Life-course trajectories of body mass index from adolescence to old age: Racial and educational disparities.

No research exists on how body mass index (BMI) changes with age over the full life span and social disparities therein. This study aims to fill the gap using an innovative life-course research design and analytic methods to model BMI trajectories from early adolescence to old age across 20th-century birth cohorts and test sociodemographic variation in such trajectories. We conducted the pooled integrative data analysis (IDA) to combine data from four national population-based NIH longitudinal cohort studies that collectively cover multiple stages of the life course (Add Health, MIDUS, ACL, and HRS) and estimate mixed-effects models of age trajectories of BMI for men and women. We examined associations of BMI trajectories with birth cohort, race/ethnicity, parental education, and adult educational attainment. We found higher mean levels of and larger increases in BMI with age across more recent birth cohorts as compared with earlier-born cohorts. Black and Hispanic excesses in BMI compared with Whites were present early in life and persisted at all ages, and, in the case of Black-White disparities, were of larger magnitude for more recent cohorts. Higher parental and adulthood educational attainment were associated with lower levels of BMI at all ages. Women with college-educated parents also experienced less cohort increase in mean BMI. Both race and education disparities in BMI trajectories were larger for women compared with men.

Ten-year weight gain is not associated with multiple cardiometabolic measures in Alaska EARTH study participants.

BACKGROUND AND AIMS: Alaska Native (AN) traditional lifestyle may be protective against chronic disease risk. Weight gain in adulthood has been linked to increases in chronic disease risk among other populations; yet, its impact among Alaska Native people has never been evaluated. We aimed to evaluate changes in obesity-related metrics over time, and determine associations of changes with cardiometabolic markers of chronic disease risk among AN people. METHODS AND RESULTS: Study participants enrolled in the southcentral Alaska Education and Research Towards Health Study in 2004-2006 were invited to participate in a follow-up study conducted 2015-2017. Of the original 1320 participants, 388 completed follow-up health assessments consisting of multiple health surveys, anthropometric measurements, and cardiometabolic measures including blood sugars, blood lipids, and blood pressure. Differences in measurements between visits were determined and associations of weight change with cardiometabolic measures evaluated. Body mass index increased by 3.7 kg/m2 among men and 4.8 kg/m2 among women. Hip circumference (1.1 cm, p < 0.01) and waist circumference (0.7 cm, p < 0.01) increased among women; only waist circumference increased among men (1.6 cm, p < 0.01). Among men, there were no associations of weight change with cardiometabolic measures. Among women, there was an inverse association between weight gain and high-density lipoprotein cholesterol only (0.17 mg/dL (CI: -3.1, -0.03), p = 0.02). CONCLUSIONS: While weight increase over a 10-year period was not associated with substantive changes in cardiometabolic measures among AN men, there was a decrease in high density lipid cholesterol associated with weight gain among AN women.

More rapid increase in BMI from age 5-15 is associated with elevated weight status at age 24 among non-Hispanic white females.

BACKGROUND: A rapidly increasing BMI trajectory throughout childhood is associated with negative health outcomes in adulthood such as obesity, cardiovascular disease, and diabetes. The purpose of the current study was to assess whether BMI trajectories from age 5-15 predicted changes in weight and BMI from adolescence to adulthood, and dieting-related behaviors in young adulthood. METHODS: Non-Hispanic White female participants from Early Dieting in Girls (n = 182), a longitudinal cohort study, were followed from age 5 to 15 and completed a follow-up survey at age 24. Participants were classified by age 5-15 BMI trajectory groups: UPC, accelerated weight gain from age 5-9; DDPC, accelerated weight gain from 5 to 9 followed by a decrease; 60PT, weight tracked along 60th percentile; 50PT, weight tracked along 50th percentile. Data at age 24 included self-reported weight, height, dietary restraint, disinhibition, and dieting. RESULTS: Majority of participants (80.8%) completed the follow-up survey; of these participants, 60% in UPC group had obesity at age 24, compared to <10% in the other 3 groups. Participants in the UPC group had greater increases in BMI since age 15, compared to the 50PT group, and trend-level greater weight increases than those in the DDPC and 60PT groups. Dietary restraint, but not disinhibition, differed across the groups. CONCLUSIONS: Children with accelerated weight gain continued to have the greatest weight gain from adolescence to adulthood and the highest prevalence of obesity in adulthood.

Body Composition Growth Patterns in Early Infancy: A Latent Class Trajectory Analysis of the Ethiopian iABC Birth Cohort.

OBJECTIVE: The objective of this study was to identify subgroups with distinct fat and fat-free growth patterns in the first 6 months of life and describe predictors of these different patterns. METHODS: A total of 510 apparently healthy Ethiopian infants were followed from birth to 6 months of age. Each infant had at least three and up to six repeated measurements of fat and fat-free mass using air-displacement plethysmography. Latent class trajectory analyses were used to categorize infants in groups with distinct body composition patterns. RESULTS: Four distinct fat mass and two fat-free mass growth patterns were identified. Of the infants measured, 5% presented a delayed fat growth pattern and 3% presented a catch-up fat growth pattern involving low birth weight but a significant fat growth velocity from 2.5 to 6 months. A large class had a high fat level at birth and an accelerated fat growth pattern in early infancy. Fat-free growth was represented by two distinct classes with less variability. Catch-up growth was primarily seen in fat mass. CONCLUSIONS: We identified distinct patterns of delayed, catch-up, and accelerated fat growth in early infancy. This variability is not detected in regular anthropometric assessment and could be a mechanism linking early growth with later obesity and cardiometabolic risk.

Maternal body weight trajectories across the life course and risk of preterm delivery.

We examined the association between life course body weight percentile trajectories and risk for preterm delivery (PTD). Data about women's weight at birth, age 18, and before pregnancy were obtained by retrospective self-report in a cohort of 1410 black women in metropolitan Detroit. Growth mixture models were used to categorize women with similar weight percentile trajectories across these time points. Log-Poisson models were used to examine the association between the trajectory groups and PTD. Four trajectory groups with different beginning and endpoints of their weight percentiles (high-high, high-low, low-high and low-low) best fit the data. The groups with the highest prevalence of PTD were those that started low (low-high, 21%; low-low, 18%). The low-high group had a higher prevalence of PTD than the high-high trajectory group in unadjusted models (prevalence ratio=1.49 [95% confidence interval (CI) 1.11, 2.00]). The association became not significant after adjusting for maternal age at delivery, income, diabetes and hypertension. When compared with the high-high trajectory group, the low-low trajectory seemed to also have a higher prevalence of PTD after adjusting for maternal age at delivery, income, diabetes and hypertension (prevalence ratio=1.35 [95% CI 1.00, 1.83]). Results suggest that a woman's risk for PTD is influenced by her body weight trajectory across the life course.