Effect of physical activity on bone mineralization in premature infants. Daily physical activity program increases bone mineralization and growth in preterm very low birth weight infants. Randomized trial of physical activity and calcium supplementation on bone mineral content in 3- to 5-year-old children. Diet and bone mineral content at term in premature infants. Effects of motor physical therapy on bone mineralization in premature infants: a randomized controlled study. Moderate nutrient supplementation of mother's milk for preterm infants supports adequate bone mass and short-term growth: a randomized, controlled trial. Effects of exercise and nutrition on postural balance and risk of falling in elderly people with decreased bone mineral density: randomized controlled trial pilot study.
A 4-week pilot study was done with 26 preterm infants to evaluate whether a physical activity program would result in greater bone mineralization.
                Subjects were matched by birth weight, gender, and gestational age, and randomly assigned to the physical activity program (group EX; n = 13) or to the control group (group C; n = 13). Physical activity consisted of range of motion with passive resistance to all extremities for 5 to 10 minutes daily. Baseline and 4-week values were determined for both bone mineral analyses and serum levels of calcium, phosphate, alkaline phosphatase, parathyroid hormone, and 25-hydroxy-vitamin D.
                Despite similar nutrient intake at advised levels for preterm infants, EX infants gained more weight than control subjects (17.8 vs 13.4 gm/kg body weight per day; p = 0.01). A difference in radial bone mass and density change as determined by single-beam photon absorptiometry (+/- 2% error) was found between groups (p = 0.006 by analysis of covariance). Changes in bone width and in bone mineral content and density were enhanced by physical activity. Group EX infants had 12%, 18%, and 34% gains in bone width and in bone mineral density and content, respectively; group C infants had only a 2% gain in bone width and 11% and 14% losses from baseline in bone mineral content and density, respectively, during the 4-week study. Serum biochemical values were similar in the groups except for lower alkaline phosphatase levels in group EX. There was a negative association between bone mineral content and parathyroid hormone values: r = -0.83, p = 0.01.
                A physical activity program may increase the effects of adequate nutrition in healthy preterm very low birth weight infants by promoting weight gain and bone mass and by decreasing the risk of osteopenia. A study of daily physical activity was performed with 32 preterm infants to evaluate changes in body weight and bone mineralization.
                Subjects were matched by birth weight and gestational age and randomly assigned to the physical activity (PA; n = 16) or to the control (C; n = 16) program. PA consisted of range of motion against passive resistance to all extremities for 5 to 10 minutes daily. Peripheral dual-energy x-ray of the right forearm (ulna and radius); biomarkers of bone formation (serum type I collagen C-terminal propeptide [PICP]) and resorption (urine pyridinoline cross-links of collagen [Pyd]); serum calcium, phosphate, alkaline phosphatase, parathyroid hormone (PTH), and 1, 25-(OH)(2) vitamin D; and urine levels of calcium, phosphate, and creatinine were obtained. All measurements were made at study entry and at 2.0 kg of body weight.
                Despite a similar nutrient intake at advised levels for preterm infants, gains in body weight (g) and forearm bone length (cm), bone area (BA; cm(2)), bone mineral content (BMC; mg), and fat-free mass (g) were greater in PA infants. Forearm bone mineral density and fat mass gains did not differ between groups. Serum PICP levels remained constant in PA infants but decreased in C infants suggesting a slower rate of bone formation. Urine Pyd or bone resorption activity was similar between groups. A higher level of serum PTH was observed in PA infants at 2. 0 kg of body weight; however, the change from study entry to completion did not differ between groups. All other serum and urine values were similar and within normal limits.
