Genetic hemoglobin disorders, infection, and deficiencies of iron and vitamin A determine anemia in young Cambodian children.
ABSTRACT: In Cambodia, many factors may complicate the detection of iron deficiency. In a cross-sectional survey, we assessed the role of genetic hemoglobin (Hb) disorders, iron deficiency, vitamin A deficiency, infections, and other factors on Hb in young Cambodian children. Data on sociodemographic status, morbidity, and growth were collected from children (n = 3124) aged 6 to 59 mo selected from 3 rural provinces and Phnom Penh municipality. Blood samples were collected (n = 2695) for complete blood count, Hb type (by DNA analysis), ferritin, soluble transferrin receptor (sTfR), retinol-binding protein (RBP), C-reactive protein, and ?(1)-acid glycoprotein (AGP). Genetic Hb disorders, anemia, and vitamin A deficiency were more common in rural than in urban provinces (P < 0.001): 60.0 vs. 40.0%, 58.2 vs. 32.7%, and 7.4 vs. 3.1%, respectively. Major determinants of Hb were age group, Hb type, ferritin, sTfR, RBP, AGP >1.0 g/L (P < 0.001), and rural setting (P < 0.05). Age group, Hb type, RBP, elevated AGP, and rural setting also influenced ferritin and sTfR (P < 0.02). Multiple factors affected anemia status, including the following: age groups 6-11.99 mo (OR: 6.1; 95% CI: 4.3, 8.7) and 12-23.99 mo (OR: 2.7; 95% CI: 2.1, 3.6); Hb type, notably Hb EE (OR: 18.5; 95% CI: 8.5, 40.4); low ferritin (OR: 3.2; 95% CI: 2.2, 4.7); elevated AGP (OR: 1.4; 95% CI: 1.2,1.7); rural setting (OR: 2.3; 95% CI: 1.7, 3.1); low RBP (OR: 3.6; 95% CI: 2.2, 5.9); and elevated sTfR (OR: 2.1; 95% CI: 1.7, 2.7). In Cambodia, where a high prevalence of genetic Hb disorders exists, ferritin and sTfR are of limited use for assessing the prevalence of iron deficiency. New low-cost methods for detecting genetic Hb disorders are urgently required.
Project description:<h4>Background and objective</h4>In resource-poor settings, micronutrient deficiencies such as vitamin A deficiency may co-exist with iron-deficiency. In this study we assessed the iron and vitamin A status of schoolchildren and the association between vitamin A and iron status.<h4>Methods</h4>A cross-sectional design using the baseline data of a dietary intervention trial conducted among randomly selected 5-12 years old schoolchildren (n = 224) from 2 rural schools in northern Ghana. Hemoglobin (Hb), serum ferritin (SF) and serum transferrin receptor (sTfR) concentrations were used as measures of iron status. Retinol binding protein (RBP) was used as a measure of vitamin A status. Subclinical inflammation (SCI) was measured using C-reactive protein (CRP) and ?1-acid glycoprotein (AGP) concentrations. We examined the cross-sectional association between vitamin A and iron status biomarkers with multiple linear regressions.<h4>Results</h4>The proportions of schoolchildren with anemia (WHO criteria), iron-deficiency (ID, SF <15?g/l and/or sTfR >8.5mg/l) and iron-deficiency anemia (IDA, concurrent anemia and ID) were 63.8%, 68.3% and 46.4% respectively. Low or marginal vitamin A status (0.70 ?mol/l ? RBP < 1.05?mol/l) was present in 48.2% while 37.5% of the schoolchildren had vitamin A deficiency (VAD, RBP <0.70 ?mol/l). The prevalence of SCI as well as concurrent VAD and ID were 48.7% and 25% respectively. RBP was associated with Hb (? = 7.2, P = 0.05) but not SF (? = 20.7, P = 0.33) and sTfR concentration (? = 12.0, P = 0.63). In the presence of SCI, RBP was not associated with hemoglobin status but a significant positive association was observed among children without SCI.<h4>Conclusions</h4>The study shows that RBP is significantly associated with Hb concentration but not with SF and sTfR. The observed relationship between RBP and Hb is only significant in the absence of SCI.
