Upload
ifsd14
View
332
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Citation preview
Biochemical correlates of anemia in Cambodian women of reproductive age
Crystal Karakochuk1,2, Kyly Whitfield1,2, Aminuzzaman Talukder3, Suzanne Vercauteren4, Judy McLean1, Tim Green1,2
1University of British Columbia, Vancouver; 2Child and Family Research Institute, Vancouver; 3Helen Keller International, Phnom Penh; 4BC Children’s Hospital, Vancouver
International Food Security Dialogue 2014Enhancing Food Production, Gender Equity and Nutritional Security in a Changing World
The Fish on Farms project is being jointly conducted by the University of British Columbia (UBC) and Helen Keller International (HKI), with
technical assistance from World Fish, in Prey Veng Province, Cambodia.
This randomized control trial investigates an integrated Homestead Food Production models in relation to poverty, gender empowerment, and food
and nutrition security, particularly among women and children.
This is the first project known to rigorously measure the effectiveness of different models of Homestead Food Production at reducing undernutrition
using biochemical and anthropometric measurements.
University of British Columbia Ministry of Health, CambodiaDr. Tim Green, Associate Professor, Human Nutrition Ministry of Planning,
CambodiaDr. Judy McLean, Assistant Professor, Human NutritionDr. Susan Barr, Professor, Human NutritionDr. Larry Lynd, Professor & Director, Collaboration for Outcomes Research & EvaluationDr. Tony Farrell, Professor, Centre for Aquaculture and Environmental ResearchDr. David Kitts, Professor, Food Science & Associate Dean of ResearchDr. Ian Forster, Centre for Aquaculture and Environmental ResearchJen Foley, Fish on Farms Program Coordinator
Helen Keller International - Cambodia Graduate StudentsDr. Zaman Talukder Kyly Whitfield (PhD, Nutrition)Mr. Hou Kroeun Crystal Karakochuk (PhD,
Nutrition)Ms. Ly Sokhoing Vashti Verbowski (MSc, Nutrition)Field Research Team Pardis Lakzadeh (MSc, Public
Health Jeff Tang (BSc, Science)
World Fish
Global Prevalence of Anemia
Iron and Hemoglobin
Iron: a natural metal found in the environment and in food
Primarily important for the synthesis of Hemoglobin (Hb) in red blood cells which is essential for oxygen transport
Anemia in women of reproductive age: defined as Hb <120 g/L
Image courtesy of antranik.org
Potential Causes of Anemia in Cambodia
disease
blood loss
inflammation
Anemia
micronutrient genetic hemoglobin
deficiencies disorders
iron, vitamin A, folate & vitamin B12
Potential Causes of Anemia in Cambodia
disease
blood loss
inflammation
Anemia
micronutrient genetic hemoglobin
deficiencies disorders
induces hepcidin = anemia of chronic inflammation
Potential Causes of Anemia in Cambodia
disease
blood loss
inflammation
Anemia
micronutrient genetic hemoglobin
deficiencies disorders
hookworm, parasites, malaria
Potential Causes of Anemia in Cambodia
disease
blood loss
inflammation
Anemia
micronutrient genetic hemoglobin
deficiencies disorders
menses, losses from childbirth
Potential Causes of Anemia in Cambodia
disease
blood loss
inflammation
Anemia
micronutrient genetic hemoglobin
deficiencies disorders
Inherited disorders that result in a defective hemoglobin
Autosomal Recessive Disorder
Audience Poll
What is the prevalence of genetic hemoglobin disorders in Cambodia?
a) 5%
b) 10%
c) 20%
d) >50%
Audience Poll
What is the prevalence of genetic hemoglobin disorders in Cambodia?
