Pubertal Development and Prepubertal Height and Weight Jointly Predict Young Adult Height and Body Mass Index in a Prospective Study in South Africa

The association between the timing, intensity and magnitude of adolescent growth and body composition in early adulthood

OBJECTIVES

There's paucity of longitudinal studies assessing the role of adolescent growth on adult body composition in developing countries. The aims of this study were to assess the association between adolescent change in height, weight and BMI and early adult height, weight, body fat and lean mass.

METHODS

Magnitude, timing and intensity of height, weight and BMI growth were modelled for participants from the Birth to Thirty (Bt30) cohort (7-23 years). Early adult height, weight, BMI and DXA-derived body composition were obtained 1881 black participants (21-24 years). Linear regression analyses were used to assess associations.

RESULTS

Adolescents with an earlier onset of puberty were heavier in childhood and had an earlier timing and faster weight gain velocity in late adolescence. The intensity of adolescent weight gain was positively associated with adult BMI and fat mass index (FMI) in females. Early timing of adolescent BMI gain was associated with increased weight and BMI in adult females and FMI in adult males. Achieving peak weight velocity around age at peak height velocity was associated with lower BMI and fat mass in both sexes.

CONCLUSION

This study confirms the adverse consequences of excessive weight gain prior to puberty, which is associated with an earlier and faster resurgence in weight gain velocity in early adulthood. Factors that contribute to an asynchronous timing of ages of peak weight and peak height velocities may accentuate the risk of adult obesity.

Sertoli cell-conditioned medium can improve blood-testis-barrier function and spermatogenesis in azoospermia mice induced by scrotal hyperthermia: An experimental study

Background

An increase in the temperature of the testis is associated with damage to the epithelium of seminiferous tubules and disruption of sperm production.

Objective

The current study aimed to investigate the effect of the Sertoli cell-conditioned medium (SCCM) on the blood-testis-barrier associated genes and spermatogenesis process following scrotal hyperthermia.

Materials and Methods

In this experimental study, 40 adult NMRI mice (8 wk, 25-30 gr) were allocated into 4 groups: I) control, II) DMEM (10 μl Dulbecco's Modified Eagle Medium), III) scrotal hyperthermia, and IV) scrotal hyperthermia+SCCM (10 μl SCCM). Hyperthermia was induced by placing the mice scrotum in water at 43 C for 20 min every other day for 10 days. Mice were treated every other day for 5 wk. Then the animals were euthanized, and the tails of epididymis were removed to analyze sperm parameters, testis were taken for stereological assessment, reactive oxygen spices and glutathione levels, and the expression of Ocln, Gja1, Cdh2, and Itgb1.

Results

The results of sperm analysis indicated that SCCM-treated mice significantly increased sperm count and motility and reduced DNA fragmentation. In addition, histological and molecular findings showed that the volume of testicular tissue, the number of germ cells, the glutathione level, and the expression of Ocln, Gja1, Cdh2, and Itgb1 genes were significantly increased in the SCCM-treated mice.

Conclusion

Findings suggest that growth factors of SCCM stimulate the proliferation and differentiation of germ cells through paracrine effects and upregulate the blood-testis-barrier-associated genes in mice subjected to scrotal hyperthermia.

Prevalence and Associated Factors of Adolescent Obesity among Rural School Adolescents in Nepal: A Cross-Sectional Study

Background

Overweight and obesity are major risk factors for chronic diseases and are the leading cause of mortality worldwide. Obesity during adolescence is strongly associated with adulthood obesity leading to increased morbidities and mortality. As a developing country undergoing rapid urbanization, Nepal is in a transitional phase where undernutrition coexists with obesity; however, there is a dearth of literature on the status of adolescent obesity in the rural section of Nepal. The aim of this study was to determine the prevalence of adolescent obesity in a rural district of Nepal and find out its associated factors.

Methods

An institution-based cross-sectional study was conducted among the adolescent students studying in classes 8, 9, and 10 in four secondary schools of Gosaikunda rural municipality of Rasuwa district, Nepal. Total enumerative sampling was used, and Global School-based Health Survey (GSHS) standard questionnaires were used in collecting the information. Height and weight measurements were taken, and the body mass index was classified according to Asia-Pacific criteria. The collected data were analyzed using "SPSS" version 22. Logistic regression analysis was used to evaluate the associated factors, and a p value of ≤0.05 was considered statistically significant.

