Early and late weight gain and the timing of puberty

Birth and early life influences on the timing of puberty onset: results from the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study

BACKGROUND

Early age at puberty onset may predispose an individual to many currently prevalent diseases, including cancer and adiposity.

OBJECTIVE

The objective was to investigate whether early life exposures influence the timing of puberty, as defined by both early and late markers, in healthy German girls and boys.

DESIGN

Term participants (n = 215; 49.8% female) of the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study, with sufficient repeated anthropometric measurements between 6 and 13 y to allow estimation of age at take-off of the pubertal growth spurt (ATO) and information on a variety of early life exposures, including birth weight, breastfeeding status, velocity of weight gain, and parental characteristics, were studied. Age at peak height velocity (APHV) and menarche were also considered.

RESULTS

Children who weighed between 2500 and <3000 g at birth were approximately 7 mo younger at ATO than were the other children (beta +/- SE: -0.56 +/- 0.20 y; P = 0.006). Children who had gained weight rapidly between birth and 24 mo (increase in weight SD score >0.67) experienced ATO 4 mo earlier than those who had gained weight normally (-0.34 +/- 0.15 y; P = 0.02). Rapid weight gain was also associated with an earlier APHV (P = 0.0006) and, in girls, with an earlier menarche (P = 0.002). Adjustment for body mass index SD score or body fat percentage 1, 2, or 3 y before ATO did not account for these effects.

CONCLUSION

In both boys and girls, intrauterine and early postnatal growth factors appear to influence both early and later markers of puberty onset independently of prepubertal body composition.

Rapid infant weight gain and advanced skeletal maturation in childhood

OBJECTIVE

To test the hypothesis that rapid infant weight gain is associated with advanced skeletal maturity in children from the United States and South Africa.

STUDY DESIGN

Longitudinal data from 467 appropriate-for-gestational-age infants in the Fels Longitudinal Growth Study (Dayton, Ohio) and 196 appropriate-for-gestational-age infants in the Birth to Twenty birth cohort study (Johannesburg, South Africa) were used. Multiple linear regression models tested the association between internal SD score change in weight from 0 to 2 years and relative skeletal age at 9 years, adjusting for body mass index, stature, and other covariates.

RESULTS

In both studies, faster infant weight gain was associated with more advanced skeletal maturity (approximately 0.2 years or 2.4 months per SD score) at age 9 years (P <.0001-.005), even when adjusting for the positive associations of both birth weight and body mass index at age 9 years. This effect appeared to be accounted for by the greater childhood stature of subjects with more rapid infant weight gain.

CONCLUSIONS

Relatively rapid infant weight-gain is associated with advanced skeletal development in late childhood, perhaps via effects on stature.

Early nutrition and long-term health: a practical approach

Nutrition in early life, a critical period for human development, can have long-term effects on health in adulthood. Supporting evidence comes from epidemiological studies, animal models and experimental interventions in human subjects. The mechanism is proposed to operate through nutritional influences on growth. Substantial evidence now supports the hypothesis that 'accelerated' or too fast infant growth increases the propensity to the major components of the metabolic syndrome (glucose intolerance, obesity, raised blood pressure and dyslipidaemia), the clustering of risk factors that predispose to cardiovascular morbidity and mortality. The association between infant growth and these risk factors is strong, consistent, shows a dose-response effect and is biologically plausible. Moreover, experimental data from prospective randomised controlled trials strongly support a causal link between infant growth and later risk factors for atherosclerosis. Evidence that infant growth affects the development of atherosclerosis therefore suggests that the primary prevention of CVD should begin from as early as the first few months of life. The present review considers this evidence, the underlying mechanisms involved and its implications for public health.

Onset of breast and pubic hair development and menses in urban chinese girls

OBJECTIVES

To determine the current prevalence and mean ages of onset of pubertal characteristics in healthy urban Chinese girls.

