Birth weight, weight at 1 y of age, and body composition in older men: findings from the Hertfordshire Cohort Study

The effect of low birth weight as an intrauterine exposure on the early onset of sarcopenia through possible molecular pathways

Sarcopenia, a musculoskeletal disease characterized by the progressive loss of skeletal muscle mass, strength, and physical performance, presents significant challenges to global public health due to its adverse effects on mobility, morbidity, mortality, and healthcare costs. This comprehensive review explores the intricate connections between sarcopenia and low birth weight (LBW), emphasizing the developmental origins of health and disease (DOHaD) hypothesis, inflammatory processes (inflammaging), mitochondrial dysfunction, circadian rhythm disruptions, epigenetic mechanisms, and genetic variations revealed through genome-wide studies (GWAS). A systematic search strategy was developed using PubMed to identify relevant English-language publications on sarcopenia, LBW, DOHaD, inflammaging, mitochondrial dysfunction, circadian disruption, epigenetic mechanisms, and GWAS. The publications consist of 46.2% reviews, 21.2% cohort studies, 4.8% systematic reviews, 1.9% cross-sectional studies, 13.4% animal studies, 4.8% genome-wide studies, 5.8% epigenome-wide studies, and 1.9% book chapters. The review identified key factors contributing to sarcopenia development, including the DOHaD hypothesis, LBW impact on muscle mass, inflammaging, mitochondrial dysfunction, the influence of clock genes, the role of epigenetic mechanisms, and genetic variations revealed through GWAS. The DOHaD theory suggests that LBW induces epigenetic alterations during foetal development, impacting long-term health outcomes, including the early onset of sarcopenia. LBW correlates with reduced muscle mass, grip strength, and lean body mass in adulthood, increasing the risk of sarcopenia. Chronic inflammation (inflammaging) and mitochondrial dysfunction contribute to sarcopenia, with LBW linked to increased oxidative stress and dysfunction. Disrupted circadian rhythms, regulated by genes such as BMAL1 and CLOCK, are associated with both LBW and sarcopenia, impacting lipid metabolism, muscle mass, and the ageing process. Early-life exposures, including LBW, induce epigenetic modifications like DNA methylation (DNAm) and histone changes, playing a pivotal role in sarcopenia development. Genome-wide studies have identified candidate genes and variants associated with lean body mass, muscle weakness, and sarcopenia, providing insights into genetic factors contributing to the disorder. LBW emerges as a potential early predictor of sarcopenia development, reflecting the impact of intrauterine exposures on long-term health outcomes. Understanding the complex interplay between LBW with inflammaging, mitochondrial dysfunction, circadian disruption, and epigenetic factors is essential for elucidating the pathogenesis of sarcopenia and developing targeted interventions. Future research on GWAS and the underlying mechanisms of LBW-associated sarcopenia is warranted to inform preventive strategies and improve public health outcomes.

Parental Height and Weight Influence Offspring Adiposity at 2 Years; Findings from the ROLO Kids Birth Cohort Study

OBJECTIVE

The perinatal period and in utero environment are important for fetal growth, development, and fetal programming. This study aimed to determine the effect of parental anthropometry and the maternal metabolic milieu on offspring adiposity at 2 years of age.

STUDY DESIGN

This longitudinal birth cohort includes analysis of maternal (n = 337) and paternal (n = 219) anthropometry and maternal and fetal metabolic markers (n = 337), including glucose, homeostatic model of assessment (HOMA), C-peptide, and leptin from participants of the ROLO (the Randomized Control Trial of Low) pregnancy study, and their partners, to determine an association with offspring anthropometry at two years of age.

RESULTS

Linear regression, when adjusted for confounders, indicated maternal and paternal anthropometry and was associated with offspring weight and length at 2 years of age. Maternal height was negatively associated with general adiposity in the total cohort of children (p = 0.002) and in female children (p = 0.006) and central adiposity in the total child cohort (p < 0.001). Paternal height was also negatively associated with general adiposity in all children (p = 0.002) and central adiposity in total (p = 0.023) and female children (p = 0.008). Maternal glucose, insulin resistance, and fetal C-peptide positively correlated with anthropometry in total, male, and female children.

CONCLUSION

Parental anthropometry in the perinatal period has a long-lasting effect on offspring anthropometry beyond the neonatal period. Maternal and fetal metabolic factors influence adiposity, and this extends beyond the perinatal period. Parental adiposity may play a significant role in early childhood adiposity and may be a target for interventions to decrease the risk of early childhood obesity.

KEY POINTS

· Parental height and weight were associated with offspring anthropometry and measures of offspring adiposity at 2 years of age.. · Maternal glucose, insulin resistance, and fetal C-peptide correlated with offspring anthropometry.. · Parental anthropometry has long-term effect on offspring adiposity and is seen at 2 years of age..

Childhood BMI and other measures of body composition as a predictor of cardiometabolic non-communicable diseases in adulthood: a systematic review

OBJECTIVE

There is growing evidence that childhood malnutrition is associated with non-communicable diseases (NCD) in adulthood and that body composition mediates some of this association. This review aims to determine if childhood body composition can be used to predict later-life cardiometabolic NCD and which measures of body composition predicts future NCD.

DESIGN

Electronic databases were searched for articles where: children aged under 5 years had body composition measured; cardiometabolic health outcomes were measured a minimum of 10 years later.

SETTING

The databases Embase, Medline and Global Health were searched through July 2020.

PARTICIPANTS

Children aged under 5 years with a follow-up of minimum 10 years.

RESULTS

Twenty-nine studies met the inclusion criteria. Though a poor proxy measure of body composition, body mass index (BMI) was commonly reported (n 28, 97 %). 25 % of these studies included an additional measure (ponderal index or skinfold thickness). Few studies adjusted for current body size (n 11, 39 %).

CONCLUSIONS

Many studies reported that low infant BMI and high childhood BMI were associated with an increased risk of NCD-related outcomes in later life but no conclusions can be made about the exact timing of child malnutrition and consequent impact on NCD. Because studies focussed on BMI rather than direct measures of body composition, nothing can be said about which measures of body composition in childhood are most useful. Future research on child nutrition and long-term outcomes is urgently needed and should include validated body composition assessments as well as standard anthropometric and BMI measurements.

Anemic hypoxemia reduces myoblast proliferation and muscle growth in late-gestation fetal sheep

Fetal skeletal muscle growth requires myoblast proliferation, differentiation, and fusion into myofibers in addition to protein accretion for fiber hypertrophy. Oxygen is an important regulator of this process. Therefore, we hypothesized that fetal anemic hypoxemia would inhibit skeletal muscle growth. Studies were performed in late-gestation fetal sheep that were bled to anemic and therefore hypoxemic conditions beginning at ∼125 days of gestation (term = 148 days) for 9 ± 0 days (n = 19) and compared with control fetuses (n = 16). A metabolic study was performed on gestational day ∼134 to measure fetal protein kinetic rates. Myoblast proliferation and myofiber area were determined in biceps femoris (BF), tibialis anterior (TA), and flexor digitorum superficialis (FDS) muscles. mRNA expression of muscle regulatory factors was determined in BF. Fetal arterial hematocrit and oxygen content were 28% and 52% lower, respectively, in anemic fetuses. Fetal weight and whole body protein synthesis, breakdown, and accretion rates were not different between groups. Hindlimb length, however, was 7% shorter in anemic fetuses. TA and FDS muscles weighed less, and FDS myofiber area was smaller in anemic fetuses compared with controls. The percentage of Pax7⁺ myoblasts that expressed Ki67 was lower in BF and tended to be lower in FDS from anemic fetuses indicating reduced myoblast proliferation. There was less MYOD and MYF6 mRNA expression in anemic versus control BF consistent with reduced myoblast differentiation. These results indicate that fetal anemic hypoxemia reduced muscle growth. We speculate that fetal muscle growth may be improved by strategies that increase oxygen availability.

Maternal investment, life-history trajectory of the off-spring and cardiovascular disease risk in Emirati females in the United Arab Emirates

Background

Variations in cardiovascular disease risk (CVD) are suggested to be partly influenced by factors that affect prenatal growth patterns and outcomes, namely degree of maternal investment (proxied by birth weight and gestational age). Using the life history trajectory model, this study investigates whether maternal investment in early prenatal life associates with menarcheal age and whether maternal investment affects CVD risk in adulthood and predicts adult size and adiposity levels.

Methods

A cross-sectional study was conducted among 94 healthy Emirati females. Birth weight, gestational age and menarcheal age were obtained. Anthropometrical measurements, body composition analysis, and blood pressure values were collected. Regression analyses were conducted to establish associations.

Results

There was no association between birth weight standard deviation score (SDS) and age at menarche. When investigating the associations of birth weight SDS and age at menarche with growth indices, it was found that only birth weight was positively and significantly associated with both height (β = 1.342 cm, 95% CI (0.12, 2.57), p = 0.032) and leg length (β = 0.968 cm, 95% CI (0.08, 1.86), p = 0.034). Menarcheal age was significantly and inversely associated with fat mass index (FMI) (β = − 0.080 cm, 95% CI (− 0.13, − 0.03), p = 0.002), but not with waist circumference and fat free mass index (FFMI) (p > 0.05). Birth weight SDS was positively and significantly associated with waist circumference (β = 0.035 cm, 95% CI (0.01, 0.06), p = 0.009), FMI (β = 0.087 cm, 95% CI (0.01, 0.16), p = 0.027), and FFMI (β = 0.485 cm, 95% CI (0.17, 0.80), p = 0.003). Birth weight SDS was not significantly associated with either systolic blood pressure (SBP) or diastolic blood pressure (DBP) (p > 0.05). However, FMI, waist circumference, and FFMI were positively and significantly associated with SBP. Regarding DBP, the relationship was negatively and significantly associated with only FFMI (β = − 1.6111 kg/m2, 95% CI (− 2.63, − 0.60), p = 0.002).

Conclusion

Although the results do not fully support that Emirati females fast-life history is associated with increased chronic disease risk, the data does suggest a link between restricted fetal growth in response to low maternal investment and metabolic and reproductive health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11182-0.

Paternal bisphenol A exposure in mice impairs glucose tolerance in female offspring

Humans are ubiquitously exposed bisphenol A (BPA), and epidemiological studies show a positive association between BPA exposure and diabetes risk, but the impact of parental exposure on offspring diabetes risk in humans is unknown. Our previous studies in mice show disruption of metabolic health upon maternal BPA exposure. The current study was undertaken to determine whether exposure in fathers causes adverse metabolic consequences in offspring. Male C57BL/6 J mice were exposed to BPA in the diet beginning at 5 weeks of age resulting in the following dietary exposure groups: Control (0 μg/kg/day), Lower BPA (10 μg/kg/day) and Upper BPA (10 mg/kg/day). After 12 weeks of dietary exposure, males were mated to control females. Mothers and offspring were maintained on the control diet. Post-pubertal paternal BPA exposure did not affect offspring body weight, body composition or glucose tolerance. However, when fathers were exposed to BPA during gestation and lactation, their female offspring displayed impaired glucose tolerance in the absence of compromised in vivo insulin sensitivity or reduced ex vivo glucose-stimulated insulin secretion. Male offspring exhibited normal glucose tolerance. Taken together, these studies show there is an early window of susceptibility in which paternal BPA exposure can cause sex-specific impairments in glucose homeostasis.

Predictors of Developmental Patterns of Obesity in Young Children

Introduction: The current study characterizes longitudinal patterns in obesity in young children and their prediction from developmental programming and social determinant hypotheses. Materials and Methods: The data are based on the Family Life Project, a prospective longitudinal study of 1,292 families recruited from low-income, racially diverse, rural communities in Pennsylvania, and North Carolina. Pre-natal, peri-natal, and post-natal risks for childhood obesity were collected from 2 months of age; in-person assessments of child growth were used to identity obesity on multiple occasions from 24 to 90 months of age. Results: Two major novel findings emerged. First, longitudinal analyses identified four distinct obesity development profiles: stable obesity, later-onset obesity, moderate/declining obesity, and non-obese; these groups had distinct risk profiles. Second, prediction analyses favored developmental programming explanations for obesity, including evidence even in early childhood that both low- and high birth weight was associated with stable obesity. There was no indication that pre- and peri-natal and post-natal factors predicted obesity differently in non-minority and minority children. Discussion: Factors derived from the developmental programming model of obesity overlapped with, but predicted early onset obesity independently from, risks associated with social determinant models of obesity.

Postnatal β2 adrenergic treatment improves insulin sensitivity in lambs with IUGR but not persistent defects in pancreatic islets or skeletal muscle

Key points

Previous studies in fetuses with intrauterine growth restriction (IUGR) have shown that adrenergic dysregulation was associated with low insulin concentrations and greater insulin sensitivity.

Although whole‐body glucose clearance is normal, 1‐month‐old lambs with IUGR at birth have higher rates of hindlimb glucose uptake, which may compensate for myocyte deficiencies in glucose oxidation.

Impaired glucose‐stimulated insulin secretion in IUGR lambs is due to lower intra‐islet insulin availability and not from glucose sensing.

We investigated adrenergic receptor (ADR) β2 desensitization by administering oral ADRβ modifiers for the first month after birth to activate ADRβ2 and antagonize ADRβ1/3. In IUGR lambs ADRβ2 activation increased whole‐body glucose utilization rates and insulin sensitivity but had no effect on isolated islet or myocyte deficiencies.

IUGR establishes risk for developing diabetes. In IUGR lambs we identified disparities in key aspects of glucose‐stimulated insulin secretion and insulin‐stimulated glucose oxidation, providing new insights into potential mechanisms for this risk.

Abstract

Placental insufficiency causes intrauterine growth restriction (IUGR) and disturbances in glucose homeostasis with associated β adrenergic receptor (ADRβ) desensitization. Our objectives were to measure insulin‐sensitive glucose metabolism in neonatal lambs with IUGR and to determine whether daily treatment with ADRβ2 agonist and ADRβ1/β3 antagonists for 1 month normalizes their glucose metabolism. Growth, glucose‐stimulated insulin secretion (GSIS) and glucose utilization rates (GURs) were measured in control lambs, IUGR lambs and IUGR lambs treated with adrenergic receptor modifiers: clenbuterol atenolol and SR59230A (IUGR‐AR). In IUGR lambs, islet insulin content and GSIS were less than in controls; however, insulin sensitivity and whole‐body GUR were not different from controls. Of importance, ADRβ2 stimulation with β1/β3 inhibition increases both insulin sensitivity and whole‐body glucose utilization in IUGR lambs. In IUGR and IUGR‐AR lambs, hindlimb GURs were greater but fractional glucose oxidation rates and ex vivo skeletal muscle glucose oxidation rates were lower than controls. Glucose transporter 4 (GLUT4) was lower in IUGR and IUGR‐AR skeletal muscle than in controls but GLUT1 was greater in IUGR‐AR. ADRβ2, insulin receptor, glycogen content and citrate synthase activity were similar among groups. In IUGR and IUGR‐AR lambs heart rates were greater, which was independent of cardiac ADRβ1 activation. We conclude that targeted ADRβ2 stimulation improved whole‐body insulin sensitivity but minimally affected defects in GSIS and skeletal muscle glucose oxidation. We show that risk factors for developing diabetes are independent of postnatal catch‐up growth in IUGR lambs as early as 1 month of age and are inherent to the islets and myocytes.

Previous studies in fetuses with intrauterine growth restriction (IUGR) have shown that adrenergic dysregulation was associated with low insulin concentrations and greater insulin sensitivity.

Although whole‐body glucose clearance is normal, 1‐month‐old lambs with IUGR at birth have higher rates of hindlimb glucose uptake, which may compensate for myocyte deficiencies in glucose oxidation.

Impaired glucose‐stimulated insulin secretion in IUGR lambs is due to lower intra‐islet insulin availability and not from glucose sensing.

We investigated adrenergic receptor (ADR) β2 desensitization by administering oral ADRβ modifiers for the first month after birth to activate ADRβ2 and antagonize ADRβ1/3. In IUGR lambs ADRβ2 activation increased whole‐body glucose utilization rates and insulin sensitivity but had no effect on isolated islet or myocyte deficiencies.

IUGR establishes risk for developing diabetes. In IUGR lambs we identified disparities in key aspects of glucose‐stimulated insulin secretion and insulin‐stimulated glucose oxidation, providing new insights into potential mechanisms for this risk.

Ergot alkaloid exposure during gestation alters: 3. Fetal growth, muscle fiber development, and miRNA transcriptome1

The objective of this study was to assess how exposure to ergot alkaloids during 2 stages of gestation alters fetal growth, muscle fiber formation, and miRNA expression. Pregnant ewes (n = 36; BW = 83.26 ± 8.14 kg; 4/group; 9 groups) were used in a 2 × 2 factorial arrangement with 2 tall fescue seed treatments [endophyte-infected (E+) vs. endophyte-free (E-)] fed during 2 stages of gestation (MID, days 35 to 85 vs. LATE, days 86 to 133), which created 4 possible treatments (E-/E-, E+/E-, E-/E+, or E+/E+). Ewes were individually fed a total mixed ration containing E+ or E- fescue seed according to treatment assignment. Terminal surgeries were conducted on day 133 of gestation for the collection of fetal measurements and muscle samples. Data were analyzed as a 2 × 2 factorial with fescue treatment, stage of gestation, and 2-way interaction as fixed effects. Fetuses exposed to E+ seed during LATE gestation had reduced (P = 0.0020) fetal BW by 10% compared with E- fetuses; however, fetal body weight did not differ (P = 0.41) with E+ exposure during MID gestation. Fetuses from ewes fed E+ seed during MID and LATE gestation tended to have smaller (P = 0.058) kidney weights compared with E- fetuses. Liver weight was larger (P = 0.0069) in fetuses fed E- during LATE gestation compared with E+. Fetal brain weight did not differ by fescue treatment fed during MID (P = 0.36) or LATE (P = 0.40) gestation. The percentage of brain to empty body weight (EBW) was greater (P = 0.0048) in fetuses from ewes fed E+ fescue seed during LATE gestation, which is indicative of intrauterine growth restriction (IUGR). Primary muscle fiber number was lower (P = 0.0005) in semitendinosus (STN) of fetuses exposed to E+ during MID and/or LATE gestation compared with E-/E-. miRNA sequencing showed differential expression (P < 0.010) of 6 novel miRNAs including bta-miR-652_R+1, mdo-miR-22-3p, bta-miR-1277_R-1, ppy-miR-133a_L+1_1ss5TG, hsa-miR-129-1-3p, and ssc-miR-615 in fetal STN muscle. These miRNA are associated with glucose transport, insulin signaling, intracellular ATP, hypertension, or adipogenesis. This work supports the hypothesis that E+ tall fescue seed fed during late gestation reduces fetal weight and causes asymmetrical growth, which is indicative of IUGR. Changes in primary fiber number and miRNA of STN indicate that exposure to E+ fescue fed during MID and LATE gestation alters fetal muscle development that may affect postnatal muscle growth and meat quality.

