Prevalence and risk factors for anemia among female students of ethnicminorities in thai nguyen province vietnam

PREVALENCE AND RISK FACTORS FOR ANEMIA AMONG FEMALE STUDENTS OF ETHNIC MINORITIES IN THAI NGUYEN PROVINCE, VIETNAM MISS HOA THI HONG HANH A THESIS FOR DEGREE OF MASTER OF SCIENCE KHON

PREVALENCE AND RISK FACTORS FOR ANEMIA AMONG FEMALE STUDENTS OF ETHNIC MINORITIES

IN THAI NGUYEN PROVINCE, VIETNAM

MISS HOA THI HONG HANH

A THESIS FOR DEGREE OF MASTER OF SCIENCE

KHON KAEN UNIVERSITY

2018

AMONG FEMALE STUDENTS OF ETHNIC MINORITIES

IN THAI NGUYEN PROVINCE, VIETNAM

MISS HOA THI HONG HANH

A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE

GRADUATED SCHOOL KHON KAEN UNIVERSITY

2018

THESIS APPROVAL KHON KAEN UNIVERSITY

FOR MASTER OF SCIENCE

IN MEDICAL SCIENCE

Thesis title: Prevalence and risk factors for anemia among female students of ethnic

minorities in Thai Nguyen province, Vietnam

Author: Miss Hoa Thi Hong Hanh

Thesis Examination committee

Prof Dr Sastri

Assoc Prof Dr Kanokwan

Assist Prof Dr Pattara

Prof Dr Supan

Assoc Prof Goonnapa Prof Dr Arunee

Saowakhontha Sanchaisuriya Sanchaisuriya Fucharoen Fucharoen Jetsrisuparp Chairperson Member Member Member Member Member Thesis Advisers ……… Advisor (Assoc Prof Dr Kanokwan Sanchaisuriya)

……… Co-Advisor (Assist Prof Dr Pattara Sanchaisuriya )

………

(Prof Dr Surasukdi Wongratanacheewin) Dean, Graduated School ……… (Assoc Prof Dr Patcharee Jearanaikoon) Dean, Faculty of Associated medical Science

Copyright of Khon Kaen University

Hoa Thi Hong Hanh

ความชุกและปัจจัยเสี่ยงภาวะเลือดจางในนักศึกษาหญิงที่เป็นชน กลุ่มน้อยในจังหวัดไทเหงียน ประเทศเวียดนาม

2 7 5

ร า ย ท า ก า ร เ ก็ บ ข้ อ มู ล พื้ น ฐ า น ทั่ ว ไ ป แ ล ะ ข้ อ มู ล สุ ข ภ า พ โ ด ย ก า ร สั ม ภ า ษ ณ์ และเก็บตัวอย่างเลือดหลังจากอาสาสมัครลงนามในแบบค ายินยอม ในเบื้องต้น ตัวอย่างเลือดทุกรายถูกน าไปตรวจ

