Tanner's tempo of growth in adolescence: recent SITAR insights with the Harpenden Growth Study and ALSPAC.
ABSTRACT: Background: James Tanner emphasised the "tempo" of growth, i.e. the adolescent spurt as summarised by its timing (age at peak velocity or APV) and intensity (peak velocity, PV).Aim: The paper applies the SITAR growth curve model to pubertal growth data with the aim of clarifying the growth pattern across multiple measurements and the spectrum of APV and PV.Subjects and methods: Data for 7-20?years on ten anthropometric measurements in 619 children from the Harpenden Growth Study, and on height in 10410 children from the ALSPAC study, were analysed using SITAR (SuperImposition by Translation And Rotation). SITAR models pubertal growth as a mean curve with APV and PV fitted as subject-specific random effects, and a random measurement intercept.Results: Mean APV for Harpenden girls and boys averaged 12.0 and 13.9?years across the ten measurements. PV expressed as percent per year lay in the narrow range 4-8%. Splitting the ALSPAC subjects into 9 by 5 APV and PV groups and fitting separate SITAR models to each group confirmed SITAR's good fit while highlighting the spectrum of growth patterns.Conclusion: SITAR works well to summarise pubertal growth. The disappointment is that Tanner did not live to see it in action.
Project description:To explore associations between pubertal growth and later bone health in a cohort with infrequent measurements, using another cohort with more frequent measurements to support the modelling, data from the Medical Research Council (MRC) National Survey of Health and Development (2-26 years, 4901/30 004 subjects/measurements) and the Avon Longitudinal Study of Parents And Children (ALSPAC) (5-20 years) (10 896/74 120) were related to National Survey of Health and Development (NSHD) bone health outcomes at 60-64 years.NSHD data were analysed using Super-Imposition by Translation And Rotation (SITAR) growth curve analysis, either alone or jointly with ALSPAC data. Improved estimation of pubertal growth parameters of size, tempo and velocity was assessed by changes in model fit and correlations with contemporary measures of pubertal timing. Bone outcomes of radius [trabecular volumetric bone mineral density (vBMD) and diaphysis cross-sectional area (CSA)] were regressed on the SITAR parameters, adjusted for current body size.The NSHD SITAR parameters were better estimated in conjunction with ALSPAC, i.e. more strongly correlated with pubertal timing. Trabecular vBMD was associated with early height tempo, whereas diaphysis CSA was related to weight size, early tempo and slow velocity, the bone outcomes being around 15% higher for the better vs worse growth pattern.By pooling NSHD and ALSPAC data, SITAR more accurately summarized pubertal growth and weight gain in NSHD, and in turn demonstrated notable associations between pubertal timing and later bone outcomes. These associations give insight into the importance of the pubertal period for future skeletal health and osteoporosis risk.
Project description:Gestational weight gain is often characterized by the total amount of weight gained during pregnancy, however, the pattern of gain may be an important determinant of health outcomes. The SITAR (Super Imposition by Translation And Rotation) model has been used to describe childhood growth trajectories and has appeal because of the biological interpretability of its parameters. The objective of this study was to determine the feasibility of applying this model to gestational weight gain trajectories.The study cohort included 3470 normal-weight, overweight, and obese women delivering at Magee-Womens Hospital in Pittsburgh, Pennsylvania, 1998 to 2010. We applied the SITAR model, a non-linear mixed effects model, to serial prenatal weight gain measurements in each pre-pregnancy body mass index (BMI) category. We fit models of varying complexity, and chose the best-fitting model to describe the pattern of weight gain (by its absolute amount, timing, and acceleration) for each BMI group.The most complex SITAR models failed to converge, but reduced models could successfully be fit by specifying fewer random effects and simplifying the modelling of gestational age. Best-fitting models for each BMI group explained between 95% and 97% of the variation in weight gain trajectories. Peak rates of weight gain were reached between the 20th and 22nd weeks, and were higher for normal and overweight women (0.59 kg/week and 0.57 kg/week, respectively) than obese women (0.46 kg/week).Following some modifications, the SITAR model can be used to characterize pregnancy weight gain patterns.
Project description:Various studies have been conducted on children using the Ellisras Longitudinal Study Survey in South Africa, but none of these has addressed growth variations of children in this rural location. The aim of this paper is to assess the age at peak height velocity using the superimposition by translation and rotation (SITAR) method for both boys and girls in rural South Africa. The study is part of the on-going Ellisras Longitudinal Study, and has employed secondary data during the period from November 1996 to November 2003. The data was collected biannually in May and November each year. The Ellisras study initially followed a cluster sampling method. All participating children underwent a series of anthropometric measurements of height and weight according to the standard procedures recommended by the International Society for the Advancement of Kinanthropometry. The analysis was done using the SITAR model. Age at peak height velocity for Ellisras rural children was at 14.45 years for boys at 11.82 years for girls. Ellisras rural girls had their age at peak height velocity way earlier than Ellisras rural boys did by an estimated 2.63 years. Ellisras rural children and their growth variations were comparable to other studies.