Adolescent body composition and associations with body size and growth from birth to late adolescence. The Tromsø study: Fit Futures-A Norwegian longitudinal cohort study

BACKGROUND

Fat and fat-free masses and fat distribution are related to cardiometabolic risk.

OBJECTIVES

to explore how birth weight, childhood body mass index (BMI) and BMI gain were related to adolescent body composition and central obesity.

METHODS

In a population-based longitudinal study, body composition was measured by dual-energy X-ray absorptiometry in 907 Norwegian adolescents (48% girls). Associations between birth weight, BMI categories, and BMI gain were evaluated by fitting linear mixed models and conditional growth models with fat mass index (FMI, kg/m² ), fat-free mass index (FFMI, kg/m² ) standard deviation scores (SDS), and central obesity at 15 to 20 years, as well as change in FMI SDS and FFMI SDS between ages 15 to 17 and 18 to 20 as outcomes.

RESULTS

Birth weight was associated with FFMI in adolescence. Greater BMI gain in childhood, conditioned on prior body size, was associated with higher FMI, FFMI, and central overweight/obesity with the strongest associations seen at age 6 to 16.5 years: FMI SDS: β = 0.67, 95% CI (0.63-0.71), FFMI SDS: 0.46 (0.39, 0.52), in girls, FMI SDS: 0.80 (0.75, 0.86), FFMI SDS: 0.49 (0.43, 0.55), in boys.

CONCLUSIONS

Compared with birth and early childhood, high BMI and greater BMI gain at later ages are strong predictors of higher fat mass and central overweight/obesity at 15 to 20 years of age.

Addressing the Double Burden of Malnutrition in Developing Countries: Need for Strategies to Improve the Lean Body Mass

The double burden of childhood undernutrition and adult-onset adiposity-related chronic diseases is a key concern in many developing countries that are currently undergoing epidemiological and nutrition transition. Impaired linear growth with suboptimal lean body mass development seems to be the link between these 2 seemingly contrasting forms of malnutrition. Studies assessing the role of early nutrition in the later lean body mass development have shown consistent positive association. In addition, the nutrition during life course, especially the dietary intake of protein, zinc, calcium, and vitamin D status, impacts the lean body mass. Promoting increased intake of these important nutrients throughout life course would, therefore, be important for optimal development and maintenance of lean body mass. Diversified diets with increased consumption of nutrient-rich foods, especially milk and other animal source foods, are crucial for the development of optimal body composition and alleviation of the double burden of malnutrition.

The Hertfordshire Cohort Study: an overview

The Hertfordshire Cohort Study is a nationally unique study of men and women born in the English county of Hertfordshire in the early part of the 20 ^th century. Records that detail their health in infancy and childhood have been preserved, their sociodemographic, lifestyle, medical and biological attributes have been characterised in later life, and routinely collected data on their hospital use and mortality have been acquired. This paper provides an overview of the study since its inception in the 1980s, including its methods, findings, and plans for its future.

Nutritional Programming Effects on Development of Metabolic Disorders in Later Life

Developmental programming resulting from maternal malnutrition can lead to an increased risk of metabolic disorders such as obesity, insulin resistance, type 2 diabetes and cardiovascular disorders in the offspring in later life. Furthermore, many conditions linked with developmental programming are also known to be associated with the aging process. This review summarizes the available evidence about the molecular mechanisms underlying these effects, with the potential to identify novel areas of therapeutic intervention. This could also lead to the discovery of new treatment options for improved patient outcomes.

Sarcopenia

Sarcopenia is a condition that is characterized by loss of muscle mass, muscle strength and muscle functional impairment with ageing. The definition of sarcopenia has been through various permutations; however, an enormous recent breakthrough is the inclusion of the condition in the ICD-10 classification of diseases. This chapter covers the background issues regarding definition before describing the epidemiology of the disease according to human and environmental factors. It then provides a practical guide for the assessment of sarcopenia in a clinical setting and finishes with advice on present treatment and the exciting frontiers of future therapies.

Epidemiology of Sarcopenia: Determinants Throughout the Lifecourse

Sarcopenia is an age-related syndrome characterised by progressive and generalised loss of skeletal muscle mass and strength; it is a major contributor to the risk of physical frailty, functional impairment in older people, poor health-related quality of life and premature death. Many different definitions have been used to describe sarcopenia and have resulted in varying estimates of prevalence of the condition. The most recent attempts of definitions have tried to integrate information on muscle mass, strength and physical function and provide a definition that is useful in both research and clinical settings. This review focuses on the epidemiology of the three distinct physiological components of sarcopenia, and highlights the similarities and differences between their patterns of variation with age, gender, geography and time and the individual risk factors that cluster selectively with muscle mass, strength and physical function. Methods used to measure muscle mass, strength and physical functioning and how differences in these approaches can contribute to the varying prevalence rates will also be described. The evidence for this review was gathered by undertaking a systematic search of the literature. The descriptive characteristics of muscle mass, strength and function described in this review point to the urgent need for a consensual definition of sarcopenia incorporating these parameters.

Growth patterns in early childhood: Better trajectories in Afro-Ecuadorians independent of sex and socioeconomic factors

The first years of life are the most dynamic period for childhood growth. There are limited data available on growth patterns of infants and children living in rural Latin America. The aim of this study was to describe the growth patterns from birth to 5years in children living in a rural District of tropical coastal Ecuador using data from a birth cohort of 2404 neonates. We hypothesize that there would be growth differences according to ethnicity and sex. Evaluations were conducted at birth or until 2weeks of age and at 7, 13, 24, 36 and 60months during clinic and home visits. Individual growth trajectories for weight-for-age, height-for-age and weight/height-for-age Z-scores were estimated using multilevel models. Girls were lighter and shorter than boys at birth. However, Afro-Ecuadorian children (versus mestizo or indigenous) were longer/taller and heavier throughout the first 5years of life and had greater mean trajectories for HAZ and WAZ independent of sex and socioeconomic factors. Our data indicate that ethnicity is a determinant of growth trajectories during the first 5years of life independent of socioeconomic factors in a birth cohort conducted in a rural region of Latin America.

Pain in knee osteoarthritis is associated with variation in the neurokinin 1/substance P receptor (TACR1) gene

BACKGROUND

Substance P (SP) is a pain- and inflammation-related neuropeptide which preferentially binds to the neurokinin receptor 1 (NK₁ ). SP and NK₁ receptors have been implicated in joint pain, inflammation and damage in animal models and human studies of osteoarthritis (OA). The aim of this study was to test if genetic variation at the neurokinin 1 receptor gene (TACR1) is associated with pain in individuals with radiographic knee OA.

METHODS

Participants from the Genetics of OA and Lifestyle study were used for the discovery group (n = 1615). Genotype data for six SNPs selected to cover most variation in the TACR1 gene were used to test for an association with symptomatic OA. Replication analysis was performed using data from the Chingford 1000 Women Study, Hertfordshire Cohort Study, Tasmanian Older Adult Cohort Study and the Clearwater OA Study. In total, n = 1715 symptomatic OA and n = 735 asymptomatic OA individuals were analysed.

RESULTS

Out of six SNPs tested in the TACR1 gene, one (rs11688000) showed a nominally significant association with a decreased risk of symptomatic OA in the discovery cohort. This was then replicated in four additional cohorts. After adjusting for age, gender, body mass index and radiographic severity, the G (minor) allele at rs11688000 was associated with a decreased risk of symptomatic OA compared to asymptomatic OA cases (p = 9.90 × 10^-4 , OR = 0.79 95% 0.68-0.90 after meta-analysis).

CONCLUSIONS

This study supports a contribution from the TACR1 gene in human OA pain, supporting further investigation of this gene's function in OA.

SIGNIFICANCE

This study contributes to the knowledge of the genetics of painful osteoarthritis, a condition which affects millions of individuals worldwide. Specifically, a contribution from the TACR1 gene to modulating pain sensitivity in osteoarthritis is suggested.

Epidemiology of sarcopenia and insight into possible therapeutic targets

Musculoskeletal ageing is a major public health concern owing to demographic shifts in the population. Sarcopenia, generally defined as the age-related loss of muscle mass and function, is associated with considerable risk of falls, loss of independence in older adults and hospitalization with poorer health outcomes. This condition is therefore associated with increased morbidity and health care costs. As with bone mass, muscle mass and strength increase during late adolescence and early adulthood, but begin to decline substantially from ∼50 years of age. Sarcopenia is characterized by many features, which include loss of muscle mass, altered muscle composition, infiltration with fat and fibrous tissue and alterations in innervation. A better understanding of these factors might help us to develop strategies that target these effects. To date, however, methodological challenges and controversies regarding how best to define the condition, in addition to uncertainty about what outcome measures to consider, have delayed research into possible therapeutic options. Most pharmacological agents investigated to date are hormonal, although new developments have seen the emergence of agents that target myostatin signalling to increase muscle mass. In this review we consider the current approaching for defining sarcopenia and discuss its epidemiology, pathogenesis, and potential therapeutic opportunities.

