Body mass trajectories through adulthood: results from the National Longitudinal Survey of Youth 1979 Cohort (1981-2006)

Longitudinal Trajectories of Antiretroviral Treatment Adherence and Associations With Durable Viral Suppression Among Adolescents Living With HIV in South Africa

BACKGROUND

Compared with other age groups, adolescents living with HIV (ALHIV) are estimated to have lower levels of adherence to antiretroviral treatment. Despite this, we lack evidence on adolescents' adherence patterns over time to inform the customization of intervention strategies.

SETTING

Eastern Cape province, South Africa.

METHODS

We analyzed data from a cohort of ALHIV (N = 1046, aged 10-19 years at baseline) recruited from 53 public health facilities. The cohort comprised 3 waves of data collected between 2014 and 2018 and routine viral load data from the National Institute for Communicable Disease data warehouse (2014-2019). Durable viral suppression was defined as having suppressed viral load (<1000 copies/mL) at ≥2 consecutive study waves. Group-based multitrajectory model was used to identify adherence trajectories using 5 indicators of self-reported adherence. Logistic regression modeling evaluated the associations between adherence trajectories and durable viral suppression.

RESULTS

Overall, 933 ALHIV (89.2%) completed all 3 study waves (55.1% female, mean age: 13.6 years at baseline). Four adherence trajectories were identified, namely, "consistent adherence" (49.8%), "low start and increasing" (20.8%), "gradually decreasing" (23.5%), and "low and decreasing" (5.9%). Adolescents experiencing inconsistent adherence trajectories were more likely to be older, live in rural areas, and have sexually acquired HIV. Compared with the consistent adherence trajectory, the odds of durable viral suppression were lower among adolescents in the low start and increasing (adjusted odds ratio [aOR]: 0.62, 95% CI: 0.41 to 0.95), gradually decreasing (aOR: 0.40, 95% CI: 0.27 to 0.59), and the low and decreasing adherence (aOR: 0.25, 95% CI: 0.10 to 0.62) trajectories.

CONCLUSIONS

Adherence to antiretroviral treatment remains a challenge among ALHIV in South Africa. Identifying adolescents at risk of nonadherence, based on their adherence trajectories may inform the tailoring of adolescent-friendly support strategies.

Acculturation and Health Status in the Children's Healthy Living Program in the Pacific Region

Acculturation/enculturation has been found to impact childhood health and obesity status. The objective of this study is to use cross-sectional data to examine the association between proxies of adult/caregiver acculturation/enculturation and child health status (Body Mass Index [BMI], waist circumference [WC], and acanthosis nigricans [AN]) in the U.S.-Affiliated Pacific Islands (USAPI), Alaska, and Hawai'i. Study participants were from the Children's Healthy Living (CHL) Program, an environmental intervention trial and obesity prevalence survey. Anthropometric data from 2-8 year olds and parent/caregiver questionnaires were used in this analysis. The results of this study (n = 4121) saw that those parents/caregivers who identified as traditional had children who were protected against overweight/obesity (OWOB) status and WC > 75th percentile (compared to the integrated culture identity) when adjusted for significant variables from the descriptive analysis. AN did not have a significant association with cultural classification. Future interventions in the USAPI, Alaska, and Hawai'i may want to focus efforts on parents/caregivers who associated with an integrated cultural group as an opportunity to improve health and reduce child OWOB prevalence.

Ideal 24-h physical activity trajectory reduces all-cause, cause-specific mortality and cardiovascular outcomes through aging deceleration and inflammation regulation: A UK biobank study

BACKGROUND

Physical activity (PA) is associated with mortality and cardiovascular disease (CVD). However, the effect of circadian PA trajectories remains ambiguous. This study aimed to explore ideal circadian PA patterns to reduce mortality and CVD, and potential mediators.

METHODS

502,400 participants from UK Biobank were recruited between 2006 and 2010. Among them, 102,323 participants got valid continuously capturing acceleration data over 7 days by wrist-worn accelerometer. K-means cluster analysis was used to identify PA trajectories. The associations of PA with all-cause, cause-specific mortality and CVD were assessed by cox regression. A sensitivity test was also conducted, starting from the time of acceleration collection and excluding participants with corresponding disease prior to it. Furthermore, the mediation of aging and inflammation were explored.

RESULTS

During a median follow-up of 12.9 years, 3482 deaths were recorded (704 were due to CVD). Five distinct PA trajectories were identified: Persistently Low, Moderate and Stable, Single Increase, Double Increase, and Vigorous patterns. Ideal PA trajectory patterns offered progressively protective benefits against all-cause, CVD caused mortality and CVD, especially in Double Increase and Vigorous patterns. Other cause-specific mortality and renal failure incidence showed similar trend. The sensitivity result was consistent. The mediating effects of phenotypic age and inflammation markers were statistically significant.

CONCLUSION

Ideal PA trajectories offered protective benefits against all-cause, cause-specific mortality and CVD. The protection was associated with both intensity and circadian distribution. Double Increase and Vigorous activity patterns decreased these risks more significantly. Crucially, this protection was mediated by aging deceleration and inflammation regulation.

Associations of blood pressure trajectories in early life with target organ damage in midlife : a 30-year cohort study

Hypertension is a pivotal factor in cardiovascular risk. However, the association of longitudinal blood pressure (BP) trajectories in the early life and cardiovascular risk assessed by target organ damage (TOD) in adulthood is poorly reported. The objective of this study was to identify the association between systolic BP, diastolic BP, and mean atrial pressure (MAP) trajectories early in life with a single or multiple TOD in later life. We identified BP trajectories from 6 to 45 year-old using group-based trajectory models among 2430 individuals in the Hanzhong Adolescent Hypertension Study and examined the relationship between BP trajectories and cardiovascular risk in later life. Four discrete long-term systolic BP, diastolic BP, and MAP trajectories were identified, namely, low stable, moderate stable, high stable (low increasing), and moderate increasing groups, based on the BP levels at baseline and in the 30-year follow-up. The carotid intima-media thickness were higher in persistently high or increasing trajectories in comparison to the low stable group. Individuals with deteriorative trajectories during early life were at an increased risk of suffering from a single TOD, including left ventricular hypertrophy (LVH) and carotid atherosclerosis (CA) in middle age (36-49 years old). Moreover, higher BP trajectories were correlated with the presence of combined TODs load stage which were assessed by CA, LVH, arteriosclerosis and subclinical renal damage (SRD). Higher longitudinal BP trajectories early in life were associated with increased cardiovascular risk in midlife, and identifying BP trajectories in early life can help screen individuals with TOD later. LVH, left Ventricular Hypertrophy; CA, carotid atherosclerosis; SRD, subclinical renal damage; TOD, target organ damage.

Heterogenous trajectories in physical, mental and cognitive health among older Americans: Roles of genetics and life course contextual factors

We investigate the roles of genetic predispositions, childhood SES and adult educational attainment in shaping trajectories for three important components of the overall health of older adults -- BMI, depressive symptoms and cognition. We use the Health & Retirement Study (HRS) and group-based trajectory modeling (GBTM) to identify subgroups of people who share the same underlying trajectories ages 51-94 years. After identifying common underlying health trajectories, we use fractional multinomial logit models to estimate associations of (1) polygenic scores for BMI, depression, ever-smoked, education, cognition and subjective wellbeing, (2) childhood SES and (3) educational attainment with the probabilities of trajectory group memberships. While genetic predispositions do play a part in predicting trajectory group memberships, our results highlight the long arm of socioeconomic factors. Educational attainment is the most robust predictor-it predicts increased probabilities of belonging to trajectories with BMI in the normal range, low depressive symptoms and very-high initial cognition. Childhood circumstances are manifested in trajectories to a lesser extent, with childhood SES predicting higher likelihood of being on the low depressive symptoms and very-high initial cognition trajectories. We also find suggestive evidence that associations of educational attainment on the probabilities of being on trajectories with BMI in the normal range, low depressive symptoms and very-high initial cognition vary with genetic predispositions. Our results suggest that policies to increase educational attainment may improve population health by increasing the likelihood of belonging to "good" aging trajectories.

Weight gain is associated with shorter lifespan: a longitudinal study of New Zealand soldiers serving in both world wars

Obesity is an increasing public health concern with important mortality consequences. Weight gain or maximum adult BMI, not BMI at one point in time, has been shown to be an important risk factor in cohorts studied recently during an era of rapid increase in population levels of overweight and obesity. However, there is limited evidence on individual weight trajectories from cohorts born before the mid-twentieth century. Archival world war military personnel files from New Zealand are freely available online, and identify service in both wars. A pilot study of 316 soldiers confirmed the files contain sufficient information to examine health trajectories and lifespan. Because this cohort are now entirely deceased, nearly the entire sample can be found in death records to estimate the impact of weight increases on lifespan. Weight change over 20-30 years and its relationship with lifespan is examined using ordinary least squares regression. The study demonstrates that military records are a feasible source for collecting data on adult weight and health trajectories in the first half of the twentieth century. Although this sample is likely to be composed of men fitter than average, there is a clear pattern of increasing weight from early to mid-adulthood. Weight gain from early adulthood to middle-age was found to be more strongly associated with mortality than weight in early adulthood. A one unit increase in BMI over the inter-war period was found to be associated with an 8 month decline in lifespan. These results confirm that weight gain in adulthood has an important impact on mortality in an earlier birth cohort than previously studied, and that data exist to measure any changes more precisely over time.

Effects of Morning Vs. Evening exercise on appetite, energy intake, performance and metabolism, in lean males and females

Exercise is an important component of a weight management strategy. However, little is known about whether circadian variations in physiological and behavioural processes can influence the appetite and energy balance responses to exercise performed at different times of the day. This study compared the effects of morning and evening exercise on appetite, post-exercise energy intake, and voluntary performance. In randomised, counterbalanced order, 16 healthy males and females (n = 8 each) completed two trials, performing morning exercise at 10:30 (AMEx) or evening exercise at 18:30 (PMEx). Exercise consisted of 30 min steady-state cycling (60% V˙ O_2peak), and a 15-min performance test. A standardised meal (543 ± 86 kcal) was consumed 2-h before exercise and ad-libitum energy intake was assessed 15 min after exercise, with subjective appetite measured throughout. Absolute ad-libitum energy intake was 152 ± 126 kcal greater during PMEx (P < 0.001), but there was no differences in subjective appetite between trials immediately pre-exercise, or immediately before the post-exercise meal (P ≥ 0.060). Resting energy expenditure (P < 0.01) and carbohydrate oxidation (P < 0.05) were greater during AMEx, but there were no differences in substrate oxidation or energy expenditure during exercise (P ≥ 0.155). Exercise performance was not different between trials (P = 0.628). In conclusion, acute morning and evening exercise prompt similar appetite responses, but post-exercise ad-libitum energy intake is greater following evening exercise. These findings demonstrate discordant responses between subjective appetite and ad-libitum energy intake but suggest that exercise might offset circadian variations in appetite. Longer-term studies are required to determine how exercise timing affects adherence and weight management outcomes to exercise interventions. TRIAL REGISTRATION: NCT04742530, February 8, 2021.

Post-exercise skimmed milk, but not a sucrose beverage decreases energy intake at the next meal compared to a placebo beverage in active males

This study compared the appetite and energy intake effects of three post-exercise beverages at a subsequent post-exercise meal. On three occasions, ten active males: (mean ± sd) age 21.3 ± 1.2 y, V˙ O₂peak 58 ± 5 mL/kg/min) performed 30-min cycling at ∼60% V˙ O₂peak and five 4-min intervals at 85% V˙ O₂peak. Post-exercise, placebo (PLA: 57 kJ), skimmed milk (MILK: 1002 kJ) or sucrose (CHO: 1000 kJ) beverages (615 mL) were consumed. Sixty min post-beverage, subjects consumed an ad-libitum pasta lunch in a 30 min eating period. Subjective appetite and plasma acylated ghrelin and plasma glucose were determined pre-exercise, post-exercise and pre-meal, with sensory characteristics of beverages rated. Ad-libitum energy intake in MILK (6746 ± 2035) kJ) was lower than CHO (7762 ± 1921) kJ) (P = 0.038; dz = 0.98; large effect) and tended to be lower than PLA (7672 (2005) kJ) (P = 0.078; dz = 0.76; medium effect). Including energy consumed in beverages, energy intake was greater in CHO than PLA (P = 0.010; dz = 1.24; large effect) or MILK (P = 0.026; dz = 0.98; large effect), with PLA and MILK not different (P = 0.960; dz = 0.02; trial effect). Plasma ghrelin, plasma glucose and appetite were not different between trials. MILK was perceived thicker than CHO (P = 0.020; dz = 1.11; large effect) and creamier than PLA (P = 0.026; dz = 1.06; large effect). These results suggest that when energy balance is important for an exerciser, post-exercise skimmed milk ingestion reduces energy intake compared to a sucrose beverage and might therefore help facilitate recovery/adaptation without affecting energy balance.

Obesity and Overweight Among Children With Medical Complexity

OBJECTIVES

To assess the prevalence of overweight or obesity among children with medical complexity (CMC), compared with children without medical complexity, and explore potentially modifiable mechanisms.

METHODS

This study involved a retrospective cohort of 41 905 children ages 2 to 18 seen in 2019 at a single academic medical center. The primary outcome was overweight or obesity, defined as a body mass index of ≥85% for age and sex. CMC was defined as ≥1 serious chronic condition in ≥1 system. Obesogenic conditions and medications were defined as those typically associated with excess weight gain. Multivariable logistic regression was used to adjust for common confounders.

RESULTS

Of the children in the cohort, 29.5% were CMC. Overweight or obesity prevalence was higher among CMC than non-CMC (31.9% vs 18.4%, P ≤.001, adjusted odds ratio [aOR] 1.27, 95% confidence interval [CI] 1.20-1.35). Among CMC, the risk for overweight or obesity was higher among children with metabolic conditions (aOR 2.09, 95% CI 1.88-2.32), gastrointestinal conditions (aOR 1.23 95% CI 1.06-1.41), malignancies (aOR 1.21 95% CI 1.07-1.38), and Spanish-speaking parents (aOR 1.47 95% CI 1.30-1.67). Among overweight or obese CMC, 91.6% had no obesogenic conditions, and only 8.5% had been seen by a registered dietitian in the previous year.

CONCLUSIONS

CMC are significantly more likely to be overweight or obese when compared with children without medical complexity. Although many CMC cases of overweight appear to be preventable, further research is necessary to determine if and how to prevent comorbid obesity among CMC.

Appetitive interoception, the hippocampus and western-style diet

Obesity, Type 2 diabetes and other metabolic disorders continue to pose serious challenges to human health and well-being. An important source of these challenges is the overconsumption of saturated fats and sugar, main staples of what has been called the Western-style diet (WD). The current paper describes a theoretical model and supporting evidence that links intake of a WD to interference with a specific brain substrate that underlies processing of interoceptive signals of hunger and satiety. We review findings from rats and humans that the capacity of these signals to modulate the strength of appetitive and eating behavior depends on the functional integrity of the hippocampus and the learning memory operations it performs. Important among these operations is the use of contextual information to retrieve memories that are associated with other events. Within our framework, satiety provides an interoceptive context that informs animals that food cues and appetitive behavior will not be followed by rewarding postingestive outcomes. This serves to prevent those cues and responses from retrieving those reward memories. The findings reviewed provide evidence that consuming a WD and the high amounts of saturated fat and sugar it contains (a) is associated with the emergence of pathophysiologies to which the hippocampus appears selectively vulnerable (b) impairs hippocampal-dependent learning and memory (HDLM) and (c) weakens behavioral control by interoceptive hunger and satiety contextual stimuli. It is hypothesized that these consequences of WD intake may establish the conditions for a vicious cycle of further WD intake, obesity, and potentially cognitive decline.

Influential Periods in Longitudinal Clinical Cardiovascular Health Scores

The prevalence of ideal cardiovascular health (CVH) among adults in the United States is low and decreases with age. Our objective was to identify specific age windows when the loss of CVH accelerates, to ascertain preventive opportunities for intervention. Data were pooled from 5 longitudinal cohorts (Project Heartbeat!, Cardiovascular Risk in Young Finns Study, The Bogalusa Heart Study, Coronary Artery Risk Development in Young Adults, Special Turku Coronary Risk Factor Intervention Project) from the United States and Finland from 1973 to 2012. Individuals with clinical CVH factors (i.e., body mass index, blood pressure, cholesterol, blood glucose) measured from ages 8 to 55 years were included. These factors were categorized and summed into a clinical CVH score ranging from 0 (worst) to 8 (best). Adjusted, segmented, linear mixed models were used to estimate the change in CVH over time. Among the 18,343 participants, 9,461 (52%) were female and 12,346 (67%) were White. The baseline mean (standard deviation) clinical CVH score was 6.9 (1.2) at an average age of 17.6 (8.1) years. Two inflection points were estimated: at 16.9 years (95% confidence interval: 16.4, 17.4) and at 37.2 years (95% confidence interval: 32.4, 41.9). Late adolescence and early middle age appear to be influential periods during which the loss of CVH accelerates.