Project description:Infant growth trajectories, in terms of size, tempo and velocity, may programme lifelong obesity risk. Timing of breastfeeding cessation and weaning are both implicated in rapid infant growth; we examined the association of both simultaneously with a range of growth parameters.Longitudinal population-based twin birth cohort.The Gemini cohort provided data on 4680 UK infants with a median of 10 (interquartile range=8-15) weight measurements between birth and a median of 6.5 months. Age at breastfeeding cessation and weaning were reported by parents at mean age 8.2 months (s.d.=2.2, range=4-20). Growth trajectories were modelled using SuperImposition by Translation And Rotation (SITAR) to generate three descriptors of individual growth relative to the average trajectory: size (grams), tempo (weeks, indicating the timing of the peak growth rate) and velocity (% difference from average, reflecting mean growth rate). Complex-samples general linear models adjusting for family clustering and confounders examined associations between infant feeding and SITAR parameters.Longer breastfeeding (>4 months vs never) was independently associated with lower growth velocity by 6.8% (s.e.=1.3%) and delayed growth tempo by 1.0 (s.e.=0.2 weeks), but not with smaller size. Later weaning (?6 months vs <4 months) was independently associated with lower growth velocity by 4.9% (s.e.=1.1%) and smaller size by 102?g (s.e.=25?g).Infants breastfed for longer grew slower for longer after birth (later peak growth rate) but were no different in size, while infants weaned later grew slower overall and were smaller but the timing of peak growth did not differ. Slower trajectories with a delayed peak in growth may have beneficial implications for programming later obesity risk. Replication in cohorts with longer follow-up, alternative confounding structures or randomised controlled trials are required to confirm the long-term effects and directionality, and to rule out residual confounding.
Project description:Objectives Japanese and South Koreans have traditionally been shorter than Europeans, but have recently become appreciably taller. The aim was to quantify the secular trend patterns in height and weight growth in the two countries over 50 years using the SITAR growth curve model. Methods Data on mean height and weight by sex in 1-year age groups from 1 to 20 years were obtained by decade in South Korea (1965-2005) and Japan (1950-2010). The data were analyzed using SITAR (SuperImposition by Translation And Rotation), which estimates a mean curve and three adjustments-size, timing and intensity-reflecting how the individual surveys differ from the mean. A sensitivity analysis compared results for the Japanese data based on cohort as well as period. Results Growth patterns in the two countries changed dramatically over the study period, affecting not only height and weight but also developmental age, in that the growth period advanced in timing and shrank in duration. SITAR fitted the data well. The trends were larger in South Korea than Japan, and puberty timing in Japan stabilized by 1970. Most of the height increment seen in adults had already accrued by age 1.5 years, whereas the adult weight increment accrued throughout childhood. Conclusions The secular height trend in these countries represents increased growth in the long bones during infancy, so it can be viewed as the inverse of stunting. There are striking country differences in growth pattern, but they are not easily explained by differences in national income, diet or lifestyle.
Project description:On a sample of 1,317 children aged 9.9 years we developed a novel method of measuring humeral dimensions from total body dual-energy X-ray absorptiometry (DXA) scans and showed that gender differences in the ratio between humeral width and length are established prior to puberty.It is recognised that long bone cross-sectional area is greater in males compared to females, which is thought to reflect more rapid periosteal bone growth in boys. However, it is currently unclear whether these findings reflect gender differences in bone size or shape. In the present study, we investigated whether gender differences exist in the balance between longitudinal and periosteal long bone growth in children, leading to gender differences in bone shape, based on a novel method for evaluating shape of the humerus. We also examined whether these differences are established prior to puberty.Length, area and width of the humerus were estimated from total body DXA scans in 1,317 children aged 9.9 +/- 0.33 years, who had participated in a nested case-control study of fractures within the Avon Longitudinal Study of Parents and Children (ALSPAC) (a geographically based birth cohort based in South West England). No differences were observed with respect to parameters of humeral geometry according to fracture history, and so both groups were pooled for further analysis. Aspect ratio (AR) of the humerus was calculated as humeral width divided by length. Total body height and weight were measured at the same time as the DXA scan. Puberty was assessed using self-completion questionnaires.Humeral width and length were positively associated with age and height in boys and girls combined (P<0.001), and with Tanner stage in girls (P<0.002). In contrast, age, height and Tanner stage were not related to humeral AR. We then examined gender differences in humeral shape according to pubertal stage. In prepubertal children (i.e. Tanner stage 1), humeral length was similar in boys and girls, but width (1.92 vs 1.88 cm, P<0.001) and area (47.7 vs 46.9 cm(2), P<0.001) were greater in boys, resulting in a greater AR (7.78 vs 7.53, P<0.001). Similar gender differences were observed in early pubertal children (i.e. Tanner stage 2).We conclude that the greater periosteal diameter of boys compared to girls reflects differences in the balance between longitudinal and periosteal bone growth. Interestingly, resulting gender differences in humeral AR are established in prepubertal children.