เ พื่ อ คั ด ตั ว อ ย่ า ง เ ลื อ ด ที่ ต ร ว จ พ บ ภ า ว ะ เ ลื อ ด จ า งไ ป ต ร ว จ วั ด ร ะ ดั บ เ ฟ อ ร ์ไ ร ทิ นใ น ซี รั ม หลังจากนั้นจึงน าตัวอย่างเลือดที่เหลือทุกรายมาตรวจวินิจฉัยธาลัสซีเมีย ณ ประเทศไทย จากตัวอย่าง 275 ราย พบความชุกภาวะเลือดจาง และ ภาวะเลือดจางจากการขาดธาตุเหล็กเท่ากับ ร ้อยละ 31.6 (95% CI = 26-37%) และร ้อยละ 6 (95% CI = 4-11%) ตามล าดับ ผลการตรวจวินิจฉัยธาลัสซีเมีย ผลการตรวจวินิจฉัยธาลัสซีเมีย พบพาหะของธาลัสซีเมียที่มีความส าคัญทางคลินิก 3 ชนิด ได้แก่ 0 -thalassemia ( 0 - -thalassemia ( -thal) และ hemoglobin E (Hb E) รวมทั้งสิ้น 57 ราย (ร ้อยละ 20.7) และพบว่าในกลุ่มผู้ที่มีภาวะเลือดจาง มี ผู้ เ ป็ น พ า ห ะ ธ า ลั ส ซี เ มี ย ร ้อ ย ล ะ 42.5 มี ภ า ว ะ ข า ด ธ า ตุ เ ห ล็ ก ร ้อ ย ล ะ 17.2 เป็นพาหะธาลัสซีเมียร่วมกับภาวะขาดธาตุเหล็ก ร ้อยละ 8.1 เมื่อวิเคราะห ์ข้อมูลโดยใช ้สมการถดถอยโลจิสติก พบว่า ธาลัสซีเมียที่สัมพันธ ์กับภาวะเลือดจางอย่างมีนัยส าคัญ คือ -thal [adjusted Odd ratio (AOR) = 66.4; 95%

เมื่อวิเคราะห ์ความสัมพันธ ์ระหว่างธาลัสซีเมียกับชาติพันธุ ์ พบว่า ชาติพันธุ ์ที่มีสัดส่วนของ 0 -thal และ -thal สูง คือ Tay ( 0 -thal ร ้อยละ 12.9 และ -thal ร ้อยละ 6.1), Muong ( 0 -thal ร ้อยละ 10.9 และ -thal ร ้อยละ 2.2), และ Nung ( 0 -thal ร ้อยละ 12.5 และ -thal ร ้อยละ 4.5) และชาติพันธุ ์ที่พบสัดส่วน Hb E สูงสุด คือ

ผลการศึกษามีประโยชน์ส าหรับก าหนดมาตรการควบคุมภาวะเลือดจางและป้องกันการแพร่กระจายของโรคธาลัสซีเมีย ชนิดรุนแรงในภูมิภาค

Hoa Thi Hong Hanh Prevalence and risk factors for anemia among female students of

ethnic minorities in Thai Nguyen province, Vietnam

Master of Science Thesis in Medical Sciences, Graduate School, KhonKaen University

Thesis Advisor: Assoc Prof Dr Kanokwan Sanchaisuriya

Co-Advisor: Asst Prof Dr Pattara Sanchaisuriya

ABSTRACT

Anemia is one of the health problems among ethnic minorities In Vietnam, there are up

to 54 ethnic minority groups residing in mountainous regions of the country This study aimed to determine the prevalence and risk factors for anemia among reproductive-age women of ethnic minorities in northern Vietnam Participants included 275 medical female students of various minority groups studying at Thai Nguyen University Information on socio-demographic and health status was collected by means of interview After getting written informed-consent, blood samples were collected Complete blood count was measured initially at Thai Nguyen General Hospital Blood samples of anemic individuals were determined further for serum ferritin The remaining blood samples were then carried to Thailand for investigation of thalassemia (thal) Of the 275 women, the prevalence of anemia and iron deficiency anemia (IDA) was 31.6% (95% CI

= 26-37%), and 7.6 % (95% CI = 4-11%), respectively The three forms of thalassemia, including α0

-thal, β-thal, and Hb E were identified in 57/275 women (20.7%) Amongst anemic women, 42.5% had thalassemia, and 17.2% had ID Coincident of thal with ID was found in 7 women (8.1%) Applying multiple logistic regression revealed that types of thalassemia that associated significantly with anemia were -thal [adjusted OR (AOR) = 66.4 (95% CI 8.3-533.7)] and 

-thal (AOR = 25.3; 95% CI = 8.9-72.5) Additional analysis of thalssemia in relation with ethnicities revealed the high proportions of α0

