Seroprevalence of SARS-CoV-2 antibodies among rural healthcare workers.

The objective of this longitudinal cohort study was to determine the seroprevalence of antibodies to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in healthcare workers employed at healthcare settings in three rural counties in eastern South Dakota and western Minnesota from May 13, 2020, through December 22, 2020. Three blood draws were performed at five clinical sites and tested for the presence of antibodies against the SARS-CoV-2. Serum samples were tested for the presence of antibodies using a fluorescent microsphere immunoassay (FMIA), neutralization of SARS-CoV-2 spike-pseudotyped particles (SARS-CoV-2pp) assay, and serum virus neutralization (SVN) assay. The seroprevalence was determined to be 1/336 (0.29%) for samples collected from 5/13/20 to 7/13/20, 5/260 (1.92%) for samples collected from 8/13/20 to 9/25/20, and 35/235 (14.89%) for samples collected from 10/16/20 to 12/22/20. Eight of the 35 (22.8%) seropositive individuals identified in the final draw did not report a previous diagnosis with COVID-19. There was a high correlation (>90%) between the FMIA and virus neutralization assays. Each clinical site's seroprevalence was higher than the cumulative incidence for the general public in the respective county as reported by state public health agencies. As of December 2020, there was a high percentage (85%) of seronegative individuals in the study population.

Individual participant data (IPD)-level meta-analysis of randomised controlled trials with vitamin D-fortified foods to estimate Dietary Reference Values for vitamin D.

CONTEXT AND PURPOSE: Individual participant data-level meta-regression (IPD) analysis is superior to meta-regression based on aggregate data in determining Dietary Reference Values (DRV) for vitamin D. Using data from randomized controlled trials (RCTs) with vitamin D3-fortified foods, we undertook an IPD analysis of the response of winter serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among children and adults and derived DRV for vitamin D. METHODS: IPD analysis using data from 1429 participants (ages 2-89 years) in 11 RCTs with vitamin D-fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D DRV estimates across a range of serum 25(OH)D thresholds using unadjusted and adjusted models. RESULTS: Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25 and ≥ 30 nmol/L are 6 and 12 µg/day, respectively (unadjusted model). The intake estimates to maintain 90%, 95% and 97.5% of concentrations ≥ 50 nmol/L are 33.4, 57.5 and 92.3 µg/day, respectively (unadjusted) and 17.0, 28.1 and 43.6 µg/day, respectively (adjusted for mean values for baseline serum 25(OH)D, age and BMI). CONCLUSIONS: IPD-derived vitamin D intakes required to maintain 90%, 95% and 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L are much higher than those derived from standard meta-regression based on aggregate data, due to the inability of the latter to capture between person-variability. Our IPD provides further evidence that using food-based approaches to achieve an intake of 12 µg/day could prevent vitamin D deficiency (i.e., serum 25(OH)D < 30 nmol/L) in the general population.

Association Between Prepregnancy Obesity and Health Behaviors, Adverse Conditions, and Birth Outcomes in South Dakota.

INTRODUCTION: Prepregnancy obesity has been shown to be associated with increased risk of adverse birth outcomes but little is known about the associations with health-related behaviors and conditions before, during and after pregnancy. METHODS: This retrospective cohort study used data from the South Dakota Pregnancy Risk Assessment Monitoring System (SD PRAMS) survey, which is an ongoing state-based surveillance system of maternal behaviors, attitudes, and experiences before, during, and shortly after pregnancy. The 2017 and 2018 SD PRAMS sampled a total of 3,805 mothers who were randomly selected from birth certificate records to be representative of all South Dakota women who delivered a live-born infant. Logistic regression was used to determine whether prepregnancy obesity was associated with adverse health conditions after controlling for demographic factors. RESULTS: Women with prepregnancy obesity, compared to those who were non-obese, were more likely to report an unintended pregnancy (45 percent vs. 39 percent), smoking three months before pregnancy (32 percent vs. 22 percent), delayed prenatal care (12 percent vs. 16 percent), hypertension during pregnancy (22 percent vs. 9 percent), gestational diabetes (19 percent vs. 8 percent), depression during pregnancy (21 percent vs. 14 percent), C-section delivery (35 percent vs. 22 percent), high birth weight (15 percent vs. 8 percent), and the infant hospitalized for three or more days (41 percent vs. 30 percent). Of women with prepregnancy obesity, 37 percent had been talked to by health care providers about maintaining a healthy weight the 12 months before pregnancy compared to 13 percent of non-obese women. CONCLUSIONS: Health care workers should be more intentional about stressing the potential risks of prepregnancy obesity to properly educate mothers and women of childbearing age.

