Breastfeeding duration is associated with higher adiposity at 6-8 months of age.

Breastfeeding (BF) has been identified as a protective factor against childhood obesity. However, evidence of the association between BF duration and adiposity remains inconclusive. Few studies have been conducted among Southeast Asian infants that have measured body composition during infancy using the gold standard stable isotope method. This study aimed to evaluate the association between BF duration and body composition during infancy. Healthy full-term Thai infants aged 6-8 months (n = 60) receiving exclusive or predominant BF for at least 3 months were recruited. Skinfold thickness (SFT) was measured by well-trained investigators. Body composition was assessed by the deuterium dilution technique. Infants with longer BF duration (>6 months; mean 7.5 ± 0.5 months, n = 29) had a higher subscapular SFT z-score than those with shorter BF duration (≤6 months; mean 5.3± 0.9 months, n = 31) by 0.48 (95% confidence interval [CI]: 0.01-0.94). After adjustment for age and sex, BF duration and age at introduction of complementary feeding (CF) were positively associated with fat mass and fat mass index at 6-8 months. One month increase in BF duration and CF age was associated with a 0.37 (95% CI: 0.05, 0.69) kg/m2 and 0.76 (95% CI: 0.18, 1.34) kg/m2 increase in the fat mass index, respectively. After adjusting for infant body mass index (BMI) during the earlier infancy period, the strength of the association was attenuated. This finding may reflect reverse causality where infants with lower BMI received formula or CF earlier. A longitudinal study with follow-up into childhood is warranted to confirm the effects of BF on adiposity in infancy and childhood.

Protein Quality Assessment of Follow-up Formula for Young Children and Ready-to-Use Therapeutic Foods: Recommendations by the FAO Expert Working Group in 2017.

The FAO of the UN convened an Expert Working Group meeting to provide recommendations related to protein quality evaluation of Follow-up Formula for Young Children (FUF-YC) and Ready-to-Use Therapeutic Foods (RUTFs). The protein and amino acid (AA) scoring patterns for the target age groups were defined and recommendations provided on the use of currently available protein and indispensable AA digestibility data. For FUF-YC, an age category of 1-2.9 y was identified, and a matching protein requirement of 0.86 g · kg-1 · d-1 with corresponding AA requirements were recommended. For RUTF, the protein requirement recommended was 2.82 g · kg-1 · d-1, to achieve a catch-up weight gain of 10 g · kg-1 · d-1 in children recovering from severe acute malnutrition. The AA requirements were factorially derived based on the adult protein requirement for maintenance and tissue AA composition. A flowchart was proposed for the best available methods to estimate digestibility coefficients (of either protein or AAs), in the following order: human, growing pig, and rat true ileal AA digestibility values. Where this is not possible, fecal protein digestibility values should be used. The Expert Working Group recommends the use of the Protein Digestibility Corrected Amino Acid Score (PDCAAS), with existing protein digestibility values, or the Digestible Indispensable Amino Acid Score provided that individual AA digestibility values are available for protein quality evaluation using the latter score. The Group also recommends the use of ileal digestibility of protein or of AAs for plant-based protein sources, recognizing the possible effects of antinutritional factors and impaired gut function. A PDCAAS score of ≥90% can be considered adequate for these formulations, whereas with a score <90%, the quantity of protein should be increased to meet the requirements. Regardless of the protein quality score, the ability of formulations to support growth in the target population should be evaluated. Future research recommendations are also proposed based on the knowledge gaps identified.

Inventory on the dietary assessment tools available and needed in africa: a prerequisite for setting up a common methodological research infrastructure for nutritional surveillance, research, and prevention of diet-related non-communicable diseases.

OBJECTIVE: To carry out an inventory on the availability, challenges, and needs of dietary assessment (DA) methods in Africa as a pre-requisite to provide evidence, and set directions (strategies) for implementing common dietary methods and support web-research infrastructure across countries. METHODS: The inventory was performed within the framework of the "Africa's Study on Physical Activity and Dietary Assessment Methods" (AS-PADAM) project. It involves international institutional and African networks. An inventory questionnaire was developed and disseminated through the networks. Eighteen countries responded to the dietary inventory questionnaire. RESULTS: Various DA tools were reported in Africa; 24-Hour Dietary Recall and Food Frequency Questionnaire were the most commonly used tools. Few tools were validated and tested for reliability. Face-to-face interview was the common method of administration. No computerized software or other new (web) technologies were reported. No tools were standardized across countries. CONCLUSIONS: The lack of comparable DA methods across represented countries is a major obstacle to implement comprehensive and joint nutrition-related programmes for surveillance, programme evaluation, research, and prevention. There is a need to develop new or adapt existing DA methods across countries by employing related research infrastructure that has been validated and standardized in other settings, with the view to standardizing methods for wider use.