Inferring temporal dynamics from cross-sectional data using Langevin dynamics

Cross-sectional studies are widely prevalent since they are more feasible to conduct compared with longitudinal studies. However, cross-sectional data lack the temporal information required to study the evolution of the underlying dynamics. This temporal information is essential to develop predictive computational models, which is the first step towards causal modelling. We propose a method for inferring computational models from cross-sectional data using Langevin dynamics. This method can be applied to any system where the data-points are influenced by equal forces and are in (local) equilibrium. The inferred model will be valid for the time span during which this set of forces remains unchanged. The result is a set of stochastic differential equations that capture the temporal dynamics, by assuming that groups of data-points are subject to the same free energy landscape and amount of noise. This is a 'baseline' method that initiates the development of computational models and can be iteratively enhanced through the inclusion of domain expert knowledge as demonstrated in our results. Our method shows significant predictive power when compared against two population-based longitudinal datasets. The proposed method can facilitate the use of cross-sectional datasets to obtain an initial estimate of the underlying dynamics of the respective systems.

The role of electronic cigarette use for quitting or reducing combustible cigarette use in the 30s: Longitudinal changes and moderated relationships

BACKGROUND

Evidence for use of electronic cigarettes (e-cigs) as a potential aid in quitting or reducing combustible cigarette (c-cig) use is mixed. This study examined the extent to which e-cig initiation among smokers in their 30 s predicted quitting or reducing smoking or nicotine dependence symptoms by age 39, and whether the role of e-cigs in quitting differed by prospectively assessed moderators.

METHODS

Data were from the Seattle Social Development Project (SSDP), a panel study of 808 diverse participants with high retention. A subsample of 221 smokers at age 33 was selected for analysis. Self-reports of c-cig use and dependence were assessed longitudinally at ages 33 and 39. Sixteen potential moderators were examined, including social demographics, smoking attitudes and desire to quit, other health behaviors and status, and adolescent and early adult assessments of smoking history.

RESULTS

The use of e-cigs was consistently associated with a lower likelihood of quitting c-cigs by age 39, after accounting for frequency of prior c-cig use at age 33. This negative association persisted across all moderators examined, although it was nonsignificant among those with a definite desire to cut down. Among those who did not quit smoking, e-cig use had no association with decreases in either quantity of c-cigs used or dependence symptoms.

CONCLUSIONS

Results indicate that e-cigarette use was not helpful for quitting or reducing combustible cigarette use in the 30 s. Rather, across extensive tests of moderation, e-cig initiation consistently predicted less quitting during this important age period for successful cessation.

Long-term body mass trajectories and hypertension by sex among Chinese adults: a 24-year open cohort study

Evidence was limited on trajectory of body mass index (BMI) through adulthood and its association with hypertension. We aimed to evaluate their association by sex in large-scale study. Data were obtained from the China Health and Nutrition Survey (CHNS) from 1991 to 2015. Latent class trajectory analysis (LCTA) was used to capture BMI change trajectories. Hazard risks (HRs) were estimated from Cox proportion hazard regression. Among 14,262 participants (mean age, 38.8; 47.8% men), 5138 hypertension occurred (2687 men and 2451 women) occurred during a mean follow-up 9.6 years. Four body mass trajectory groups were identified as BMI loss, stable, moderate and substantial gain. Appropriately half of participants (48.0%) followed 1 of the 2 BMI gain trajectories, where BMI increased at least 3 kg/m2 overtime. Compared with participants with stable BMI, those gaining BMI substantially had higher risk of hypertension by 65% (HR 1.65, 95% CI 1.45-1.86) in male and 83% (HR 1.83, 95% CI 1.58-2.12) in female. The HRs in BMI loss patterns were 0.74 (0.62-0.89) in men and 0.87 (0.75-1.00) in women. Our findings imply that majority of Chinese adults transited up to a higher BMI level during follow-up. Avoiding excessive weight gain and maintaining stable weight might be important for hypertension prevention.

Life-long body mass index trajectories and mortality in two generations

PURPOSE

To identify life-long body mass index (BMI) trajectories across two related generations and estimate their associated mortality risks and population attributable deaths.

METHODS

We use prospective cohort data from the Framingham Heart Study (1948-2011) original (4576 individuals, 3913 deaths) and offspring (3753 individuals, 967 deaths) cohorts and latent trajectory models to model BMI trajectories from age 31 to 80 years. Survival models are used to estimate trajectory-specific mortality risk.

RESULTS

We define seven BMI trajectories among original cohort and six among offspring cohort. Among original cohort, people who are normal weight at age 31 years and gradually move to overweight status in middle or later adulthood have the lowest mortality risk even compared to those who maintain normal weight throughout adulthood, followed by overweight stable, lower level of normal weight, overweight downward, class I obese upward, and class II/III upward trajectories. Mortality risks associated with obesity trajectories have declined across cohorts, while the prevalence of high-risk trajectories has increased.

CONCLUSIONS

The mortality impact of weight gain depends on an individual's BMI trajectory. Population attributable deaths associated with unhealthy weight trajectories have grown over generations because the prevalence has increased, offsetting the decline in trajectory-specific mortality risks.

A 'case-mix' approach to understand adherence trajectories for a falls prevention exercise intervention: A longitudinal cohort study

OBJECTIVE

We identified adherence-based case-mixes from participants' longitudinal adherence to falls prevention exercise interventions over 12 months. Second, we identified modifiable baseline predictors (cognition, mobility and functional status) based on participants' case-mix adherence trajectories.

STUDY DESIGN AND OUTCOME MEASURES

This study was a 12-month longitudinal secondary analysis of data from 172 participants who received the Otago Exercise Program (OEP) in a randomized controlled trial. Adherence to the OEP was ascertained monthly via self-report. Case-mixes, groups of individuals who followed similar adherence trajectories, were visually defined using 12-month longitudinal trajectories; we used latent class growth modeling. Baseline predictors of adherence were examined for the following categories: 1) cognition, 2) mobility and 3) functional status.

RESULTS

Four distinct case-mixes were identified. The "non-adherent" case-mix (18 %) was distinguished by a non-adherent and decreasing adherence trajectory over time. The "low adherence" case-mix (45 %) did not have complete adherence or consistent adherence over the 12-month follow-up. The "moderate adherence" case-mix (27 %) was characterized by a stable (i.e., non-variable) adherence trajectory with a slightly increasing pattern at midpoint. The "high adherence" case-mix (10 %) demonstrated consistent and high adherence over the 12-month follow-up. For individuals with "moderate adherence", the Digit Symbol Substitution Test (DSST) significantly predicted adherence (relative risk ratio (RRR) = 1.12 (0.95 CI: 1.0-1.26); p = 0.049). For individuals with "high adherence", the Digits Forward minus Digits Backward (RRR = 0.43 (0.95 CI: 0.23-0.79); p = 0.002) and Instrumental Activities of Daily Living (RRR = 0.36 (0.95 CI: 0.16-0.81); p = 0.01) significantly predicted adherence.

CONCLUSIONS

Cognitive profile and activities of daily living at baseline may predict the longitudinal pattern of adherence.

Adult Social Environments and the Use of Combustible and Electronic Cigarettes: Opportunities for Reducing Smoking in the 30s

INTRODUCTION

Reducing cigarette use is a major public health goal in the United States. Questions remain, however, about the potential for the social environment in the adult years-particularly in the 30s and beyond-to influence cigarette use. This study tested pathways hypothesized by the social development model to understand the extent to which social environmental factors at age 33 (eg, involvement with smokers or with physically active people) contribute to changes in cigarette use from age 30 to age 39. Both combustible and electronic cigarette use were investigated.

METHODS

Data were from the Seattle Social Development Project, a longitudinal study of 808 diverse participants with high retention. Self-reports assessed social developmental constructs, combustible and electronic cigarette use, and demographic measures across survey waves.

RESULTS

At age 30, 32% of the sample reported past-month cigarette use. Using structural equation modeling, results showed high stability in cigarette use from age 30 to 39. After accounting for this stability, cigarette-using social environments at age 33 predicted personal beliefs or norms about smoking (eg, acceptability and social costs), which in turn predicted combustible cigarette use at age 39. Cigarette-using environments, however, directly predicted electronic cigarette use at age 39, with no significant role for beliefs about smoking.

CONCLUSIONS

Cigarette use was highly stable across the 30s, but social environmental factors provided significant partial mediation of this stability. Pathways were different for combustible and electronic cigarette use, however, with personal smoking norms playing an important role for the former but not the latter.

IMPLICATIONS

This study addresses the need for longitudinal investigation of social mechanisms and cigarette use in the 30s. Findings reinforce efforts to prevent the uptake of cigarettes prior to the 30s because, once started, smoking is highly stable. But social environmental factors remain viable intervention targets in the 30s to disrupt this stability. Addressing personal norms about smoking's acceptability and social costs is likely a promising approach for combustible cigarette use. Electronic cigarettes, however, present a new challenge in that many perceived social costs of cigarette use do not readily translate to this relatively recent technology.