Safe Sleep Behaviors Among South Dakota Mothers and the Role of the Healthcare Provider.

INTRODUCTION: The purpose of this report was to determine the prevalence of safe sleep practices among South Dakota mothers, and the impact that education from their healthcare provider had on infant safe sleep practices as defined by the American Academy of Pediatrics (AAP). METHOD: A population-based survey was administered to a random sample of mothers delivering in 2017. Data were weighted to obtain statewide and race-specific (white, non-Hispanic; American Indian; other races) prevalence rates. RESULTS: Weighted response rate was 67 percent, with 9.9 percent of mothers giving birth in 2017 completing a survey. Greater than 85 percent of mothers met recommendations regarding placing their infant on their back, breastfeeding, not consuming alcohol or illicit drugs during pregnancy, and attending 80 percent or more of prenatal visits. Less than 85 percent met recommendations regarding infant always sleeping alone on an approved sleep surface (30.8 percent), room-sharing without bed-sharing (44.3 percent), keeping soft objects and loose bed- ding out of crib (47.7 percent), and avoiding smoke exposure during and after pregnancy (82.1 percent). Only 7.7 percent of mothers met all eight recommendations. Healthcare providers talking to the mother about placing the infant to sleep in a crib and placing the crib in the mother's room were associated with a higher percent of mothers meeting these recommendations. Although the health care provider asking the mother if she was going to breastfeed was not associated with ever breastfeeding (p=0.95), if the mother received information from the doctor about breastfeeding she was slightly more likely to breastfeed than if she did not receive information (90.3 vs. 85 percent, p=0.06). CONCLUSIONS: A low percentage of South Dakota mothers met all eight AAP safe sleep recommendations that could be assessed using these data. Health care providers can influence a mother's compliance with some of the safe sleeping recommendations.

Comparison of Physical Activity by Lifestyle Between Two Rural Pediatric Population Groups.

BACKGROUND: Obesity prevalence is higher among rural populations than urban, including youth. Reduced physical activity levels are associated with childhood obesity. It could be assumed that the obesity disparity between rural and urban children is attributable, in part, to differences in physical activity levels; however, previous research quantifying and comparing physical activity levels between rural and urban youth are mixed. Lifestyle may be more important than geographic location in determining physical activity levels. Therefore, the objective of this study was to compare sex and lifestyle group (Hutterite vs. non-Hutterite) differences in physical activity in a free-living, rural pediatric population. METHODS: Youth (n=58) were instructed to wear accelerometers for seven days. Mean percent time in light, moderate or vigorous activity during waking hours was calculated. Two-way ANOVAs and multiple regression models were used for analyses. RESULTS: Percent time in vigorous activity was significantly greater for Hutterite males than Hutterite females, and Hutterite males had greater percent time in vigorous activity and moderate plus vigorous activity than non-Hutterite males. CONCLUSIONS: There is evidence to support differences in rural lifestyles to be associated with differences in physical activity levels between children living in the same geographic location, particularly among males. Active transportation and having a safe environment for unstructured outdoor play may account for activity and lifestyle differences between the two rural groups.

Sports Participation in High School and College Leads to High Bone Density and Greater Rates of Bone Loss in Young Men: Results from a Population-Based Study.

