title: Infant body mass index peak and early childhood cardio-metabolic risk markers in a multi-ethnic Asian birth cohort.
abstract: : Infant body mass index (BMI) peak has received much interest recently as a potential predictor of future obesity and metabolic risk. No studies, however, have examined infant BMI peak in Asian populations, in whom the risk of metabolic disease is higher.
  
  
  
  : We utilized data among 1020 infants from a mother-offspring cohort, who were Singapore citizens or permanent residents of Chinese, Malay or Indian ethnicity with homogeneous parental ethnic backgrounds, and did not receive chemotherapy, psychotropic drugs or have diabetes mellitus. Ethnicity was self-reported at recruitment and later confirmed using genotype analysis. Subject-specific BMI curves were fitted to infant BMI data using natural cubic splines with random coefficients to account for repeated measures in each child. We estimated characteristics of the child's BMI peak [age and magnitude at peak, average pre-peak velocity (aPPV)]. Systolic (SBP) and diastolic blood pressure (DBP), BMI, sum of skinfolds (SSF) and fat-mass index (FMI) were measured during a follow-up visit at age 48 months. Weighted multivariable linear regression was used to assess the predictors (maternal BMI, gestational weight gain, ethnicity, infant sex, gestational age, birthweight-for-gestational age and breastfeeding duration) of infant BMI peak and its associations with outcomes at 48 months. Comparisons between ethnicities were tested using Bonferroni post-hoc correction.
  
  
  
  : Of 1020 infants, 80.5% were followed up at the 48-month visit. Mean (SD) BMI, SSF and FMI at 48 months were 15.6 (1.8) kg/m 2 , 16.5 (5.3) mm and 3.8 (1.3) kg/m 2 , respectively. Mean (SD) age at peak BMI was 6.0 (1.6) months, with a magnitude of 17.2 (1.4) kg/m 2 and pre-peak velocity of 0.7 (0.3) kg/m 2 /month. Compared with Chinese infants, the peak occurred later in Malay {B [95% confidence interval (CI): 0.64 mo (0.36, 0.92)]} and Indian infants [1.11 mo (0.76, 1.46)] and was lower in magnitude in Indian infants [-0.45 kg/m 2 (-0.69, -0.20)]. Adjusting for maternal education, BMI, gestational weight gain, ethnicity, infant sex, gestational age, birthweight-for-gestational-age and breastfeeding duration, higher peak and aPPV were associated with greater BMI, SSF and FMI at 48 months. Age at peak was positively associated with BMI at 48 months [0.15 units (0.09, 0.22)], whereas peak magnitude was associated with SBP [0.17 units (0.05, 0.30)] and DBP at 48 months [0.10 units (0.01, 0.22)]. Older age and higher magnitude at peak were associated with increased risk of overweight at 48 months [Relative Risk (95% CI): 1.35 (1.12-1.62) for age; 1.89 (1.60-2.24) for magnitude]. The associations of BMI peak with BMI and SSF at 48 months were stronger in Malay and Indian children than in Chinese children.
  
  
  
  : Ethnic-specific differences in BMI peak characteristics, and associations of BMI peak with early childhood cardio-metabolic markers, suggest an important impact of early BMI development on later metabolic outcomes in Asian populations.
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore.
authors.forename: Izzuddin M
authors.initials: IM
authors.lastname: Aris
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore.
authors.forename: Jonathan Y
authors.initials: JY
authors.lastname: Bernard
authors.affiliation: Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Ling-Wei
authors.initials: LW
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Mya Thway
authors.initials: MT
authors.lastname: Tint
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Wei Wei
authors.initials: WW
authors.lastname: Pang
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Wai Yee
authors.initials: WY
authors.lastname: Lim
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore.
authors.forename: Shu E
authors.initials: SE
authors.lastname: Soh
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
authors.affiliation: MRC Lifecourse Epidemiology Unit and NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Godfrey
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore.|Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gluckman
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore.|Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Yap-Seng
authors.initials: YS
authors.lastname: Chong
authors.affiliation: Department of Paediatrics, KK Women's and Children's Hospital, Singapore.|Duke-NUS Medical School, Singapore, Singapore.|Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
authors.forename: Fabian
authors.initials: F
authors.lastname: Yap
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.|Department of Pediatrics and of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kramer
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore.|Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.|Department of Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Singapore, Singapore.
authors.forename: Yung Seng
authors.initials: YS
authors.lastname: Lee
mesh_terms: D050154:Adiposity; D015415:Biomarkers / Q000378:metabolism; D001724:Birth Weight; D001794:Blood Pressure; D001823:Body Composition; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000208:ethnology*; D002657:Child Development; D002675:Child, Preschool; D002681:China / Q000208:ethnology; D015331:Cohort Studies; D005006:Ethnicity; D005260:Female; D005865:Gestational Age; D006801:Humans; D007194:India / Q000208:ethnology; D007223:Infant; D016014:Linear Models; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology* / Q000208:ethnology*; D015233:Models, Statistical; D015999:Multivariate Analysis; D050177:Overweight / Q000503:physiopathology; D012307:Risk Factors; D012846:Singapore
chemical_list: D015415:Biomarkers
keywords: adiposity; blood pressure; body composition; cardio-metabolic risk markers; cohort study; infant growth