Growth retardation at early life and metabolic adaptation among North Korean children

Trends and patterns of North Korea’s disease burden from 1990 to 2019: Results from Global Burden of Disease study 2019

Background

Evidence for the trends and patterns of disease burden in North Korea is limited, and in-depth analysis based on several health outcomes for a better understanding remains challenging. Therefore, we aimed to investigate the trends and patterns of disease burden in North Korea between 1990 and 2019.

Methods

We used data from the Global Burden of Diseases (GBD) 2019 study to analyze the North Korean disease burden in comparison with four groups: global, South Korea, low-sociodemographic index (SDI) countries, Central and Eastern Europe, and Central Asia (former socialist countries). We also examined changes in the disease burden between 1990 and 2019 by disease category and age group.

Findings

In 2019, in North Korea, death rates and disability-adjusted life years (DALYs) rates were reduced by 22.2% and 30.7%, respectively, compared to 1990. The rates showed similar trends and patterns to that in former socialist countries. However, these reductions were lower than those of the global rates and rates in low-SDI countries and South Korea. Death rates and DALY rates for under five years dramatically decreased by more than 78%, similar to the trend in South Korea. In contrast, the decline in the death rates and DALY rates of adults was less than those worldwide and in low-SDI countries and South Korea. The burden of diseases among those aged ≥30 years increased largely due to the persistently high burden of non-communicable diseases (NCDs). Cardiovascular diseases, neoplasms, and chronic respiratory diseases were the leading causes of the disease burden in both 1990 and 2019.

Interpretation

North Korea’s disease burden patterns and trends show clear improvements over the past 30 years but suggest that the current challenges of NCDs in the country are very serious. NCDs should be no longer neglected and should be prioritized in public health agendas in North Korea.

A growth area: A review of the value of clinical studies of child growth for palaeopathology

Studies of living children demonstrate that early life stress impacts linear growth outcomes. Stresses affecting linear growth may also impact later life health outcomes, including increased cardiometabolic disease risk. Palaeopathologists also assess the growth of children recovered from bioarchaeological contexts. Early life stresses are inferred to affect linear growth outcomes, and measurements of skeletal linear dimensions alongside other bioarchaeological information may indicate the types of challenges faced by past groups. In clinical settings, the impacts of stress on growing children are typically measured by examining height. Palaeopathologists are limited to examining bone dimensions directly and must grapple with incomplete pictures of childhood experiences that may affect growth. Palaeopathologists may use clinical growth studies to inform observations among past children; however, there may be issues with this approach. Here, we review the relationship between contemporary and palaeopathological studies of child and adolescent growth. We identify approaches to help bridge the gap between palaeopathological and biomedical growth studies. We advocate for: the creation of bone-specific growth reference information using medical imaging and greater examination of limb proportions; the inclusion of children from different global regions and life circumstances in contemporary bone growth studies; and greater collaboration and dialogue between palaeopathologists and clinicians as new studies are designed to assess linear growth past and present. We advocate for building stronger bridges between these fields to improve interpretations of growth patterns across human history and to potentially improve interventions for children living and growing today.

Developmental origins of metabolic diseases

Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the "double burden of malnutrition," where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases.

Body composition of children with moderate and severe undernutrition and after treatment: a narrative review

BACKGROUND

Until recently, undernourished children were usually assessed using simple anthropometric measurements, which provide global assessments of nutritional status. There is increasing interest in obtaining more direct data on body composition to assess the effects of undernutrition on fat-free mass (FFM) and its constituents, such as muscle and organs, and on fat mass (FM) and its regional distribution.

MAIN TEXT

Recent studies show that severe-acute undernutrition, categorised as 'wasting', is associated with major deficits in both FFM and FM that may persist in the long-term. Fat distribution appears more central, but this is more associated with the loss of peripheral fat than with the elevation of central fat. Chronic undernutrition, categorised as 'stunting', is associated with deficits in FFM and in specific components, such as organ size. However, the magnitude of these deficits is reduced, or - in some cases - disappears, after adjustment for height. This suggests that FFM is largely reduced in proportion to linear growth. Stunted children vary in their FM - in some cases remaining thin throughout childhood, but in other cases developing higher levels of FM. The causes of this heterogeneity remain unclear. Several different pathways may underlie longitudinal associations between early stunting and later body composition. Importantly, recent studies suggest that short children are not at risk of excess fat deposition in the short term when given nutritional supplementation.

CONCLUSION

The short- and long-term functional significance of FFM and FM for survival, physical capacity and non-communicable disease risk means that both tissues merit further attention in research on child undernutrition.

Height Trajectory During Early Childhood Is Inversely Associated with Fat Mass in Later Childhood in Mexican Boys

BACKGROUND

Childhood obesity continues to be a global health problem. Previous research suggests that linear growth retardation or stunting during early childhood increases the risk of obesity, but others have reported that rapid linear growth poses a greater concern than early nutritional status.

OBJECTIVE

The objective of this study was to determine if growth trajectories are associated with body composition at age 8-10 y.