METHODS

A cross-sectional study of sexual maturation of healthy Chinese girls was conducted in 9 representative cities of the eastern, western, southern, and northern parts and central region of China between 2003 and 2005. At examination, stages of breast and pubic hair development were rated on girls 3 through 19.83 years of age, and height and weight were also recorded. Data on menses were collected by the status quo method. Probit analysis was used to calculate the median age and 95% confidence interval (CI) for onset of breast and pubic hair development and menarche.

RESULTS

Data were analyzed for 20654 apparently healthy girls. At age 8 years, 19.57% of these girls had evidence of breast development. The median ages of onset of Tanner stages 2 and 3 for breast development were 9.20 (95% CI: 9.06-9.32) years and 10.37 (95% CI: 10.28-10.45) years, respectively. The median ages of onset of Tanner stages 2 and 3 for pubic hair development were 11.16 (95% CI: 11.03-11.29) years and 12.40 (95% CI: 12.25-12.55) years, respectively. Menses occurred at 12.27 years (95% CI: 12.16-12.39).

CONCLUSIONS

These data suggest that urban Chinese girls are actually experiencing earlier breast development than currently used norms. The up-to-date reference for normal pubertal development in urban Chinese girls needs to be established for the purpose of determining precocious puberty or pubertal delay.

Childhood obesity and the timing of puberty

The potential relationship between childhood obesity and earlier puberty onset has major public health implications. Earlier menarche in girls is associated with increased risk of adult obesity, type 2 diabetes and breast cancer. Current methods for assessing puberty are unreliable, with a lack of consensus regarding the impact of childhood obesity on breast development and/or age of menarche. Effects of obesity on early puberty in boys are more contentious, necessitating development of robust biomarkers. The possibility of the obesity epidemic lowering the age of puberty onset fuels concerns over the growing mismatch in age of sexual and social maturity. Here, we describe the biological basis linking childhood obesity to early puberty and consider evidence for a trend towards its earlier onset.

Birth weight, postnatal growth, and age at menarche

Larger body size in childhood is correlated with earlier age at menarche; whether birth and infant body size changes are also associated with age at menarche is less clear. The authors contacted female participants enrolled in the New York site of the US National Collaborative Perinatal Project born between 1959 and 1963 (n = 262). This racially and ethnically diverse cohort (38% white, 40% African American, and 22% Puerto Rican) was used to investigate whether maternal (body size, pregnancy weight gain, age at menarche, smoking) and birth (birth weight, birth length, placental weight) variables and early infant body size changes were associated with age at menarche even after considering later childhood body size. Higher percentile change in weight from ages 4 months to 1 year was associated with earlier age at menarche even after adjustment for later childhood growth (beta = -0.15, 95% confidence interval: -0.27, -0.02 years per 10-percentile change in weight from ages 4 months to 1 year). The association was in the same direction for all 3 racial/ethnic groups but was largest for the white group. These New York Women's Birth Cohort Adult Follow-up data (2001-2006) suggest that infant weight gain, in addition to childhood weight gain, may be associated with earlier age at menarche.

Changes in satiety hormones and expression of genes involved in glucose and lipid metabolism in rats weaned onto diets high in fibre or protein reflect susceptibility to increased fat mass in adulthood

Risk of developing obesity and diabetes may be influenced by the nutritional environment early in life. We examined the effects of high fibre or protein diets on satiety hormones and genes involved in glucose and lipid metabolism during postnatal development and on adult fat mass. At 21 days of age, Wistar rat pups were weaned onto control (C), high fibre (HF) or high protein (HP) diet. Tissue and blood were collected at 7, 14, 21, 28 and 35 days after birth. A second group of rats consumed the weaning diets until 4 months when they were switched to a high fat-high sugar diet for 6 weeks, after which body and fat mass and plasma glucose were determined. In young rats, HF diet increased plasma glucagon-like peptide (GLP-1) compared to C and HP and decreased leptin compared to C at postnatal days 28 and 35. Hepatic fatty acid synthase mRNA was down-regulated by HF and HP compared to C at days 28 and 35. In brown adipose tissue, HF increased uncoupling protein-3 mRNA whereas HP increased mRNA of the inflammatory cytokine interleukin-6. Body weight, fat mass and glycaemia in adult males and fat mass in females were greater after the high fat challenge in rats that consumed the HP diet from weaning. Increasing fibre or protein in postnatal diets causes rapid change in satiety hormone secretion and genes involved in glucose and lipid metabolism which appear to influence fat mass and glycaemia in adulthood, high protein being associated with increased susceptibility to obesity.

