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This prospective study evaluated changes in dual energy X-ray absorptiometry (DXA) whole body bone mineral content (WB-BMC) and spine areal bone mineral density (spine-BMD), and tibia quantitative computed tomography (QCT) trabecular and cortical volumetric BMD and cortical area in 56 children over 12 months following renal transplantation. At transplant, spine-BMD Z-scores were greater in younger recipients (<13 years), versus 898 reference participants (p < 0.001). In multivariate models, greater decreases in spine-BMD Z-scores were associated with greater glucocorticoid dose (p < 0.001) and declines in parathyroid hormone levels (p = 0.008). Changes in DXA spine-BMD and QCT trabecular BMD were correlated (r = 0.47, p < 0.01). At 12 months, spine-BMD Z-scores remained elevated in younger recipients, but did not differ in older recipients (≥ 13) and reference participants. Baseline WB-BMC Z-scores were significantly lower than reference participants (p = 0.02). Greater glucocorticoid doses were associated with declines in WB-BMC Z-scores (p < 0.001) while greater linear growth was associated with gains in WB-BMC Z-scores (p = 0.01). Changes in WB-BMC Z-scores were associated with changes in tibia cortical area Z-scores (r = 0.52, p < 0.001), but not changes in cortical BMD Z-scores. Despite resolution of muscle deficits, WB-BMC Z-scores at 12 months remained significantly reduced. These data suggest that spine and WB DXA provides insight into trabecular and cortical outcomes following pediatric renal transplantation., (© Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Objective: To determine the prevalence, trends, and severity of injuries attributable to playground falls relative to other common unintentional mechanisms that resulted in an emergency department (ED) visit in the United States., Design and Setting: Data from the emergency subset of the National Hospital Ambulatory Medical Care Survey collected from 1992 to 1997 for children <20 years., Methods: Injury rates and 95% confidence intervals (CIs) were estimated and injury severity scores were computed., Results: There were 920551 (95% CI: 540803 to 1300299) ED visits over the 6-year study period by children and adolescents that were attributable to falls from playground equipment. The annual incidence of visits for playground injuries did not significantly decrease over the course of the study (187000 to 98000, P =.053). Injury visits for playground falls were twice as prevalent as pedestrian mechanisms, but they were less prevalent than visits for motor vehicle-- and bicycle-related injuries. A larger proportion of playground falls resulted in "moderate-to-severe" injury than did bicycle or motor vehicle injuries. Children aged 5 to 9 years had the highest number of playground falls (P =.0014). Playground falls were most likely to occur at school compared to home, public, and other locations (P =.0016)., Conclusions: Playground injury emergency visits have not significantly declined and remain a common unintentional mechanism of injury. Injury visits for playground falls were proportionally more severe than injury visits attributable to other common unintentional mechanisms. Interventions targeting schools and 5- to 9-year-old children may have the greatest impact in reducing emergency visits for playground injuries.

Objective: To determine whether higher dietary fiber intake (water soluble and insoluble) is associated with lower insulin requirements and better glycemic control in pregnant women with type 1 diabetes consuming a self-selected diet., Design: A longitudinal, observational study., Subjects: Pregnant women (n=141) with type 1 diabetes participating in an interdisciplinary program examining the effects of glycemic control on pregnancy outcome (Diabetes and Pregnancy Program, University of Cincinnati Medical Center)., Measurements: We determined total, water soluble and insoluble fiber intakes from 3-day food records kept each trimester during pregnancy. Outcome measures were insulin dose, pre-meal blood glucose, and glycated hemoglobin concentrations., Statistical Analyses: Correlation coefficients, multiple regression, mixed-model analysis of variance., Results: Mean intakes (g/day) of total, water soluble fiber, and insoluble fiber were 14.0 (range, 1.8-33.1), 4.8 (range, 0.6-10.5) and 9.0 (range, 1.1-24.0), respectively. In the second and third trimesters of pregnancy, insulin requirements were inversely associated with total, water soluble, and insoluble fiber intakes; the correlation coefficients ranged from -0.22 to -0.17 (P=.02 to .08). Insulin requirements associated with a higher fiber intake (20.5 g/day) were 16% to 18% lower than for a lower fiber intake (8.1 g/day). These relations remained after adjustment for body weight, disease severity and duration, insulin type, and study year in the second (P=.03 to .10) but not in the third trimester. Pre-meal blood glucose and glycated hemoglobin concentrations were not associated with fiber intake., Conclusions: Among pregnant women with type 1 diabetes, higher fiber intake is associated with lower daily insulin requirements. Dietary fiber intake should be considered when counseling patients about the management of blood glucose concentrations.