Maternal and infant prediction of the child BMI trajectories; studies across two generations of Northern Finland birth cohorts

BACKGROUND/OBJECTIVE

Children BMI is a longitudinal phenotype, developing through interplays between genetic and environmental factors. Whilst childhood obesity is escalating, we require a better understanding of its early origins and variation across generations to prevent it.

SUBJECTS/METHODS

We designed a cross-cohort study including 12,040 Finnish children from the Northern Finland Birth Cohorts 1966 and 1986 (NFBC1966 and NFBC1986) born before or at the start of the obesity epidemic. We used group-based trajectory modelling to identify BMI trajectories from 2 to 20 years. We subsequently tested their associations with early determinants (mother and child) and the possible difference between generations, adjusted for relevant biological and socioeconomic confounders.

RESULTS

We identified four BMI trajectories, 'stable-low' (34.8%), 'normal' (44.0%), 'stable-high' (17.5%) and 'early-increase' (3.7%). The 'early-increase' trajectory represented the highest risk for obesity. We analysed a dose-response association of maternal pre-pregnancy BMI and smoking with BMI trajectories. The directions of effect were consistent across generations and the effect sizes tended to increase from earlier generation to later. Respectively for NFBC1966 and NFBC1986, the adjusted risk ratios of being in the early-increase group were 1.08 (1.06-1.10) and 1.12 (1.09-1.15) per unit of pre-pregnancy BMI and 1.44 (1.05-1.96) and 1.48 (1.17-1.87) in offspring of smoking mothers compared to non-smokers. We observed similar relations with infant factors including birthweight for gestational age and peak weight velocity. In contrast, the age at adiposity peak in infancy was associated with the BMI trajectories in NFBC1966 but did not replicate in NFBC1986.

CONCLUSIONS

Exposures to adverse maternal predictors were associated with a higher risk obesity trajectory and were consistent across generations. However, we found a discordant association for the timing of adiposity peak over a 20-year period. This suggests the role of residual environmental factors, such as nutrition, and warrants additional research to understand the underlying gene-environment interplay.

Group‐based trajectory modeling of body mass index and body size over the life course: A scoping review

Background

Group‐based trajectory modeling has been applied to identify distinct trajectories of growth across the life course. Objectives of this study were to describe the methodological approaches for group‐based modeling of growth across the life course and to summarize outcomes across studies.

Methods

A scoping review with a systematic search of Medline, EMBASE, CINAL, and Web of Science was conducted. Studies that used a group‐based procedure to identify trajectories on any statistical software were included. Data were extracted on trajectory methodology, measures of growth, and association with outcomes.

Results

A total of 59 studies were included, and most were published from 2013 to 2020. Body mass index was the most common measure of growth (n = 43). The median number of identified trajectories was 4 (range: 2–9). PROC TRAJ in SAS was used by 33 studies, other procedures used include TRAJ in STATA, lcmm in R, and Mplus. Most studies evaluated associations between growth trajectories and chronic disease outcomes (n = 22).

Conclusions

Group‐based trajectory modeling of growth in adults is emerging in epidemiologic research, with four distinct trajectories observed somewhat consistently from all studies. Understanding life course growth trajectories may provide further insight for population health interventions.

Effects of Social Development Intervention in Childhood on Adult Life at Ages 30 to 39

Elementary schools can be effective sites for universal preventive interventions. Less is known about how long effects of intervention in elementary grades last. Can they improve outcomes in adulthood? To test effects of a social developmental intervention in the elementary grades on adult life through the 30s, the Seattle Social Development Project, a nonrandomized controlled trial, followed all consenting 5th-grade students (N = 808) from 18 Seattle public elementary schools from age 10 (in 1985) to age 39 (in 2014), with 88% retention. The sample was gender balanced and ethnically and economically diverse. The full intervention, called Raising Healthy Children, continued from Grades 1 through 6 and consisted of teacher in-service training in classroom management and instructional methods; cognitive, social, and refusal skills training for children; and parent workshops in child behavior monitoring and management, academic support, and anticipatory guidance. Using structural equation modeling, we examined intervention effects from age 30 to age 39 across 9 constructs indicating 3 domains of adult life: health behavior, positive functioning, and adult health and success. An omnibus test across all 9 constructs indicated a significant positive overall intervention-control difference. Examined individually, significant intervention effects included better health maintenance behavior, mental health, and overall adult health and success. Significant effects were not found on substance use disorder symptoms, sex-risk behaviors, or healthy close relationships in the 30s. Results indicate that sustained, theory-based, multicomponent intervention in the elementary grades can produce lasting changes in health maintenance, mental health, and adult functioning through the 30s.

Weight change and risk of the foundation of National Institute of Health Sarcopenia-defined low lean mass: Data from the National Health and Nutrition examination surveys 1999-2004

BACKGROUND

Self-reported weight change may lead to adverse outcomes. We evaluated weight change with cutpoints of low lean mass (LLM) in older adults.

METHODS

Of 4984 subjects ≥60 years from NHANES 1999-2004, we applied LLM cutoffs of appendicular lean mass (ALM):body mass index (BMI) males<0.789, females<0.512. Self-reported weight was assessed at time of survey, and questions asked participants their weight one and 10 years earlier, and at age 25. Weight changes were categorized as greater/less/none than 5%. Logistic regression assessed weight change (gain, loss, no change) on LLM, after adjustment.

RESULTS

Of 4984 participants (56.5% female), mean age and BMI were 71.1 years and 28.2 kg/m2. Mean ALM was 19.7 kg. In those with LLM, 13.5% and 16.3% gained/lost weight in the past year, while 48.9% and 19.4% gained/lost weight in the past decade. Compared to weight at age 25, 85.2 and 6.1% of LLM participants gained and lost ≥5% of their weight, respectively. Weight gain over the past year was associated with a higher risk of LLM (OR 1.35 [0.99,1.87]) compared to weight loss ≥5% over the past year (0.89 [0.70,1.12]). Weight gain (≥5%) over 10-years was associated with a higher risk of LLM (OR 2.03 [1.66, 2.49]) while weight loss (≥5%) was associated with a lower risk (OR 0.98 [0.76,1.28]). Results were robust compared to weight at 25 years (gain OR 2.37 [1.76,3.20]; loss OR 0.95 [0.65,1.39]).

CONCLUSION

Self-reported weight gain suggests an increased risk of LLM. Future studies need to verify the relationship with physical function.

Body Mass Index Trajectory-Specific Changes in Economic Circumstances: A Person-Oriented Approach Among Midlife and Ageing Finns

Economic disadvantage is related to a higher risk of adulthood obesity, but few studies have considered whether changes in economic circumstances depend on a person's body mass index (BMI) trajectory. We identified latent BMI trajectories among midlife and ageing Finns and captured individual-level changes in economic circumstances within the BMI trajectories utilizing sequence analysis. We used the Helsinki Health Study cohort data of initially 40-60-year-old Finnish municipal employees, with four survey questionnaire phases (2000-2017). Each survey included identical questions on height and weight, and on economic circumstances incorporating household income and current economic difficulties. Based on computed BMI, we identified participants' (n = 7105; 82% women) BMI trajectories over the follow-up using group-based trajectory modeling. Four BMI trajectories were identified: stable healthy weight (34% of the participants), stable overweight (42%), overweight to class I obesity (20%), and stable class II obesity (5%). Lower household income level and having economic difficulties became more common and persistent when moving from lower- to higher-level BMI trajectories. Differences in household income widened over the follow-up between the trajectory groups, whereas economic difficulties decreased equally in all trajectory groups over time. Our study provides novel information on the dynamic interplay between long-term BMI changes and economic circumstances.

Severely restricting energy intake for 24 h does not affect markers of bone metabolism at rest or in response to re-feeding

PURPOSE

Intermittent energy restriction commonly refers to ad libitum energy intake punctuated with 24 h periods of severe energy restriction. This can improve markers of metabolic health but the effects on bone metabolism are unknown. This study assessed how 24 h severe energy restriction and subsequent refeeding affected markers of bone turnover.

METHODS

In a randomised order, 16 lean men and women completed 2, 48 h trials over 3 days. On day 1, participants consumed a 24 h diet providing 100% [EB: 9.27 (1.43) MJ] or 25% [ER: 2.33 (0.34) MJ] of estimated energy requirements. On day 2, participants consumed a standardised breakfast (08:00), followed by an ad libitum lunch (12:00) and dinner (19:30). Participants then fasted overnight, returning on day 3. Plasma concentrations of C-terminal telopeptide of type I collagen (CTX), procollagen type 1 N-terminal propeptide (P1NP) and parathyroid hormone (PTH) were assessed as indices of bone metabolism after an overnight fast on days 1-3, and for 4 h after breakfast on day 2.