Project description:Background:Anemia during infancy in Indonesia is common, with iron deficiency (ID) assumed to be the major cause. Other micronutrients besides iron may have a role in determining hemoglobin (Hb) but have not yet been explored in Indonesia. Objective:We investigated 7 micronutrient biomarkers and selected nonnutritional factors as potential predictors of Hb and anemia at ages 6, 9, and 12 mo in a cohort of Indonesian infants at risk of coexisting micronutrient deficiencies. Methods:Apparently healthy breastfed infants were randomly selected from birth registries at 6 mo (n = 230) and followed-up at 9 mo (n = 202) and 12 mo (n = 190). Hb, serum micronutrient biomarkers-iron [as ferritin and serum soluble transferrin receptor (sTfR)], zinc, selenium, folate, vitamin A [as retinol-binding protein (RBP)], vitamin B-12, and vitamin D (as 25-hydroxyvitamin D) (adjusted for inflammation, where appropriate)-and maternal sociodemographic status, health, BMI, heminthiasis, and selected Hb genetic disorders were measured. Multivariate analysis examined relations between micronutrient biomarkers and nonnutritional factors (except helminthiasis and genetic Hb disorders) with Hb and anemia at 6 and 12 mo. Results:ID (based on ferritin) was a predictor of lower Hb and anemia at both 6 and 12 mo of age (P < 0.02). Additional predictors at 6 mo were tertiary education and higher maternal Hb for higher Hb, sex (being male) and inflammation (P < 0.05) for both lower Hb and anemia, and greater maternal height (P = 0.036) for anemia only. At 12 mo, a significant biomarker predictor besides ID was RBP (P = 0.035) for Hb. Conclusion:ID was a major contributor to lower Hb and anemia, although RBP was also associated.
Project description:The Quansys multiplex (Q-Plex) measures ferritin (Fer), soluble transferrin receptor (sTfR), C-reactive protein (CRP), ?-1-acid glycoprotein (AGP), and retinol-binding protein (RBP). We compared Q-Plex results with reference-type assays and evaluated Q-Plex performance. Pearson correlation and Lin's concordance coefficients between the Q-Plex and reference assay were: Fer 0.98 and 0.91, sTfR 0.88 and 0.35, CRP 0.98 and 0.98, AGP 0.82 and 0.81, and RBP 0.68 and 0.31, respectively. The median relative difference between the Q-Plex and reference assay were: Fer -2.4%, sTfR 107%, CRP 0.03%, AGP -1.3%, and RBP 51%. The Q-Plex intra-assay CVs were <5%; the inter-assay CVs were higher: Fer 11%, sTfR 14%, CRP 9.3%, AGP 7.5%, and RBP 19%. EDTA plasma produced 74% higher Q-Plex sTfR concentrations compared to serum. Analyte stability was good for ?5 freeze-thaw cycles. After adjusting Q-Plex data to the reference assays, sensitivity and specificity were >85% for Fer and CRP; specificity was >85% for sTfR, AGP, and RBP. Using performance criteria derived from biologic variation, Fer, CRP, and AGP met the minimum allowable imprecision (<10.7%, <31.7%, and <8.5%, respectively) and difference from the reference assay (<±7.7%, <±32.7%, and <±10.3%, respectively), while sTfR and RBP exceeded these thresholds (<8.5% and <7.8% for imprecision and <±7.7% and <±12% for difference, respectively). The Q-Plex measures multiple biomarkers simultaneously, is easy to perform, and uses small sample volumes. With some improvements in accuracy and precision (i.e., sTfR and RBP), this assay could be a useful tool for low-resource laboratories conducting micronutrient surveys for epidemiologic screening applications. These findings need to be verified using other populations, particularly those with inadequate micronutrient status.