Association of prepubertal body composition in healthy girls and boys with the timing of early and late pubertal markers

BACKGROUND

It is controversial whether prepubertal body composition is implicated in the timing of puberty onset.

OBJECTIVE

The objective was to investigate whether body composition in the 2 y preceding the start of the pubertal growth spurt -- a marker of puberty onset -- is associated with the attainment of early and late pubertal markers in healthy German boys and girls.

DESIGN

Multivariate-adjusted regression analyses were performed in 215 participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study for whom body mass index (BMI) and its components fat mass/height(2) (FM/m(2)) and fat-free mass/height(2) (FFM/m(2)) 1 and 2 y before the onset of the pubertal growth spurt (age at takeoff; ATO) and information on early life exposures were available. In addition, age at peak height velocity (APHV) and menarche were examined.

RESULTS

Higher BMIs and FM/m(2) z scores 1 and 2 y before ATO showed modest associations with chronological age at ATO among girls only (girls: P for = trend 0.05-0.1, adjusted for early life factors; boys: P = 0.2-0.6). FFM/m(2) z scores were not related to age at ATO (P for trend = 0.5-0.8). Conversely, prepubertal BMI and FM/m(2) more clearly predicted APHV and puberty duration (APHV minus ATO) in both sexes and age at menarche in girls (girls: adjusted P for trend <0.0001-0.03; boys: P = 0.01-0.046).

CONCLUSION

This longitudinal study suggests that prepubertal body composition in healthy boys and girls may not be critical for the initiation of the pubertal growth spurt but instead affects the progression of pubertal development, which results in earlier attainment of later pubertal stages.

Age at menarche in the Canadian population: secular trends and relationship to adulthood BMI

PURPOSE

Studies from around the world indicate a trend toward younger ages of menarche. The extent of this trend in the Canadian population is unknown, and the relationship to later-life health indicators has not yet been fully elucidated. The objective of this study is to estimate the trend in age at menarche (AAM) in the Canadian population and evaluate the relationship between AAM and adult body mass index (BMI).

METHODS

Our data source was a nationally representative survey (the Canadian Community Health Survey, 2.2), and analyses included 8080 women, aged 15 and older, who self-reported AAM. Height and weight were measured by the interviewers for the calculation of current BMI. We modeled the secular trend in AAM over time, and the relationship between current BMI and AAM.

RESULTS

We found a statistically significant decline in AAM in successive age cohorts, indicating a 0.73-year (8.8-month) decrease in AAM between the oldest and youngest age cohorts in the sample. A 1-year increase in AAM was associated with a decrease in mean BMI of approximately 0.5 kg/m(2), after adjustment for covariates. A current age-AAM interaction term was nonsignificant, indicating that the relationship was stable throughout increasing temporal separation from puberty.

CONCLUSION

The observed trend toward earlier menarche could be an indicator of a change in insulin-related metabolism, possibly mediated by behavioral and environmental variables. This study suggests that AAM may be an important clinical and public health indicator of susceptibility to overweight and obesity and attendant morbidity.

Taller stature after postnatal rapid weight gain in early infancy predicts overweight status at age 3

AIM

To evaluate whether postnatal rapid weight gain in early infancy is associated with subsequent tall stature and being overweight at age 3, and taller stature after postnatal rapid weight gain predicts overweight status at age 3.