METHODS

Study participants consisted of 255 girls and 281 boys who participated in a follow-up of the Prenatal Omega-3 Fatty Acid Supplementation and Child Growth and Development (POSGRAD) Study. Sex-specific latent height class (LHC) trajectories were derived from 11 measures of height from birth to 5 y of age and used to calculate 3 distinct growth classes for boys (low, intermediate, and high) and 2 distinct classes for girls (low and high). Body composition at age 8-10 y was estimated using bioelectrical impedance analysis. Multivariable linear regression analysis was used to determine the relationship between growth trajectory classes and fat mass (FM) and fat-free mass (FFM) in late childhood, controlling for confounding factors.

RESULTS

In girls, there were no significant associations between LHC and FM or FFM. In boys, relative to the intermediate LHC, the low LHC had higher FM (β = 0.69 kg; 95% CI: 0.26-1.11 kg) and the high LHC had lower FM (β = -0.40 kg; 95% CI: -0.76 to -0.05 kg). Boys in the low LHC had significantly less FFM (β = -0.69 kg; 95% CI: -1.11 to -0.26 kg), and boys in the high LHC had more FFM (β = 0.40 kg; 95% CI: 0.05-0.76 kg) compared with the intermediate LHC.

CONCLUSION

Gain in height among boys, but not girls, in early childhood was associated with lower adiposity in late childhood compared with children with a slower rate of growth. Clinical trial registration number: NCT00646360.

The Effect of Body Mass Index on Acute Cardiometabolic Responses to Graded Exercise Testing in Children: A Narrative Review

Although the beneficial role of exercise for health is widely recognized, it is not clear to what extent the acute physiological responses (e.g., heart rate (HR) and oxygen uptake (VO₂)) to a graded exercise test are influenced by nutritional status (i.e., overweight vs. normal-weight). Therefore, the main objectives of the present narrative review were to examine the effect of nutritional status on acute HR, and VO₂ responses of children to exercise testing. For this purpose, we examined existing literature using PubMed, ISI, Scopus, and Google Scholar search engines. Compared with their normal-body mass index (BMI) peers, a trend of higher HRrest, higher HR during submaximal exercise testing, and lower HRmax was observed among overweight and obese children (according to BMI). Independent from exercise mode (walking, running, cycling, or stepping), exercise testing was metabolically more demanding (i.e., higher VO₂) for obese and overweight children than for their normal-weight peers. Considering these cardiometabolic differences according to BMI in children might help exercise specialists to evaluate the outcome of a graded exercise test (GXT) (e.g., VO2max, HRmax) and to prescribe optimal exercise intensity in the context of development of exercise programs for the management of body mass.

Developmental origins of health and disease: current knowledge and potential mechanisms

Epidemiologic and clinical research has provided a large body of evidence supporting the developmental origins of health and disease (DOHaD), but there has been a relative dearth of mechanistic studies in humans due to the complexity of working with large, longitudinal cohorts. Nonetheless, animal models of undernutrition have provided substantial evidence for the potential epigenetic, metabolic, and endocrine mechanisms behind DOHaD. Furthermore, recent research has explored the interaction between the environment and the gastrointestinal system by investigating how the gut microbial ecology may impact the capacity for nutrient processing and absorption in a manner that may limit growth. This review presents a summary of current research that supports the concept of DOHaD, as well as potential mechanisms and interactions that explain how nutrition in utero and during early childhood influences lifelong health.

Evaluation of nutritional care of hospitalized children in a tertiary pediatric hospital

BACKGROUND AND AIMS

Hospitalized children are at risk of malnutrition. The aim of the present study was to evaluate a clinical practice in a tertiary hospital. The nutritional team developed a specific software for screening of malnutrition and risk of malnutrition (Evalnut) that provides also recommendations for the nutritional management of the patient. The data recorded into this program and the tool itself were analyzed and optimizations are highlighted.

METHODS

A retrospective study analyzed the data collected in 2015 during 4931 consecutive hospitalizations (3984 children) at the University Children's Hospital Queen Fabiola. Pivot tables analysis (Excel) of the database of the screening tool was compared with the clinical practice of the dietitians. First data processing excluded records with abnormal or missing values. Impact of nutritional care analysis needs at least 2 evaluations and a positive patient's height trend. In case of height equality, only length of hospital stays less than 2 weeks were kept.

RESULTS

This study highlighted inaccurate database records related to imperfections of the computer program, missing or erroneous measures and incomplete encoding. First analysis on 3219 valid hospitalizations showed statistical correlations. Prevalence of malnutrition on admission was 33%, split into 14,5% acute malnutrition, 15% chronic malnutrition and 3,5% mixed malnutrition. Overall, 30,3% of the children were categorized at risk of developing malnutrition during their stay. Positive impact of nutritional management on the resulting nutritional status was demonstrated on the second data selection (352 hospitalizations): WFH median (interquartile range) increased from 96,1% (87,1-106,4) on admission to 96,9% (89,1-106,1) (p < 0,01) on discharge. An optimization of the existing software was finally proposed.