An approach towards method development for untargeted urinary metabolite profiling in metabonomic research using UPLC/QToF MS.

The application of LC-MS for untargeted urinary metabolite profiling in metabonomic research has gained much interest in recent years. However, the effects of varying sample pre-treatments and LC conditions on generic metabolite profiling have not been studied. We aimed to evaluate the effects of varying experimental conditions on data acquisition in untargeted urinary metabolite profiling using UPLC/QToF MS. In-house QC sample clustering was used to monitor the performance of the analytical platform. In terms of sample pre-treatment, results showed that untreated filtered urine yielded the highest number of features but dilution with methanol provided a more homogenous urinary metabolic profile with less variation in number of features and feature intensities. An increased cycle time with a lower flow rate (400 microl/min vs 600 microl/min) also resulted in a higher number of features with less variability. The step elution gradient yielded the highest number of features and the best chromatographic resolution among three different elution gradients tested. The maximum retention time and mass shift were only 0.03 min and 0.0015 Da respectively over 600 injections. The analytical platform also showed excellent robustness as evident by tight QC sample clustering. To conclude, we have investigated LC conditions by studying variability and repeatability of LC-MS data for untargeted urinary metabolite profiling.

Increased prevalence of constipation in pre-school children is attributable to under-consumption of plant foods: A community-based study.

AIM: To evaluate consumption of foods rich in dietary fibre and its relation to the prevalence of constipation in pre-school children. METHODS: In total, 368 children aged 3-5 years were randomly selected from kindergartens in Hong Kong. Constipation was confirmed by Rome-criteria. Children with normal bowel habits served as non-constipated controls. Consumption of vegetables, fruits, whole-grain cereals and fluid were determined using a 3-day food record. RESULTS: A total of 28.8% children were reported to have constipation. Median dietary fibre intake of constipated children was significantly lower than non-constipated children (3.4 g/d (inter-quartile range (IQR): 2.3-4.6 g/d) vs. 3.8 g/d (IQR: 2.7-4.9 g/d); P = 0.044) corresponding to 40% reference dietary fibre intake. Constipated children also had significantly lower intakes of vitamin C (P = 0.041), folate (P = 0.043) and magnesium (P = 0.002). Fruit intake and total plant foods intake were significantly lower in the constipated than non-constipated children: (61 g/d (IQR: 23.8-115 g/d) vs. 78 g/d (IQR: 41.7-144.6 g/d); P = 0.047) and (142.5 g/d (IQR: 73.7-214.7 g/d) vs. 161.1 g/d (IQR: 98.3-233.3 g/d); P = 0.034), respectively. Total fluid intake did not differ between groups but milk intake among the constipated children was marginally higher than the non-constipated children (P = 0.055) CONCLUSION: Insufficient dietary fibre intake is common in Hong Kong pre-school children. Constipated children had significantly lower intakes of dietary fibre and micronutrients including vitamin C, folate and magnesium than non-constipated counterparts which was attributable to under-consumption of plant foods. However, milk intake was marginally higher in the constipated children. More public education is necessary for parents to help develop healthy dietary habit and bowel habit in early life in order to prevent childhood constipation.

Adjusting bone mass for differences in projected bone area and other confounding variables: an allometric perspective.

The traditional method of assessing bone mineral density (BMD; given by bone mineral content [BMC] divided by projected bone area [Ap], BMD = BMC/Ap) has come under strong criticism by various authors. Their criticism being that the projected bone "area" (Ap) will systematically underestimate the skeletal bone "volume" of taller subjects. To reduce the confounding effects of bone size, an alternative ratio has been proposed called bone mineral apparent density [BMAD = BMC/(Ap)3/2]. However, bone size is not the only confounding variable associated with BMC. Others include age, sex, body size, and maturation. To assess the dimensional relationship between BMC and projected bone area, independent of other confounding variables, we proposed and fitted a proportional allometric model to the BMC data of the L2-L4 vertebrae from a previously published study. The projected bone area exponents were greater than unity for both boys (1.43) and girls (1.02), but only the boy's fitted exponent was not different from that predicted by geometric similarity (1.5). Based on these exponents, it is not clear whether bone mass acquisition increases in proportion to the projected bone area (Ap) or an estimate of projected bone volume (Ap)3/2. However, by adopting the proposed methods, the analysis will automatically adjust BMC for differences in projected bone size and other confounding variables for the particular population being studied. Hence, the necessity to speculate as to the theoretical value of the exponent of Ap, although interesting, becomes redundant.