Skeletal fragility at the end of the life span (osteoporosis) is a major source of morbidity and mortality. Adequate calcium intake from childhood to the end of the life span is critical for the formation and retention of a healthy skeleton. High intakes of calcium and vitamin D potentiate the bone loss prevention effects of hormone replacement therapy in postmenopausal women. Pregnancy and lactation are not risk factors for skeletal fragility, although lactation is associated with a transient loss of bone that cannot be prevented by calcium supplementation. Low calcium intake has been implicated in the development of hypertension, colon cancer, and premenstrual syndrome, and it is associated with low intakes of many other nutrients. Encouragement of increased consumption of calcium-rich foods has the potential to be a cost-effective strategy for reducing fracture incidence later in life and for increasing patients' dietary quality and overall health.

Calcium has been shown to inhibit iron absorption. The consequences of chronic calcium supplementation on iron status are unclear, however. As part of a randomized calcium-supplementation trial in lactating and nonlactating women in the postpartum period, we determined whether long-term calcium supplementation and lactation status affected iron stores as measured by serum ferritin concentrations. Subjects (95 lactating and 92 nonlactating) were enrolled at approximately 6 mo postpartum and then randomly assigned to receive either 500 mg Ca as calcium carbonate or a placebo twice daily with meals for 6 mo. Lactating women weaned their infants approximately 2 mo after enrollment (ie, approximately 8 mo postpartum). Calcium supplementation had no effect on serum ferritin concentrations. At the end of the study, geometric mean serum ferritin concentrations were 28.4 microg/L in the calcium-supplemented group and 27.5 microg/L in the placebo group (P > 0.5). Lactation status was significantly related to serum ferritin concentrations. At baseline, serum ferritin concentrations were higher in lactating women than in nonlactating women (47.7 compared with 31.5 microg/L, P < 0.001). In lactating women, serum ferritin concentrations decreased by a mean of 17 microg/L after weaning. By 12 mo postpartum, mean serum ferritin concentrations in women who were previously lactating were not significantly higher than those of nonlactating women (30.5 compared with 25.5 microg/L). These findings provide reassurance that long-term calcium supplementation does not impair iron stores. Furthermore, lactation status should be considered when assessing iron nutriture of women and determinants of iron status in populations.

Measurement of milk intake by breast-fed infants is difficult and a simple measure would be helpful for research and clinical practice. Maternal urinary lactose excretion has been proposed as a simple measure of lactation performance. The objectives of this study were to describe the pattern of urinary lactose excretion postpartum, and to determine whether lactose excretion could predict breast milk output. Lactose excretion was determined in 50 lactating and 49 nonlactating women at 0.5, 3, and 6 mo postpartum, and in 29 weaning women and 30 nonlactating women at 5, 8, and 11 mo postpartum. Lactose excretion was 4- to 17-fold higher in lactating than in nonlactating women, depending on the time point studied, and was highest in both groups 0.5 mo postpartum. Lactose excretion decreased after weaning but remained higher than in nonlactating women 1.3 mo after weaning was completed. Sixty-two additional women between 1.5 and 12 mo postpartum were studied to determine the ability of urinary lactose to predict milk output. There was a positive association between milk output and urinary lactose excretion, with correlation coefficients ranging from 0.17 to 0.30 depending on the measurement interval for lactose excretion. Lactose excretion could explain 2-9% of the variance in milk output, and could correctly classify 29-40% of individuals into tertiles of milk output. Although urinary lactose excretion reflects changes in biological activity of the mammary gland and gross changes in milk production, it is not a precise predictor of milk output.

