P0059 PP SUBCUTANEOUS FAT DISTRIBUTION IN PRETERM AND TERM NEWBORNS

Introduction: Assessment of subcutaneous fat tissue by skinfold thickness (ST) is a fast and noninvasive method that has shown good correlation with the amount of fat mass in newborns (1). A better knowledge of neonatal body mass composition could aid us to find relationships between perinatal body fatness and early infant outcome or later development of metabolic diseases. The aim of the study is to describe the normal pattern and distribution of subcutaneous fat assessed at birth, in term and pre-term newborn infants, and to analyze their gestational age and gender related variations. Methods: Data were obtained from 4634 singleton neonates, 2445 males and 2189 females, born in the University Clinical Hospital ‘Lozano Blesa’, Zaragoza (Spain), with a gestational age from 32 to 41 weeks. Infants from minority ethnical groups or with alterations that could affect body composition were excluded. Weight, length and ST (triceps, biceps, subscapular and suprailiac) were measured using standardized methodology (2). The sum of the four skinfolds (SS) (mm) and various ratios were calculated: central to total skinfold ratio (%) (CTS) [CTS = (tricepsST+bicepsST)/SS ×100], the sum of the four skinfolds per weight unit (SS/weight) and central skinfolds per weight unit [(tricepsST+bicepsST)/Weight]. Results: Skinfold thicknesses were greater in females than in males, particularly from 38 weeks. Females also had bigger values of CTS than males in every gestational age, and differences were significant from 35 week. All subcutaneous fat variables and ratios analyzed in this study significantly increased (each of ST, SS) or decreased (SS/weight, (tricepsST+bicepsST)/Weight) with gestational age (p<0.0001); except for CTS which did not show variations throughout the gestational period. Conclusion: Term and preterm female infants have more amount and a more centralized pattern of subcutaneous body fat than males. ST measurements increase with gestational age but CTS does not vary significantly from 32 to 41 weeks, neither in male nor in female newborns. Therefore, CTS must be considered as an index of centripetal fat store that is not gestational age dependent.