Results

Out of 267 adolescents, 14.6% were obese and 14.6% were overweight. Of the female participants, 39.6% were either obese or overweight, while 12.6% of the male adolescents were overweight/obese. Among the total participants, 16.5% were underweight, including 14.0% females and 20.4% males. Female adolescents were about five times (AOR: 5.2, 95% CI (2.5-10.9), p < 0.01) more likely of being overweight/obese than male adolescents.

Conclusions

More than one-quarter of the adolescents were found to be obese/overweight, and the prevalence was significantly more among female adolescents. It emphasizes the necessity of school-based programs promoting a healthy lifestyle among students to maintain healthy weight status.

Growth in Infancy and Childhood and Age at Menarche in Five Low- or Middle-Income Countries: Consortium of Health Orientated Research in Transitional Societies (COHORTS)

BACKGROUND

Earlier age at menarche is associated with behavioral and noncommunicable disease risks. The influence of birth weight (BW) (intrauterine) and postnatal growth on age at menarche is not well studied in low- and middle-income countries (LMICs).

OBJECTIVE

Therefore, we investigated these associations in 5 LMIC birth cohorts.

METHODS

We analyzed data from Brazil, Guatemala, India, the Philippines, and South Africa (n = 3983). We derived stunting (< -2 SD scores) at 24 mo using the WHO child growth standards. We generated interaction terms with categorized BW and conditional weight (lighter < 0 or heavier ≥ 0), and height (shorter < 0 or taller ≥ 0) z-scores. We categorized early-, modal-, and late-onset menarche and used multilevel ordinal regression. We used multilevel linear regression on continuous age at menarche.

RESULTS

Mean age at menarche was 12.8 y (95% CI: 12.7 12.9). BW was not associated with age at menarche. Conditional height at 24 mo and mid-childhood (OR: 1.35; 95% CI: 1.27, 1.44 and 1.32; 1.25, 1.41, respectively) and conditional weight at 24 mo and mid-childhood (OR: 1.15; 1.08, 1.22 and 1.18; 1.11, 1.25, respectively) were associated with increased likelihood of early-onset menarche. Being heavier at birth and taller at 24 mo was associated with a 4-mo (95% CI: 0.8, 7.6) earlier age at menarche than being lighter at birth and shorter at 24 mo. Being heavier at birth but lighter in mid-childhood was associated with a 3-mo (95% CI: 0.8, 4.8) later age at menarche than being lighter at birth and mid-childhood. Age at menarche was 7 mo later in stunted than nonstunted girls.

CONCLUSION

Age at menarche is inversely related to relative weight gain but also to rapid linear growth among those born shorter but remained stunted, and those born taller and grew excessively. These findings do not deter the global health goal to reduce growth faltering but emphasize the potential adverse effects of an obesogenic environment on adolescent development.

Maternal body mass index in early pregnancy is associated with overweight and obesity in children up to 16 years of age

AIMS

Childhood obesity is an increasing public health problem. The aim of this study was to investigate the correlation between maternal body mass index in early pregnancy and body mass index in children up to the age of 16 years, and to estimate the prevalence of childhood overweight and obesity in a rural municipality in Sweden.

METHODS

The study population comprised 312 pregnant women who attended the antenatal clinics in Lidköping during the year 1999 and their 319 children. Data on body mass index from antenatal clinics, child health care centres and school health care were used in linear and multinomial logistic regressions adjusted for maternal age, smoking status, and parity.

RESULTS

Overweight or obesity were found in 23.0% of 16-year-olds. The correlation between maternal and child body mass index at all studied ages was positive and significant. Body mass index in 16-year-old boys showed the strongest correlation with maternal body mass index (adjusted r-square = 0.31). The adjusted relative-risk ratio for 16-year old children to be classified as obese as compared to normal weight, per 1 unit increase in maternal body mass index was 1.46 (95% confidence interval 1.29-1.65, p<0.001). Among adolescents with obesity, 37.6% had been overweight or obese at 4 years of age.

CONCLUSIONS

This study confirms the correlation between maternal and child body mass index and that obesity can be established early in childhood. Further, we showed a high prevalence of overweight and obesity in children, especially in boys, in a Swedish rural municipality. This suggests a need for early intervention in the preventive work of childhood obesity, preferably starting at the antenatal clinic and in child health care centres.