RESULTS

There were no differences between trials in fasting concentrations of CTX, P1NP or PTH on days 1-3 (P > 0.512). During both trials, consuming breakfast reduced CTX between 1 and 4 h (P < 0.001) and PTH between 1 and 2 h (P < 0.05), but did not affect P1NP (P = 0.773) Postprandial responses for CTX (P = 0.157), P1NP (P = 0.148) and PTH (P = 0.575) were not different between trials. Ad libitum energy intake on day 2 was greater on ER [12.62 (2.46) MJ] than EB [11.91 (2.49) MJ].

CONCLUSIONS

Twenty-four hour severe energy restriction does not affect markers of bone metabolism.

How youth cognitive and sociodemographic factors relate to the development of overweight and obesity in the UK and the USA: a prospective cross-cohort study of the National Child Development Study and National Longitudinal Study of Youth 1979

OBJECTIVES

We investigated how youth cognitive and sociodemographic factors are associated with the aetiology of overweight and obesity. We examined both onset (who is at early risk for overweight and obesity) and development (who gains weight and when).

DESIGN

Prospective cohort study.

SETTING

We used data from the US National Longitudinal Study of Youth 1979 (NLSY) and the UK National Child Development Study (NCDS); most of both studies completed a cognitive function test in youth.

PARTICIPANTS

12 686 and 18 558 members of the NLSY and NCDS, respectively, with data on validated measures of youth cognitive function, youth socioeconomic disadvantage (eg, parental occupational class and time spent in school) and educational attainment. Height, weight and income data were available from across adulthood, from individuals' 20s into their 50s.

PRIMARY AND SECONDARY OUTCOME MEASURES

Body mass index (BMI) for four time points in adulthood. We modelled gain in BMI using latent growth curve models to capture linear and quadratic components of change in BMI over time.

RESULTS

Across cohorts, higher cognitive function was associated with lower overall BMI. In the UK, 1 SD higher score in cognitive function was associated with lower BMI (β=-0.20, 95% CI -0.33 to -0.06 kg/m²). In America, this was true only for women (β=-0.53, 95% CI -0.90 to -0.15 kg/m²), for whom higher cognitive function was associated with lower BMI. In British participants only, we found limited evidence for negative and positive associations, respectively, between education (β=-0.15, 95% CI -0.26 to -0.04 kg/m²) and socioeconomic disadvantage (β=0.33, 95% CI 0.23 to 0.43 kg/m²) and higher BMI. Overall, no cognitive or socioeconomic factors in youth were associated with longitudinal changes in BMI.

CONCLUSIONS

While sociodemographic and particularly cognitive factors can explain some patterns in individuals' overall weight levels, differences in who gains weight in adulthood could not be explained by any of these factors.

Change in prepregnancy body mass index and gastroschisis

PURPOSE

Maternal body mass index (BMI) is inversely associated with gastroschisis, but a causal relationship has not been established. As data demonstrating that a change in exposure status is related to a change in the frequency of the outcome can add to the evidence for causality, we conducted a case-control study of change in maternal BMI, assessed using interpregnancy change in BMI (IPC-BMI), and gastroschisis.

METHODS

Data for 258 gastroschisis cases and 2561 controls were obtained from the Texas Birth Defects Registry and vital records (2006-2012). Logistic regression was used to estimate the adjusted association between IPC-BMI and gastroschisis.

RESULTS

The continuous IPC-BMI variable was inversely associated with gastroschisis (adjusted odds ratio [aOR] = 0.90, 95% confidence interval [CI]: 0.86, 0.95). When assessed as a six-level categorical variable, with weight stable women as the referent, the odds of gastroschisis were higher following a BMI decrease of greater than 1 unit (aOR = 1.37, 95% CI: 0.91, 2.06) and lower after a BMI increase of ≥3 units (aOR = 0.62, 95% CI: 0.42, 0.94).

CONCLUSIONS

Our findings suggest that maternal change in BMI is associated with gastroschisis and, thus, add to the epidemiological evidence that can be used to inform our understanding of the relationship between BMI and gastroschisis.

Interpregnancy change in body mass index and infant outcomes in Texas: a population-based study

Background

Maternal prepregnancy body mass index (BMI) is associated with several infant outcomes, but it is unclear whether these associations reflect causal relationships. We conducted a study of interpregnancy change in BMI (IPC-BMI) to improve understanding of the associations between BMI and large for gestational age (LGA), small for gestational age (SGA), and preterm birth (PTB).

Methods

Birth certificate data from 2481 linked sibling pairs (Texas, 2005–2012) were used to estimate IPC-BMI and evaluate its association with LGA, SGA, and PTB in the younger sibling of the pair. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) using data from the full sample and within strata defined by prepregnancy BMI for the older sibling.

Results

On average, women gained 1.1 BMI units between pregnancies. In the full sample, interpregnancy BMI decreases were associated with reduced odds of LGA and increased odds of SGA and PTB (IPC-BMI < -1 versus 0 to < 1: LGA aOR 0.7, 95% CI 0.4, 1.1; SGA aOR 1.6, 95% CI 1.0, 2.7; PTB aOR 1.9, 95% CI 1.3, 2.8). In stratified analyses, similar associations were observed in some, but not all, strata. Findings for interpregnancy BMI increases were less consistent, with little evidence for associations between these outcomes and the most extreme IPC-BMI increases.

Conclusions

There is growing evidence that interpregnancy BMI decreases are associated with LGA, SGA, and PTB. However, taken as a whole, the literature provides insufficient evidence to establish causal links between maternal BMI and these outcomes.

A single day of mixed-macronutrient overfeeding does not elicit compensatory appetite or energy intake responses but exaggerates postprandial lipaemia during the next day in healthy young men

Discrete episodes of overconsumption may induce a positive energy balance and impair metabolic control. However, the effects of an ecologically relevant, single day of balanced macronutrient overfeeding are unknown. Twelve healthy men (of age 22 (sd 2) years, BMI 26·1 (sd 4·2) kg/m2) completed two 28 h, single-blind experimental trials. In a counterbalanced repeated measures design, participants either consumed their calculated daily energy requirements (energy balance trial (EB): 10 755 (sd 593) kJ) or were overfed by 50 % (overfeed trial (OF): 16 132 (sd 889) kJ) under laboratory supervision. Participants returned to the laboratory the next day, after an overnight fast, to complete a mixed-meal tolerance test (MTT). Appetite was not different between trials during day 1 (P&gt;0·211) or during the MTT in the fasted or postprandial state (P&gt;0·507). Accordingly, plasma acylated ghrelin, total glucagon-like peptide-1 and total peptide YY concentrations did not differ between trials during the MTT (all P&gt;0·335). Ad libitum energy intake, assessed upon completion of the MTT, did not differ between trials (EB 6081 (sd 2260) kJ; OF 6182 (sd 1960) kJ; P=0·781). Plasma glucose and insulin concentrations were not different between trials (P&gt;0·715). Fasted NEFA concentrations were lower in OF compared with EB (P=0·005), and TAG concentrations increased to a greater extent on OF than on EB during the MTT (P=0·009). The absence of compensatory changes in appetite-related variables after 1 d of mixed macronutrient overfeeding highlights the limited physiological response to defend against excess energy intake. This supports the concept that repeated discrete episodes of overconsumption may promote weight gain, while elevations in postprandial lipaemia may increase CVD risk.

Body mass index trajectories during the first year of life and their determining factors

OBJECTIVE

The purpose of this study was to examine the trajectories of body mass index (BMI) in the first year of life and their determining factors.

METHODS

We used data from the Infant Feeding Practices Survey II restricted to children with 2 or more time points of BMI data during follow-up visits within the first year of life (n = 2320). Latent class growth analysis was used to identify distinct BMI trajectories. Using multinomial logistic regression, we examined the prenatal and early life determinants of the identified trajectories.

RESULTS

Three BMI trajectories were identified during the first year of life: "low-stable" (81.6%), "high-stable" (15.6%), and "rising" (2.8%) trajectories. Boys, preterm infants, infants born to overweight mothers, Hispanic mothers, non-Hispanic Black mothers, and mothers who smoked during pregnancy were significantly more likely to have high-stable versus low-stable trajectories. Infants born to non-Hispanic Black mothers were more likely to have a rising versus a low-stable trajectory. Household income ≥350% of the federal poverty level and full adherence to the guidelines of the American Academy of Pediatrics for both breastfeeding exclusivity and duration reduced the likelihood of infants being in the rising versus the low-stable trajectory.

