title: UK-born Pakistani-origin infants are relatively more adipose than white British infants: findings from 8704 mother-offspring pairs in the Born-in-Bradford prospective birth cohort.
abstract: BACKGROUND
  Previous studies have shown markedly lower birth weight among infants of South Asian origin compared with those of White European origin. Whether such differences mask greater adiposity in South Asian infants and whether they persist across generations in contemporary UK populations is unclear. Our aim was to compare birth weight, skinfold thickness and cord leptin between Pakistani and White British infants and to investigate the explanatory factors, including parental and grandparental birthplace.
  
  
  METHODS
  We examined the differences in birth weight and skinfold thickness between 4649 Pakistani and 4055 White British infants born at term in the same UK maternity unit and compared cord leptin in a subgroup of 775 Pakistani and 612 White British infants.
  
  
  RESULTS
  Pakistani infants were lighter (adjusted mean difference -234 g 95% CI -258 to -210) and were smaller in both subscapular and triceps skinfold measurements. The differences for subscapular and triceps skinfold thickness (mean z-score difference -0.27 95% CI -0.34 to -0.20 and -0.23 95% CI -0.30 to -0.16, respectively) were smaller than the difference in birth weight (mean z-score difference -0.52 95% CI -0.58 to -0.47) and attenuated to the null with adjustment for birth weight (0.03 95% CI -0.03 to 0.09 and -0.01 95% CI -0.08 to 0.05, respectively). Cord leptin concentration (indicator of fat mass) was similar in Pakistani and White British infants without adjustment for birth weight, but with adjustment became 30% higher (95% CI 17% to 44%) among Pakistani infants compared with White British infants. The magnitudes of difference did not differ by generation.
  
  
  CONCLUSIONS
  Despite being markedly lighter, Pakistani infants had similar skinfold thicknesses and greater total fat mass, as indicated by cord leptin, for a given birth weight than White British infants. Any efforts to reduce ethnic inequalities in birth weight need to consider differences in adiposity and the possibility that increasing birth weight in South Asian infants might inadvertently worsen health by increasing relative adiposity.
authors.affiliation: Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK. jane.west@bthft.nhs.uk
authors.forename: Jane
authors.initials: J
authors.lastname: West
authors.forename: Debbie A
authors.initials: DA
authors.lastname: Lawlor
authors.forename: Lesley
authors.initials: L
authors.lastname: Fairley
authors.forename: Raj
authors.initials: R
authors.lastname: Bhopal
authors.forename: Noel
authors.initials: N
authors.lastname: Cameron
authors.forename: Patricia A
authors.initials: PA
authors.lastname: McKinney
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.forename: John
authors.initials: J
authors.lastname: Wright
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001724:Birth Weight / Q000502:physiology; D015992:Body Mass Index; D016640:Diabetes, Gestational / Q000453:epidemiology; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005865:Gestational Age; D018149:Glucose Intolerance / Q000453:epidemiology; D006771:Hospitals, Maternity; D006801:Humans; D007231:Infant, Newborn; D020738:Leptin / Q000097:blood*; D010154:Pakistan / Q000208:ethnology; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D037841:Pregnant People / Q000208:ethnology* / Q000523:psychology; D011446:Prospective Studies; D012044:Regression Analysis; D012885:Skinfold Thickness; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data
chemical_list: D020738:Leptin
keywords: BIRTH WEIGHT; EPIDEMIOLOGY; ETHNICITY