title: The height-, weight- and BMI-for-age of preschool children from Nizhny Novgorod city, Russia, relative to the international growth references.
abstract: BACKGROUND
  Monitoring a child's growth status helps to diagnose diseases and implement curative and preventive measures. The aim of this study was to assess how well preschool children of Russian city (Nizhny Novgorod) match with, or diverge from, international growth charts (WHO2006,2007; USCDC2000).
  
  
  METHODS
  Cross-sectional study included 3,130 children aged 3-7 years attending municipal preschools of Nizhny Novgorod, the city in the European part of Russia. The study was held from February 2012 to October 2013. The international WHO2006,2007 and USCDC2000 growth references were used to calculate the height, weight and BMI z-scores. The distributions of z-scores were analysed with descriptive and inferential statistical methods. Z-score equal 0.25 was considered as a benchmark for clinically significant differences.
  
  
  RESULTS
  Means height z-scores calculated with the use of WHO2006, 2007 and USCDC2000 references were above the 50th centile (0.13 - 0.47) for both boys and girls. The means height z-scores was less than 0.25 SD above the 50th centile only for WHO2006. Stunting prevalence (the height-for-age z-score less than -2) was slightly higher under WHO2006 (3-4%) than under USCDC 2000 (2-3%). Stunting prevalence among children aged 5-7 years was similar under WHO2007 and USCDC2000 references (1%). For boys and girls aged 3-4 years the thinness prevalence, using WHO2006 was 2%, using USCDC2000 was 6% (p < 0.05). At the age 5-7 years this proportion under WHO2007 was 3% in both sex groups, under USCDC2000 was 8% for boys and 6% for girls (p < 0.05). A proportion of preschoolers aged 3-4 years with overweight was slightly higher under WHO2006 reference (13-15%) than under USCDC2000 (12-14%). In the case of age 5-7 years the overweight prevalence under WHO2007 (13-12 %) was lower than under USCDC2000 (14%). Obesity prevalence under WHO2006,2007 (3-4%) was slightly higher than that under USCDC2000 reference (2-3%). Preschoolers' distribution by groups of normal weight, overweight, obesity didn't significantly differ among the references (chi-square).
  
  
  CONCLUSIONS
  The growth assessment of children aged 3-7 years attending municipal preschools of the Russian city Nizhny Novgorod under the international references (WHO2006,2007; USCDC 2000), demonstrated that the height fit to the WHO2006 standard for the children aged 3 and 4 was generally fine, since all the mean values were within 0.25 of the standard deviations of the mean. Beyond the age of 5 the fit to the WHO2007 was poor while the fit to the USCDC2000 was poor throughout.
authors.affiliation: Privolzhsky Federal Medical Research Centre, Nizhny, Novgorod, Russia. evnazarova55@yandex.ru.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Nazarova
authors.affiliation: Nizhny Novgorod State Medical Academy, Nizhny, Novgorod, Russia.
authors.forename: Yury
authors.initials: Y
authors.lastname: Kuzmichev
mesh_terms: D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D057238:Growth Charts; D006130:Growth Disorders / Q000453:epidemiology; D006801:Humans; D008297:Male; D050177:Overweight / Q000453:epidemiology; D015995:Prevalence; D012426:Russia / Q000453:epidemiology; D013851:Thinness / Q000453:epidemiology
keywords: BMI z-score; Body mass index; Growth charts; Growth references; Height; Height-for-age z-score; Preschool children; Weight; Weight-for –age z-score