Precocious glucocorticoid exposure reduces skeletal muscle satellite cells in the fetal rat

Perinatal skeletal muscle growth rates are a function of protein and myonuclear accretion. Precocious exposure of the fetus to glucocorticoids (GLC) in utero impairs muscle growth. Reduced muscle protein synthesis rates contribute to this response, but the consequences for myonuclear hyperplasia are unknown. To test the hypothesis that blunting of Pax7+ muscle progenitor cell proliferative activity by GLC in vivo also contributes to reduced fetal muscle growth, pregnant rats were administered dexamethasone (DEX: 1 mg/L drinking water) from embryonic day (ED) 13 to ED21. Their responses were compared to pair-fed (PF) and ad libitum-fed controls (CON). Bromodeoxyuridine (BrdU) was administered before delivery to measure myonuclear accretion. Fetal hind limb and diaphragm muscles were collected at term and analyzed for myofiber cross-sectional area (CSA), total and BrdU+ myonuclei, Pax7+ nuclei, MyoD and myogenin protein and mRNA abundance and myosin heavy chain (MyHC) isoform composition. Mean fiber CSA, myonuclei/myofiber and Pax7+ nuclei/myofiber ratios were reduced in DEX compared to those in CON and PF muscles; CSA/myonucleus, BrdU+/total myonuclei and BrdU+ myonuclei/Pax7+ nuclei were similar among groups. Myogenin abundance was reduced and MyHC-slow was increased in DEX fetuses. The data are consistent with GLC inhibition of muscle progenitor cell proliferation limiting satellite cell and myonuclear accretion. The response of PF-fed compared to CON muscles indicated that decreased food consumption by DEX dams contributed to the smaller myofiber CSA but did not affect Pax7+ nuclear accretion. Thus, the effect on satellite cell reserve and myonuclear number also contributes to the blunting of fetal muscle growth by GLC.

Impact of placental insufficiency on fetal skeletal muscle growth

Intrauterine growth restriction (IUGR) caused by placental insufficiency is one of the most common and complex problems in perinatology, with no known cure. In pregnancies affected by placental insufficiency, a poorly functioning placenta restricts nutrient supply to the fetus and prevents normal fetal growth. Among other significant deficits in organ development, the IUGR fetus characteristically has less lean body and skeletal muscle mass than their appropriately-grown counterparts. Reduced skeletal muscle growth is not fully compensated after birth, as individuals who were born small for gestational age (SGA) from IUGR have persistent reductions in muscle mass and strength into adulthood. The consequences of restricted muscle growth and accelerated postnatal "catch-up" growth in the form of adiposity may contribute to the increased later life risk for visceral adiposity, peripheral insulin resistance, diabetes, and cardiovascular disease in individuals who were formerly IUGR. This review will discuss how an insufficient placenta results in impaired fetal skeletal muscle growth and how lifelong reductions in muscle mass might contribute to increased metabolic disease risk in this vulnerable population.

Does skeletal muscle have an 'epi'-memory? The role of epigenetics in nutritional programming, metabolic disease, aging and exercise

Skeletal muscle mass, quality and adaptability are fundamental in promoting muscle performance, maintaining metabolic function and supporting longevity and healthspan. Skeletal muscle is programmable and can ‘remember’ early‐life metabolic stimuli affecting its function in adult life. In this review, the authors pose the question as to whether skeletal muscle has an ‘epi’‐memory? Following an initial encounter with an environmental stimulus, we discuss the underlying molecular and epigenetic mechanisms enabling skeletal muscle to adapt, should it re‐encounter the stimulus in later life. We also define skeletal muscle memory and outline the scientific literature contributing to this field. Furthermore, we review the evidence for early‐life nutrient stress and low birth weight in animals and human cohort studies, respectively, and discuss the underlying molecular mechanisms culminating in skeletal muscle dysfunction, metabolic disease and loss of skeletal muscle mass across the lifespan. We also summarize and discuss studies that isolate muscle stem cells from different environmental niches in vivo (physically active, diabetic, cachectic, aged) and how they reportedly remember this environment once isolated in vitro. Finally, we will outline the molecular and epigenetic mechanisms underlying skeletal muscle memory and review the epigenetic regulation of exercise‐induced skeletal muscle adaptation, highlighting exercise interventions as suitable models to investigate skeletal muscle memory in humans. We believe that understanding the ‘epi’‐memory of skeletal muscle will enable the next generation of targeted therapies to promote muscle growth and reduce muscle loss to enable healthy aging.

The association between maternal nutrition and lifestyle during pregnancy and 2-year-old offspring adiposity: analysis from the ROLO study

Aim

To examine the association between maternal nutrition and lifestyle factors and offspring adiposity, using baseline and 2-year postpartum follow-up data from a randomised control trial of low glycaemic index diet.

Subject and methods

Food diaries and lifestyle questionnaires were completed during pregnancy and infant feeding and maternal lifestyle questionnaires 2 years postpartum for 281 mother and infant pairs from the ROLO study. Maternal anthropometry was measured throughout pregnancy and infant and maternal anthropometry was measured 2 years postpartum.

Results

Maternal 2 year postpartum body mass index (BMI) was positively associated with offspring BMI-for-age z-score (B = 0.105, p = 0.015). Trimester 2 saturated fat intake was positively associated with offspring subscapular:triceps skinfold ratio (B = 0.018, p = 0.001). Trimester 1 glycaemic index was also positively associated with offspring sum of subscapular and triceps skinfolds (B = 0.009, p = 0.029).

Conclusions

Maternal BMI 2 years postpartum was positively associated with offspring BMI. Pregnancy saturated fat intake was positively and polyunsaturated fat negatively associated with offspring adiposity. While further research is necessary, pregnancy and the postpartum period may be early opportunities to combat childhood obesity.

Electronic supplementary material

The online version of this article (doi:10.1007/s10389-016-0740-9) contains supplementary material, which is available to authorized users.

Developmental programming: State-of-the-science and future directions-Summary from a Pennington Biomedical symposium

OBJECTIVE

On December 8-9, 2014, the Pennington Biomedical Research Center convened a scientific symposium to review the state-of-the-science and future directions for the study of developmental programming of obesity and chronic disease. The objectives of the symposium were to discuss: (i) past and current scientific advances in animal models, population-based cohort studies, and human clinical trials, (ii) the state-of-the-science of epigenetic-based research, and (iii) considerations for future studies.

RESULTS

This symposium provided a comprehensive assessment of the state of the scientific field and identified research gaps and opportunities for future research in order to understand the mechanisms contributing to the developmental programming of health and disease.

CONCLUSIONS

Identifying the mechanisms which cause or contribute to developmental programming of future generations will be invaluable to the scientific and medical community. The ability to intervene during critical periods of prenatal and early postnatal life to promote lifelong health is the ultimate goal. Considerations for future research including the use of animal models, the study design in human cohorts with considerations about the timing of the intrauterine exposure, and the resulting tissue-specific epigenetic signature were extensively discussed and are presented in this meeting summary.

Intrauterine growth-restricted sheep fetuses exhibit smaller hindlimb muscle fibers and lower proportions of insulin-sensitive Type I fibers near term

Intrauterine growth restriction (IUGR) reduces muscle mass and insulin sensitivity in offspring. Insulin sensitivity varies among muscle fiber types, with Type I fibers being most sensitive. Differences in fiber-type ratios are associated with insulin resistance in adults, and thus we hypothesized that near-term IUGR sheep fetuses exhibit reduced size and proportions of Type I fibers. Placental insufficiency-induced IUGR fetuses were ∼54% smaller (P < 0.05) than controls and exhibited hypoxemia and hypoglycemia, which contributed to 6.9-fold greater (P < 0.05) plasma norepinephrine and ∼53% lower (P < 0.05) plasma insulin concentrations. IUGR semitendinosus muscles contained less (P < 0.05) myosin heavy chain-I protein (MyHC-I) and proportionally fewer (P < 0.05) Type I and Type I/IIa fibers than controls, but MyHC-II protein concentrations, Type II fibers, and Type IIx fibers were not different. IUGR biceps femoris muscles exhibited similar albeit less dramatic differences in fiber type proportions. Type I and IIa fibers are more responsive to adrenergic and insulin regulation than Type IIx and may be more profoundly impaired by the high catecholamines and low insulin in our IUGR fetuses, leading to their proportional reduction. In both muscles, fibers of each type were uniformly smaller (P < 0.05) in IUGR fetuses than controls, which indicates that fiber hypertrophy is not dependent on type but rather on other factors such as myoblast differentiation or protein synthesis. Together, our findings show that IUGR fetal muscles develop smaller fibers and have proportionally fewer Type I fibers, which is indicative of developmental adaptations that may help explain the link between IUGR and adulthood insulin resistance.

Maternal oral administration of osteocalcin protects offspring from metabolic impairment in adulthood

OBJECTIVE

Maternal diet during pregnancy has been found to influence the health of offspring. However, strategies for modulation of maternal energy metabolism without an adverse effect on the fetus have remained limited. It was recently shown that oral administration of uncarboxylated osteocalcin (GluOC) improves metabolic status in adult female mice. Whether maternal GluOC administration during gestation might improve the metabolic status of offspring was investigated.