Estimated lifetime risk of an osteoporotic fracture in men over the age of 50 years is substantial and lifestyle factors such as physical activity may explain variation in bone mass and bone loss associated with aging. Men (n = 253) aged 20-66 years were followed for 7.5 years and factors that influence changes in means and rates of change in bone mass, density, and size using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) were investigated; in particular, seasons of sports participation during high school and college. Men with greater sports participation had higher total hip bone mineral content (BMC) (48.4 ± 0.9 and 48.6 ± 0.9 g for 7-12 and 13+ seasons vs. 45.6 ± 0.8 and 45.4 ± 0.7 g for 0 and 1-6 seasons, respectively p < 0.05) and areal bone mineral density (aBMD) (1.082 ± 0.015 and 1.087 ± 0.015 g/cm2 for 7-12 and 13+ seasons vs. 1.011 ± 0.015 and 1.029 ± 0.013 g/cm2 for 0 and 1-6 seasons, respectively p < 0.05) than men who participated in less sport-seasons. However, men with higher sports participation also had greater rates of bone loss in their mid-twenties at the hip (BMC - 0.8 and - 1.2% and aBMD - 0.8 and - 0.9% for 7-12 and 13+ seasons of sport participation, respectively) compared to those with 0 seasons of sport participation (BMC - 0.6% and aBMD - 0.6%) (all p < 0.05). Similar results were observed for femoral neck aBMD. Men with 7+ seasons of sport participation had higher cross-sectional area at the 20% distal radius site than those with no sports participation (all p < 0.05). These findings support significant effects of high school and/or college sports participation on bone mass and geometry in men throughout adulthood.

Protein Supplementation During a 6-Month Concurrent Training Program: Effect on Body Composition and Muscular Strength in Sedentary Individuals.

We examined the effect of a protein supplement on muscular strength and body composition during 6 months of a 5 days/week concurrent strength and endurance training program. Sedentary males (n = 26) and females (n = 25), 18-25 years, were randomly assigned to receive a protein (PRO, 42 g/serving) or carbohydrate (CON) supplement twice daily. Strength and body composition (dual-energy X-ray absorptiometry) were assessed at baseline, 3 (3M), and 6 (6M) months. Protein intake was higher in PRO (PRO: 2.2 g/kg; CON: 1.1 g/kg; p < .001). Females in both groups gained similar strength at 3M and 6M in bench press and hip sled. Males in PRO gained more bench press strength at 3M (PRO: 24.6 ± 3.2 kg; CON: 14.3 ± 3.8 kg; p = .06) and 6M (PRO: 34.4 ± 4.3 kg; CON: 18.7 ± 5.1 kg; p = .03) and hip sled strength at 3M (PRO: 67.7 ± 9.2 kg; CON: 40.8 ± 10.8 kg, p = .07) and 6M (PRO: 94.0 ± 10.6 kg; CON: 65.1 ± 12.4 kg; p = .09) compared with CON. Females in PRO experienced a greater reduction in fat mass over the course of the study (6M) than CON (PRO: -1.7 ± 0.5 kg; CON: 0.1 ± 0.5 kg; p = .06). Changes in lean mass were similar for females in PRO and CON. Loss in fat mass was similar for males in PRO and CON at 3M and 6M. Males in PRO gained more lean mass at 3M compared with CON (PRO: 3.2 ± 0.3 kg; CON: 2.2 ± 0.4 kg; p = .1) but similar gains at 6M (PRO: 2.6 ± 0.4 kg; CON: 2.2 ± 0.5 kg; p = .6). The results of this study demonstrate that PRO used during a concurrent training program may augment positive changes in body composition in young sedentary males and females, and strength gains in males.

Feasibility and informative value of environmental sample collection in the National Children's Vanguard Study.