Project description:<h4>Background</h4>Iron deficiency (ID) is common in toddlers in developing countries. Iron fortified or meat-based complementary foods may be effective to prevent ID.<h4>Objective</h4>Our objective was to compare iron status at 18 months and growth from 6 to 18 months in rural poor toddlers fed 3 different complementary foods.<h4>Methods</h4>The study was nested within a larger trial in which 6-month-old infants were randomized to receive 50g/d meat (MG), an equi-caloric fortified cereal supplement (FG) or local cereal supplement (LG) for 1 year. Hb, sTfR, HsCRP, ferritin and AGP were measured in 410 blood samples collected by a random sampling (MG, 137; FG, 140; LG, 133); calprotectin was measured in feces. Body iron = -[log (sTfR ×1000/ferritin)-2.8229] /0.1207. ID = ferritin<12ug/L.<h4>Results</h4>The toddlers in FG had the significantly highest levels in serum ferritin and body iron (P = 0.043, 0.004), and the rates of both ID and iron deficiency anemia (IDA) were the lowest in FG (P = 0.010, 0.021). The rate of systemic inflammation in FG was 30.71%, which was the highest among three groups (P = 0.042). No intervention effects on either the rates of ID and IDA or iron stores (serum ferritin and body iron) were shown in MG. The change in length-for-age z scores (LAZ) from 6 to 18 months among three groups was significantly different (P = 0.021) and a smaller decrease of LAZ in MG and a larger decrease of LAZ in FG were observed.<h4>Conclusion</h4>Iron fortified cereal improved iron status of poor rural toddlers but was also associated with systemic inflammation which was likely to impair their growth.
Project description:Anemia and micronutrient (MN) deficiencies in pregnant women are associated with adverse pregnancy outcomes. In Niger, 58.6% of pregnant women are anemic; however, MN statuses are unknown. The study objectives were to estimate the prevalence of MN deficiencies among pregnant women in Zinder, Niger and explore associated risk factors. Pregnant women living in randomly selected rural villages (n = 88) were included. Capillary and venous blood samples (n = 770) were analyzed for hemoglobin (Hb) and plasma ferritin, soluble transferrin receptor (sTfR), zinc (pZn), retinol binding protein (RBP), folate and vitamin B12. C-reactive protein and alpha-1-acid glycoprotein were measured to adjust for inflammation. The prevalence of MN deficiencies in pregnant woman was high, indicative of a severe public health problem. Prevalence of iron deficiency was 20.7% and 35.7%, by ferritin (<15 µg/L) and sTfR (>8.3 mg/L), respectively. In total, 40.7% of women had low pZn (<50 µg/dL), 79.7% had marginal RBP (<1.32 µmol/L), 44.3% of women had low folate (<10 nmol/L) and 34.8% had low B12 concentrations (<148 pmol/L). Common risk factors associated with MN status included gravidity, mid-upper-arm circumference, geophagy, malaria, and result of the woman's last pregnancy. Interventions to promote the strengthening of antenatal care, and access and adherence to nutrition and health interventions are critical among pregnant women in this population.
Project description:BACKGROUND:Iron deficiency derives from a low intake of dietary iron, poor absorption of iron, and high requirements due to growth as well as blood loss. An estimated number of about 50% of all anemia may be attributed to iron deficiency among young children in Cambodia. METHODS:A cross-sectional survey was conducted in rural Cambodia in September 2012. Villages in pre-selected communes were randomly chosen using stunting as a primary indicator of nutritional status. In total, 928 randomly selected households with children aged 3-23 months were included. Hemoglobin, ferritin, soluble transferrin receptor (sTfR), and retinol binding protein (RBP) were assessed from capillary blood samples. In addition, length/height and weight of mothers and children were taken and data on dietary diversity was collected. A child feeding index (CFI) was created. Associations between biomarkers of iron and vitamin A status and nutritional status or food intake were explored. RESULTS:Anemia prevalence was highest among 6- to 12-months-olds (71%). Ferritin and sTfR inversely correlated and were significantly associated with hemoglobin concentrations. The consumption of animal source foods (ASF) significantly impacts on the interaction between ferritin, sTfR and hemoglobin. Concentrations of RBP were significantly higher in children who had received a vitamin A supplement. The CFI was associated with sTfR and hemoglobin. Lower length and weight were associated with lower ferritin levels and showed an indirect effect on hemoglobin through ferritin. CONCLUSION:Nutrition programs targeting children under 2 years of age need to focus on the preparation of complementary foods with high nutrient density to sustainably prevent micronutrient deficiency and generally improve nutritional status. Future assessments of the micronutrient status should include identification of hemoglobinopathies and parasitic infections to better understand all causes of anemia in Cambodian infants and young children. TRIAL REGISTRATION:German Clinical Trials Register DRKS00004379.