METHODS

Female C57BL/6 mice were fed a normal diet (ND) or high-fat, high-sucrose diet (HFS) and were given saline or GluOC by oral administration during pregnancy. The resulting offspring were in turn assigned to ND- or HFS-fed groups immediately after weaning, and their body weight, glucose metabolism, serum lipid parameters, and level of adipose tissue inflammation were subsequently assessed.

RESULTS

Maternal HFS feeding during gestation had adverse effects on glucose and lipid parameters, body weight, and adipose tissue inflammation in female offspring fed the same diet, and these effects were attenuated by maternal oral GluOC administration.

CONCLUSIONS

Maternal oral administration of GluOC protects HFS-fed female offspring from metabolic disorders induced by maternal obesity.

Early Life Exposure to Chronic Intermittent Hypoxia Primes Increased Susceptibility to Hypoxia-Induced Weakness in Rat Sternohyoid Muscle during Adulthood

Intermittent hypoxia is a feature of apnea of prematurity (AOP), chronic lung disease, and sleep apnea. Despite the clinical relevance, the long-term effects of hypoxic exposure in early life on respiratory control are not well defined. We recently reported that exposure to chronic intermittent hypoxia (CIH) during postnatal development (pCIH) causes upper airway muscle weakness in both sexes, which persists for several weeks. We sought to examine if there are persistent sex-dependent effects of pCIH on respiratory muscle function into adulthood and/or increased susceptibility to re-exposure to CIH in adulthood in animals previously exposed to CIH during postnatal development. We hypothesized that pCIH would cause long-lasting muscle impairment and increased susceptibility to subsequent hypoxia. Within 24 h of delivery, pups and their respective dams were exposed to CIH: 90 s of hypoxia reaching 5% O2 at nadir; once every 5 min, 8 h per day for 3 weeks. Sham groups were exposed to normoxia in parallel. Three groups were studied: sham; pCIH; and pCIH combined with adult CIH (p+aCIH), where a subset of the pCIH-exposed pups were re-exposed to the same CIH paradigm beginning at 13 weeks. Following gas exposures, sternohyoid and diaphragm muscle isometric contractile and endurance properties were examined ex vivo. There was no apparent lasting effect of pCIH on respiratory muscle function in adults. However, in both males and females, re-exposure to CIH in adulthood in pCIH-exposed animals caused sternohyoid (but not diaphragm) weakness. Exposure to this paradigm of CIH in adulthood alone had no effect on muscle function. Persistent susceptibility in pCIH-exposed airway dilator muscle to subsequent hypoxic insult may have implications for the control of airway patency in adult humans exposed to intermittent hypoxic stress during early life.

Developmental aspects of a life course approach to healthy ageing

We examine the mechanistic basis and wider implications of adopting a developmental perspective on human ageing. Previous models of ageing have concentrated on its genetic basis, or the detrimental effects of accumulated damage, but also have raised issues about whether ageing can be viewed as adaptive itself, or is a consequence of other adaptive processes, for example if maintenance and repair processes in the period up to reproduction are traded off against later decline in function. A life course model places ageing in the context of the attainment of peak capacity for a body system, starting in early development when plasticity permits changes in structure and function induced by a range of environmental stimuli, followed by a period of decline, the rate of which depends on the peak attained as well as the later life conditions. Such path dependency in the rate of ageing may offer new insights into its modification. Focusing on musculoskeletal and cardiovascular function, we discuss this model and the possible underlying mechanisms, including endothelial function, oxidative stress, stem cells and nutritional factors such as vitamin D status. Epigenetic changes induced during developmental plasticity, and immune function may provide a common mechanistic process underlying a life course model of ageing. The life course trajectory differs in high and low resource settings. New insights into the developmental components of the life course model of ageing may lead to the design of biomarkers of later chronic disease risk and to new interventions to promote healthy ageing, with important implications for public health.

Maternal Nutrition and Glycaemic Index during Pregnancy Impacts on Offspring Adiposity at 6 Months of Age--Analysis from the ROLO Randomised Controlled Trial

Childhood obesity is associated with increased risk of adult obesity and metabolic disease. Diet and lifestyle in pregnancy influence fetal programming; however the influence of specific dietary components, including low glycaemic index (GI), remains complex. We examined the effect of a maternal low GI dietary intervention on offspring adiposity at 6 months and explored the association between diet and lifestyle factors in pregnancy and infant body composition at 6 months. 280 6-month old infant and mother pairs from the control (n = 142) and intervention group (n = 138), who received low GI dietary advice in pregnancy, in the ROLO study were analysed. Questionnaires (food diaries and lifestyle) were completed during pregnancy, followed by maternal lifestyle and infant feeding questionnaires at 6 months postpartum. Maternal anthropometry was measured throughout pregnancy and at 6 months post-delivery, along with infant anthropometry. No difference was found in 6 months infant adiposity between control and intervention groups. Maternal trimester three GI, trimester two saturated fats and trimester one and three sodium intake were positively associated with offspring adiposity, while trimester two and three vitamin C intake was negatively associated. In conclusion associations were observed between maternal dietary intake and GI during pregnancy and offspring adiposity at 6 months of age.

Birth weight predicted baseline muscular efficiency, but not response of energy expenditure to calorie restriction: An empirical test of the predictive adaptive response hypothesis

OBJECTIVES

Aiming to test the evolutionary significance of relationships linking prenatal growth conditions to adult phenotypes, this study examined whether birth size predicts energetic savings during fasting. We specifically tested a Predictive Adaptive Response (PAR) model that predicts greater energetic saving among adults who were born small.

METHODS

Data were collected from a convenience sample of young adults living in Albuquerque, NM (n = 34). Indirect calorimetry quantified changes in resting energy expenditure (REE) and active muscular efficiency that occurred in response to a 29-h fast. Multiple regression analyses linked birth weight to baseline and postfast metabolic values while controlling for appropriate confounders (e.g., sex, body mass).

RESULTS

Birth weight did not moderate the relationship between body size and energy expenditure, nor did it predict the magnitude change in REE or muscular efficiency observed from baseline to after fasting. Alternative indicators of birth size were also examined (e.g., low v. normal birth weight, comparison of tertiles), with no effects found. However, baseline muscular efficiency improved by 1.1% per 725 g (S.D.) increase in birth weight (P = 0.037).

CONCLUSIONS

Birth size did not influence the sensitivity of metabolic demands to fasting-neither at rest nor during activity. Moreover, small birth size predicted a reduction in the efficiency with which muscles convert energy expended into work accomplished. These results do not support the ascription of adaptive function to phenotypes associated with small birth size. © 2015 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:484-492, 2016. © 2015 Wiley Periodicals, Inc.

Association between weight at birth and body composition in childhood: A Brazilian cohort study

BACKGROUND AND AIM

Previous studies have shown that the association between birth weight and obesity later in life apparently follows a U-shaped curve. However, due to the continuous increase of mean birth weight in several countries worldwide, it is expected that higher birth weight will play a more important role as a risk factor for further obesity than low birth weight. This study investigated the association between birth weight and body composition of children in order to establish their relationship in an earlier period of life.

STUDY DESIGN AND SUBJECTS

Prospective cohort study carried out from 1997 to 2006 in Jundiai city, Brazil, involving 486 children at birth and from 5 to 8 years of age. The following anthropometric measurements were determined: birth weight, weight, height, waist circumference and triceps skinfold thickness. Fat mass percentage, fat mass and fat-free mass were measured by electrical bioimpedance analysis by the 310 Body Composition Analyzer, Biodynamics(®). Five multiple linear regression models were developed considering waist circumference, triceps skinfold thickness, fat mass percentage, fat mass and fat-free mass as markers of body composition, and outcomes.

RESULTS

Significant positive associations were observed between birth weight and waist circumference (p<0.001), triceps skinfold thickness (p=0.006), fat mass (p=0.007) and fat-free mass (p<0.001). Approximately 10% of the children presented excess body fat assessed by bioimpedance, and 27.6% of them had central adiposity (waist circumference ≥95th percentile).

CONCLUSIONS

Intrauterine growth, assessed by weight at birth, was positively associated with body composition of children aged 5-8 years, indicating that those with the highest birth weight are more at risk for obesity, and probably to chronic diseases in adulthood.

Living long and ageing well: is epigenomics the missing link between nature and nurture?

Human longevity is a complex trait and increasingly we understand that both genes and lifestyle interact in the longevity phenotype. Non-genetic factors, including diet, physical activity, health habits, and psychosocial factors contribute approximately 50% of the variability in human lifespan with another 25% explained by genetic differences. Family clusters of nonagenarian and centenarian siblings, who show both exceptional age-span and health-span, are likely to have inherited facilitatory gene groups, but also have nine decades of life experiences and behaviours which have interacted with their genetic profiles. Identification of their shared genes is just one small step in the link from genes to their physical and psychological profiles. Behavioural genomics is beginning to demonstrate links to biological mechanisms through regulation of gene expression, which directs the proteome and influences the personal phenotype. Epigenetics has been considered the missing link between nature and nurture. Although there is much that remains to be discovered, this article will discuss some of genetic and environmental factors which appear important in good quality longevity and link known epigenetic mechanisms to themes identified by nonagenarians themselves related to their longevity. Here we suggest that exceptional 90-year old siblings have adopted a range of behaviours and life-styles which have contributed to their ageing-well-phenotype and which link with important public health messages.

