Additive influences of maternal and paternal body mass index on weight status trajectories from childhood to mid-adulthood in the 1970 British Cohort Study

This study aimed to (i)describe the weightstatus trajectories from childhood to mid-adulthood and (ii) investigate the influence ofmaternal and paternal body massindex (BMI) onoffspring’s trajectories in a nationally representative study inGreat Britain. Thesample comprised 4,174 (43% male) participantsfrom the 1970 British Cohort Study withcompleteBMI data at ages 10, 26, 30, 34, and 42years. Individuals’ weight status was categorised as overweight/obese or non-overweight/obese at eachage, and trajectories of weightstatus from 10 to42 years of age were assessed. Sex-stratified multinomial logistic regressionmodels were used to assess associations of maternal andpaternal BMI with trajectory group membership, adjusting for potential confounders (e.g.socioeconomicposition and puberty). Thirty per cent ofindividuals were never overweight/obese (reference trajectory),6%, 44%and 8%hadchildhood, early- and mid-adulthood onset of overweight/obesity (respectively), and 12% other trajectories. In fully adjusted models,highermaternal and paternal BMI significantlyincreased the risk of childhood (relativerisk ratio: 1.2-1.3) and early adulthood onset(1.2) of overweight/obesity in both sexes. Relative risk ratios were generall higher formaternal than paternal BMI in females but similar in males. Earlypuberty also increasedtherisk ofchildhood (1.8-9.2 and early-adulthoodonset (3.7-4.7)of overweight/obesity. Results highlight the importance of primary prevention, as mostindividuals remained overweight/obese after onset. Maternal and paternal BMI had additive effects on offspring weight status trajectories across 32 years of the life course,suggesting thatprevention/interventionprogrammes should focuson the whole famil

Patterns of BMI development between 10-42 years of age and their determinants in the 1970 British Cohort Study

Background Mixture modelling is a useful approach to identify sub-groups in a population who share similar trajectories. We aimed to identify distinct BMI trajectories between 10-42 years and investigate how known early-life risk factors are related to trajectories. Methods Sample: 9,187 participants in the 1970 British Birth Cohort Study, with BMI observations between 10-42 years and data on birth-weight, parental BMI, socioeconomic status (SES), breastfeeding and puberty. Latent growth mixture modelling in Mplus was used to model age-related BMI trajectories and test associations of risk factors with trajectory membership. Results A three latent class model was most credible; 1) Normative: 92%: started normal weight but gradually increased BMI to become overweight in adulthood; 2) Childhood onset persistent obesity (COP): 4%: persistently high BMI from childhood; 3) Adolescent and young adulthood onset obesity (AYAO): 4%: normal weight in childhood but had a steep ascending trajectory. Higher maternal and paternal BMI and early puberty increased the probability of being in either the COP or the AYAO classes compared with the normative class. Conclusion Most individuals gradually increased BMI and became overweight in mid-adulthood. Only 8% demonstrated more severe BMI trajectories. Further research is needed to understand the underlying body composition changes and health risks in the COP and AYAO classes

Cost-effectiveness of a community-delivered multicomponent intervention compared with enhanced standard care of obese adolescents: cost-utility analysis alongside a randomised controlled trial (the HELP trial)

Objective To undertake a cost-utility analysis of a motivational multicomponent lifestyle-modification intervention in a community setting (the Healthy Eating Lifestyle Programme (HELP)) compared with enhanced standard care. Design Cost-utility analysis alongside a randomised controlled trial. Setting Community settings in Greater London, England. Participants 174 young people with obesity aged 12–19 years. Interventions Intervention participants received 12 one to-one sessions across 6months, addressing lifestyle behaviours and focusing on motivation to change and self esteem rather than weight change, delivered by trained graduate health workers in community settings. Control participants received a single 1-hour one-to-one nurse delivered session providing didactic weight-management advice. Main outcome measures Mean costs and quality adjusted life years (QALYs) per participant over a 1-year period using resource use data and utility values collected during the trial. Incremental cost-effectiveness ratio (ICER) was calculated and non-parametric bootstrapping was conducted to generate a cost-effectiveness acceptability curve (CEAC). Results Mean intervention costs per participant were £918 for HELP and £68 for enhanced standard care. There were no significant differences between the two groups in mean resource use per participant for any type of healthcare contact. Adjusted costs were significantly higher in the intervention group (mean incremental costs for HELP vs enhanced standard care £1003 (95% CI £837 to £1168)). There were no differences in adjusted QALYs between groups (mean QALYs gained 0.008 (95% CI −0.031 to 0.046)). The ICER of the HELP versus enhanced standard care was £120 630 per QALY gained. The CEAC shows that the probability that HELP was cost-effective relative to the enhanced standard care was 0.002 or 0.046, at a threshold of £20 000 or £30 000 per QALY gained. Conclusions We did not find evidence that HELP was more effective than a single educational session in improving quality of life in a sample of adolescents with obesity. HELP was associated with higher costs, mainly due to the extra costs of delivering the intervention and therefore is not cost-effective

Linear mixed-effect models for saliva hormones.

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Number (%) of waves with available hormone measurements for each hormone for females and males.

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Scatterplots showing the relationship between age and (log-transformed) saliva hormone levels for females and males with hormone values above the detection limit.

To illustrate the longitudinal nature of the data, repeated measures over the follow-up period have been connected (black lines) for 10 randomly selected individuals.</p

Descriptive statistics for age at saliva collection, time of saliva collection, saliva flow rate, and hormone measurements at waves 1 to 4 for females (n = 667) and males (n = 572).

Descriptive statistics for age at saliva collection, time of saliva collection, saliva flow rate, and hormone measurements at waves 1 to 4 for females (n = 667) and males (n = 572).</p

Number (%) of females and males in cross-classifications of individuals by hormone level at age 9 years and hormone progression rate over time.

L1, L2, and L3 respectively indicate low, normal, and high predicted hormone levels compared to population; R1 and R2 indicate slow/normal and fast predicted progression rate over time compared to population.</p

Estimates of standard deviation and correlation parameters in the mixed-effects models for adrenal hormone measured at age 9 years old.

Estimates of standard deviation and correlation parameters in the mixed-effects models for adrenal hormone measured at age 9 years old.</p

Percentage of individuals who changed class after excluding hormone measurements collected after 11am (n = 51).

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