Project description:The prevalence of iron-deficiency anemia (IDA) is high in infants in Sub-Saharan Africa. Exclusive breastfeeding of infants to 6 months of age is recommended by the World Health Organization, but breast milk is low in iron. Some studies suggest exclusive breastfeeding, although beneficial for the infant, may increase risk for IDA in resource-limited settings. The objective of this study was to determine if duration of exclusive breastfeeding is associated with anemia and iron deficiency in rural Kenyan infants. This was a cross-sectional study of 6-10-month-old infants (n = 134) in southern coastal Kenya. Anthropometrics, hemoglobin (Hb), plasma ferritin (PF), soluble transferrin receptor (sTfR), and C-reactive protein were measured. Body iron stores were calculated from the sTfR/PF ratio. Socioeconomic factors, duration of exclusive breastfeeding, nature of complementary diet, and demographic characteristics were determined using a questionnaire. Mean ± SD age of the infants was 7.7 ± 0.8 months. Prevalence of anemia, ID, and IDA were 74.6%, 82.1%, and 64.9%, respectively. Months of exclusive breastfeeding correlated positively with Hb (r = 0.187; p < .05) and negatively with sTfR (r = -0.246; p < .05). sTfR concentrations were lower in infants exclusively breastfed at least 6 months compared with those exclusively breastfed for less than 6 months (7.6 (6.3, 9) vs. 8.9 (6.7, 13.4); p < .05). Controlling for gender, birth weight, and inflammation, months spent exclusively breastfeeding was a significant negative predictor of sTfR and a positive predictor of Hb (p < .05). The IDA prevalence in rural Kenyan infants is high, and greater duration of exclusive breastfeeding predicts better iron status and higher Hb in this age group.
Project description:Background: Even though it is well-known that iron deficiency is the result of chronic kidney disease (CKD), whether iron will affect kidney function and disease in the general population is not clear. We thus conducted a nationwide cross-sectional study using data from the China Health and Nutrition Survey (CHNS) to assess the relationship of iron status with estimated glomerular filtration rate (eGFR) and CKD among general adults. Methods: A total of 8,339 adults from the China Health and Nutrition Survey in the wave of 2009 were included to assess the association between iron status and eGFR/CKD. Serum ferritin (SF), transferrin, soluble transferrin receptor (sTfR), and hemoglobin (Hb) were measured. The relationship of iron status and eGFR was evaluated by using multi-variable linear regression model. The effect of iron status on the odds of CKD was calculated by logistic regression model. Results: For the association between iron status and eGFR, every 100 ?g/L increase in SF was correlated with 0.26 ml/min per 1.73 m2 (95% CI: 0.08-0.44) decrease in eGFR, and every 5 mg/L increase in sTfR was associated with a decrease of 6.00 ml/min per 1.73 m2 (95% CI: 3.79-8.21) in eGFR. There were no significant associations between Hb or transferrin with eGFR. For the association between iron status and CKD, every 5 g/L increase in sTfR was associated with an odds ratio of 3.72 (95% CI: 2.16-6.13) for CKD. The concentrations of Hb were associated with the odds of CKD in a U-shaped manner, with the lowest risk in the Hb range of 136-141 g/L. There was a positive correlation between SF concentration and CKD prevalence but not in a dose-response manner. The odds of CKD for participants in the highest tertile increased by 28% (98% CI: 1-63%) compared with those in the lowest tertile. Conclusion: The concentration of SF and sTfR was positively correlated with the odds of CKD, and Hb was associated with the odds of CKD in a U-shaped manner. Further large prospective researches are warranted to confirm these findings.