Slow early growers have more muscle in relation to adult activity: evidence from Cebu, Philippines

Background/objectives

Adult skeletal muscle mass (SMM) protects against type 2 diabetes but little is known about its developmental antecedents. We examined whether pace of early weight gain predicted adult SMM in a birth cohort from Cebu City, Philippines. Additionally, we examined whether increases in SMM associated with adult muscle-building exercise varied according to early growth.

Subjects/methods

Data came from 1472 participants of the Cebu Longitudinal Health and Nutrition Survey. Weight was measured at birth and at 6-month intervals through age 24 months. Adult SMM was estimated from anthropometric measurements when participants were 20-22 years old. Interviews provided information on adult exercise/lifestyle habits.

Results

SMM (mean ± SD) was 20.8 ± 3.9 kg (men) and 13.6 ± 3.4 kg (women). Faster early weight gain predicted higher adult SMM. After adjustment for height and lifestyle factors, strongest associations with SMM were found for 6-12 months growth in men (β=0.17, p=0.001) and for birth weight in women (β=0.14, p=0.001). Individuals who had grown slowly displayed greater SMM in association with adult weight lifting, basketball playing, and physically demanding forms of employment (men) or household chores (women).

Conclusions

These results suggest heightened sensitivity of activity-induced muscle hypertrophy among adults who were born light or who gained weight slowly as infants. Future research should test this finding by comparing responses of muscle mass to an intervention in slow v. fast early growers. Findings suggest that adults who display reduced SMM following suboptimal early growth may be good candidates for new anti-diabetes interventions that promote muscle-building activities.

Childhood adiposity trajectories and risk of nonalcoholic fatty liver disease in adolescents

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) and its metabolic risk factors are recognized during childhood and adolescence. Identification of adolescents at risk of NAFLD from childhood anthropometry may expose opportunities to influence the hepatic and metabolic destinies of individuals. We sought associations between NAFLD diagnosed during adolescence and earlier life trajectories of anthropometry, in a population-based cohort of predominantly Caucasian adolescents.

METHODS

Assessment for NAFLD, using questionnaires and liver ultrasound, was performed on 1170 adolescents, aged 17 years, from the population-based Raine cohort. We sought associations between NAFLD in adolescents and serial anthropometric measurements recorded from birth, childhood, and adolescence.

RESULTS

NAFLD was diagnosed in 15.2% of adolescents. Birth anthropometry, including birth weight, skinfold thickness, and ponderal index, was not associated with NAFLD. However, adiposity differences between 17-year-old adolescents with NAFLD and those without NAFLD were apparent from age 3 years. Greater adiposity trajectories for weight, body mass index, skinfold thickness, mid-arm circumference, and chest circumference from age 3 years onwards, particularly in males, were associated with the diagnosis of NAFLD and severity of hepatic steatosis at age 17 years (P < 0.05). The strength of the associations increased with age after 3 years for each adiposity measure (all P < 0.001).

CONCLUSIONS

Trajectories of childhood adiposity are associated with NAFLD. Adiposity attained by 3 years of age and older, but not at birth, was associated with the diagnosis and severity of hepatic steatosis in late adolescence. Exploration of clinically relevant risk factors and preventative measures for NAFLD should begin during childhood.

Nutritional influences over the life course on lean body mass of individuals in developing countries

The double burden of childhood undernutrition and adult-onset adiposity in transitioning societies poses a significant public health challenge. The development of suboptimal lean body mass (LBM) could partly explain the link between these two forms of malnutrition. This review examines the evidence on both the role of nutrition in “developmental programming” of LBM and the nutritional influences that affect LBM throughout the life course. Studies from developing countries assessing the relationship of early nutrition with later LBM provide important insights. Overall, the evidence is consistent in suggesting a positive association of early nutritional status (indicated by birth weight and growth during first 2 years) with LBM in later life. Evidence on the impact of maternal nutritional supplementation during pregnancy on later LBM is inconsistent. In addition, the role of nutrients (protein, zinc, calcium, vitamin D) that can affect LBM throughout the life course is described. Promoting optimal intakes of these important nutrients throughout the life course is important for reducing childhood undernutrition as well as for improving the LBM of adults.

Early child care and obesity at 12 months of age in the Danish National Birth Cohort

Background/Objectives

Evidence suggests that the child care environment may be more obesogenic than the family home, and previous studies have found that child care use may be associated with obesity in children. Few studies, however, have focused on child care during infancy, which may be an especially vulnerable period. This study examined child care use in infancy and weight status at 12 months of age in a country where paid maternity leave is common and early child care is not as prevalent as in other developed countries.

Subjects/Methods

We studied 27821 children born to mothers participating in the Danish National Birth Cohort (DNBC), a longitudinal study of pregnant women enrolled between 1997 and 2002, who were also included in the Childcare Database, a national record of child care use in Denmark. The exposure was days in child care from birth to 12 months. The outcomes were sex-specific body mass index (BMI) z-score and overweight/obesity (BMI ≥85^th percentile based on the World Health Organization classification) at 12 months. We conducted multivariable linear and logistic regression analyses examining child care use and weight outcomes.

Results

A total of 17721 (63.7%) children attended child care during their first year of life. After adjustment for potential confounders, a 30-day increment of child care was associated with a modestly higher BMI z-score at 12 months (0.03 units; 95% CI: 0.01, 0.05; p=0.003). Similarly, child care use was associated with increased odds of being overweight/obese at 12 months of age (OR 1.05; 95% CI: 1.01, 1.10; p=0.047).

Conclusions

Child care in the first year of life was associated with slightly higher weight at 12 months, suggesting that child care settings may be important targets for obesity prevention in infancy.

The developmental origins of sarcopenia: from epidemiological evidence to underlying mechanisms

Sarcopenia is defined as the loss of skeletal muscle mass and strength with age. There is increasing recognition of the serious health consequences in terms of disability, morbidity and mortality as well as major healthcare costs. Adult determinants of sarcopenia including age, gender, size, levels of physical activity and heritability have been well described. Nevertheless, there remains considerable unexplained variation in muscle mass and strength between older adults that may reflect not only the current rate of loss but the peak attained earlier in life. To date most epidemiological studies of sarcopenia have focused on factors modifying decline in later life; however, a life course approach to understanding sarcopenia, additionally, focuses on factors operating earlier in life including developmental influences. The epidemiological evidence linking low birth weight with lower muscle mass and strength is strong and consistent with replication in a number of different groups including children, young and older adults. However, most of the evidence for the cellular, hormonal, metabolic and molecular mechanisms underlying these associations comes from animal models. The next stage is to translate the understanding of mechanisms from animal muscle to human muscle enabling progress to be made not only in earlier identification of individuals at risk of sarcopenia but also in the development of beneficial interventions across the life course.

The relationship of birthweight, muscle size at birth and post-natal growth to grip strength in 9-year-old Indian children: findings from the Mysore Parthenon study

Foetal development may permanently affect muscle function. Indian newborns have a low mean birthweight, predominantly due to low lean tissue and muscle mass. We aimed to examine the relationship of birthweight, and arm muscle area (AMA) at birth and post-natal growth to handgrip strength in Indian children. Grip strength was measured in 574 children aged 9 years, who had detailed anthropometry at birth and every 6-12 months post-natally. Mean (standard deviation (s.d.)) birthweight was 2863 (446) g. At 9 years, the children were short (mean height s.d. -0.6) and light (mean weight s.d. -1.1) compared with the World Health Organization growth reference. Mean (s.d.) grip strength was 12.7 (2.2) kg (boys) and 11.0 (2.0) kg (girls). Weight, length and AMA at birth, but not skinfold measurements at birth, were positively related to 9-year grip strength (β = 0.40 kg/s.d. increase in birthweight, P < 0.001; and β = 0.41 kg/s.d. increase in AMA, P < 0.001). Grip strength was positively related to 9-year height, body mass index and AMA and to gains in these measurements from birth to 2 years, 2-5 years and 5-9 years (P < 0.001 for all). The associations between birth size and grip strength were attenuated but remained statistically significant for AMA after adjusting for 9-year size. We conclude that larger overall size and muscle mass at birth are associated with greater muscle strength in childhood, and that this is mediated mainly through greater post-natal size. Poorer muscle development in utero is associated with reduced childhood muscle strength.

Stage of perinatal development regulates skeletal muscle mitochondrial biogenesis and myogenic regulatory factor genes with little impact of growth restriction or cross-fostering

Foetal growth restriction impairs skeletal muscle development and adult muscle mitochondrial biogenesis. We hypothesized that key genes involved in muscle development and mitochondrial biogenesis would be altered following uteroplacental insufficiency in rat pups, and improving postnatal nutrition by cross-fostering would ameliorate these deficits. Bilateral uterine vessel ligation (Restricted) or sham (Control) surgery was performed on day 18 of gestation. Males and females were investigated at day 20 of gestation (E20), 1 (PN1), 7 (PN7) and 35 (PN35) days postnatally. A separate cohort of Control and Restricted pups were cross-fostered onto a different Control or Restricted mother and examined at PN7. In both sexes, peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), cytochrome c oxidase subunits 3 and 4 (COX III and IV) and myogenic regulatory factor 4 expression increased from late gestation to postnatal life, whereas mitochondrial transcription factor A, myogenic differentiation 1 (MyoD), myogenin and insulin-like growth factor I (IGF-I) decreased. Foetal growth restriction increased MyoD mRNA in females at PN7, whereas in males IGF-I mRNA was higher at E20 and PN1. Cross-fostering Restricted pups onto a Control mother significantly increased COX III mRNA in males and COX IV mRNA in both sexes above controls with little effect on other genes. Developmental age appears to be a major factor regulating skeletal muscle mitochondrial and developmental genes, with growth restriction and cross-fostering having only subtle effects. It therefore appears that reductions in adult mitochondrial biogenesis markers likely develop after weaning.