BACKGROUND: Birth cohort studies provide the opportunity to advance understanding of the impact of environmental factors on childhood health and development through prospective collection of environmental samples. METHODS: We evaluated the feasibility and informative value of the environmental sample collection methodology in the initial pilot phase of the National Children's Study, a planned U.S. environmental birth cohort study. Environmental samples were collected from January 2009-September 2010 at up to three home visits: pre-pregnancy (n=306), pregnancy (n=807), and 6-months postnatal (n=117). Collections included air for particulate matter ≤2.5 µm (PM2.5), nitrogen dioxide, ozone, volatile organic compounds (VOCs), and carbonyls; vacuum dust for allergens/endotoxin; water for VOCs, trihalomethanes (THMs), and haloacetic acids (HAAs); and wipe samples for pesticides, semi-volatile organics, and metals. We characterized feasibility using sample collection rates and times and informative value using analyte detection frequencies (DF). RESULTS: Among the 1230 home visits, environmental sample collection rates were high across all sample types (mean=89%); all samples except the air PM2.5 samples had collection times <30 min. Informative value was low for water VOCs (median DF=0%) and pesticide floor wipes (median DF=5%). Informative value was moderate for air samples (median DF=35%) and high for water THMs and HAAs (median DF=91% and 75%, respectively). CONCLUSIONS: Though collection of environmental samples was feasible, some samples (e.g., wipe pesticides and water VOCs) yielded limited information. These results can be used in conjunction with other study design considerations, such as target population size and hypotheses of interest, to inform the method selection of future environmental health birth cohort studies.

Bone densitometry in infants and young children: the 2013 ISCD Pediatric Official Positions.

Infants and children <5 yr were not included in the 2007 International Society for Clinical Densitometry Official Positions regarding Skeletal Health Assessment of Children and Adolescents. To advance clinical care of very young children, the International Society for Clinical Densitometry 2013 Position Development Conference reviewed the literature addressing appropriate methods and skeletal sites for clinical dual-energy X-ray absorptiometry (DXA) measurements in infants and young children and how results should be reported. DXA whole-body bone mineral content and bone mineral density for children ≥3 yr and DXA lumbar spine measurements for infants and young children 0-5 yr were identified as feasible and reproducible. There was insufficient information regarding methodology, reproducibility, and reference data to recommended forearm and femur measurements at this time. Appropriate methods to account for growth delay when interpreting DXA results for children <5 yr are currently unknown. Reference data for children 0-5 yr at multiple skeletal sites are insufficient and are needed to enable interpretation of DXA measurements. Given the current scarcity of evidence in many areas, it is likely that these positions will change over time as new data become available.

Factors Associated with Breastfeeding Initiation and Continuation at Two Months Postpartum in American Indian Women: An Exploratory Analysis.

This study aimed to determine the prevalence of breastfeeding initiation and continuation at two months postpartum in American Indian (AI) mothers in South Dakota and to identify factors associated with breastfeeding. Using logistic regression, data from the South Dakota Pregnancy Risk Assessment Monitoring System were used to investigate the relationship between binary breastfeeding initiation and continuation outcomes and maternal behaviors and experiences including access to health care, safe sleep practices, ability to handle life events, depression, and sources of breastfeeding information. Higher odds of initiation were seen for factors including access to health care services, ability to handle life events, and sources of breastfeeding information, while lower odds were seen for factors including safe sleep. Higher odds of continuation were seen among mothers who reported not taking long to get over setbacks and among mothers who reported no postpartum depression, while lower odds of continuation were seen among mothers practicing safe sleep. Several modifiable factors were identified as reasons for stopping breastfeeding. This information about factors associated with higher odds of breastfeeding initiation and continuation at two months postpartum can be used to inform interventions, programs, and policies designed to support breastfeeding among AI women and to guide future research in this area.

Feasibility and Effects on Muscle Function of an Exercise Program for Older Adults.