Project description:It has been postulated that pubertal hormones may drive some neuroanatomical changes during adolescence, and may do so differently in girls and boys. Here, we use growth curve modeling to directly assess how sex hormones [testosterone (T) and estradiol (E?)] relate to changes in subcortical brain volumes utilizing a longitudinal design. 126 adolescents (63 girls), ages 10 to 14, were imaged and restudied ?2 years later. We show, for the first time, that best-fit growth models are distinctly different when using hormones as compared to a physical proxy of pubertal maturation (Tanner Stage) or age, to predict brain development. Like Tanner Stage, T and E? predicted white matter and right amygdala growth across adolescence in both sexes, independent of age. Tanner Stage also explained decreases in both gray matter and caudate volumes, whereas E? explained only gray matter decreases and T explained only caudate volume decreases. No pubertal measures were related to hippocampus development. Although specificity was seen, sex hormones had strikingly similar relationships with white matter, gray matter, right amygdala, and bilateral caudate volumes, with larger changes in brain volume seen at early pubertal maturation (as indexed by lower hormone levels), followed by less robust, or even reversals in growth, by late puberty. These novel longitudinal findings on the relationship between hormones and brain volume change represent crucial first steps toward understanding which aspects of puberty influence neurodevelopment.
Project description:AIM:The aim was to assess the influence of dietary counselling on the pubertal development and hormonal status in healthy adolescents. METHODS:We used a subcohort of 193 healthy boys (52%) and girls (48%) from the Special Turku Coronary Risk Factor Intervention Project. Participants were recruited by nurses at the well-baby clinics in Turku Finland in 1990-1992 and randomised into intervention and control groups. Intervention children received low-saturated fat and low-cholesterol dietary counselling initiated at seven months of age. Participants were examined once a year with Tanner staging, anthropometric measurements and serial reproductive hormones from 10 to 19 years of age. In girls, postmenarcheal hormones were not analysed. RESULTS:Pubertal hormones in boys or girls did not differ between the intervention and control groups. However, we observed slight differences in pubertal progression by Tanner staging and in anthropometric parameters. The intervention boys progressed faster to G4 (p = 0.008), G5 (p = 0.008) and P5 (p = 0.03). The intervention boys were taller than control boys (p = 0.04), while weight and body mass index did not differ. CONCLUSION:Dietary intervention did not affect pubertal hormonal status. This finding supports the safety of implemented counselling in respect to puberty.
Project description:BACKGROUND:Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls. METHODS:We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006-2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche. RESULTS:In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7-48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10-32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1-5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0-3%) longer time to menarche in multivariable models. CONCLUSIONS:Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.
Project description:Anecdotal reports suggest that adolescent males consume large quantities of food to meet the growth demands of pubertal development. However, limited experimental data exist to support this impression.The objective was to measure energy intakes of youth at different pubertal stages.Participants were 204 volunteers (50.5% male) aged 8-17 y. Pubertal development was categorized by physical examination into prepuberty (males: testes < 4 mL; females: Tanner breast stage 1), early-mid puberty (males: testes = 4-12 mL; females: Tanner breast stages 2-3), or late puberty (males: testes >12 mL; females: Tanner breast stages 4-5). Energy intake was measured as consumption from a 9835-kcal food array during 2 lunch time meals.Males consumed more energy than did females across all pubertal stages (P < 0.001). Intake increased with pubertal development (P < 0.001), but the timing and magnitude of change varied by sex (P = 0.02). Males' unadjusted energy intake was greater in late puberty (mean +/- SE: 1955 +/- 70 kcal) than in prepuberty (1287 +/- 90 kcal) or early-mid puberty (1413 +/- 92 kcal) (P < 0.001). Females' unadjusted energy intake tended to be lower among prepubertal girls (905 +/- 140 kcal) than among females in early-mid puberty (1278 +/- 82 kcal, P = 0.07) or late puberty (1388 +/- 68 kcal, P = 0.01). After adjustment for fat-free mass, fat mass, height, overweight status, race, and meal instruction, the main effect of sex (P < 0.001) remained significant, but the effect of puberty was not significant (P = 0.66).The observed intake patterns are congruent with known sexual dimorphisms for body composition, peak growth velocity, and pubertal development. Consistent with their higher energy requirements, males can consume significantly larger amounts of food than females, especially during later puberty. This trial was registered at clinicaltrials.gov as NCT00320177.