Review Nutritional interventions during adolescence and their possible effects

Nutrition is one of the most important factors affecting pubertal development. Increasing demands for energy proteins and micronutrients are necessary to cope with the rapid linear pubertal growth and development, change in body composition, and increased physical activity. Adequate nutrition is a key permissive factor for the normal timing and tempo of pubertal development. Severe primary or secondary malnutrition also can adversely delay the onset and progression of puberty. The higher incidence of anorexia nervosa and bulimia in adolescents imposes a nutritional risk on pubertal development. Here we provide an overview of nutritional requirements (macronutrients and micronutrients) necessary to cope with these changes. In addition, we discuss possible nutritional interventions trials and their effects on several aspects of growth and development in undernourished and stunted adolescents, in low- and middle-income countries (LMIC), who require nutritional rehabilitation. This mini-review sums up some important findings in this important complex that links between nutrition, nutritional interventions, and pubertal development.

Stunting in infancy, pubertal trajectories and adult body composition: the Birth to Twenty Plus cohort, South Africa

BACKGROUND/OBJECTIVES

Childhood rapid growth and earlier puberty onset have been associated with adult obesity. However, the association between childhood stunting, pubertal timing and adult obesity is unclear. We examined whether the relationship between stunting at age 2 years (y) and body composition at 23 years is mediated by adolescent body mass index, and pubertal development, using the Birth-to-Twenty Plus cohort (South Africa).

SUBJECTS/METHODS

For 1036 participants, data on anthropometrics between birth and 23 years, maternal factors, and pubertal development (Tanner scale at 9-16 years) were collected. Stunting at 2 years (height-for-age z-score < -2), 5-18 years BMI-for-age trajectories, pubertal development trajectories, and DXA-derived fat mass (FM) and fat free mass (FFM) at 23 years were determined. Data were analysed using hierarchical regressions and structural equation models.

RESULTS

Stunting was directly associated with slower pubertal development and with shorter adult stature, but was not associated with adolescent BMI trajectories, adult FM or FFM. However, stunting was indirectly associated with adult FM and FFM through the direct associations between slower pubertal development and lower FM and between shorter height and lower FFM. BMI trajectories were independently associated with FM and FFM.

CONCLUSIONS

Being stunted in this population predicted adult body composition through slower pubertal development and shorter adult stature.

The tempo of puberty and its relationship to adolescent health and well-being: A systematic review

AIM

Emerging evidence suggests that pubertal tempo, that is rate of passage through puberty, has relevance to adolescent mood and behaviour. However, its wider health and developmental significance remain unclear. This systematic review sought to clarify the relationship of pubertal tempo to indicators of health and development, and to document tempo definitions and pubertal durations reported in the literature.

METHODS

Eight electronic databases were searched from earliest record to July 2018. Study eligibility: healthy participants; age 8-21 years; ≥2 longitudinal measures of puberty; analysis of tempo against a health or developmental indicator.

RESULTS

Thirty-eight studies met eligibility, and these reported on diverse tempo definitions and seven health- and development-related domains. Data sets with varying tempo definitions converged on an association of rapid pubertal progression to: (a) higher adiposity during childhood and adolescence in both sexes; and (b) lower psychosocial well-being in adolescent males. Later thelarche unanimously predicted faster progression to menarche in females, but this compensation was largely undetected when alternate definitions of pubertal timing and/or tempo were used. Duration of puberty ranged from 2.5-4.1 years.

CONCLUSION

Pubertal tempo may be clinically relevant when considering trajectories of adiposity and psychosocial well-being among adolescents, especially males. Consensus on the definition of tempo would facilitate between-study comparisons.

Adiposity and attained height in adolescents: a longitudinal analysis from the LabMed Physical Activity Study

Background To investigate the associations between adiposity and attained height over a 2-year period in healthy adolescents. Methods One thousand and seventeen adolescents aged 12-18 years participated in this cohort study; 893 (87.8%) were reevaluated 1 year later (T2) and 734 (72.2%) subjects 2 years later (T3). Body fat and anthropometry were measured according to standardized procedures. Socioeconomic status, pubertal stage and lifestyles determinants were gathered and used as confounders. Prospective associations between adiposity and height were examined using generalized linear models. Results Greater adiposity at T1 was significantly associated with a lower attained height over time, when adjusting for confounders, which varied between 0.03 and 1 cm in T2 and 0.1 and 1 cm in T3. Conclusions Excess of adiposity in early adolescence may exert an effect on attained height in late adolescence. This study supports future lifestyles intervention studies aiming at preventing overweight and obesity and improving attained height.