We investigated whether intestinal calcium absorption and serum 1,25-dihydroxycholecalciferol (calcitriol) concentrations are higher in women during lactation and after weaning to compensate for calcium lost in breast milk. Measurements were obtained at 4.6 mo postpartum in 24 lactating women and 24 nonlactating women, at 9.6 mo postpartum in 24 lactating women (2.6 mo after complete weaning) and 24 nonlactating women. One-half of the women in each group were randomly assigned to receive 1 g supplemental Ca/d as calcium carbonate. Fractional calcium absorption was measured by using stable isotopic tracers 42Ca and 44Ca. Fractional absorption was 0.32+/-0.02 (+/-SEM) in both lactating and nonlactating women, but was higher in lactating women after weaning (0.37+/-0.02) compared with nonlactating postpartum control subjects (0.31+/-0.02). These effects were independent of calcium intake. Changes in serum calcitriol paralleled changes in fractional absorption. There were no differences in calcitriol concentrations between lactating and nonlactating women, but calcitriol was greater in women after weaning compared with postpartum control subjects. Lactating women who had resumed menses had higher fractional absorption and serum calcitriol than did lactating women who had not. Serum calcium and phosphorus concentrations were greater in lactating compared with nonlactating women; there were no differences between groups after weaning. We conclude that lactation stimulates increases in fractional calcium absorption and serum calcitriol, but the responses are only apparent after weaning or the resumption of menses.

The effects of exercise training on riboflavin requirements and of riboflavin intake on endurance were examined in 14 women, 50-67 y of age, who participated in a 10-wk, two-period crossover exercise study at two riboflavin intakes, 0.15 micrograms/kJ (0.6 micrograms/kcal) and 0.22 micrograms/kJ (0.9 micrograms/kcal). Subjects exercised 20-25 min/d, 6 d/wk, for 4-wk periods on a cycle ergometer at 75-85% of their maximal heart rate. Riboflavin status was assessed by measuring the erythrocyte glutathione reductase activity coefficient (EGRAC) and urinary riboflavin excretion. Physical performance was evaluated by using a walking treadmill test to determine maximal oxygen capacity (VO2max) and anaerobic threshold by gas exchange (ATGE). Exercise significantly affected riboflavin status as EGRAC increased (P less than 0.001) and riboflavin excretion decreased (P less than 0.01) in both groups. VO2max increased significantly with exercise (P less than 0.01). However, changes in VO2max (L/min) and ATGE with exercise training were not different in the two groups. Riboflavin requirements of older women increased with exercise training, but increased riboflavin intake did not enhance improvements in endurance.

The present study was designed to evaluate our previous estimates for riboflavin requirement, 0.96 mg/1000 kcal during nonexercise and 1.16 mg/1000 kcal during exercise in overweight women. Two groups of 6 weight reducing women consumed either 1.16 mg riboflavin/1000 kcal (HR) or 0.96 mg/1000 kcal (MR). The study was two, 3 period by 2 treatment (exercise or nonexercise) crossover designs, one design at each level of riboflavin. Erythrocyte glutathione reductase activity coefficients (AC) significantly increased in both groups from 1.16 +/- .02 to 1.20 +/- .03 in group HR and from 1.31 +/- .04 to 1.36 +/- .02 in the MR group during nonexercise and exercise, respectively. ACs increased in the HR group due to an increase in total enzyme activity while ACs increased in the MR group due to a decrease in basal enzyme activity reflecting decreased flavin availability. There were no differences in aerobic capacity, weight loss, nor change in lean body mass between the two groups. Thus, 0.96 mg/1000 kcal was not adequate during either nonexercise or exercise periods while the 1.16 mg/1000 kcal was adequate.

Energy intake, fecal energy output, and gastrointestinal symptoms were measured in 12 females who consumed either approximately 23 g/d supplementary fiber or a 4 g/d fiber control. Fiber supplements were crackers containing psyllium gum, wheat bran, or a combination of the two fiber sources. After 1 wk on the control cracker, subjects consumed the three high-fiber crackers and the control cracker for 2-wk periods in a balanced design. Gum and combination supplements gave increased bloating and flatulence. Increase in abdominal pain was reported with gum supplement. Mean daily fecal energy was 96 kcal/d with control crackers and was increased by 63 kcal with high-fiber crackers. Gum and combination supplements significantly decreased intake of digestible energy by 153 and 115 kcal/d, respectively. This suppression was not dependent upon fiber intolerance. Wheat bran supplement had no effect on energy intake.