a) 5%
b) 10%
c) 20%
d) >50% *majority are heterozygous traits that are asymptomatic, but serious risk
of homozygous form inherited by offspring
(Carnley et al, 2006; George et al, 2012)
Structural hemoglobin variants
Thalassemias
-result from amino acid substitutions in the globin
chain of hemoglobin
-result from an amino acid deletion causing impaired
synthesis of the globin chains (α- or β)
Examples: Hb AE (heterozygous), EE
(homozygous), Constant Spring (CS)
Examples: α- or β thalassemias
(α-3.7 most common)
Diagnostic method: Hb gel electrophoresis
(% of Hb variants of total Hb)
Diagnostic method: Polymerase Chain Reaction
(PCR) for DNA typing
Genetic Hemoglobin Disorders
(Bain, 2006)
Objectives
1. To explore the correlates of anemia in Cambodian women of reproductive age
2. To estimate the proportion of anemia associated with iron deficiency using biochemical indicators
Study Design & Methods
Cross sectional survey design: Baseline data from ongoing RCT in Cambodia
Participants: 450 Cambodian women 18-45 yrs of age from poor
households in rural Prey Veng province
Data collected in June 2012: Venous blood sample collected Complete blood count (CBC) and serum analyses
Prevalence of Genetic Hemoglobin Disorders
*underestimated due to incomplete data for α-thalassemias (trait, co-inherited)
Table 1: Prevalence of genetic hemoglobin disorders (n=450)
Hemoglobin n %
Normal hemoglobin AA 249 59%
Hemoglobin variant Any variant 171 41%*
Heterozygous E trait AE 99 24%
Homozygous E EE 31 7%
Constant spring CS 17 4%
β -thalassemia trait β 11 3%
Other - 13 3%
Micronutrients & Inflammation
Table 2: Micronutrients and inflammation characteristics (n=450)
Cut off n %
Ferritin1, iron stores deficiency <15 ug/L 13 2.8
sTfR, tissue iron deficiency >8.3 mg/L 84 18.7
Vitamin B12 <150 pmol/L 7 1.6
Folate <3 ng/mL 11 2.4
RBP1 (Vitamin A) <0.7 mmol/L 0 0
CRP (acute inflammation) >5 mg/L 39 8.7
AGP (chronic inflammation) >1 g/L 113 25.1
1Ferritin and RBP corrected for inflammation by methods proposed by Thurnham et al (Lancet 2003, AJCN 2010). sTfR, serum transferrin receptor; RBP, retinol binding protein; CRP, c-reactive protein; AGP, alpha-1 acid glycoprotein
Anemia
Table 3: Anemia (n=420 non-pregnant women)
n %
Anemia total, Hb <120 g/L
Mild anemia, >110 to <120 g/L Moderate anemia, 90-110 g/L Severe anemia, <90 g/L
Microcytic anemia, MCV <80 fL Normocytic anemia, MCV 80-95 fL Macrocytic, anemia, MCV >95 fL
124
85390
78451
29.5
69310
6336<1
MCV; mean corpuscular volume
Hemoglobin, Ferritin & sTfR by Hb Variant
Table 4: Hemoglobin, ferritin and sTfR by hemoglobin variant (n=420 non-pregnant women)
AA(No variant)
AEHeterozygous
(trait)
EEHomozygous
CSConstant
spring
Total, n (%) 249 (59%) 99 (24%) 31 (7.4%) 17 (4%)
Hb, g/L 128.1 ± 9.71 123.3 ± 9.32 108.5 ± 7.32 119.6 ± 8.22
Ferritin, ug/L 93.5 ± 54.8 88.5 ± 47.7 129.0 ± 90.62 93.8 ± 36.9
sTfR, mg/L 6.4 ± 1.9 6.8 ± 2.2 9.5 ± 3.62 9.6 ± 3.02
1Mean±SD. 2pairwise comparisons showed significant differences (p<0.0001) compared to women with a normal hemoglobin (AA)
Anemia & Iron Deficiency by Hb Variant
Table 5: Anemia and iron deficiency by hemoglobin variant (n=420 non-pregnant women)
Without Hb Variantn=249
With Hb Variant n=171
Anemia prevalence, Hb <120 g/L 15.3% 50.3%
Ferritin, Iron stores deficiency, <15 ug/L 2.8% 1.2%
sTfR, Tissue iron deficiency, >8.3 mg/L 11.2% 30.4%
IDA, Hb <120g/L & Ferritin <15 ug/L <1% <1%
IDA, Hb <120g/L & sTfR >8.3 mg/L <1% 7%
Conclusions
1. Genetic Hb disorders cannot be ignored in South East Asia; more than just assessment of Hb is required for anemia
2. More research is warranted on hemoglobin disorders and anemia; low-cost methods for testing for genetic disorders
3. No biochemical evidence of B12, folate or vitamin A deficiencies in Cambodian women in our study
4. Iron deficiency? Ferritin & sTfR likely confounded in those with Hb disorders. However, even in those with no Hb disorder, anemia is only 15% and IDA is <1%
Next Steps & Future Research
1. Complete PCR analysis for α-thalassemia analysis
2. Multivariate logistic regression
3. Investigate potential deficiency of riboflavin, B6 and zinc as contributors to anemia in this population (May survey)
4. Further investigation of potential iron sources in diet• Dietary intake of iron (24-hr recalls)• Assessment of ground well water for iron content• Iron supplementation trial
Acknowledgements
Dr. Angela DevlinDr. Susan BarrDr. Suzanne VercauterenHKI Cambodia research teamGreen-McLean lab