-thal and -thal among the Tay (12.9% 0

-thal and 6% -thal), Muong (10.9% 0

-thal and 2.2% -thal), and Nung (12.5% 0

thal and 4.2% -thal) A highest proportion of Hb E (26%) was detected in the Muong group The results are useful for implementing appropriate measures to control anemia and prevent the spread of severe thalassemia syndromes in this region

-Goodness portion of the present thesis is dedicated to my parents, my thesis

advisory committee and the entire teaching staff

ACKNOWLEDGEMENTS

I would like to express my deepest and sincere gratitude to my research advisor, Associate Professor Kanokwan Sanchaisuriya, and my co-advisor, Assistant Professor Pattara Sanchaisuriya for their kindness to provide me an opportunity to be their advisee and for their valuable motivation, suggestions, and guidance throughout my study

I would like to express my greatest appreciation and sincere to Faculty of Associated Medical Sciences, Khon Kaen university and Khon Kaen University for giving me a scholarship for studying here

I would like to take this opportunity to thank all the professors in the Faculty of Associated Medical Sciences for providing me valuable knowledge and experience during my study

I am also very grateful to Prof Dr Sastri Saowakhontha, Prof Dr Supan Fucharoen, Assoc Prof Goonnapa Fucharoen, Prof Dr Arunee Jetsrisuparp for being as examination committee and for their valuable suggestions as well as encouragement

I would like to thank Dr Attawut Chaibunruang, Assist Prof Dr Supawadee Yamsri,

Dr Hataichanok Sriwarakun, Miss Jutatip Jamnok, Mr Phongsathorn Wichian, Miss Benchawan Kingchaiyaphum, graduate students of Thalassemia Group and other graduate students Faculty

of Associated Medical Sciences, Khon Kaen University as well as my family for the suggestion, support, consolation, helpful, cheerfulness and friendliness

Finally, I deeply appreciate the financial support from the Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University

Hoa Thi Hong Hanh

TABLE OF CONTENTS

ABSTRACT ii

LIST OF TABLES vii

LIST OF ABBREVIATIONS viii

CHAPTER I INTRODUCTION 1

1 Background and rationale 1

2 Research questions 2

3 Objectives 2

4 Anticipated outcomes 3

CHAPER II LITERATURE REVIEW 4

Part I: General consideration of anemia, ID and IDA 4

1 Anemia 4

2 Iron deficiency (ID) and iron deficiency anemia (IDA) 5

Part II: Related research 6

1 Prevalence and risk factors for anemia in Vietnam 6

2 Prevalence of thalassemia and hemoglobinopathies in Vietnam 9

Conceptual framework 11

CHAPTER III RESEARCH METHODOLOGY 12

1 Study design 12

2 Study population 12

3 Sample size 12

4 Data collection & tools 13

5 Statistical analysis 14

6 Ethical consideration 14

7 Scope and limitation of the study 14

CHAPTER IV RESULTS 16

1 General characteristics of the study population 16

2 Prevalence of anemia, IDA, and thalassemia among 275 women of ethnic minorities 16

3 Hematologic features among anemic and non-anemic women 17

4 Factors associated with anemia among 275 women of ethnic minorities 17

5 Distribution of thalassemia among different ethnic groups 17

CHAPER V DISCUSSION 26

CHAPER VI CONCLUSION 29

REFERENCES 30

APPENDIX A INFORMATION SHEET 34

APPENDIX B QUESTIONNAIRE FORM 39

APPENDIX C ETHICAL APPROVAL FORM 44

APPENDIX D RESEACH PRESENTATION 45

LIST OF TABLES

Page

Table 4 Prevalence of the three clinically significant thalassemia in Vietnam 10 Table 5 Socio-demographic characteristics of the 275 participants 18 Table 6 Basic information on health status of the 275 participants 19 Table 7 Prevalence of anemia, IDA, and thalassemia among 275 women of