The role of dietary fat in the regulation of energy intake was assessed by manipulating a conventional diet and measuring spontaneous food consumption. Twenty-four women each consumed a sequence of three 2-wk dietary treatments in which 15-20%, 30-35%, or 45-50% of the energy was derived from fat. These diets consisted of foods that were similar in appearance and palatability but differed in the amount of high-fat ingredients used. Relative to their energy consumption on the medium-fat diet, the subjects spontaneously consumed an 11.3% deficit on the low-fat diet and a 15.4% surfeit on the high-fat diet (p less than 0.0001), resulting in significant changes in body weight (p less than 0.001). A small amount of caloric compensation did occur (p less than 0.02), which was greatest in the leanest subjects (p less than 0.03). These results suggest that habitual, unrestricted consumption of low-fat diets may be an effective approach to weight control.

The effect of dietary fiber from wheat bran and psyllium gum on the apparent absorption of riboflavin was studied in 12 healthy women. The test fiber was consumed in crackers that contained approximately 7.5 gm fiber from psyllium gum, wheat bran, or a combination of the two sources. Each subject was given a riboflavin load test after consuming one of the three different fiber supplements or a control supplement that contained 1.3 gm fiber. Fractional urine collections were made for 24 hours, and riboflavin was measured by fluorometric techniques. The psyllium gum and combination supplements reduced the 24-hour apparent absorption of riboflavin from 31.8% to 25.4% and 26.1%, respectively (p less than .01). No effect of the wheat bran supplement on riboflavin was detected.

The accuracy of heart-rate monitoring and activity diaries for measuring energy expenditure in free-living individuals was studied in 12 women. Estimates of energy expenditure were calculated from heart-rate monitoring by use of four different prediction equations to describe the relationship between heart rate and energy expenditure. Estimates of energy expenditure from activity diaries were calculated using both individually measured and published values for the energy cost of activities. Energy intake adjusted for changes in body-energy stores was used as a reference. Heart-rate monitoring overestimated group energy expenditure from 2 to 9% and the errors in estimating individual energy expenditure ranged from -53 to 67%. Activity diaries underestimated group energy expenditure by 2-6% and the errors in estimating individual energy expenditure ranged from -39 to 56%. Heart-rate monitoring and activity diaries may prove useful for estimating the energy expenditure of groups but not individuals.

The riboflavin requirement of young women during periods of sedentary living and exercise was determined during a 12-wk metabolic study. The study was divided into a 6-wk no exercise period followed by a 6-wk exercise period in which subjects jogged around a track for 20 to 50 min/day. Twelve subjects, aged 19 to 27 yr, were fed a basic diet containing 0.6 mg riboflavin/1000 kcal of intake. Riboflavin intake was increased by 0.2 mg/1000 kcal increments by provision of riboflavin in a glucose polymer mixture. Linear regression analysis was used to estimate the riboflavin intake required for an erythrocyte glutathione reductase activity coefficient of 1.25 during both the no exercise and exercise periods. Individual riboflavin requirements ranged from 0.62 to 1.21 mg/1000 kcal before exercise and 0.63 to 1.4 mg/1000 kcal during the exercise periods. Riboflavin requirement could not be related to the kilocalorie intake or lean body mass of the subjects. It is concluded that healthy young women require more riboflavin to achieve biochemical normality than the 1980 Recommended Dietary Allowances and that exercise increases riboflavin requirements.

The effects of ultraviolet (UV) irradiation on plasma levels of carotenoids and vitamin A in human subjects were investigated in two crossover trials. UV exposures were given on 11 r 12 days of a 2-wk period. The 12 female and 12 male subjects received mean cumulative UV-A (320-400 nm) doses of 17.8 +/- 1.9 J/cm2 and 21.0 +/- 3.3 J/cm2 to the anterior and posterior sides of the body, respectively. UV-B (280-320 nm) doses were equivalent to 10% of UV-A doses given. Significant reductions in plasma total carotenoid levels were observed in both female (p less than 0.004) and male (p less than 0.05) subjects after repeated irradiation. There was no significant effect on plasma vitamin A levels. It was concluded that UV treatment can reduce plasma carotenoid levels in vivo.