Associations of early childhood body mass index trajectories with body composition and cardiometabolic markers at age 10 years: the Ethiopian iABC birth cohort study

Background Variability in BMI trajectories is associated with body composition and cardiometabolic markers in early childhood, but it is unknown how these associations track to later childhood. Objectives We aimed to assess associations of BMI trajectories from 0-5 years with body composition and cardiometabolic markers at 10 years. Methods In the Ethiopian iABC birth cohort, we previously identified 4 distinct BMI trajectories from 0-5 years: stable low BMI (19.2%), normal BMI (48.8%), rapid growth to high BMI (17.9%), and slow growth to high BMI (14.1%). At 10 years, we obtained data from 320 children on anthropometry, body composition, abdominal subcutaneous and visceral fat, and cardiometabolic markers. Associations of BMI trajectories and 10-year outcomes were analyzed using multiple linear regression. Results Compared to children with the normal BMI trajectory, those with rapid growth to high BMI had 1.7 cm (95%CI: 0.1, 3.3) larger waist circumference and slow growth to high had 0.63 kg/m2 (95%CI: 0.09, 1.17) greater fat mass index and 0.19 cm (95%CI: 0.02, 0.37) greater abdominal subcutaneous fat, while stable low BMI had -0.28 kg/m2 (95%CI: -0.59, 0.03) lower fat-free mass at 10 years. Although the confidence bands were wide and included the null value, children with rapid growth to high BMI trajectory had 48.6% (95%CI: -1.4, 123.8) higher C-peptide, and those with slow growth to high BMI had 29.8% (95%CI: -0.8, 69.8) higher insulin and 30.3% (95%CI: -1.1, 71.6) higher HOMA-IR, whereas rapid growth to high BMI had -0.23 mmol/L (95%CI: -0.47, 0.02) lower total cholesterol. The trajectories were not associated with abdominal visceral fat, blood pressure, glucose, and other lipids at 10 years. Conclusions Children with rapid and slow growth to high BMI trajectories before 5 years showed higher measures of adiposity and higher levels of markers related to glucose metabolism at 10 years. Clinical Trial Registration Trial registration number: ISRCTN46718296URL of registration: https://www.isrctn.com/ISRCTN46718296