                A daily PA program promotes greater gains in body weight, forearm length, BA, BMC, and fat-free mass in premature infants. A meta-analysis of adult exercise studies and an infant activity trial show a possible interaction between physical activity and calcium intake on bone. This randomized trial of activity and calcium supplementation was conducted in 239 children aged 3-5 years (178 completed). Children were randomized to participate in either gross motor or fine motor activities for 30 minutes/day, 5 days per week for 12 months. Within each group, children received either calcium (1000 mg/day) or placebo. Total body and regional bone mineral content by DXA and 20% distal tibia measurements by peripheral quantitative computed tomography (pQCT) were obtained at 0 and 12 months. Three-day diet records and 48-h accelerometer readings were obtained at 0, 6, and 12 months. Higher activity levels were observed in gross motor versus fine motor activity groups, and calcium intake was greater in calcium versus placebo (1354 +/- 301 vs. 940 +/- 258 mg/day, p < 0.001). Main effects of activity and calcium group were not significant for total body bone mineral content or leg bone mineral content by DXA. However, the difference in leg bone mineral content gain between gross motor and fine motor was more pronounced in children receiving calcium versus placebo (interaction, p = 0.05). Children in the gross motor group had greater tibia periosteal and endosteal circumferences by pQCT compared with children in the fine motor group at study completion (p < 0.05). There was a significant interaction (both p < or = 0.02) between supplement and activity groups in both cortical thickness and cortical area: among children receiving placebo, thickness and area were smaller with gross motor activity compared with fine motor activity, but among children receiving calcium, thickness and area were larger with gross motor activity. These findings indicate that calcium intake modifies the bone response to activity in young children. Premature infants are at risk of developing metabolic bone disease mainly because of low calcium and phosphorus intake. We have examined the effect of different mineral supplements on bone mineral content at term in 127 premature infants with gestational age <32 wk in a double-blinded randomized trial. We used either phosphate supplementation of human milk as recommended by the European Society of Pediatric Gastroenterology and Nutrition or fortified supplementation with protein, calcium, and phosphorus or preterm formula as recommended by the American Academy of Pediatrics. The intervention period was from 1 week old until 36 wk of gestational age, and the infants were fed approximately 200 mL x kg(-1) x d(-1). Bone mineral content was measured at term by dual-energy x-ray absorptiometry scan. Surprisingly, neither phosphate, fortifier, nor preterm formula supplementation had any significant effect on bone mineral content at term compared with infants fed their own mother's milk only. There was a tendency to higher total bone mineral content in infants fed preterm formula compared with infants fed their own mother's milk only (p = 0.05), but when the bone mineral content was corrected for the size of the infant, there was no difference (p = 0.68). Infants fed preterm formula had a significantly higher weight at term compared with infants fed their own mother's milk only (p = 0.02), but did not differ significantly in length or head circumference. In a regression analysis, the amount of supplemented phosphorus was significantly associated with weight at term (p = 0.008). We conclude that when feeding 200 mL x kg(-1) x d(-1), mineral supplementation of human milk or use of preterm formula does not significantly improve bone mineralization outcome at term. To study the effect of physical therapy on bone mineralization, weight gain and growth in preterm infants.
                After fulfilling the inclusion criteria, preterm infants were matched for gestational age and birth weight and then randomly assigned to the physiotherapy group (PG, n=15) and control group (CG, n=14). The PG received motor physical therapy for 15 min daily, 5 times per week until hospital discharge. Bone mineralization was measured by total body dual energy X-ray beam absorptiometry (DEXA) at the onset and end of the study. Statistical analysis was realized by ANCOVA and linear correlation tests.
                The physical therapy group (PG) presented greater body weight gain per day (27.4+/-2.4 vs 21.01+/-4.4 g, P<0.001) and length (1.3+/-0.3 vs 0.8+/-0.2 cm week(-1), P<0.001) than did the control group (CG). Body composition values verified by DEXA were greater for the PG. The mean gain in bone mineral content (BMC) (mg) was greater in the PG (434+/-247.5 vs -8.9+/-11.4, P<0.001), as was the mean bone mineral density (BMD) gain (mg cm(-2)) (8.4+/-5.6 vs -3.1+/-5.5, P<0.001). The gain in bone area (BA,cm(2)) was 10.3+/-5 in the PG vs 1.5 +/-2 in the CG (P<0.001). The gain in lean mass (LM) (g) in the PG was also greater than in the CG (271.1+/-21.4 vs 109.1+/-1.0, P<0.009). The fat mass (g) was similar between the groups (P=0.432).