CONCLUSION

In our hospital, the dietitians are the most aware on the importance of nutritional assessment and management during hospitalization. Encouraging results are obtained. Inclusion of a nutritional program in the medical file is useful to raise interest amongst caregivers and is particularly valuable for the nutritional follow up of the patients by the nutrition team.

North Korean children: nutrition and growth

North Korea suffered from severe famine in the mid-1990s; this impacted many areas, including people's transnational movement, child growth, and mortality. This review carefully examined nutritional status trends of children in North Korea using published reports from national nutrition assessment surveys. Nutritional adaptation of North Korean child refugees living in South Korea was also studied with their growth and food consumption, using published researches. The nutritional status of children in North Korea has recovered to a "low" level acute malnutrition status and a "medium" level chronic malnutrition status. Large disparities by geographic region still remain. North Korean child refugees in South Korea were significantly shorter and lighter than their age- and sex-matched South Korean counterparts (P<0.05); however, North Korean child refugees were catching up, and weight was improving faster than height. Linear growth retarded (height for age Z-score < -1) North Korean children showed a significantly higher respiratory quotient than nonlinear growth retarded children, indicating metabolic adaptation responding to the food shortage. These changes, accompanied by abundant access to food in South Korea, have led to the elimination of significant differences in the obesity ratio between North Korean and South Korean children living in South Korea after approximately 2 years of residency. This nutritional adaptation may not be beneficial to North Korean child refugees, especially given the prediction of Barker's theory. The lack of studies prevented a better understanding of this issue; therefore, large cohort studies, preferably with random sampling strategies, are needed to further understand this issue and to design appropriate interventions.

Microbiome, growth retardation and metabolism: are they related?

CONTEXT

Despite an improvement in food security and the delivery of nutritional supplements to children living in impoverished parts of the world, poor growth is still highly prevalent. Given that the microbiome is related to both nutrient absorption, as well as overweight/obesity, it may play a central role in limiting or modifying normal growth processes while contributing to chronic disease risks.

OBJECTIVE

The objective of this paper is to describe normal growth processes, the role of the microbiome in supporting or disrupting normal growth processes, and its potential impact on long-term health.

METHODS

A literature search of relevant human and laboratory research on growth, microbiome and the relationship between poor growth and chronic diseases was conducted. This review focuses on potential mechanisms that implicate the microbiome as a mediator of poor growth and later metabolic outcomes. In this relationship, attention was given to the potential for gastrointestinal infections to disrupt the microbiome.

RESULTS

Based on the studies reviewed, it is clear that exposure to infections disturbs both intestinal functioning as well as normal growth and changes in the microbiome may influence micronutrient availability and metabolic processes.

CONCLUSIONS

The microbiome may play a significant role in limiting human growth, but little is known about changes in the microbiome during periods of undernutrition. Thus, it is of great scientific and public health importance to improve the understanding of how the microbiome changes during nutrient deprivation. To best address the issue of the double burden and poor growth in low-income countries, research is warranted to advance the knowledge of the long-term role of the microbiome in the health of children exposed to undernutrition.

Stunting in Infancy Is Associated with Decreased Risk of High Body Mass Index for Age at 8 and 12 Years of Age

BACKGROUND

Effects of early-life stunting on adiposity development later in childhood are not well understood, specifically with respect to age in the onset of overweight and obesity.

OBJECTIVES

We analyzed associations of infant stunting with prevalence of, incidence of, and reversion from high body mass index-for-age z score (BMIZ) later in life. We then estimated whether associations of infant stunting with BMIZ varied by sex, indigenous status, and rural or urban residence.

METHODS

Data were collected from 1942 Peruvian children in the Young Lives cohort study at ages 1, 5, 8, and 12 y. Multivariable generalized linear models estimated associations of stunting (height-for-age z score <-2) at age 1 y with risk of BMIZ > 1 and BMIZ > 2 prevalence, incidence (moving above a BMIZ threshold between ages), and reversion (moving below a BMIZ threshold between ages) at later ages.

RESULTS

After adjustment for covariates, stunting at age 1 y was associated with a lower prevalence of BMIZ > 1 at age 8 y (RR: 0.81; 95% CI: 0.66, 1.00; P = 0.049) and 12 y (RR: 0.75; 95% CI: 0.61, 0.91; P = 0.004), as well as a lower prevalence of BMIZ > 2 at age 8 y. Stunting was not associated with incident risk of BMIZ > 1 or BMIZ > 2. Stunting was positively associated at age 5 y with risk of reversion from BMIZ > 1 (RR: 1.22; 95% CI: 1.05, 1.42; P = 0.008) and BMIZ > 2. We found evidence that the association of stunting with prevalent and incident BMIZ > 1 was stronger for urban children at ages 5 and 8 y, and for nonindigenous children at age 8 y.

CONCLUSIONS

Stunting predicted a lower risk of prevalent BMIZ > 1 and BMIZ > 2, even after controlling for potential confounders. This finding may be driven in part by a higher risk of reversion from BMIZ > 1 by age 5 y. Our results contribute to an understanding of how nutritional stunting in infancy is associated with BMIZ later in life.