INTRODUCTION: Study objective was to determine feasibility and compliance with a 3-month exercise intervention in older adults, and if peripheral quantitative computed tomography muscle measures and jumping mechanography could detect changes in muscle mass and function. METHODS: A parallel group, nonblinded, pilot trial with individuals 70 yr or older randomized to control group of walking-only (WALK) or an intervention group of walking combined with exercises to improve balance and strength (W + EX). Both groups attended similar weekly nutrition education sessions. Body composition, muscle density, intramuscular adipose tissue area, and muscle function were assessed before and after the intervention using dual-energy x-ray, peripheral quantitative computed tomography, functional tests, and mechanography. RESULTS: Eighty-five (90%) of 94 individuals enrolled completed (41WALK, 44W + EX). Eighty-six percent of participants attended seven or more nutrition sessions, and log sheets, used to assess exercise compliance, were returned by 66% of participants, and of those, 88% logged activity on 50%+ days. Sixty-seven percent of participants stated that they increased activity levels, and 82% stated that they felt better overall. Both groups increased lean and lost fat mass, resulting in decreases in fat percentage (all, P < 0.05). Intramuscular adipose tissue area decreased and muscle density increased among WALK (P < 0.05 and P = 0.056, respectively) but were not different between groups. Improvement in force efficiency and chair-rise power were greater among W + EX group than WALK (5.9% ± 1.8% vs -1.2% ± 2.0% [P = 0.01] and 0.25 ± 0.19 W·kg and -0.37 ± 0.23 W·kg [P = 0.04], respectively). Differences in mechanography results became greater in a per-protocol analysis. CONCLUSIONS: A larger trial is feasible, and the program was well accepted. Both groups showed improvements, the program that included strength and balance lead to greater jump force efficiency and power than walking only. Whether these differences lead to differences in fall rates need to be determined in a larger trial.

Pregnancy Survey of Smoking and Alcohol Use in South Dakota American Indian and White Mothers.

INTRODUCTION: American Indian populations are believed to have relatively high tobacco use and alcohol consumption before and during pregnancy compared with other populations despite little evidence. METHODS: Population-based survey distributed 2-6 months postpartum to 1,814 South Dakota mothers having a live birth in 2014. Prevalence of self-reported smoking and alcohol use before and during pregnancy were calculated for American Indian and white mothers and AORs were determined controlling for Hispanic status, marital status, age, education, and income. Analysis was completed in 2017-2018. RESULTS: Smoking among American Indian mothers was similar to white mothers before and during pregnancy (AOR=1.60, 95% CI=0.95, 2.67 and AOR=0.67, 95% CI=0.37, 1.21, respectively). Among smokers, a higher percentage of American Indian mothers smoked less than six cigarettes/day than white mothers (AOR=6.79, 95% CI=3.21, 14.35, before and AOR=4.85, 95% CI=1.08, 21.7, during pregnancy), and American Indian mothers had greater odds of quitting (AOR=3.60, 95% CI=1.74, 7.43). No difference in relapse rates by race were found (AOR=0.57, 95% CI=0.19, 1.72). Alcohol consumption before pregnancy was less among American Indian than white mothers (AOR=0.53 95% CI=0.30, 0.94), and among those who drank no differences by race in drinks/week were observed (AOR for American Indians drinking more than four drinks/week=1.20, 95% CI=0.56, 2.55) or binge drinking (AOR=1.50, 95% CI=0.75, 3.04). Rates of alcohol consumption during pregnancy and topics covered by healthcare providers during prenatal visits did not differ by race. CONCLUSIONS: After adjusting for covariates, no differences by race in smoking rates before or during pregnancy were observed and American Indian mothers who smoked were more likely to smoke fewer cigarettes and quit smoking during pregnancy than white mothers. Lower alcohol consumption among American Indian mothers before pregnancy challenges the commonly held belief of elevated alcohol consumption among American Indians compared with other races.

Effects of genes, sex, age, and activity on BMC, bone size, and areal and volumetric BMD.