Precocious Puberty and the Lin28/Let7 Pathway: The Therapeutic Effect of the Nourishing "Yin" and Purging "Fire" Traditional Chinese Medicine Mixture in a Rat Model

The present study aims to investigate the effects of the nourishing “Yin” and purging “Fire” Traditional Chinese Medicine (TCM) herb mixture on precocious puberty and TCM may act through hypothalamic Lin28/let7 pathway expression in the precocious puberty model rats. Meanwhile, to confirm the relationship between Lin28/let7 pathway and puberty by overexpression Lin28a, in the first part of this study, female rats were randomly allocated into untreated controls, the precocious puberty (PP) model group, the PP control group, and the PP + TCM group. Rats on postnatal day 5 were injected danazol to establish the PP model. From days 15 to 35, the rats in the TCM group were given the TCM twice daily. Vaginal opening, sex-related hormones, and body and reproductive organ weights were measured, and the expressions of hypothalamic Lin28a and Lin28b mRNA and let7a and let7b miRNA were detected. In addition, in the second part, the effects of overexpression of Lin28a on the vaginal opening time were evaluated. In the two parts of the study, we found that, at the onset of puberty, a decrease in ovary weight, an increase in the serum levels of luteinizing hormone and progesterone, and increased expression levels of hypothalamic Lin28b mRNA were observed in the PP + TCM group compared to the PP model group. The vaginal opening time was significantly delayed upon overexpression of Lin28a. Above all, the mechanism by which the TCM treats precocious puberty is thus likely to be associated with inhibition of the hypothalamic Lin28/let7 signaling pathway and our findings provide in-depth insight into the relationship between the overexpression of Lin28a gene in the hypothalamus and the onset of puberty.

Rural-urban variations in age at menarche, adult height, leg-length and abdominal adiposity in black South African women in transitioning South Africa

Background: The pre-pubertal socioeconomic environment may be an important determinant of age at menarche, adult height, body proportions and adiposity: traits closely linked to adolescent and adult health.

Aims: This study explored differences in age at menarche, adult height, relative leg-length and waist circumference between rural and urban black South African young adult women, who are at different stages of the nutrition and epidemiologic transitions.

Subjects and methods: We compared 18–23 year-old black South African women, 482 urban-dwelling from Soweto and 509 from the rural Mpumalanga province. Age at menarche, obstetric history and household socio-demographic and economic information were recorded using interview-administered questionnaires. Height, sitting-height, hip and waist circumference were measured using standardised techniques.

Results: Urban and rural black South African women differed in their age at menarche (at ages 12.7 and 14.5 years, respectively). In urban women, a one-year increase in age at menarche was associated with a 0.65 cm and 0.16% increase in height and relative leg-length ratio, respectively. In both settings, earlier age at menarche and shorter relative leg-length were independently associated with an increase in waist circumference.

Conclusions: In black South African women, the earlier onset of puberty, and consequently an earlier growth cessation process, may lead to central fat mass accumulation in adulthood.

Body Mass Index Categories and Attained Height in Portuguese Adults

OBJECTIVE

To analyze the associations between height and BMI categories in a Portuguese representative sample.

METHODS

This is a cross-sectional study with a representative sample of 32,644 Portuguese adults (52.4% females). Sociodemographic and lifestyle characteristics were obtained along with self-reported height and weight. We performed generalized linear models to assess the differences in attained height across BMI categories; analyses were adjusted for age, gender, education, family income per month, proxy reporting information, dietary patterns, and smoking.

RESULTS

BMI categories included underweight and normal weight (46.4%), overweight (37.6%), obese class I and II (15.2%), and obese class III (0.8%). Adults with normal weight had a significantly higher height (females +7 cm and males +5 cm) when compared to obese class III. As BMI categories increased, height decreased. In females and males, after adjusting for confounders, estimates of attained height decreased when compared to the unadjusted model (β = -0.049, 95% CI = -0.050; -0.049 and β = -0.030, 95% CI = -0.031; -0.029, respectively), although they remained still significant.

CONCLUSION

Our results suggest a significant difference in attained height between BMI categories. Future intervention programs aiming at preventing overweight and obesity should monitor sociodemographic, health and environmental conditions that affect attained height potential.