METHODS

Data from a retrospective cohort study (time period 2003-2004, total number = 1353 subjects in Kumamoto, Japan) were used. The rate of weight gain during the first 3-4 months was calculated as 100 g/month, and postnatal rapid and slow growth were calculated by using weight standard deviation (SD). Overweight status at 3 years of age was determined according to the definition of the International Obesity Task Force.

RESULTS

In total, 4.7% of subjects were overweight at age 3. Postnatal rapid weight gain, associated with height increases until age 3 (p < 0.0001), and the rate of weight gain were significant risk factors for being overweight in children at age 3. Taller heights at 6-9 months and 17-20 months of age following postnatal rapid weight gain were associated with overweight status at age 3 (p < 0.05).

CONCLUSION

Taller stature following postnatal rapid weight gain in early infancy predicts overweight status at age 3; additionally, rapid infancy weight gain contributes to the acceleration of statural growth in overweight children.

Adolescent obesity and puberty: the "perfect storm"

Obesity is the most serious long-term health risk currently facing America's adolescents. Weight gain during adolescence carries a higher risk for adult obesity and the metabolic syndrome. This review highlights early adolescence as a particularly high-risk time for weight gain due to the synergy of naturally occurring metabolic changes along with increasing behavioral risk factors. One of the first potential health effects of abnormal weight gain during this period is earlier puberty, usually manifested as thelarche. The obesity epidemic is clearly implicated in the national trend toward earlier thelarche, although the data are not as strong in relation to menarche. Leptin activation of the hypothalamic-pituitary axis, combined with insulin resistance, and increased adiposity may result in the higher estrogen levels that are linked to breast development. Young adolescents also experience a sharp decline in their level of physical activity, worsening nutritional habits, and other important psychosocial and developmental risk factors that may contribute to obesity and estrogen-dependent disease in later life, including polycystic ovary syndrome and breast cancer. Unfortunately, the very psychosocial factors that contribute to abnormal weight gain during early adolescence make prevention and treatment in this population particularly challenging. Therefore, intervening prior to pubertal onset becomes even more important given the risk factors present once puberty begins.

Endocrine disruptors and abnormalities of pubertal development

Onset and development of puberty is regulated by the neuroendocrine system. Population-based studies worldwide have observed secular trends towards earlier puberty development. These changes are apparently caused by environmental factors such as improved socio-economic status, improved health care and nutrition. However, they may also partly result from endocrine-disrupting chemicals in the environment. Epidemiological studies have investigated the relationship between pubertal development and exposure to endocrine-disrupting chemicals (polychlorinated biphenyls, polybrominated biphenyls, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, phthalate esters, furans and the pesticide endosulfan). Associations with both perinatal and postnatal exposure have been reported. Studies in experimental animals support some of these findings and point to differential endocrine regulatory mechanisms linked to pubertal development acting in the perinatal and the pre-pubertal period. Pubertal development is naturally associated with growth and body composition. There is increasing evidence for a link between prenatal development and pubertal onset. In girls born small for gestational age (SGA), pubertal onset and age at menarche often are advanced, especially if there has been an extensive catch-up growth during the first months of life. In utero growth retardation may have multiple causes including exposure to xenobiotic substances as was suggested for some endocrine-disrupting chemicals. An abnormal perinatal environment of children born SGA may alter the endocrine status and the sensitivity of the receptors for endocrine and metabolic signalling that may have effects on maturation of brain and gonads. However, the causal pathways and the molecular mechanisms that may link the pubertal growth pattern of children born SGA, pubertal development and endocrine-disrupting chemicals need further study.

Impaired endothelial and smooth muscle functions and arterial stiffness appear before puberty in obese children and are associated with elevated ambulatory blood pressure

AIMS

To determine whether impaired brachial endothelial (flow-mediated dilation, FMD) and smooth muscle function (nitroglycerin-mediated dilation, NTGMD), and remodelling of the common carotid artery (CCA) develop before puberty in obese children.