UNLABELLED: Quantitative genetic analyses of bone data for 710 inter-related individuals 8-85 yr of age found high heritability estimates for BMC, bone area, and areal and volumetric BMD that varied across bone sites. Activity levels, especially time in moderate plus vigorous activity, had notable effects on bone. In some cases, these effects were age and sex specific. INTRODUCTION: Genetic and environmental factors play a complex role in determining BMC, bone size, and BMD. This study assessed the heritability of bone measures; characterized the effects of age, sex, and physical activity on bone; and tested for age- and sex-specific bone effects of activity. MATERIALS AND METHODS: Measures of bone size and areal and volumetric density (aBMD and vBMD, respectively) were obtained by DXA and pQCT on 710 related individuals (466 women) 8-85 yr of age. Measures of activity included percent time in moderate + vigorous activity (%ModVig), stair flights climbed per day, and miles walked per day. Quantitative genetic analyses were conducted to model the effects of activity and covariates on bone outcomes. RESULTS: Accounting for effects of age, sex, and activity levels, genes explained 40-62% of the residual variation in BMC and BMD and 27-75% in bone size (all p<0.001). Decline in femoral neck (FN), hip, and spine aBMD with advancing age was greater among women than men (age-by-sex interaction; all p

Fat mass gain is lower in calcium-supplemented than in unsupplemented preschool children with low dietary calcium intakes.

BACKGROUND: Dietary calcium may play a role in the stimulation of lipolysis and the inhibition of lipogenesis, thereby reducing body fat. OBJECTIVE: The aim was to determine whether an association existed between change in percentage body fat (%BF) or fat mass and calcium intake in children aged 3-5 y. DESIGN: A secondary analysis of a 1-y randomized calcium and activity trial in 178 children was conducted. Three-day diet records and 48-h accelerometer readings were obtained at 0, 6, and 12 mo. Body composition was measured by dual-energy X-ray absorptiometry at 0 and 12 mo. RESULTS: The decrease in %BF was less in girls (-0.6 +/- 2.8%) than in boys (-1.5 +/- 2.6%; P = 0.03) and correlated with age (r = 0.19, P = 0.01) and maternal body mass index (r = 0.19, P = 0.02). Changes in fat mass were not significantly different by activity group or between children randomly assigned to receive calcium or placebo (0.5 +/- 0.9 and 0.6 +/- 0.8 kg, respectively; P = 0.32). Similar findings were observed for the change in %BF. No correlations between %BF and fat mass changes and dietary calcium (r = -0.01, P = 0.9 and r = -0.05, P = 0.5) or total (dietary + supplement) calcium intake (r = -0.02, P = 0.8 and r = -0.06, P = 0.4) were observed. Among children in the lowest tertile of dietary calcium (<821 mg/d), fat mass gain was lower in the calcium group (0.3 +/- 0.5 kg) than in the placebo group (0.8 +/- 1.1 kg) (P = 0.04) but was not correlated with mean total calcium intake (r = -0.20). CONCLUSION: These findings support a weak relation between changes in fat mass gain and calcium intake in preschool children, who typically consume below recommended amounts of dietary calcium.

Effect of protein supplementation during a 6-month strength and conditioning program on areal and volumetric bone parameters.

BACKGROUND: Skeletal loading and proper nutrition are necessary for optimal bone health. The appropriate amount of dietary protein to maximize skeletal health, however, is under constant debate. OBJECTIVE: To determine if 6 months of protein supplementation in conjunction with a strength and conditioning training program improves areal and volumetric bone mineral density (BMD). DESIGN: Fifty-two apparently healthy males and females ages 18-25 years were randomized to protein supplement (PRO, Myoplex, EAS, Inc. Golden CO) containing 280 kcal, 42 g protein, 21 g carbohydrate, and 1.5 g fat) or calorically equivalent carbohydrate control (CS). All subjects participated in a 5 sessions/week strength and conditioning program. Volumetric and areal BMD measurements were made by peripheral quantitative computed tomography (pQCT) of the tibia and whole body DXA. pSSI a measure of torsional bone strength, based on structural and material properties was obtained by pQCT. RESULTS: Measurements at the 20% tibia by pQCT revealed that overall there were significant increases in cortical vBMD (4.3 +/- 1.3 mg/cm(3)), cortical area (1.9 +/- 0.6 cm(2)), cortical thickness (0.05 +/- 0.02 mm) and pSSI (67 +/- 24 mm(3)), and a decrease in endosteal circumference (- 0.5 +/- 0.2 mm) over the intervention period (all, P < 0.05). None of the changes in DXA measures were found to differ by group or sex, there was a trend for a greater increase in whole body BMC among the carbohydrate compared to protein supplemented group and a greater increase among males (16 +/- 8 g) compared to females (-9 +/- 9 g) (P = 0.06). CONCLUSIONS: The results of this study indicate that the consumption of additional protein does not improve measurements of vBMD or bone size during a 6-month strength and conditioning program. Longer duration studies may be necessary to determine the influence of increased dietary protein on bone in young adults. Males and females may have different bone responses to increased protein intake while participating in a strength and conditioning program.

Peripheral quantitative computed tomography (pQCT) bone measurements in children with cystic fibrosis.

BACKGROUND: Individuals with cystic fibrosis (CF) have low bone density and increased fracture risk. METHODS: Cross-sectional study investigating whole body bone mineral content (WBBMC), bone geometry and strength in 12 children with CF compared to 23 age- and sex-matched controls with and without adjusting for age, height, and body composition. RESULTS: CF group had lower WBBMC than controls (P = 0.007) with larger differences at older ages (age-by-group, P = 0.08). CF group had decreased height (P = 0.006), a trend of lower lean mass per height (P = 0.08), and no difference in relationship between WBBMC and lean mass compared to controls (P = 0.65). Periosteal and endosteal circumferences were smaller in CF (each, P = 0.02). Positive relationships of cortical area and bone strength with age were attenuated with CF (group-by-age; each, P < 0.01). CONCLUSION: Children with CF have similar WBBMC relative to lean mass as controls. Cortical bone area and bone strength were less in CF group compared to controls, with greater differences in older children.

Global Consensus Recommendations on Prevention and Management of Nutritional Rickets.

BACKGROUND: Vitamin D and calcium deficiencies are common worldwide, causing nutritional rickets and osteomalacia, which have a major impact on health, growth, and development of infants, children, and adolescents; the consequences can be lethal or can last into adulthood. The goals of this evidence-based consensus document are to provide health care professionals with guidance for prevention, diagnosis, and management of nutritional rickets and to provide policy makers with a framework to work toward its eradication. EVIDENCE: A systematic literature search examining the definition, diagnosis, treatment, and prevention of nutritional rickets in children was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system that describes the strength of the recommendation and the quality of supporting evidence. PROCESS: Thirty-three nominated experts in pediatric endocrinology, pediatrics, nutrition, epidemiology, public health, and health economics evaluated the evidence on specific questions within five working groups. The consensus group, representing 11 international scientific organizations, participated in a multiday conference in May 2014 to reach a global evidence-based consensus. RESULTS: This consensus document defines nutritional rickets and its diagnostic criteria and describes the clinical management of rickets and osteomalacia. Risk factors, particularly in mothers and infants, are ranked, and specific prevention recommendations including food fortification and supplementation are offered for both the clinical and public health contexts. CONCLUSION: Rickets, osteomalacia, and vitamin D and calcium deficiencies are preventable global public health problems in infants, children, and adolescents. Implementation of international rickets prevention programs, including supplementation and food fortification, is urgently required.

Global Consensus Recommendations on Prevention and Management of Nutritional Rickets.

BACKGROUND: Vitamin D and calcium deficiencies are common worldwide, causing nutritional rickets and osteomalacia, which have a major impact on health, growth, and development of infants, children, and adolescents; the consequences can be lethal or can last into adulthood. The goals of this evidence-based consensus document are to provide health care professionals with guidance for prevention, diagnosis, and management of nutritional rickets and to provide policy makers with a framework to work toward its eradication. EVIDENCE: A systematic literature search examining the definition, diagnosis, treatment, and prevention of nutritional rickets in children was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system that describe the strength of the recommendation and the quality of supporting evidence. PROCESS: Thirty-three nominated experts in pediatric endocrinology, pediatrics, nutrition, epidemiology, public health, and health economics evaluated the evidence on specific questions within five working groups. The consensus group, representing 11 international scientific organizations, participated in a multiday conference in May 2014 to reach a global evidence-based consensus. RESULTS: This consensus document defines nutritional rickets and its diagnostic criteria and describes the clinical management of rickets and osteomalacia. Risk factors, particularly in mothers and infants, are ranked, and specific prevention recommendations including food fortification and supplementation are offered for both the clinical and public health contexts. CONCLUSION: Rickets, osteomalacia, and vitamin D and calcium deficiencies are preventable global public health problems in infants, children, and adolescents. Implementation of international rickets prevention programs, including supplementation and food fortification, is urgently required.

Effect of protein supplementation during a 6-mo strength and conditioning program on insulin-like growth factor I and markers of bone turnover in young adults.

BACKGROUND: Exercise is beneficial for bone when adequate nutrition is provided. The role of protein consumption in bone health, however, is controversial. OBJECTIVE: The objective was to ascertain the effect of high protein intake on insulin-like growth factor I (IGF-I) and markers of bone turnover during 6 mo of exercise training. DESIGN: Fifty-one subjects aged 18-25 y (28 men, 23 women) received a protein supplement (42 g protein, 24 g carbohydrate, 2 g fat) or a carbohydrate supplement (70 g carbohydrate) twice daily. Exercise consisted of alternating resistance training and running 5 times/wk. Plasma concentrations of IGF-I, insulin-like growth factor-binding protein 3, serum bone alkaline phosphatase, and urinary N-telopeptide collagen crosslink (NTx) concentrations were measured at 0, 3, and 6 mo after 24 h without exercise and a 12-h fast. RESULTS: Three-day diet records indicated no difference in energy intake between the groups. Average protein intakes after supplementation began in the protein and carbohydrate groups were 2.2 +/- 0.1 and 1.1 +/- 0.1 g/kg, respectively (P < 0.001). The increase in plasma IGF-I was greater in the protein group than in the carbohydrate group (time x supplement interaction, P = 0.01). There were no significant changes over time or significant differences by supplement in plasma insulin-like growth factor-binding protein 3 (44 and 40 kDa). Serum bone alkaline phosphatase increased significantly over time (P = 0.04) and tended to be higher in the protein group than in the carbohydrate group (P = 0.06). NTx concentrations changed over time (time and time squared; P < 0.01 for both) and were greater in the protein group than in the carbohydrate group (P = 0.04). Men had higher NTx concentrations than did women (74.6 +/- 3.4 and 60.0 +/- 3.8 nmol/mmol creatinine; P = 0.005). CONCLUSION: Protein supplementation during a strength and conditioning program resulted in changes in IGF-I concentrations.

Validation of drinking water disinfection by-product exposure assessment for rural areas in the National Children's Study.

The objective of this study was to provide evidence to evaluate the proposed National Children's Study (NCS) protocol for household water sampling in rural study areas. Day-to-day variability in total trihalomethane (TTHM) concentrations in community water supplies (CWS) in rural areas was determined, and the correlation between TTHM concentrations from household taps and CWS monitoring reports was evaluated. Daily water samples were collected from 7 households serviced by 7 different CWS for 15 days. Coefficients of variation for TTHM concentration over 15 days ranged from 8% to 20% depending on the household. Correlations were tested between TTHM household concentrations and the closest date- and location-matched CWS monitoring reports for the 15-day mean (R=0.85, P<0.01). To simulate the NCS-proposed protocol, correlations were tested for 30 additional NCS household samples (polynomial fit: R=0.74, P=0.04). CWS reported TTHM concentrations >50 µg/l corresponded to measured NCS household concentrations ranging from 2 to 60 µg/l. TTHM concentrations were higher in CWS than NCS samples (11.2±3.2 µg/l, mean difference±SE, P<0.01). These results show that in rural areas there is high variability within households and poor correlation at higher concentrations, suggesting that TTHM concentrations from CWS monitoring reports are not an accurate measure of exposure in the household.