CONCLUSION

Distinct BMI trajectories were evident as early as infancy. The predictors of these trajectories offer information about high-risk groups, and important and preventable prenatal and postnatal risk factors for future intervention programs.

Life course trajectories of cardiovascular risk: Impact on atherosclerotic and metabolic indicators

BACKGROUND AND AIMS

In this analysis, we estimated population-level trajectory groups of life course cardiovascular risk to explore their impact on mid-life atherosclerotic and metabolic outcomes.

METHODS

This prospective study followed n = 1269 Bogalusa Heart participants, each with at least 4 study visits from childhood in 1973 through adulthood in 2016. We used discrete mixture modeling to determine trajectories of cardiovascular risk percentiles from childhood to adulthood. Outcomes included mid-life subclinical atherosclerotic measures [(carotid intima-media thickness (cIMT), pulse wave velocity (PWV)], metabolic indicators [(diabetes and body mass index (BMI)], and short physical performance battery (SPPB).

RESULTS

Between the mean ages of 9.6-48.3 years, we estimated five distinct trajectory groups of life course cardiovascular risk (High-Low, High-High, Mid-Low, Low-Low, and Low-High). Adult metabolic and vascular outcomes were significantly determined by life course cardiovascular risk trajectory groups (all p < 0.01). Those in the High-Low group had lower risks of diabetes (20% vs. 28%, respectively; p = .12) and lower BMIs (32.4 kg/m²vs. 34.6 kg/m²; p = .06) than those who remained at high risk (High-High) throughout life. However, the High-Low group had better cIMT (0.89 mm vs. 1.05 mm; p < .0001) and PWV (7.8 m/s vs. 8.2 m/s; p = .03) than the High-High group. For all outcomes, those in the Low-Low group fared best.

CONCLUSIONS

We found considerable movement between low- and high-relative cardiovascular risk strata over the life course. Children who improved their relative cardiovascular risk over the life course achieved better mid-life atherosclerotic health despite maintaining relatively poor metabolic health through adulthood.

24-h severe energy restriction impairs postprandial glycaemic control in young, lean males

Intermittent energy restriction (IER) involves short periods of severe energy restriction interspersed with periods of adequate energy intake, and can induce weight loss. Insulin sensitivity is impaired by short-term, complete energy restriction, but the effects of IER are not well known. In randomised order, fourteen lean men (age: 25 (sd 4) years; BMI: 24 (sd 2) kg/m2; body fat: 17 (4) %) consumed 24-h diets providing 100 % (10 441 (sd 812) kJ; energy balance (EB)) or 25 % (2622 (sd 204) kJ; energy restriction (ER)) of estimated energy requirements, followed by an oral glucose tolerance test (OGTT; 75 g of glucose drink) after fasting overnight. Plasma/serum glucose, insulin, NEFA, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and fibroblast growth factor 21 (FGF21) were assessed before and after (0 h) each 24-h dietary intervention, and throughout the 2-h OGTT. Homoeostatic model assessment of insulin resistance (HOMA2-IR) assessed the fasted response and incremental AUC (iAUC) or total AUC (tAUC) were calculated during the OGTT. At 0 h, HOMA2-IR was 23 % lower after ER compared with EB (P<0·05). During the OGTT, serum glucose iAUC (P<0·001), serum insulin iAUC (P<0·05) and plasma NEFA tAUC (P<0·01) were greater during ER, but GLP-1 (P=0·161), GIP (P=0·473) and FGF21 (P=0·497) tAUC were similar between trials. These results demonstrate that severe energy restriction acutely impairs postprandial glycaemic control in lean men, despite reducing HOMA2-IR. Chronic intervention studies are required to elucidate the long-term effects of IER on indices of insulin sensitivity, particularly in the absence of weight loss.

Energy depletion by 24-h fast leads to compensatory appetite responses compared with matched energy depletion by exercise in healthy young males

Although there is a growing interest for the effects of intermittent fasting on energy balance, this study aimed to compare appetite, energy intake and food reward responses with an energy depletion induced either by 24-h food restriction or an equivalent deficit with exercise in healthy males. In all, twelve healthy lean males (21·5 (sd 0·5) years old; BMI: 22·5 (sd 1·7) kg/m2) participated in this study. Body composition, aerobic capacity, food preferences and energy intake were assessed. They randomly completed three conditions: (i) no depletion (CON); (ii) full 24-h energy restrictions (Def-EI); and (iii) exercise condition (Def-EX). Ad libitum energy intake and food reward were assessed at the end of each session. Appetite feelings were assessed regularly. Ad libitum energy intake was higher on Def-EI (7330 (sd 2975) kJ (1752 (sd 711) kcal) compared with that on CON (5301 (sd 1205) kJ (1267 (sd 288) kcal)) (P<0·05), with no difference between CON and Def-EX (6238 (sd 1741) kJ (1491 (sd 416) kcal) (P=0·38) and between Def-EX and Def-EI (P=0·22). There was no difference in the percent energy ingested from macronutrients. Hunger was lower on CON and Def-EX compared with Def-EI (P<0·001). Satiety was higher on CON and Def-EI compared with that on Def-EX (P<0·001). There was a significant interaction condition × time for food choice fat bias (P=0·04), showing a greater preference for high-fat v. low-fat food during Def-EI and Def-EX. Although 24-h fasting leads to increased energy intake at the following test meal (without total daily energy intake difference), increased hunger profile and decreased post-meal food choice fat bias, such nutritional responses are not observed after a similar deficit induced by exercise.

Body Mass Index Trajectories From Birth to Midlife and Vertebral Dimensions in Midlife: the Northern Finland Birth Cohort 1966 Study

Vertebral fracture risk is higher among individuals with small vertebral dimensions. Obesity is a global health problem and may also contribute to bone size and fracture risk. In this work we report the association between life course body mass index (BMI) and vertebral cross-sectional area (CSA) in midlife. The Northern Finland Birth Cohort 1966 study with its 46-year follow-up provided the material for this study. A subsample of 780 individuals had attended lumbar magnetic resonance imaging (MRI) at the age of 46 years, and had records of objectively measured BMI from the ages of 0, 7, 15, 31, and 46 years. Of these, MRI-derived data on vertebral size was available for 682 individuals. We identified latent lifelong BMI trajectories by performing latent class growth modeling (LCGM) on the BMI data, and then used sex-stratified linear regression models to compare the identified trajectory groups in terms of midlife vertebral CSA. Gestational age, education years, adult height, lifelong physical activity, lifelong smoking history, and adulthood diet were assessed as potential confounders. Three distinct trajectory groups ("stable slim," "stable average," and "early onset overweight") were identified among both sexes. Comparisons to the stable slim trajectory revealed that vertebral CSA was significantly (p < 0.001) larger among the stable average and early onset overweight trajectories (69.8 and 118.6 mm² larger among men, 57.7 and 106.1 mm² larger among women, respectively). We conclude that lifelong BMI has a positive association with midlife vertebral size among both sexes. Future studies should characterize the mediating factors of this association.

The weight of fatherhood: identifying mechanisms to explain paternal perinatal weight gain

Men appear to gain weight during the transition to parenthood, and fathers are heavier than non-fathers. Paternal perinatal weight gain may set weight trajectories in midlife and have long-term health implications. Since men do not undergo the physical demands of pregnancy and breastfeeding, the specific mechanisms underlying weight gain in new fathers warrant investigation. This review aims to stimulate research on paternal perinatal weight gain by suggesting testable potential mechanisms that (1) show change across the transition to parenthood and (2) play a role in weight and body composition. We identify seven mechanisms, within three categories: behavioural mechanisms (sleep, physical activity, and diet), hormonal mechanisms (testosterone and cortisol), and psychological mechanisms (depression and stress). We also discuss direct effects of partner pregnancy influences (e.g., 'couvade syndrome') on men's body weight. In presenting each mechanism, we discuss how it may be affected by the transition to parenthood, and then review its role in body composition and weight. Next, we describe bidirectional and interactive effects, discuss timing, and present three broad research questions to propel theoretical development.

Maternal preconception weight trajectories are associated with offsprings' childhood obesity

OBJECTIVES

This study aimed to examine the associations between (1) mothers' preconception body mass index (BMI) trajectories over 6-7 years and offspring childhood BMI, and (2) mothers' BMI changes between first and second pregnancy and the second-born child's BMI.

METHODS

We used data (1606 mothers with 2733 children with mean age 7.7 years, SD 2.9) from the Australian Longitudinal Study on Women's Health and the Mothers and their Children's Health study. Preconception BMI trajectories were identified using latent class growth modeling. Children were categorized as underweight, normal, overweight or obese based on age and sex-specific BMI cut-off points for children. Multinomial and binary logistic regression were used for analyses.