                These results showed that physiotherapy in preterm infants produced greater gains in growth, body weight, BMC, BMD, BA and LM. Our objectives were 1) to determine whether moderate nutrient supplementation of mother's milk (MM) for preterm infants, in the form of a new multinutrient fortifier (MNF), would improve short-term growth and bone mineral content (BMC) when compared with supplementation with calcium and phosphorus alone; and 2) to investigate whether moderate calcium and phosphorus intakes, in the form of calcium glycerophosphate (CaGP), resulted in a BMC similar to that of term corrected infants. Twenty-five preterm infants fed MM were randomly assigned to receive either MM+MNF or MM+CaGP. A third group of infants fed preterm formula (PTF) served as a comparison group. Whole-body BMC and lean and fat mass were determined by dual-energy X-ray absorptiometry (DXA) at full-term age. Nitrogen retention and calcium, phosphorus, and zinc intakes were determined by using mass balance techniques. Nitrogen retention was significantly lower in the MM+CaGP group than in the PTF group as were both weight and length gain (weight gain: 16.6 +/- 1.6, 14.2 +/- 2.0, and 16.1 +/- 2.9 g x kg(-1) x d(-1); length gain: 1.1 +/- 0.2, 0.9 +/- 0.2, and 1.1 +/- 0.3 cm/wk for the MM+MNF, MM+CaGP, and PTF groups, respectively). Biochemical indexes of mineral status and bone turnover were normal. Conservative amounts of calcium and phosphorus, as CaGP, resulted in adequate BMC. Moderate amounts of protein, calcium, and phosphorus plus trace elements added to MM in the form of an MNF resulted in improved linear growth but did not provide any advantages to BMC when compared with supplementation with calcium and phosphorus alone. To compare the effect of calcium/vitamin D supplements with a combination of calcium/vitamin D supplements and exercise/protein on risk of falling and postural balance.
                Randomized clinical trial.
                University hospital physiotherapy department.
                Twenty-four independently living elderly females aged 65 years and older with osteopenia or osteoporosis and mean total hip T-score (SD) of -1.8 (0.8).
                A three-month programme consisting of exercise/protein including training of muscular strength, co-ordination, balance and endurance. Calcium/ vitamin D was supplemented in all participants for a 12-month period.
                Assessment took place prior to and following the months 3, 6, 9 and at the end of the study; primary dependent variables assessed were risk of falling (Berg Balance Test) and postural balance (forceplate). Secondary measures included body composition, strength, activity level, number of falls, bone mineral content, biochemical indices, nutritional status and general health.
                Significant reductions of risk of falling (repeated measures ANOVA F = 8.90, P = 0.008), an increase in muscular strength (ANOVA F = 3.0, P = 0.03), and an increase in activity level (ANOVA F = 3.38, P = 0.02) were found in the experimental group as compared to the control group. Further on, there was 89% reduction of falls reported in the experimental group (experimental pre/post 8/1 falls; control group pre/post 5/6 falls).
                This study provides support for our intervention programme aimed at reducing the risk of falling in elderly participants diagnosed with osteopenia or osteoporosis. The data obtained from the pilot study allow the calculation of the actual sample size needed for a larger randomized trial.
There is some evidence that physical activity programs might promote short-term weight gain and bone mineralization in preterm infants. Data is inadequate to assess harm or long-term effects. Current evidence does not support the routine use of physical activity programs in preterm infants. Further trials incorporating infants with a high baseline risk of osteopenia are required. These trials should address adverse events, long-term outcomes, and the effects of nutritional intake (calories, protein, calcium, phosphorus).