A combined massage and physical activity protocol improved bone formation (PICP) but did not affect bone resorption (Pyd). Pyd increased over time in both groups, possibly due to continuous bone resorption and Ca mobilization.

Factors affecting bone turnover in premature infants are not entirely clear but certainly are different from those influencing bones of adults and children. To identify fetal and maternal factors that might influence bone turnover, we prospectively studied 50 infants (30 preterm and 20 full-term) born at Ain Shams University Obstetric Hospital in Cairo, Egypt. Maternal parity and medical history and infant's weight, gestational age, gender and anthropometrical measurements were recorded. Cord blood samples were collected and serum type I collagen Cterminal propeptide (PICP) was assessed as a marker for fetal bone formation. First morning urine samples were collected and pyridinoline cross-links of collagen (Pyd) were measured as an index for bone resorption. Serum PICP was higher in premature infants when compared with full-term infants (73.30 Ϯ 15.1 versus 64.3 Ϯ 14.7, p ϭ 0.022) and was higher in male premature infants when compared with females (81.64 Ϯ 9.06 versus 66.0 Ϯ 15.7, p ϭ 0.018). In a multiple regression model using Throughout life, bone is constantly resorbed and new bone is formed. Both modeling and remodeling occur during skeletal growth. Bone modeling results in linear growth and remodeling allows expansion of bone circumference and mineral deposition. Five to twenty percent of the bone mass is actively remodeled by about two million bone remodeling units in the human skeleton at any given time (1,2). The rate of bone turnover in adults differs from children and neonates. In addition, factors affecting such process in adults do not necessarily influence children or neonates (3,4). Premature infants represent a unique vulnerable population, in which bone growth and mineral acquisition are critical. The relation of bone turnover with gestational age and birth weight has been well described (5). However, the impact of other factors such as parity, maternal diseases, and infant's sex on bone turnover in the premature infant are yet to be identified. In this study we used serum concentration of carboxy terminal propeptide of type I procollagen (PICP) in cord blood, as a marker of fetal bone formation (6 -8), and pyridinoline (Pyd) excretion in urine as a biomarker of bone resorption (9,10). PATIENTS AND METHODSPatients. Fifty appropriate-for-gestational-age infants were included in this study. Thirty preterm and twenty term infants were prospectively enrolled. Infants with history of perinatal asphyxia, maternal fever, rupture of amniotic membranes Ͼ18 h, congenital anomalies, liver diseases, and inherited metabolic or genetic disorders were excluded from the study. The study was approved by the institutional review board and parental consents were obtained. Maternal history including maternal age, parity and diabetes mellitus. Length of gestation was estimated using the date of last menstrual period, early antenatal ultrasound when available and the new Ballard scoring system (11). All anthropometrical measurements were done by the same doctor on admission and were plotted against gestational age (1...