusions

Food insecurity is negatively associated with the linear growth of adolescents, especially on girls. High rate of childhood stunting in Ethiopia compounded with lower height of food insecure adolescents compared with their food secure peers calls for the development of direct nutrition interventions targeting adolescents to promote catch-up growth and break the intergenerational cycle of malnutrition.

Exogenous pancreatic-like enzymes are recovered in the gut and improve growth of exocrine pancreatic insufficient pigs

The exocrine pancreatic insufficient (EPI) pigs grow less due to different disturbances in feed digestion, absorption, and retention. Use of pancreatic-like enzymes of microbial origin in pigs may improve feed use and performance in slow-growing pigs. The aim was to study gut recovery and effectiveness of pancreatic-like enzymes of microbial origin supplementation on pig performance. Six male pigs 10 to 12 kg BW underwent pancreatic duct ligation surgery to induce total exocrine pancreatic insufficiency (EPI). Three cannulas to access the gastrointestinal tract content were installed in stomach, duodenum, and ileum in EPI pigs and in 3 control (healthy) pigs. One month after surgery, enzymes were given before feeding and digesta samples were collected for analyses. The BW of EPI pigs did not increase during 1 mo following surgery (11.7 vs. 11.6 kg BW); however, BW increased after 1 wk of enzyme supplementation (12.1 kg BW). Coefficient of fat and N absorption increased (P < 0.05) in EPI pigs after enzyme supplementation. Activity of amylase, lipase, and protease in chyme samples of EPI pigs was very low compared to controls. In EPI pigs after enzyme supplementation, amylase activity increased from 5.32 to 72.9 units/mL but remained lower than that of healthy pigs (162.7 units/mL). Lipase activity increased from 79.1 to 421.6 units/mL, which was similar to that of controls (507.3 units/mL). Proteolytic activity increased from 7.8 to 69.7 units/mL but still did not reach control pigs (164.3 units/mL). In conclusion, exogenous microbial enzymes mimic endogenous pancreatic enzymes being recovered along the lumen of the gastrointestinal tract. These enzymes might be a useful tool to stimulate growth of slower-growing pigs after the weaning period.

Catch-up growth: cellular and molecular mechanisms

In mammals, after a period of growth inhibition, body growth often does not just return to a normal rate but actually exceeds the normal rate, resulting in catch-up growth. Recent evidence suggests that catch-up growth occurs because growth-inhibiting conditions delay progression of the physiological mechanisms that normally cause body growth to slow and cease with age. As a result, following the period of growth inhibition, tissues retain a greater proliferative capacity than normal, and therefore grow more rapidly than normal for age. There is evidence that this mechanism contributes both to catch-up growth in terms of body length, which involves proliferation in the growth plate, and to catch-up growth in terms of organ mass, which involves proliferation in multiple nonskeletal tissues.

Influence of neonatal hypothyroidism on hepatic gene expression and lipid metabolism in adulthood

Thyroid hormones are required for normal growth and development in mammals. Congenital-neonatal hypothyroidism (CH) has a profound impact on physiology, but its specific influence in liver is less understood. Here, we studied how CH influences the liver gene expression program in adulthood. Pregnant rats were given the antithyroid drug methimazole (MMI) from GD12 until PND30 to induce CH in male offspring. Growth defects due to CH were evident as reductions in body weight and tail length from the second week of life. Once the MMI treatment was discontinued, the feed efficiency increased in CH, and this was accompanied by significant catch-up growth. On PND80, significant reductions in body mass, tail length, and circulating IGF-I levels remained in CH rats. Conversely, the mRNA levels of known GH target genes were significantly upregulated. The serum levels of thyroid hormones, cholesterol, and triglycerides showed no significant differences. In contrast, CH rats showed significant changes in the expression of hepatic genes involved in lipid metabolism, including an increased transcription of PPARα and a reduced expression of genes involved in fatty acid and cholesterol uptake, cellular sterol efflux, triglyceride assembly, bile acid synthesis, and lipogenesis. These changes were associated with a decrease of intrahepatic lipids. Finally, CH rats responded to the onset of hypothyroidism in adulthood with a reduction of serum fatty acids and hepatic cholesteryl esters and to T3 replacement with an enhanced activation of malic enzyme. In summary, we provide in vivo evidence that neonatal hypothyroidism influences the hepatic transcriptional program and tissue sensitivity to hormone treatment in adulthood. This highlights the critical role that a euthyroid state during development plays on normal liver physiology in adulthood.

Quiescence: early evolutionary origins and universality do not imply uniformity

Cell cycle investigations have focused on relentless exponential proliferation of cells, an unsustainable situation in nature. Proliferation of cells, whether microbial or metazoan, is interrupted by periods of quiescence. The vast majority of cells in an adult metazoan lie quiescent. As disruptions in this quiescence are at the foundation of cancer, it will be important for the field to turn its attention to the mechanisms regulating quiescence. While often presented as a single topic, there are multiple forms of quiescence each with complex inputs, some of which are tied to conceptually challenging aspects of metazoan regulation such as size control. In an effort to expose the enormity of the challenge, I describe the differing biological purposes of quiescence, and the coupling of quiescence in metazoans to growth and to the structuring of tissues during development. I emphasize studies in the organism rather than in tissue culture, because these expose the diversity of regulation. While quiescence is likely to be a primitive biological process, it appears that in adapting quiescence to its many distinct biological settings, evolution has diversified it. Consideration of quiescence in different models gives us an overview of this diversity.

Growth velocity and final height in elite female rhythmic and artistic gymnasts

PURPOSE

The aim of this study was to determine the impact of intensive training on adult final height in elite female rhythmic and artistic gymnasts.

METHODS

The study included 215 rhythmic gymnasts (RG) and 113 artistic gymnasts (AG).

RESULTS

AG were below the 50th percentile, while RG were taller than average. Final adult height was lower than target height in AG, while in RG, it exceeded target height. AG started training earlier than RG (p<0.001) and reported lower intensity of training (p<0.001). RG were taller than AG, with higher target height, greater Δ final height-target height and lower body fat and BMI (p<0.001). Using multiple regression analysis, the main factors influencing final height were weight SDS (p<0.001), target height SDS (p<0.001) and age of menarche (p<0.001) for RG, and weight SDS (p<0.001) and target height SDS (p<0.001) for AG.

CONCLUSION

In both elite female RG and AG, genetic predisposition to final height was not disrupted and remained the main force of growth. Although in elite RG genetic predisposition for growth was fully preserved, in elite female AG final adult height falls shorter than genetically determined target height, though within the standard error of prediction.