title: Fat and muscle mass in different groups of pre-pubertal and pubertal rural children. Cross-cultural comparisons between Sahelian (rural Senegal) and Amazonian (Beni River, Bolivia) children.
abstract: BACKGROUND
  An increase in fat accretion is essential for triggering the puberty spurt. Hence, nutritional constraints may influence puberty timing.
  
  
  OBJECTIVE
  To measure changes in fat and muscle mass in children living in natural environments but with different nutritional exposures.
  
  
  METHODS
  Cross-comparisons of children from rural Senegal and lowland (Amazonian) Bolivia were carried out. Anthropometric measurements of stature, weight, four subcutaneous skin-folds (triceps, biceps, subscapular, supra-iliac) and arm circumference were made. Children were divided into two age groups (5-9.9-year-olds or 'pre pubescents' (n = 381) and 10-15-year-olds or 'pubescents' (n = 692)).
  
  
  RESULTS
  Senegalese girls menstruated later than Bolivian girls and Senegalese boys also matured later than Bolivian boys. Bolivian children displayed more fat and muscle before puberty and during puberty than the Senegalese. They also had more fat deposited on the trunk. There were substantial differences in living conditions and nutritional patterns between both locations. In Senegal, nutritional stress is likely to appear early during in utero life and to persist throughout the growth period, including puberty. This leads to a deficit in fat accretion before and during puberty that is associated with a considerable delay in puberty occurrence. In Bolivia, such stress is far less severe.
  
  
  CONCLUSIONS
  Variability in puberty should be analysed taking into account these differences.
authors.affiliation: IRD, Ban Sisangvone, Saysettha district, Vientiane, PDR Lao, France. eric.benefice@ird.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Benefice
authors.forename: Selma J
authors.initials: SJ
authors.lastname: Luna Monrroy
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Lopez Rodriguez
authors.forename: Gnagna
authors.initials: G
authors.lastname: Ndiaye
mesh_terms: D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D001823:Body Composition; D001838:Bolivia; D002648:Child; D003431:Cross-Cultural Comparison; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D009132:Muscles / Q000033:anatomy & histology*; D009929:Organ Size; D011627:Puberty / Q000502:physiology*; D045483:Rivers; D012424:Rural Population; D012675:Senegal; D012727:Sex Characteristics