Postnatal overfeeding promotes early onset and exaggeration of high-fat diet-induced nonalcoholic fatty liver disease through disordered hepatic lipid metabolism in rats

Exposure to overnutrition in critical or sensitive developmental periods may increase the risk of developing obesity and metabolic syndrome in adults. Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome, but the relationship among postnatal nutrition, lipid metabolism, and NAFLD progression during development remains poorly understood. Here we investigated in a rat model whether postnatal overfeeding increases susceptibility to NAFLD in response to a high-fat diet. Litters from Sprague-Dawley dams were culled to three (small litters) or ten (normal litters) pups and then weaned onto a standard or high-fat diet at postnatal day 21 to generate normal-litter, small-litter, normal-litter/high-fat, and small-litter/high-fat groups. At age 16 weeks, the small-litter and both high-fat groups showed obesity, dyslipidemia, and insulin resistance. Hepatic disorders appeared earlier in the small-litter/high-fat rats with greater liver mass gain and higher hepatic triglycerides and steatosis score versus normal-litter/high-fat rats. Hepatic acetyl-CoA carboxylase activity and mRNA expression were increased in small-litter rats and aggravated in small-litter/high-fat rats but not in normal-litter/high-fat rats. The high expression in small-litter/high-fat rats coincided with high sterol regulatory element-binding protein-1c mRNA and protein expression. However, mRNA expression of enzymes involved in hepatic fatty acid oxidation (carnitine palmitoyltransferase 1) and output (microsomal triglyceride transfer protein) was decreased under a high-fat diet regardless of litter size. In conclusion, overfeeding related to small-litter rearing during lactation contributes to the NAFLD phenotype when combined with a high-fat diet, possibly through up-regulated hepatic lipogenesis.

The Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) study

Background

Because early life growth has long-lasting metabolic and behavioral consequences, intervention during this period of developmental plasticity may alter long-term obesity risk. While modifiable factors during infancy have been identified, until recently, preventive interventions had not been tested. The Intervention Nurses Starting Infants Growing on Healthy Trajectories (INSIGHT). Study is a longitudinal, randomized, controlled trial evaluating a responsive parenting intervention designed for the primary prevention of obesity. This “parenting” intervention is being compared with a home safety control among first-born infants and their parents. INSIGHT’s central hypothesis is that responsive parenting and specifically responsive feeding promotes self-regulation and shared parent–child responsibility for feeding, reducing subsequent risk for overeating and overweight.

Methods/Design

316 first-time mothers and their full-term newborns were enrolled from one maternity ward. Two weeks following delivery, dyads were randomly assigned to the “parenting” or “safety” groups. Subsequently, research nurses conduct study visits for both groups consisting of home visits at infant age 3–4, 16, 28, and 40 weeks, followed by annual clinic-based visits at 1, 2, and 3 years. Both groups receive intervention components framed around four behavior states: Sleeping, Fussy, Alert and Calm, and Drowsy. The main study outcome is BMI z-score at age 3 years; additional outcomes include those related to patterns of infant weight gain, infant sleep hygiene and duration, maternal responsiveness and soothing strategies for infant/toddler distress and fussiness, maternal feeding style and infant dietary content and physical activity. Maternal outcomes related to weight status, diet, mental health, and parenting sense of competence are being collected. Infant temperament will be explored as a moderator of parenting effects, and blood is collected to obtain genetic predictors of weight status. Finally, second-born siblings of INSIGHT participants will be enrolled in an observation-only study to explore parenting differences between siblings, their effect on weight outcomes, and carryover effects of INSIGHT interventions to subsequent siblings.

Discussion

With increasing evidence suggesting the importance of early life experiences on long-term health trajectories, the INSIGHT trial has the ability to inform future obesity prevention efforts in clinical settings.

Trial registration

NCT01167270. Registered 21 July 2010.

Myoblasts from intrauterine growth-restricted sheep fetuses exhibit intrinsic deficiencies in proliferation that contribute to smaller semitendinosus myofibres

Intrauterine growth restriction (IUGR) reduces skeletal muscle mass in fetuses and offspring. Our objective was to determine whether myoblast dysfunction due to intrinsic cellular deficiencies or serum factors reduces myofibre hypertrophy in IUGR fetal sheep. At 134 days, IUGR fetuses weighed 67% less (P < 0.05) than controls and had smaller (P < 0.05) carcasses and semitendinosus myofibre areas. IUGR semitendinosus muscles had similar percentages of pax7-positive nuclei and pax7 mRNA but lower (P < 0.05) percentages of myogenin-positive nuclei (7 ± 2% and 13 ± 2%), less myoD and myogenin mRNA, and fewer (P < 0.05) proliferating myoblasts (PNCA-positive-pax7-positive) than controls (44 ± 2% vs. 52 ± 1%). Primary myoblasts were isolated from hindlimb muscles, and after 3 days in growth media (20% fetal bovine serum, FBS), myoblasts from IUGR fetuses had 34% fewer (P < 0.05) myoD-positive cells than controls and replicated 20% less (P < 0.05) during a 2 h BrdU pulse. IUGR myoblasts also replicated less (P < 0.05) than controls during a BrdU pulse after 3 days in media containing 10% control or IUGR fetal sheep serum (FSS). Both myoblast types replicated less (P < 0.05) with IUGR FSS-supplemented media compared to control FSS-supplemented media. In differentiation-promoting media (2% FBS), IUGR and control myoblasts had similar percentages of myogenin-positive nuclei after 5 days and formed similar-sized myotubes after 7 days. We conclude that intrinsic cellular deficiencies in IUGR myoblasts and factors in IUGR serum diminish myoblast proliferation and myofibre size in IUGR fetuses, but intrinsic myoblast deficiencies do not affect differentiation. Furthermore, the persistent reduction in IUGR myoblast replication shows adaptive deficiencies that explain poor muscle growth in IUGR newborn offspring.

Endocrine regulation of fetal skeletal muscle growth: impact on future metabolic health

Establishing sufficient skeletal muscle mass is essential for lifelong metabolic health. The intrauterine environment is a major determinant of the muscle mass that is present during the life course of an individual, because muscle fiber number is set at the time of birth. Thus, a compromised intrauterine environment from maternal nutrient restriction or placental insufficiency that restricts muscle fiber number can have permanent effects on the amount of muscle an individual will live with. Reduced muscle mass due to fewer muscle fibers persists even after compensatory or 'catch-up' postnatal growth occurs. Furthermore, muscle hypertrophy can only partially compensate for this limitation in fiber number. Compelling associations link low birth weight and decreased muscle mass to future insulin resistance, which can drive the development of the metabolic syndrome and type 2 diabetes, and the risk of cardiovascular events later in life. There are gaps in knowledge about the origins of reduced muscle growth at the cellular level and how these patterns are set during fetal development. By understanding the nutrient and endocrine regulation of fetal skeletal muscle growth and development, we can direct research efforts toward improving muscle growth early in life to prevent the development of chronic metabolic diseases later in life.

Adjustment of directly measured adipose tissue volume in infants

Background:

Direct measurement of adipose tissue (AT) using magnetic resonance imaging is increasingly used to characterise infant body composition. Optimal techniques for adjusting direct measures of infant AT remain to be determined.

Objectives:

To explore the relationships between body size and direct measures of total and regional AT, the relationship between AT depots representing the metabolic load of adiposity and to determine optimal methods of adjusting adiposity in early life.

Design:

Analysis of regional AT volume (ATV) measured using magnetic resonance imaging in longitudinal and cross-sectional studies.

Subjects:

Healthy term infants; 244 in the first month (1–31 days), 72 in early infancy (42–91 days).

Methods:

The statistical validity of commonly used indices adjusting adiposity for body size was examined. Valid indices, defined as mathematical independence of the index from its denominator, to adjust ATV for body size and metabolic load of adiposity were determined using log-log regression analysis.

Results:

Indices commonly used to adjust ATV are significantly correlated with body size. Most regional AT depots are optimally adjusted using the index ATV/(height)³ in the first month and ATV/(height)² in early infancy. Using these indices, height accounts for<2% of the variation in the index for almost all AT depots. Internal abdominal (IA) ATV was optimally adjusted for subcutaneous abdominal (SCA) ATV by calculating IA/SCA^0.6.

Conclusions:

Statistically optimal indices for adjusting directly measured ATV for body size are ATV/height³ in the neonatal period and ATV/height² in early infancy. The ratio IA/SCA ATV remains significantly correlated with SCA in both the neonatal period and early infancy; the index IA/SCA^0.6 is statistically optimal at both of these ages.

