Population-based waist circumference reference values in Japanese children (0-6 years): comparisons with Dutch, Swedish and Turkish preschool children

Background: During 1978-1981 the Japanese Standards Association conducted a national survey to collect 64 distinct body measurements for Japanese children and adults. During 1978-1981, the prevalence of childhood obesity was relatively low yet the population was well nourished in Japanese children. The aim of this study is to construct waist circumference and waist circumference to stature ratio reference centile curves for Japanese preschool children. Methods: We utilized 1978-1981 national survey data on body sizes. There are 4937 boys and 4758 girls age 0-6 years for waist circumference measurements. Waist circumference was measured at the level of the umbilicus. Using LMS method, centile curves were constructed for waist circumference and waist circumference to stature ratio. These reference values were compared with those of Dutch, Swedish and Turkish children. Results: Centile reference curves were made for clinical and epidemiological use. Japanese children had smaller waist circumference centile values as compared to waist circumference measured at the midpoint of the lowest rib cage and the iliac crest of Dutch, Swedish and Turkish children. However, Japanese children had comparable waist circumference to stature ratio centile values to those of Dutch and Turkish children. Conclusions: This study presents the first age-, sex-, and ethnicity-specific reference values for waist circumference and waist circumference to stature ratio in Japanese preschool children.