METHODS AND RESULTS

Arterial intima-media thickness (IMT), FMD and NTGMD were measured by high-resolution ultrasound in 48 obese and 23 lean pre-pubertal children (8.8 +/- 1.5 years old). We assessed central pulse pressure, incremental elastic modulus (Einc), casual and ambulatory systolic (SBP) and diastolic blood pressure (DBP), and body fatness by DXA. Obese children had significantly lower FMD (4.5 +/- 4.0 vs. 8.3 +/- 1.7%), NTGMD (19.0 +/- 9.0 vs. 25.8 +/- 6.1%), and increased Einc (13.9 +/- 5.2 vs. 10.4 +/- 5.2 mmHg/10(2)), ambulatory SBP (121.3 +/- 12.6 vs. 106.6 +/- 7.1, mmHg), and DBP (69.1 +/- 5.7 vs. 63.7 +/- 4.5) than lean subjects, whereas IMT was not augmented. Ambulatory systolic hypertension was present in 47% of obese subjects. FMD, NTGMD, and Einc were correlated with body fatness, body mass index, and blood pressure (BP).

CONCLUSION

Impaired endothelial and smooth muscle functions and altered wall material develop before puberty in obese children, however remodelling of the CCA is not yet present. Arterial dysfunction may be considered as the first marker of atherosclerosis and is associated with elevated BP. Ambulatory blood pressure monitoring may be a potential tool to improve risk stratification in obese children.

Gene-environment interactions, not neonatal growth hormone deficiency, time puberty in female rhesus monkeys

The factors that influence the timing of puberty and the onset of adult fertility are poorly understood. While focus on the juvenile period has provided insights into how growth-related cues affect pubertal timing, growth velocity during infancy that is sustained into the juvenile period may be important. On the other hand, social factors, specifically exposure to psychosocial stressors, can delay sexual maturation, possibly by altering growth velocities during development. Using female rhesus monkeys, the present study used a prospective analysis to determine how neonatal growth hormone (GH) inhibition with a sandostatin analog or suppression of the pituitary-gonadal axis with a GnRH analog affected growth and sexual maturation. A separate retrospective analysis was done assessing the effects of social dominance status during development on pubertal timing. Because a specific polymorphism in the gene encoding the serotonin (5HT) reuptake transporter increases vulnerability to psychosocial stressors, females were also genotyped and were then classified as socially dominant, having both alleles for the long promoter variant or having at least one allele for the short promoter variant, or as socially subordinate, having the long variant or having the short variant. Neonatal treatments were not balanced for social status or genotype, so analyses were performed separately. Although the neonatal treatments reduced GH secretion postnatally and through the juvenile period, neither growth nor sexual maturation was affected. In contrast, the retrospective analysis showed sexual maturation was delayed significantly in subordinate females carrying at least one allele of the short promoter variant in the gene encoding the 5HT reuptake transporter, and this delay was associated with reduced GH and leptin secretion during the juvenile phase but not with differences in growth velocities from birth. These data suggest that decreased neonatal GH secretion does not adversely affect sexual maturation, but that polymorphisms in the gene encoding the 5HT transporter modulate the adverse consequences of social subordination on the timing of puberty in female rhesus monkeys.

Maternal weight gain during pregnancy and overweight in Portuguese children

OBJECTIVE

The objective of our study was to assess the association between maternal weight gain during pregnancy and childhood overweight.

DESIGN

This study was a cross-sectional analysis.

SETTING

The data were derived from a community-based survey of children from primary schools of Portugal.

SUBJECTS

The study was performed in a sample of 6-12-year-old Portuguese school children (2445 girls and 2400 boys; age was 8.5+/-0.91 years).