Calcium absorption measured by stable calcium isotopes ((42)Ca & (44)Ca) among Northern Chinese adolescents with low vitamin D status.

An adequate calcium intake and vitamin-D status is important for bone mineralization in adolescents. In Northern China, calcium intake and plasma vitamin-D level of adolescents is low due to low consumption of dairy foods and inadequate sunshine exposure. True fractional calcium absorption (TFCA) in Chinese adolescents has never been performed. This study aims to evaluate nutritional adaptation namely, TFCA and urinary calcium excretion among Chinese adolescents in northern China.

Risk factors of low vitamin D status in adolescent females in Kuwait: implications for high peak bone mass attainment.

UNLABELLED: Risks of low vitamin D status in Kuwaiti adolescent girls are high parathyroid hormone (PTH), high waist/hip ratio, veiling and not having a private room. Low vitamin D status is likely to have a negative impact on their bone mass and accrual. INTRODUCTION: Low serum 25-hydroxyvitamin D (25OHD) levels are repeatedly found in females in the Middle East, which is a cause for concern particularly for adolescent females. This is because vitamin D has been shown to promote bone mineral accrual in adolescence. PURPOSE: The aim of this study was to assess the risk factors of low vitamin D status in adolescent females and to assess its impact on their bone mass. METHODS: Serum 25OHD and PTH were measured in 232 females. Anthropometric measurements and skin colour were obtained. Bone measurements at the lumbar spine were performed using dual-energy x-ray absorptiometry (DXA). Data on food intake, physical activity (PA) and sun exposure were taken. Binary logistic regression was used to assess the risk factors of serum 25OHD levels <25 nmol/L and multiple linear regression was used to assess the predictors of bone mineral variables. RESULTS: Median 25OHD was 19.4 nmol/L (IQR 16.4-23.68), among which 98.7 % obtained <50 nmol/L. PTH >7 pmol/L (odds ratio (OR) 4.3; 95 % CI 1.8, 10.2), not having a private room (OR 3.7; 95 % CI 1.4, 9.8), veiling (OR 2.4; 95 % CI 1.1, 5.5) and waist/hip ratio >0.75 (OR 2.1; 95 % CI 1.0, 4.3) were risk factors of low vitamin D status, whereas, height, weight, month since menarche, PTH, animal protein intake and PA were independent predictors of bone mineral content (p < 0.05). CONCLUSION: Low vitamin D status is prevalent in Kuwaiti adolescent females, which may have a negative impact on their bone mineralization and accrual. Further investigation is needed to reveal the underlying causes.

The resurgence of the importance of vitamin D in bone health.

Dietary reference intakes (DRIs) for Vitamin D (VitD) have been traditionally established based on plasma 25-OHD concentration sufficient to prevent rickets and osteomalacia. While nutritional rickets is still prevalent in developing countries, hypovitaminosis D is becoming widespread around the world regardless the latitude. Emerging evidence has unravelled the physiological roles of VitD beyond calcium homeostasis. Hypovitaminosis D has been linked to cancers, diabetes, CVD, periodontal diseases and influenza. Hypovitaminosis D is multifactorial and is related to VitD scarcity in foods, latitude, solar-irradiation, atmospheric-pollution, skin-pigmentation, clothing, sunscreen-use and indoor activities, etc. Plasma 25-OHD concentration range from 25-138 nmol/L. A higher plasma 25-OHD concentration is linked to higher bone-mass in adolescents, pre- and post-menopausal women. Plasma 25-OHD > or =75 nmol/L has been shown to enhance calcium absorption, suppress PTH elevation, reduce the risks of bone loss and fractures, and certain extra-skeletal diseases. VitD supplementation with 10 microg/d is insufficient to lower fracture risks. Combined VitD and calcium supplementation in higher doses has been found superior to VitD alone to increase bone-mass in adolescents and to reduce non-vertebral fractures in postmenopausal women. In future, DRIs for VitD are likely to be established beyond its skeletal roles to include multiple health outcomes. However, the desirable level of VitD has yet to be defined. Furthermore, redefining the upper-tolerable-level of VitD intake is necessary to prevent hypercalcemia and toxicity. There is also a urgent need to harmonize laboratory methods in VitD assay in different laboratories.

Decision to breastfeed and early cessation of breastfeeding in infants below 6 months old--a population-based study of 3,204 infants in Hong Kong.