Programming effects of FTO in the development of obesity

It is becoming increasingly recognized that early-life nutritional, metabolic and environmental factors can have a long-term impact on the early onset of obesity, type 2 diabetes and cardiovascular diseases. Numerous experimental and epidemiological observations support the concept that an individual's response to their adult lifestyle and nutritional environment depends not only on their genetic susceptibility but also on their previous early-life experiences. The current research challenge is to determine the primary pathways contributing to 'non- or epi-genetic' causes of excess adult weight gain and adiposity. Evidence from the fields of genetic epidemiology, life course modelling and diet-induced foetal programming all support a role for the FTO gene in this complex biological interaction. It may provide a missing link in the developmental regulation of energy metabolism. Our review therefore considers the role of the FTO gene in the early-life determination of body weight, body composition and energy balance. We will summarize current knowledge on FTO biology combining human genetic epidemiology, molecular models and findings from animal studies. Notably, we will focus on the role of FTO in energy balance in humans, the importance of FTO polymorphisms in childhood growth and the impact of foetal nutrition. Ultimately, we propose a new hypothesis for future research designed to understand the role of FTO in setting gene expression in metabolically active tissues.

Maternal antenatal vitamin D status and offspring muscle development: findings from the Southampton Women's Survey

CONTEXT

Maternal 25-hydroxyvitamin D [25(OH)D] status in pregnancy has been associated with offspring bone development and adiposity. Vitamin D has also been implicated in postnatal muscle function, but little is known about a role for antenatal 25(OH)D exposure in programming muscle development.

OBJECTIVE

We investigated the associations between maternal plasma 25(OH)D status at 34 weeks of gestation and offspring lean mass and muscle strength at 4 years of age.

DESIGN AND SETTING

We studied a prospective UK population-based mother-offspring cohort: the Southampton Women's Survey (SWS).

PARTICIPANTS

Initially, 12,583 nonpregnant women were recruited into the SWS, of whom 3159 had singleton pregnancies; 678 mother-child pairs were included in this analysis.

MAIN OUTCOMES MEASURED

At 4 years of age, offspring assessments included hand grip strength and whole-body dual-energy x-ray absorptiometry, yielding lean mass and percent lean mass. Physical activity was assessed by 7-day accelerometry in a subset of children (n=326).

RESULTS

The maternal serum 25(OH)D concentration in pregnancy was positively associated with offspring height-adjusted hand grip strength (β=0.10 SD/SD, P=.013), which persisted after adjustment for maternal confounding factors, duration of breastfeeding, and child's physical activity at 4 years (β=0.13 SD/SD, P=.014). Maternal 25(OH)D was also positively associated with offspring percent lean mass (β=0.11 SD/SD, P=.006), but not total lean mass (β=0.06 SD/SD, P=.15). However, this association did not persist after adjustment for confounding factors (β=0.09 SD/SD, P=.11).

CONCLUSIONS

This observational study suggests that intrauterine exposure to 25(OH)D during late pregnancy might influence offspring muscle development through an effect primarily on muscle strength rather than on muscle mass.

Growth and metabolic outcome in adolescents born preterm (GROWMORE): follow-up protocol for the Newcastle Preterm Birth GRowth study (PTBGS)

Background

Preterm infants represent up to 10% of births worldwide and have an increased risk of adverse metabolic outcomes in later life. Early life exposures are key factors in determining later health but current lifestyle factors such as diet and physical activity are also extremely important and provide an opportunity for targeted intervention.

Methods/Design

This current study, GROWMORE, is the fourth phase of the Newcastle Preterm Birth Growth Study (PTBGS), which was formed from two randomised controlled trials of nutrition in early life in preterm (24–34 weeks gestation) and low birthweight infants. 247 infants were recruited prior to hospital discharge. Infant follow-up included detailed measures of growth, nutritional intake, morbidities and body composition (Dual X Ray Absorptiometry, DXA) along with demographic data until 2 years corrected age. Developmental assessment was performed at 18 months corrected age, and cognitive assessment at 9–10 years of age. Growth, body composition (DXA), blood pressure and metabolic function (insulin resistance and lipid profile) were assessed at 9–13 years of age, and samples obtained for epigenetic analysis. In GROWMORE, we will follow up a representative cohort using established techniques and novel metabolic biomarkers and correlate these with current lifestyle factors including physical activity and dietary intake. We will assess auxology, body composition (BODPOD™), insulin resistance, daily activity levels using Actigraph™ software and use ³¹P and ¹H magnetic resonance spectroscopy to assess mitochondrial function and intra-hepatic lipid content.

Discussion

The Newcastle PTBGS is a unique cohort of children born preterm in the late 1990’s. The major strengths are the high level of detail of early nutritional and growth exposures, and the comprehensive assessment over time. This study aims to examine the associations between early life exposures in preterm infants and metabolic outcomes in adolescence, which represents an area of major translational importance.

Birth weight and growth from infancy to late adolescence in relation to fat and lean mass in early old age: findings from the MRC National Survey of Health and Development

Objective:

High birth weight and greater weight gain in infancy have been associated with increased risk of obesity as assessed using body mass index, but few studies have examined associations with direct measures of fat and lean mass. This study examined associations of birth weight and weight and height gain in infancy, childhood and adolescence with fat and lean mass in early old age.

Subjects:

A total of 746 men and 812 women in England, Scotland and Wales from the MRC National Survey of Health and Development whose heights and weights had been prospectively ascertained across childhood and adolescence and who had dual energy X-ray absorptiometry measures at age 60–64 years.

Methods:

Associations of birth weight and standardised weight and height (0–2 (weight only), 2–4, 4–7, 7–11, 11–15, 15–20 years) gain velocities with outcome measures were examined.

Results:

Higher birth weight was associated with higher lean mass and lower android/gynoid ratio at age 60–64 years. For example, the mean difference in lean mass per 1 standard deviation increase in birth weight was 1.54 kg in males (95% confidence interval=1.04, 2.03) and 0.78 kg in females (0.41, 1.14). Greater weight gain in infancy was associated with higher lean mass, whereas greater gains in weight in later childhood and adolescence were associated with higher fat and lean mass, and fat/lean and android/gynoid ratios. Across growth intervals greater height gain was associated with higher lean but not fat mass, and with lower fat/lean and android/gynoid ratios.

Conclusion:

Findings suggest that growth in early life may have lasting effects on fat and lean mass. Greater weight gain before birth and in infancy may be beneficial by leading to higher lean mass, whereas greater weight gain in later childhood and adolescence may be detrimental by leading to higher fat/lean and android/gynoid ratios.

Type of milk feeding in infancy and health behaviours in adult life: findings from the Hertfordshire Cohort Study

A number of studies suggest that breast-feeding has beneficial effects on an individual's cardiovascular risk factors in adulthood, although the mechanisms involved are unknown. One possible explanation is that adults who were breastfed differ in their health behaviours. In a historical cohort, adult health behaviours were examined in relation to type of milk feeding in infancy. From 1931 to 1939, records were kept on all infants born in Hertfordshire, UK. Their type of milk feeding was summarised as breastfed only, breast and bottle-fed, or bottle-fed only. Information about adult health behaviours was collected from 3217 of these men and women when they were aged 59-73 years. Diet was assessed using an administered FFQ; the key dietary pattern was a 'prudent' pattern that described compliance with 'healthy' eating recommendations. Of the study population, 60 % of the men and women were breastfed, 31 % were breast and bottle-fed, and 9 % were bottle-fed. Type of milk feeding did not differ according to social class at birth, and was not related to social class attained in adult life. There were no differences in smoking status, alcohol intake or reported physical activity according to type of milk feeding, but there were differences in the participants' dietary patterns. In a multivariate model that included sex and infant weight gain, there were independent associations between type of feeding and prudent diet scores in adult life (P= 0.009), such that higher scores were associated with having been breastfed. These data support experimental findings which suggest that early dietary exposures can have lifelong influences on food choice.

Epilepsy, poverty and early under-nutrition in rural Ethiopia

PURPOSE

The incidence of epilepsy in Ethiopia is high compared with industrialised countries, but in most cases the cause of epilepsy is unknown. Childhood malnutrition remains widespread. We performed a case-control study to determine whether epilepsy is associated with poverty and markers of early under-nutrition.

METHODS

Patients with epilepsy (n=112), aged 18-45years, were recruited from epilepsy clinics in and around two towns in Ethiopia. Controls with a similar age and gender distribution (n=149) were recruited from patients and relatives attending general outpatient clinics. We administered a questionnaire to define the medical and social history of cases and controls, and then performed a series of anthropometric measurements. Unconditional logistic regression was used to estimate multivariate adjusted odds ratios. Multiple linear regression was used to estimate adjusted case-control differences for continuously distributed outcomes.

RESULTS

Epilepsy was associated with illiteracy/low levels of education, odds ratio=3.0 (95% confidence interval: 1.7-5.6), subsistence farming, odds ratio=2.6 (1.2-5.6) and markers of poverty including poorer access to sanitation (p=0.009), greater overcrowding (p=0.008) and fewer possessions (p<0.001). Epilepsy was also associated with the father's death during childhood, odds ratio=2.2 (1.0-4.6). Body mass index was similar in cases and controls, but patients with epilepsy were shorter and lighter with reduced sitting height (p<0.001), bitrochanteric diameter (p=0.029) and hip size (p=0.003). Patients with epilepsy also had lower mid-upper arm circumference (p=0.011) and lean body mass (p=0.037).

CONCLUSION

Epilepsy in Ethiopia is strongly associated with poor education and markers of poverty. Patients with epilepsy also had evidence of stunting and disproportionate skeletal growth, raising the possibility of a link between early under-nutrition and epilepsy.