RESULTS

We identified three preconception BMI trajectories, named as 'normative' (61.2%), 'chronically overweight' (30.7%), and 'chronically obese' (8.1%). Children born to 'chronically overweight' and 'chronically obese' mothers were more likely to be overweight than normal weight relative to children born to women with a 'normative' BMI trajectory. The corresponding adjusted relative risk ratios (RRRs) (95% confidence interval [CI]) of childhood overweight were 1.75 (1.33, 2.31) for chronically overweight mothers and 2.48 (1.65, 3.73) for chronically obese mothers. Similarly, we found a much stronger association between 'chronically overweight' and 'chronically obese' BMI trajectories and childhood risk of obesity; RRR (95% CI), 2.49 (1.41, 4.40) and 6.65 (3.40, 13.01), respectively. Second-born children of mothers with high interpregnancy weight gain (≥4 BMI units) were also at higher risk of being overweight or obese (OR = 2.20, 95% CI: 1.02, 4.75) compared with children of mothers with stable interpregnancy weight (gain or loss of 1 BMI unit or less).

CONCLUSIONS

In this population-based prospective cohort study, we found strong dose-response associations between preconception BMI trajectories and offsprings' childhood BMI.

"Take Me through the History of Your Weight": Using Qualitative Interviews to Create Personalized Weight Trajectories to Understand the Development of Obesity in Patients Preparing for Bariatric Surgery

BACKGROUND

Obesity can develop during any life stage. Understanding the contexts within which obesity develops can inform our understanding of the disease and help tailor interventions specific to life stages.

OBJECTIVE

Using life-course theory as a guiding framework, this study aimed to explain the development of obesity in bariatric surgery patients by creating personalized weight trajectories.

DESIGN

Qualitative methods using semistructured interviews were used to uncover participants' experiences with and explanations for the development of obesity. A grounded theory approach using the constant comparative method was used to analyze transcripts for categories and themes.

PARTICIPANTS/SETTING

Thirty pre-bariatric surgery patients (24 women, 6 men) were recruited from a bariatric surgery center; 25 participants were available for follow-up. Participants were interviewed before surgery and at 6 and 12 months postsurgery.

RESULTS

Four weight history groups were created based on patterns of weight changes from adolescence through adulthood: Always Heavy, Late Peak, Steady Progression, and Weight Cycling. Participants' explanations for weight changes centered around themes of transitions and life-course events or stressors. Differences in the weight history groups could be explained by the timing of transitions, life events, and responses to stress.

CONCLUSIONS

The development of obesity does not follow the same pattern for all individuals. Weight gain patterns can be explained by the timing of life-course events, stressors, and the type and effects of environmental transitions. Weight management counseling should include strategies tailored to an individual's current life-stage and circumstance, but also acknowledge previous responses to transitions and stressors.

Weight Mobility and Obesity in a Representative Sample of the US Adult Population

BACKGROUND

Despite the attention given to the prevalence of obesity, surprisingly little is known about the incidence or reduction of obesity. We report the 1-year incidence and remission of obesity in a representative sample of the US population.

METHODS

Individuals from the Medical Expenditure Panel Survey (MEPS) panel 17 were classified into standard obesity categories at enrollment and one year later. Incidence rates were calculated by age.

RESULTS

Although the overall prevalence of obesity remained nearly constant, remission rates from obesity (stratified by age) ranged from 11 to 27% while incidence rates ranged from 6 to 16%. For almost all age levels, the proportion of individuals leaving an obese or overweight state was greater than or equal to the proportion who progressed to a more severe level of overweight or obesity. Overall, 36% of adults lost at least 2.5 kg/m² in the one-year period; only 8% gained 2.5 kg/m² or more. Individuals less than 25 years of age had higher rates of leaving overweight (23% versus <16%) and obesity (27% versus 24%) classifications than people of other ages.

CONCLUSIONS

Prevalence rates of obesity are well documented in the United States, but incidence is understudied. Public health efforts that target young people with overweight or obesity may yield the greatest benefit.

Trajectories of body mass index among Canadian seniors and associated mortality risk

Background

This study aims to characterize the heterogeneity in BMI trajectories and evaluate how different BMI trajectories predict mortality risk in Canadian seniors.

Methods

Data came from the Canadian National Population Health Survey (NPHS, 1994–2011) and 1480 individuals aged 65–79 years with at least four BMI records were included in this study. Group-based trajectory model was used to identify distinct subgroups of longitudinal trajectories of BMI measured over 19 years for men and women. Cox proportional hazards models were used to examine the association between BMI trajectories and mortality risks.

Results

Distinct trajectory patterns were found for men and women: ‘Normal Weight-Down’(N-D), ‘Overweight-Normal weight’ (OV-N), ‘Obese I-Down’ (OB I-D), and ‘Obese II- Down’ (OB II-D) for women; and ‘Normal Weight-Down’ (N-D), ‘Overweight-Normal weight’ (OV-N), ‘Overweight-Stable’ (OV-S), and ‘Obese-Stable’ (OB-S) for men. Comparing with OV-N, men in the OV-S group had the lowest mortality risk followed by the N-D (HR = 1.66) and OB-S (HR = 1.98) groups, after adjusting for covariates. Compared with OV-N, women in the OB II-D group with three or more chronic health conditions had higher mortality risk (HR = 1.61); however, women in OB II-D had lower risk (HR = 0.56) if they had less than three conditions.

Conclusion

The course of BMI over time in Canadian seniors appears to follow one of four different patterns depending on gender. The findings suggest that men who were overweight at age 65 and lost weight over time had the lowest mortality risk. Interestingly, obese women with decreasing BMI have different mortality risks, depending on their chronic health conditions. The findings provide new insights concerning the associations between BMI and mortality risk.

Body mass index trajectories in childhood is predictive of cardiovascular risk: results from the 23-year longitudinal Georgia Stress and Heart study

The childhood high body mass index (BMI) is associated with cardiovascular risk, but the association between childhood BMI trajectory patterns and cardiovascular risk remains unclear. The purposes of this study are to identify subgroups of individuals with similar trajectories in BMI during childhood, and to determine the relationship of childhood BMI trajectories with subclinical cardiovascular disease in young adulthood, indexed by intima-media thickness (IMT) and left ventricular mass index (LVMI). The participants were from the Georgia Stress and Heart (GSH) study. A total of 626 participants with BMI measured 3–12 times during childhood (5–18 years old) were included. By using latent class models, three trajectory groups in BMI were identified, including high increasing (HI), moderate increasing (MI), and normal group. We found that childhood trajectory of BMI was significantly associated with IMT and LVMI in young adulthood even after adjustment for BMI in young adulthood. Our results suggested that different BMI trajectory patterns exist during childhood. We for the first time reported the association between childhood BMI trajectory patterns and subclinical cardiovascular risk in young adulthood, indicating that monitoring trajectories of BMI from childhood may help to identify a high cardiovascular risk population in early life.

Disease activity trajectories in early rheumatoid arthritis following intensive DMARD therapy over 3 years: association with persistence to therapy

OBJECTIVE

To identify the disease activity trajectories during intensive triple disease modifying anti-rheumatic drug (DMARD) therapy over 3 years in rheumatoid arthritis (RA) patients and to evaluate the association with treatment persistence.

METHODS

Disease Activity Score in 28 joints, baseline risk factors and medication usage were obtained from a longitudinal observational cohort of early RA patients, most of whom were treated with combination DMARD therapy consisting of methotrexate, sulfasalazine and hydroxychloroquine. Persistence of each DMARD was defined as the duration of time from initiation to cessation. A group-based trajectory modelling technique was used to identify disease activity trajectories.

RESULT

Three disease activity trajectories (good [43.8%], moderate [39.7%] and poor [16.5%]) were identified in a cohort of 297 patients. Most baseline risk factors, medication usage, the rate of treatment persistence and the effect of persistence on disease activity differed among patients in each of the three trajectories. Although the rate of persistence was higher in the trajectory with a good outcome, the association with persistence was more pronounced among patients who were in the poor outcome trajectory. Persistence with at least two or all three baseline DMARDs was associated with a decrease in disease activity to a broadly similar degree in all trajectories.

CONCLUSION

After correction for other baseline prognostic factors, persistence with initial DMARDs contributes to heterogeneity in disease activity trajectory and there was an association between persistence with initial DMARD therapy and lower long-term disease activity.

Childhood body mass index and endothelial dysfunction evaluated by peripheral arterial tonometry in early midlife

BACKGROUND/OBJECTIVES

Endothelial dysfunction predicts mortality but it is unknown whether childhood obesity predicts adult endothelial dysfunction. The aim of this study was to determine whether anthropometric indices of body fat in childhood, adolescence and early midlife are associated with endothelial dysfunction in early midlife.