MEASUREMENTS

Height and weight were measured according to international standards, and body mass index (BMI) was calculated. The definition of overweight was based on average centiles according to the International Obesity Task Force cutoffs. Children's parents completed a self-administered questionnaire, which provided information on general family background characteristics, maternal weight gain during pregnancy and children's physical activity. The response rate was 70.6%. Children's dietary intake was measured using a 24-h dietary recall. Logistic regression models were fitted to estimate the magnitude of the association between maternal weight gain during pregnancy and overweight in their children, adjusting for confounders (gender, age, birthweight, order of birth, breastfeeding, smoking during pregnancy, physical activity, parental BMI, parental education, calcium to protein ratio and energy intake).

RESULTS

The prevalence of overweight (including obesity) was 29% in boys and 33% in girls. The odds favouring overweight (including obesity) increased significantly for those women who gained > or =16 kg during pregnancy, compared to those with <9 kg , even after adjustment for confounders (crude odds ratio (OR)=1.53, confidence interval (CI) 95% 1.27-1.84, P-trend <0.001; Adjusted OR=1.27, CI 95% 1.01-1.61, P-trend=0.038).

CONCLUSION

Large maternal weight gain during pregnancy (> or =16 kg) was significantly associated with higher risk of overweight in Portuguese children.

The genetic basis for the timing of human puberty

Puberty is a complex, coordinated biological process with multiple levels of regulation. Epidemiological observations suggest that the timing of pubertal events is a heritable trait, although environmental factors can modulate such genetic influence. The study of pathological states of early and late puberty has provided valuable insight into those genes that regulate gonadotrophin-releasing hormone (GnRH) activity. The development of pulsatile release of GnRH secretion mediated through kisspeptin-1 activation of G-protein coupled receptor-54 appears to be a central event at the onset and during progression of puberty. Stimulating and restraining influences (e.g. in the form of glutamatergic and GABAergic neuronal inputs) are likely to influence the timing of this process. The study of extreme variants of 'normality', such as constitutional delay of growth and puberty and early puberty, may lead to the recognition of additional genes and pathways that can modulate both the timing of pubertal onset and its tempo.

Early pituitary-gonadal activation before clinical signs of puberty in 5- to 8-year-old adopted girls: a study of 99 foreign adopted girls and 93 controls

CONTEXT

Recent studies have indicated that internationally adopted girls are at high risk of developing precocious puberty. Clinical studies including a contemporary control group are lacking.

OBJECTIVE

The objective was to study clinical, biochemical, and ultrasonographic markers of pituitary-gonadal activation in prepubertal adopted girls and a control group in the same age categories.

SETTING

The study took place at University Hospital, Copenhagen, Denmark.

DESIGN AND PARTICIPANTS

The study included randomly selected internationally adopted girls [(n = 99; mean age, 6.9 (5.1-8.5) yr] and controls of Danish origin [n = 93; mean age, 6.8 (5.2-8.5) yr] who were studied cross-sectionally.

METHODS

Height, weight, and pubertal stage were assessed with serum levels of reproductive hormones. Size and morphology of internal genitals were evaluated by ultrasonography. Bone age was evaluated by x-ray of the left hand.

RESULTS

Serum values of FSH were significantly higher in prepubertal adopted girls compared with controls [median, 1.4 (95% confidence interval, 0.4-3.6) vs. 1.0 (0.4-2.4) IU/liter; P <0.001]. Serum estradiol was above detection limit (>18 pmol/liter) in 46.5% of prepubertal adopted girls and 20.7% of controls (P = 0.001). In prepubertal adopted girls, the proportion of measurable samples increased significantly with age [odds ratio, 2.5 (95% confidence interval, 1.3-5.0; P = 0.009]. In controls, the odds ratio was 1.0 (0.6-1.7) (P = 0.9). Serum SHBG levels were significantly lower in prepubertal adopted girls compared with controls [99.0 (50.4-153.0) vs. 115.0 (53.1-202.1); P < 0.001].

CONCLUSION

Five- to 8-yr-old adopted girls showed signs of increased pituitary as well as gonadal activity despite prepubertal phenotype in the majority of girls. Our findings suggest that early onset of puberty in adopted girls is centrally driven.