Disparities in children's vocabulary and height in relation to household wealth and parental schooling: A longitudinal study in four low- and middle-income countries

Children from low socio-economic status (SES) households often demonstrate worse growth and developmental outcomes than wealthier children, in part because poor children face a broader range of risk factors. It is difficult to characterize the trajectories of SES disparities in low- and middle-income countries because longitudinal data are infrequently available. We analyze measures of children's linear growth (height) at ages 1, 5, 8 and 12y and receptive language (Peabody Picture Vocabulary Test) at ages 5, 8 and 12y in Ethiopia, India, Peru and Vietnam in relation to household SES, measured by parental schooling or household assets. We calculate children's percentile ranks within the distributions of height-for-age z-scores and of age- and language-standardized receptive vocabulary scores. We find that children in the top quartile of household SES are taller and have better language performance than children in the bottom quartile; differences in vocabulary scores between children with high and low SES are larger than differences in the height measure. For height, disparities in SES are present by age 1y and persist as children age. For vocabulary, SES disparities also emerge early in life, but patterns are not consistent across age; for example, SES disparities are constant over time in India, widen between 5 and 12y in Ethiopia, and narrow in this age range in Vietnam and Peru. Household characteristics (such as mother's height, age, and ethnicity), and community fixed effects explain most of the disparities in height and around half of the disparities in vocabulary. We also find evidence that SES disparities in height and language development may not be fixed over time, suggesting opportunities for policy and programs to address these gaps early in life.

Understanding the Relationship between Socio-Economic Status, Physical Activity and Sedentary Behaviour, and Adiposity in Young Adult South African Women Using Structural Equation Modelling

Socio-economic status (SES) is an important predictor of obesity, but how it is associated with differences in physical activity and sedentary behaviour is less clear. This cross-sectional study examined the association between SES (sum of household assets), physical activity and sedentary time, and how they predict adiposity. Socio-demographic, anthropometric, and physical activity data on rural (n = 509) and urban (n = 510) South African women (18–23 years) were collected. Overweight and obesity prevalence, and sedentary time, were higher; and moderate-vigorous intensity physical activity (MVPA) was lower, in the urban sample. Structural equation models (SEMs) were constructed for BMI and waist circumference. In the urban sample SES had a direct inverse effect on MVPA (ß; 95% CI, −41.69; −73.40 to −9.98), while in the rural sample SES had a direct effect on BMI (ß; 95% CI, 0.306; 0.03 to 0.59). In the pooled sample, SES had a direct inverse effect on MVPA (ß; 95% CI, −144; −170.34 to −119.04), and MVPA was directly associated with BMI (ß; 95% CI, 0.04; 0.01 to 0.08). The influence of SES, and the role of physical activity and sedentary time on adiposity differs between the urban and rural samples, and the importance of other environmental and behavioural factors must be considered in the development of obesity and the design of effective interventions.

Birth weight and prepubertal body size predict menarcheal age in India, Peru, and Vietnam

Evidence on the associations of birth weight and prepubertal nutritional status with menarcheal age for low- and middle-income countries is limited. We investigated these relationships using the Young Lives younger cohort for 2001 Indian, Peruvian, and Vietnamese girls born in 2001-2002. Girls were followed at approximately ages 1, 5, 8, and 12 years. Weibull survival models estimated hazards of earlier menarche on the basis of birth weight Z-scores (BWZ), and age-8 BMI-for-age Z-scores (BMIZ) and height-for-age Z-scores (HAZ). Estimates controlled for potential individual-, mother-, and household-level confounders and for changes in anthropometry between 1 and 8 years. In adjusted models, BWZ predicted later age at menarche (hazard ratio (HR) = 0.90, 95% CI: 0.83-0.97). Conversely, HAZ (HR = 1.66, 95% CI 1.5-1.83) and BMIZ at 8 years (HR = 1.28, 95% CI: 1.18-1.38) predicted earlier menarche. Changes in HAZ and BMIZ between 1 and 8 years were not associated with earlier menarche. Associations were consistent across countries, though with variation in estimated magnitudes. Maternal height and age were associated with later menarche. This evidence points to consistently robust and opposite associations of birth weight versus prepubertal attained height and body mass index with menarcheal age in three diverse settings with regard to nutrition, ethnicity, and socioeconomic status.

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.