Project description:We assessed the effects of providing a package of interventions including small-quantity lipid-based nutrient supplements (SQ-LNS) containing 0, 5 or 10 mg zinc and illness treatment to Burkinabe children from 9 to 18 months of age, on biomarkers of zinc, iron and vitamin A status at 18 months and compared with a non-intervention cohort (NIC).Using a two-stage cluster randomized trial design, communities were randomly assigned to the intervention cohort (IC) or NIC, and extended family compounds within the IC were randomly assigned to different treatment groups. IC children (n?=?2435) were provided with 20 g SQ-LNS/d containing 0, 5 or 10 mg zinc, 6 mg of iron and 400 ?g of vitamin A along with malaria and diarrhea treatment. NIC children (n?=?785) did not receive the intervention package. At 9 and 18 months, hemoglobin (Hb), zinc, iron and vitamin A status were assessed in a sub-group (n?=?404). Plasma concentrations of zinc (pZC), ferritin (pF), soluble transferrin receptor (sTfR) and retinol-binding protein (RBP) were adjusted for inflammation.At baseline, 35% of children had low adjusted pZC (<65 ?g/dL), 93% were anemic (Hb <110 g/L), 25% had low adjusted pF (<12 ?g/L), 90% had high adjusted sTfR (>8.3 mg/L) and 47% had low adjusted RBP (<0.94 ?mol/L), with no group-wise differences. Compared with the NIC, at 18 months IC children had significantly lower anemia prevalence (74 vs. 92%, p?=?0.001) and lower iron deficiency prevalence (13% vs. 32% low adjusted pF and 41% vs. 71% high adjusted sTfR, p?<?0.001), but no difference in pZC. Mean adjusted RBP was greater at 18 months in IC vs. NIC (0.94 ?mol/L vs. 0.86 ?mol/L, p?=?0.015), but the prevalence of low RBP remained high in both cohorts. Within the IC, different amounts of zinc had no effect on the prevalence of low pZC or indicators of vitamin A deficiency, whereas children who received SQ-LNS with 10 mg zinc had a significantly lower mean pF at 18 months compared to children who received SQ-LNS with 5 mg zinc (p?=?0.034).SQ-LNS regardless of zinc amount and source provided along with illness treatment improved indicators of iron and vitamin A status, but not pZC.NCT00944281 (July 21, 2009).
Project description:Iron deficiency is a major public health problem worldwide, with the highest burden among children. The objective of this randomized efficacy feeding trial was to determine the effects of consuming iron-biofortified beans (Fe-Beans) on the iron status in children, compared to control beans (Control-Beans). A cluster-randomized trial of biofortified beans (Phaseolus vulgaris L), bred to enhance iron content, was conducted over 6 months. The participants were school-aged children (n = 574; 5?12 years), attending 20 rural public boarding schools in the Mexican state of Oaxaca. Double-blind randomization was conducted at the school level; 20 schools were randomized to receive either Fe-Beans (n = 10 schools, n = 304 students) or Control-Beans (n = 10 schools, n = 366 students). School administrators, children, and research and laboratory staff were blinded to the intervention group. Iron status (hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptor (sTfR), total body iron (TBI), inflammatory biomarkers C-reactive protein (CRP) and -1-acid glycoprotein (AGP)), and anthropometric indices for individuals were evaluated at the enrollment and at the end of the trial. The hemoglobin concentrations were adjusted for altitude, and anemia was defined in accordance with age-specific World Health Organization (WHO) criteria (i.e., Hb <115 g/L for <12 years and Hb <120 g/L for 12 years). Serum ferritin concentrations were adjusted for inflammation using BRINDA methods, and iron deficiency was defined as serum ferritin at less than 15.0 µg/L. Total body iron was calculated using Cook's equation. Mixed models were used to examine the effects of Fe-Beans on hematological outcomes, compared to Control-Beans, adjusting for the baseline indicator, with school as a random effect. An analysis was conducted in 10 schools (n = 269 students) in the Fe-Beans group and in 10 schools (n = 305 students) in the Control-Beans group that completed the follow-up. At baseline, 17.8% of the children were anemic and 11.3% were iron deficient (15.9%, BRINDA-adjusted). A total of 6.3% of children had elevated CRP (>5.0 mg/L), and 11.6% had elevated AGP (>1.0 g/L) concentrations at baseline. During the 104 days when feeding was monitored, the total mean individual iron intake from the study beans (Fe-bean group) was 504 mg (IQR: 352, 616) over 68 mean feeding days, and 295 mg (IQR: 197, 341) over 67 mean feeding days in the control group (p < 0.01). During the cluster-randomized efficacy trial, indicators of iron status, including hemoglobin, serum ferritin, soluble transferrin receptor, and total body iron concentrations improved from the baseline to endline (6 months) in both the intervention and control groups. However, Fe-Beans did not significantly improve the iron status indicators, compared to Control-Beans. Similarly, there were no significant effects of Fe-Beans on dichotomous outcomes, including anemia and iron deficiency, compared to Control-Beans. In this 6-month cluster-randomized efficacy trial of iron-biofortified beans in school children in Mexico, indicators of iron status improved in both the intervention and control groups. However, there were no significant effects of Fe-Beans on iron biomarkers, compared to Control-Beans. This trial was registered at clinicaltrials.gov as NCT03835377.