PhD defence: Growth in early childhood and later body composition and cardiometabolic health in Ethiopian children
PhD defence by
Bikila Soboka Megersa
About the PhD thesis
Birth weight and rapid weight gain during early childhood have been associated with childhood overweight and cardiometabolic diseases in adulthood. However, evidence of the relative importance of birth fat mass (FM), birth fat-free mass (FFM), and their accretion in early childhood on later adiposity and cardiometabolic health is limited. Despite an increasing burden of childhood overweight and cardiometabolic diseases in sub-Saharan African countries, there is limited evidence from longitudinal studies on how birth size and early childhood growth are related to adiposity and cardiometabolic risk in later childhood. Thus, this thesis aimed to examine associations of weight and body composition at birth and early childhood growth from 0-5 years with body composition and cardiometabolic markers at age 10 years.
This thesis is based on data from the Ethiopian iABC birth cohort study. Body composition from birth to 10 years was assessed using air-displacement plethysmography. The exposure variables were weight, FM, and FFM at birth, previously identified body mass index (BMI) trajectories from 0-5 years, and FM and FFM accretion in selected periods from 0-5 years (0-3, 3-6, 6-48, and 48-60 months). Outcomes were obtained from 355 children who attended the 10-year follow-up and included anthropometry, body composition, abdominal subcutaneous- and visceral fat, and cardiometabolic markers. Associations between exposure variables and the 10-year outcomes were assessed using multiple linear regression analysis.
At 10 years, the mean ( SD) height z-score and BMI z-score of the children were -0.76 (0.94) and -0.77 (1.15), respectively. Higher birth weight and FFM were associated with greater height, fat-free mass index, insulin, C-peptide, and HOMA-IR, whereas higher birth FM was associated with greater fat mass index and abdominal subcutaneous fat, but not visceral fat. FM accretion from 0-3 months and 3-6 months, but not FFM, was related to higher blood pressure and glucose levels. Furthermore, FM and FFM accretion between 6-48 months was associated with higher insulin and HOMA-IR, whereas FFM accretion during the same period was related to lower total and LDL cholesterol concentrations. Children with either rapid or slow growth to high BMI trajectories from 0-5 years had greater adiposity and markers of glucose homeostasis compared to those with normal BMI trajectories at 10 years of age.
In summary, based on the children included in this cohort, Ethiopian children were on average shorter and thinner compared with standard reference at 10 years of age. Children with higher FFM accretion in early childhood may have a lower risk of dyslipidemia later in life. Conversely, those with higher FM accretion and rapid or slow growth to high BMI in early childhood might have an increased risk of adiposity and elevated cardiometabolic markers later in life.
2024, 194 pages.
Download Publications; Table of contents; Summary; Resumé (summary in Danish)
Time
13 June 2024, 13:00
Place
Aud. A2-70.03, Thorvaldsensvej 40, st., Frederiksberg
Opponents
Professor Faidon Magkos (chair), Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark.
Associate Professor Jennifer Lyn Baker, Center for Clinical Research and Prevention, Copenhagen University Hospital, Denmark
Professor Sanjay Kinra, Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, United Kingdom.
Main supervisor
Professor Henrik Friis, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark.
CO-supervisors
Rasmus Wibæk Christensen, PhD (Postdoc), Clinical Research, Steno Diabetes Center Copenhagen.
Gregers Stig Andersen, PhD, Senior researcher, Clinical Research, Steno Diabetes Center Copenhagen.
Associate Professor Mette Frahm Olsen, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark.