Correcting for Inflammation Changes Estimates of Iron Deficiency among Rural Kenyan Preschool Children
Nutrition and Health Sciences Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA.Journal of Nutrition (Impact Factor: 3.88). 12/2011; 142(1):105-11. DOI: 10.3945/jn.111.146316
The assessment of iron status where infections are common is complicated by the effects of inflammation on iron indicators and in this study we compared approaches that adjust for this influence. Blood was collected in 680 children (aged 6-35 mo) and indicators of iron status [(hemoglobin (Hb), zinc protoporphyrin (ZP), ferritin, transferrin receptor (TfR), and TfR/ferritin index)] and subclinical inflammation [(the acute phase proteins (APP) C-reactive protein (CRP), and α-1-acid glycoprotein (AGP)] were determined. Malaria parasitemia was assessed. Subclinical inflammation was defined as CRP >5 mg/L and/or AGP >1 g/L). Four groups were defined based on APP levels: reference (normal CRP and AGP), incubation (raised CRP and normal AGP), early convalescence (raised CRP and AGP), and late convalescence (normal CRP and raised AGP). Correction factors (CF) were estimated as the ratios of geometric means of iron indicators to the reference group of those for each inflammation group. Corrected values of iron indicators within inflammation groups were obtained by multiplying values by their respective group CF. CRP correlated with AGP (r = 0.65; P < 0.001), ferritin (r = 0.38; P < 0.001), Hb (r = -0.27; P < 0.001), and ZP (r = 0.16; P < 0.001); AGP was correlated with ferritin (r = 0.39; P < 0.001), Hb (r = -0.29; P < 0.001), and ZP (r = 0.24; P < 0.001). Use of CF to adjust for inflammation increased the prevalence of ID based on ferritin < 12 μg/L by 34% (from 27 to 41%). Applying the CF strengthened the expected relationship between Hb and ferritin (r = 0.10; P = 0.013 vs. r = 0.20; P < 0.001, before and after adjustment, respectively). Although the use of CF to adjust for inflammation appears indicated, further work is needed to confirm that this approach improves the accuracy of assessment of ID.
[Show abstract] [Hide abstract]
- "Righetti et al. (2013), who studied infants and children from the Ivory Coast, and Engle-Stone et al. (2013), who included Cameroonian households with a child aged 12–59 months old into their study, also demonstrated a significant increase in the prevalence of ID when SF concentrations were corrected for inflammation. Our study contributes to an increasingly rich literature (Thurnham et al. 2010; Grant et al. 2012; Engle-Stone et al. 2013; Knowles et al. 2013) that documents the effect of inflammation on SF, and reinforces the pivotal role of APP measurements to account for the effect of inflammation, when using SF as a marker of iron status. We recognise that because we only used SF and Hb, together with the APPs, to interpret the iron status of these infants, we are unable to conclude which of the four methods determined true ID prevalence. "
ABSTRACT: We reassessed the iron deficiency (ID) prevalence in a South African trial that formed part of the International Research on Infant Supplementation study by comparing four methods that account for the high prevalence of acute (28.6%) and chronic (41.8%) inflammation observed in the study. Serum ferritin (SF) was measured as marker of iron status in 192 apparently healthy, 4-13-month-old infants. Alpha-1 glycoprotein and C-reactive protein concentrations were determined to indicate chronic and acute inflammation, respectively. The ID prevalence was obtained by four methods that adjust for inflammation: (1) excluding infants with inflammation; (2) using a higher cut-off (SF < 30 μg L(-1) ); (3) using different cut-offs for infants with vs. without inflammation (SF < 30 μg L(-1) vs. SF < 12 μg L(-1) ); and (4) adjusting SF concentrations with correction factors (CFs) were compared with a reference method (SF < 12 μg L(-1) ) not accounting for inflammation. Using the higher SF cut-off method resulted in the highest ID prevalence (52.1%), followed by using two different cut-offs (31.8%), using CFs (21.9%) and excluding subjects with inflammation (17.6%). The CF method showed the best agreement with the reference method. Disregarding inflammation resulted in a significantly lower ID prevalence (17.2%). ID anaemia (IDA) prevalence ranged from 13.2% to 24.5%, with the lowest prevalence (12.0%) for the reference method. Our analysis highlights the challenge of assessing ID and IDA using only SF as marker of iron status in the presence of inflammation. We demonstrate the importance of measuring inflammation markers to account for their elevating effect on SF. © 2015 John Wiley & Sons Ltd.Maternal and Child Nutrition 02/2015; DOI:10.1111/mcn.12175 · 3.06 Impact Factor
[Show abstract] [Hide abstract]