Breastfeeding rate has been low in Hong Kong over the last three decades. This has happened with concomitant rapid economic development and improved living standards. A population-based survey was conducted to evaluate factors influencing decision, duration and early cessation of breastfeeding in 3,204 full-term healthy infants under 6 months throughout Hong Kong in 1993. A self-administered questionnaire was used. The overall percentage of breastfed infants was particularly low (9.6%), 36.1%had already given up breastfeeding and were being formula-fed (FFBF), 54.3% have been exclusively formula-fed since birth. The proportion of breastfed infants in the 5th month was even lower than in the 1st month (4.2% vs. 14.7%). Mothers who sustained breastfeeding tended to have parity >or =2, were less educated, housewives and residing in Hong Kong <5 years when compared to FFBF mothers (p<0.009). Husbands had a decisive role on wives initiating breastfeeding while health-professionals had an influence on early switching to FFBF (p<0.003). More breastfeeding mothers perceived breastfeeding benefits than FFBF mothers (p<0.03). The Cox proportional hazard model showed that mother's residency status >or =5-year (HR=2.4), working mothers (HR=1.5) and health-professionals' opinions (HR=1.5) were associated with an early cessation of breastfeeding (p<0.001). However, strengthening immunity (HR=0.67) and parity >or =2 (HR=0.72) helped sustain breastfeeding (p<0.001). To conclude, the proportion of breastfed infants was low in Hong Kong in the early 1990s. Major factors associated with the decision to breastfeed and early cessation of breastfeeding were identified which would help formulate an inter-disciplinary approach for promotion of breastfeeding up-to 6 months and beyond.

A population-based survey on infant feeding practice (0-2 years) in Hong Kong: breastfeeding rate and patterns among 3,161 infants below 6 months old.

The prevalence of breastfeeding for the first 6 months in infants has been low in Hong Kong since the 1970s. In order to develop effective breastfeeding policies and promotion programs, an appraisal of feeding practices and factors related to initiation and early cessation of breastfeeding is necessary. A survey with a population-based representative sample was conducted to determine social-demographic, personal and cultural factors that influenced decision, duration and practice of infant feeding among infants 0-24 months old. This paper focuses on infants below 6 months old to study factors related to decision, duration and practice of breastfeeding. In 1993, 7,298 healthy infants were recruited from 46 Maternal-and-Child-Health-Clinics (MCHC) throughout Hong Kong, of whom 3161 were below 6 months old. The mother reported her feeding decision, duration and practice in a questionnaire. Breastfeeding rate was found to be very low (8.4%) for infants below 6 months old. Only 50.9% infants were breastfed. Infant formulae were widely given among partially breastfed infants. 45% mothers were full-time employed. Most mothers were aware of the benefits of breastfeeding to the infants and themselves. Husbands (43.3%) were regarded the most influential on initiation and duration on breastfeeding. Restricted food varieties (54%), sore nipple and breast engorgement (67%), perceived home confinement (41.5%) and perceived inadequate milk supply (31.7%) were major concerns upon breastfeeding. Furthermore, 76.9% mothers turned to MCHC staff for advice when they encountered difficulties during breastfeeding. In conclusion, the survey collected population-based representative data on factors determining initiation and early cessation of breastfeeding in Hong Kong in 1993. The findings will serve as a cornerstone in understanding the evolution of breastfeeding practice in Hong Kong. It merits further study to investigate how the confounders interplay to modulate initiation, duration and patterns of breastfeeding.

Generalized low bone mass of girls with adolescent idiopathic scoliosis is related to inadequate calcium intake and weight bearing physical activity in peripubertal period.

Generalized low bone mass has been well documented in patients with adolescent idiopathic scoliosis (AIS). However, studies linking calcium-intake (CA), weight-bearing physical-activity (PA) and bone mass of AIS are lacking. We aimed to study the relationship between CA, PA and bone mass in AIS girls and compared to those of healthy non-AIS controls during the peripubertal period. Newly diagnosed AIS girls (n=596) aged 11-16 years with Cobb angle >/=10 degrees were recruited to compare with age-matched healthy girls (n=302) in a cross-sectional study. Anthropometric parameters, pubertal status, CA and PA were assessed. Areal bone mass of lumbar spine and femoral neck, and volumetric bone mass of distal radius and tibia were determined by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. The results showed that weight and body mass index (BMI) of AIS were lower than the controls (P<0.05). Corrected height and arm span of AIS were longer than those of controls from 13 years onwards (P<0.02). Median CA of AIS was <410 mg/day across the ages and did not differ from the controls (P=0.063). Median PA of AIS (1.6 h/day) was lower than the controls (1.8 h/day) (P=0.025). Bone mass of AIS was on average 6.5% lower than controls across the ages (P<0.05). CA and PA were significantly correlated with bone mass of AIS (P<0.04). Multivariate analysis showed that AIS in girls was associated with lower bone mass, and that both CA and PA were independent predictors of bone mass in AIS. In conclusion, AIS girls were found to have lower body weight and BMI, longer segmental lengths and generalized low bone mass. Inadequate calcium intake and weight-bearing physical activity were significantly associated with low bone mass in AIS girls during the peripubertal period. The importance of preventing generalized osteopenia in the control of AIS progression during the peripubertal period warrants further study.

Association of osteopenia with curve severity in adolescent idiopathic scoliosis: a study of 919 girls.

Generalized osteopenia and spinal deformity occur concomitantly in adolescent idiopathic scoliosis (AIS) during the peripubertal period. No large-scale study has been performed to reveal the link between scoliotic deformity and bone-mineral status in AIS. In a cross-sectional study, the extent of scoliotic-curve severity in relation to bone-mineral status was examined for 619 AIS girls and compared with those of 300 healthy non-AIS counterparts aged 11-16 years. Curve severity was categorized into a moderate (10-39 degrees) and a severe group (> or = 40 degrees) based on Cobb angle. Anthropometric parameters, bone mineral-density (BMD) and bone mineral-content (BMC) of lumbar spine, proximal femur and distal tibia were determined by dual-energy X-ray absorptiometry and peripheral QCT. Differences in anthropometric parameters and bone mass among control and the AIS-moderate and AIS-severe groups were tested by one-way ANOVA. Association between Cobb angle and bone mass was determined by univariate and multivariate analyses. Mean Cobb angle of the moderate and severe groups were 25+/-6.3 degrees and 50.2+/-11.3 degrees, respectively. Arm span and leg length among the moderate and severe AIS subjects were almost all longer than for the controls from age 13 years. Age-adjusted arm span and leg length were significantly correlated with curve severity (p < 0.015). Starting from age 13 years, most axial and peripheral BMD and BMC of the moderate or severe AIS group was significantly lower than for the controls (p < 0.029). Age-adjusted Cobb angle was inversely correlated with BMD and BMC of the distal tibia and lumbar spine among AIS subjects (p < or = 0.042). The proportion of osteopenic AIS girls in the severe group was significantly higher than that in the moderate group (p < or = 0.033). Multivariate analysis indicated that Cobb angle was inversely and independently associated with axial and peripheral BMD and BMC (p < or = 0.042). To conclude, curve severity was an inverse and independent associated factor on bone mineral mass of AIS during peripuberty. The study implied that prevention of osteopenia could be as important as controlling spinal progression in the management of AIS.

Bone densitometry: which skeletal sites are best predicted by bone mass determinants?

Evaluation of bone mineral content/bone mass density (BMC/BMD) is important to determine bone mass development among adolescents in health and disease. It is uncertain at which skeletal site BMC/BMD is best predicted by bone mass determinants. On the other hand, intrapersonal BMC/BMD data can be clustered into a composite index score to facilitate correlation and outcome prediction analysis. This study aimed to identify the skeletal site that was best predicted by bone mass determinants and to develop a composite index score based on multisite BMC/BMD values in healthy adolescent girls. Eleven BMD/BMC variables per subject were evaluated by using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) in 236 healthy girls aged 12-15 years. Bone mass determinants, namely, weight, height, puberty, dietary calcium, physical activity, and bone turnover markers, were determined. Factor analysis was used to develop composite index scores that summarized characteristics of multisite BMC/BMD. Results showed that lumbar spinal BMD and BMC (by DXA) and tibial integral BMD (by pQCT) were the BMC/BMD sites better predicted by bone mass determinants (R2, 0.57-0.77) in multiple regression analysis. On the other hand, three composite index scores representing areal BMD, areal BMC, and vBMD were derived to summarize the original BMC/BMD values. The composite index scores had similar predicting power (R2, 0.419-0.749) compared to those of original BMC/BMD, indicating that the composite index scores were representative of the original variables. To conclude, lumbar spinal BMD and BMC and tibial integral BMD were the three BMC/BMD variables better predicted by bone mass determinants. This evaluation would help select appropriate skeletal sites as outcome measures for bone mass evaluation in future studies. Also, the development of composite index scores could help reduce the number of variables for correlation and outcome prediction analyses.