SUBJECTS/METHODS

Participants belonged to a representative birth cohort of 1037 individuals born in Dunedin, New Zealand in 1972 and 1973 and followed to age 38 years, with 95% retention (the Dunedin Multidisciplinary Health and Development Study). We assessed anthropometric indices of obesity at ages 3, 5, 7, 9, 11, 13, 15, 18, 21, 26, 32 and 38 years. We tested associations between endothelial function assessed by peripheral arterial tonometry (PAT) at age 38 and; age 38 cardiovascular risk factors; age 3 body mass index (BMI); and four BMI trajectory groups from childhood to early midlife.

RESULTS

Early midlife endothelial dysfunction was associated with BMI, large waist circumference, low high-density lipoprotein cholesterol, low cardiorespiratory fitness and increased high-sensitivity C-reactive protein. After adjustment for sex and childhood socioeconomic status, 3-year-olds with BMI 1 s.d. above the mean had Framingham-reactive hyperemia index (F-RHI) ratios that were 0.10 below those with normal BMI (β=-0.10, 95% confidence interval (CI) -0.17 to -0.03, P=0.007) at age 38. Cohort members in the 'overweight', 'obese' and 'morbidly obese' trajectories had F-RHI ratios that were 0.08 (β=-0.08, 95% CI -0.14 to -0.03, P=0.003), 0.13 (β=-0.13, 95% CI -0.21 to -0.06, P<0.001) and 0.17 (β=-0.17, 95% CI -0.33 to -0.01, P=0.033), respectively, below age-peers in the 'normal' trajectory.

CONCLUSIONS

Childhood BMI and the trajectories of BMI from childhood to early midlife predict endothelial dysfunction evaluated by PAT in early midlife.

Longitudinal Modeling of Depressive Trajectories Among HIV-Infected Men Using Cocaine

Cocaine use is prevalent among HIV-infected individuals. While cross-sectional studies suggest that cocaine users may be at increased risk for depression, long-term effects of cocaine on depressive symptoms remain unclear. This is a longitudinal study of 341 HIV-infected and uninfected men (135 cocaine users and 206 controls) ages 30-60 enrolled in the Multicenter AIDS Cohort Study during 1996-2009. The median baseline age was 41; 73% were African-American. In mixed-effects models over a median of 4.8 years of observation, cocaine use was associated with higher depressive symptoms independent of age, education level, and smoking (n = 288; p = 0.02); HIV infection modified this association (p = 0.03). Latent class mixed models were used to empirically identify distinct depressive trajectories (n = 160). In adjusted models, cocaine use was associated with threefold increased odds of membership in the class with persistent high depressive symptoms (95% confidence interval (CI) 1.38-6.69) and eightfold increased odds (95% CI (2.73-25.83) when tested among HIV-infected subjects only. Cocaine use is a risk factor for chronic depressive symptoms, particularly among HIV-infected men, highlighting the importance of integrating mental health and substance use treatments to address barriers to well-being and successful HIV-care.

Bayesian hierarchical piecewise regression models: a tool to detect trajectory divergence between groups in long-term observational studies

Background

Bayesian hierarchical piecewise regression (BHPR) modeling has not been previously formulated to detect and characterise the mechanism of trajectory divergence between groups of participants that have longitudinal responses with distinct developmental phases. These models are useful when participants in a prospective cohort study are grouped according to a distal dichotomous health outcome. Indeed, a refined understanding of how deleterious risk factor profiles develop across the life-course may help inform early-life interventions. Previous techniques to determine between-group differences in risk factors at each age may result in biased estimate of the age at divergence.

Methods

We demonstrate the use of Bayesian hierarchical piecewise regression (BHPR) to generate a point estimate and credible interval for the age at which trajectories diverge between groups for continuous outcome measures that exhibit non-linear within-person response profiles over time. We illustrate our approach by modeling the divergence in childhood-to-adulthood body mass index (BMI) trajectories between two groups of adults with/without type 2 diabetes mellitus (T2DM) in the Cardiovascular Risk in Young Finns Study (YFS).

Results

Using the proposed BHPR approach, we estimated the BMI profiles of participants with T2DM diverged from healthy participants at age 16 years for males (95% credible interval (CI):13.5–18 years) and 21 years for females (95% CI: 19.5–23 years). These data suggest that a critical window for weight management intervention in preventing T2DM might exist before the age when BMI growth rate is naturally expected to decrease. Simulation showed that when using pairwise comparison of least-square means from categorical mixed models, smaller sample sizes tended to conclude a later age of divergence. In contrast, the point estimate of the divergence time is not biased by sample size when using the proposed BHPR method.

Conclusions

BHPR is a powerful analytic tool to model long-term non-linear longitudinal outcomes, enabling the identification of the age at which risk factor trajectories diverge between groups of participants. The method is suitable for the analysis of unbalanced longitudinal data, with only a limited number of repeated measures per participants and where the time-related outcome is typically marked by transitional changes or by distinct phases of change over time.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-017-0358-9) contains supplementary material, which is available to authorized users.

Obesity disproportionately impacts lung volumes, airflow and exhaled nitric oxide in children

Background

The current literature focusing on the effect of obesity and overweight on lung function and fraction of exhaled nitric oxide (FeNO) in children, particularly among healthy children of non-European descent, remains controversial. Furthermore, whether the relationship of obesity and overweight with lung function and FeNO in children is modified by atopy is unclear. The objective of this study was to examine the effect of excess weight on lung function parameters and FeNO among Asian children, with a particular focus on exploring the potential effect modification by atopy.

Methods

We investigated the effect of excess weight on lung function and FeNO in a population sample of 1,717 children aged 5 to 18 years and explored the potential modifying effect of atopy.

Results

There were positive associations of body mass index (BMI) z-score with forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), peak expiratory flow (PEF), and forced expiratory flow at 25–75% (FEF_25-75) (all P<0.001), after controlling for confounders. The beta coefficient for FEV₁ (0.084) was smaller than that for FVC (0.111). In contrast, a negative association was found between BMI z-score and FEV₁/FVC ratio (P<0.001) and FeNO (P = 0.03). A consistent pattern of association for lung function variables was observed when stratifying by atopy. There was a negative association of BMI z-score with FeNO in atopic subjects (P = 0.006), but not in non-atopic subjects (P = 0.46).

Conclusions

Excess weight disproportionately impacts lung volumes and airflow in children from the general population, independent of atopic status. Excess weight inversely affects FeNO in atopic but not in non-atopic children.

Disentangling the Contemporaneous and Dynamic Effects of Human and Health Capital on Wages over the Life Cycle

We quantify the life-cycle effects of human and health capital on the wage distribution of women, with a focus on health capital measured by body mass. We use NLSY79 data on women followed annually up to twenty years during the time of their lives when average annual weight gain is greatest. We measure the wage impact of current body mass (i.e., the contemporaneous or direct effect) while controlling for observed measures of human capital (namely, educational attainment, employment experience, marital status tenure, and family size) and the impacts of an evolving body mass (i.e., the dynamic or indirect effects) on the endogenous histories of behaviors that produce these human capital stocks. We find significant differences in the contemporaneous and dynamic effects of body mass on wages by age, by race, and by wage level.

Steeper change in body mass across four decades predicts poorer cardiometabolic outcomes at midlife

OBJECTIVE

This study examined patterns of change in adiposity across four decades starting in young adulthood as well as associations between change and midlife cardiometabolic outcomes.

METHODS

BMI was assessed at ages 20, 40, 56, and 62 years in 977 male veterans from the Vietnam Era Twin Study of Aging. Age 62 (range 56-66) cardiometabolic outcomes included hypertension, diabetes, dyslipidemia, inflammation, and ischemic heart disease. Analyses included latent growth modeling (LGM), latent class growth modeling (LCGM), and logistic regression models.

RESULTS

Linear BMI slope was associated with all outcomes. Accelerated (quadratic) BMI slope was significantly associated with greater risk for hypertension, diabetes, dyslipidemia, and inflammation; odds ratios ranged from 1.93 (diabetes) to 3.15 (dyslipidemia). Initial BMI did not predict later outcomes. Linear slope contributed significant unique variance for diabetes and dyslipidemia even controlling for age 62 BMI. LCGM revealed three trajectories. Men with the relatively stable, lower BMI trajectory had significantly better outcomes than those with trajectories with accelerated increases, especially those including obesity.

CONCLUSIONS

How individuals reach late-midlife BMI is important. Steepness of BMI change across 40 years from young adulthood to late midlife, in addition to late-midlife BMI itself, was robustly associated with greater risk for poor cardiometabolic outcomes.