- "lood samples from a fingerstick for use in haemoglobin ( Hb ) measurements , malaria smear preparations and Microtainer ® ( Becton Dickinson , Franklin Lakes , NJ , USA ) blood collection to assess iron and vitamin A status and the presence of inflam - mation among enrolled children . Details of the labo - ratory analysis are described elsewhere ( Grant et al . 2012 ) . Hb levels were measured in the field using HemoCue ® ( HemoCue , Inc . Cypress , CA , USA ) photometers ; children with Hb < 11 . 0 g dL - 1 were classified as anaemic ( McLean et al . 2009 ) . Testing for the presence of malaria parasites and the level of parasitaemia was performed by the CDC laboratory in Kisian , Kenya . Frozen p"
ABSTRACT: To evaluate the sustainability of market-based community distribution of micronutrient powders (Sprinkles(®) , Hexagon Nutrition, Mumbai, India.) among pre-school children in Kenya, we conducted in August 2010 a follow-up survey, 18 months after study-related marketing and household monitoring ended. We surveyed 849 children aged 6-35 months randomly selected from 60 study villages. Nutritional biomarkers were measured by fingerstick; demographic characteristics, Sprinkles purchases and use were assessed through household questionnaires. We compared Sprinkles use, marketing efforts and biomarker levels with the data from surveys conducted in March 2007, March 2008 and March 2009. We used logistic regression to evaluate associations between marketing activities and Sprinkles use in the 2010 survey. At the 2010 follow-up, 21.9% of children used Sprinkles in the previous 7 days, compared with 64.9% in 2008 (P < 0.001). Average intake was 3.2 sachets week(-1) in 2008, 1.6 sachets week(-1) in 2009 and 1.1 sachets week(-1) in 2010 (P < 0.001). Factors associated with recent Sprinkles use in 2010 included young age [6-23 months vs. 24-35 months, adjusted odds ratio (aOR) = 1.5, P = 0.02], lowest 2 quintiles of socio-economic status (aOR = 1.7, P = 0.004), household attendance at trainings or launches (aOR = 2.8, P < 0.001) and ever receiving promotional items including free Sprinkles, calendars, cups and t-shirts (aOR = 1.7, P = 0.04). In 2010, there was increased prevalence of anaemia and malaria (P < 0.001), but not iron deficiency (P = 0.44), compared with that in 2008. Sprinkles use in 2010 was associated with decreased iron deficiency (P = 0.03). Sprinkles coverage reduced after stopping household monitoring and reducing marketing activities. Continued promotion and monitoring of Sprinkles usage may be important components to sustain the programme.Maternal and Child Nutrition 01/2013; 9 Suppl 1(Suppl. 1):78-88. DOI:10.1111/j.1740-8709.2012.00450.x · 3.06 Impact Factor
[Show abstract] [Hide abstract]
- "Anthropometric measurements were also made, and capillary blood samples were collected for Hb measurements and the preparation of malaria smears.Aliquots were stored for the later measurement of C-reactive protein (CRP), iron and vitamin A status, and genotyping for blood disorders. Details of the laboratory analyses are described in detail elsewhere (Grant et al. 2012). Briefly, Hb levels were measured in the field by using HemoCue ® photometers (Angelholm, Sweden), and children were classified as aanemic if their Hb was <110 g L -1 "
ABSTRACT: Although inherited blood disorders are common among children in many parts of Africa, limited data are available about their prevalence or contribution to childhood anaemia. We conducted a cross-sectional survey of 858 children aged 6-35 months who were randomly selected from 60 villages in western Kenya. Haemoglobin (Hb), ferritin, malaria, C-reactive protein (CRP) and retinol binding protein (RBP) were measured from capillary blood. Using polymerase chain reaction (PCR), Hb type, -3.7 kb alpha-globin chain deletion, glucose-6-phosphate dehydrogenase (G6PD) genotype and haptoglobin (Hp) genotype were determined. More than 2 out of 3 children had at least one measured blood disorder. Sickle cell trait (HbAS) and disease (HbSS) were found in 17.1% and 1.6% of children, respectively; 38.5% were heterozygotes and 9.6% were homozygotes for α(+) -thalassaemia. The Hp 2-2 genotype was found in 20.4% of children, whereas 8.2% of males and 6.8% of children overall had G6PD deficiency. There were no significant differences in the distribution of malaria by the measured blood disorders, except among males with G6PD deficiency who had a lower prevalence of clinical malaria than males of normal G6PD genotype (P = 0.005). After excluding children with malaria parasitaemia, inflammation (CRP > 5 mg L(-1) ), iron deficiency (ferritin < 12 μg L(-1) ) or vitamin A deficiency (RBP < 0.7 μg L(-1) ), the prevalence of anaemia among those without α(+) -thalassaemia (43.0%) remained significantly lower than that among children who were either heterozygotes (53.5%) or homozygotes (67.7%, P = 0.03). Inherited blood disorders are common among pre-school children in western Kenya and are important contributors to anaemia.Maternal and Child Nutrition 09/2012; 10(1). DOI:10.1111/j.1740-8709.2012.00454.x · 3.06 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.