ethnic minorities

20

Table 8 Prevalence of the three clinically significant thalassemia among 275

reproductive-age women of ethnic minorities

Table 12 Distribution of the 3 clinically significant thalassemia among 275

reproductive-age women with different ethnicities

25

MCHC Mean corpuscular hemoglobin concentration

RDW Red blood cell distribution width

CHAPTER I INTRODUCTION

1 Background and rationale

Anemia is a condition in which hemoglobin (Hb) and/or red blood cell (RBC) production

is reduced Anemia is defined as Hb concentration less than cutoff value adjusted for age and sex; i.e Hb < 11 g/dl for pregnant women and Hb < 12 g/dl for non-pregnant women [1] Individuals with anemia may have unpleasant outcomes that lead to reduced work performance such as fatigue, dizziness, headache and shortness of breath When anemia becomes severe (Hb

< 7.0 g/dL), heart failure may occur [2] Therefore, it is necessary to implement prevention program for anemia among the high risk population

Population in developing countries are considered at high risk due partly to the low economic status According to the World Health Organization (WHO), approximately 50% of Southeast Asian populations are anemic [1] It is assumed that iron deficiency (ID) is the main cause Poor consumption of dietary iron is thought to be related to anemia, the so-called iron deficiency anemia (IDA) While preschool-age children and pregnant women are at high risk because of the increased requirement of iron, non-pregnant women of reproductive age are also at-risk due to regular blood loss [2] Other causes include parasitic infections and micronutrient deficiency as well as inherited hemoglobin disorders, thalassemia and hemoglobinopathies Several studies conducting in this region have shown that the inherited disorders rather than ID are associated with anemia [3-6]

socio-Vietnam is one of developing countries in Southeast Asia where there are up to 54 different ethnic groups Amongst these ethnicities, the Kinh (Viet) is the majority group, accounting for nearly 86% of Vietnamese population [7] Other minority groups reside in mountainous areas where health care accessibility is limited Previous studies conducting in the country have demonstrated the high prevalence of thalassemia and hemoglobinopathies in several groups of ethnic minorities [8-11] It is therefore of interest to investigate the prevalence

of anemia and its risk factors among the minorities

Thai Nguyen University of Medicine and Pharmacy (TUMP) is in the Northeast of Vietnam and plays a key role in producing medical doctors for the mountainous provinces of Vietnam TUMP has approximate five thousand students, of which more than a third are ethnic minority students They come from different areas of the northeastern region where the rate of malnutrition is high [12-14] Being reproductive-age females of ethnic minorities, the risk of anemia is thought to be high This study aims to determine the prevalence and risk factors for anemia among females of ethnic minorities studying at the TUMP Information gained will be useful for implementing appropriate control program for anemia among the reproductive-age female of ethnic minorities

3.2.5 To explore the distribution of different types of thalassemia among different ethnic groups

4 Anticipated outcomes

Basic information on anemia prevalence and risk factors would be useful for implementing an appropriate prevention program for anemia among reproductive-age females of ethnic minorities in Vietnam The additional study on the distribution of thalassemia types is expected to inspire health staff and policy makers to initiate prevention program for thalassemia among the ethnic minority groups

CHAPER II LITERATURE REVIEW

Part I: General consideration of anemia, ID and IDA

1 Anemia

Anemia is a condition that occurs when there is a limit production of red blood cells or hemoglobin Anemia is considered as one of the major public health problems affecting more than half of the world population It has significant adverse effect on health as well as on social and economic development The severity of anemia depends on many factors including age, sex, physiological and pathological statuses In public health term, anemia is defined when

Hb level is lower the thresholds given by the WHO (Table 1) [1]

Table 1: Classification of anemia by age and gender [1]

Children (6 months to under 5 years) 11

Children (5 years to under 12 years) 11.5

Children (12 years to under 15 years) 12

Non-pregnant women (15 years and over) 12

There are many ways to classify anemia Using MCV as classification criterion, there are three groups; microcytic anemia (MCV < 80 fl), normocytic anemia (MCV 80-100 fl), and macrocytic anemia (MCV > 100 fl) [2] Based on the mechanism that causes anemia, three categories are defined, i.e deficient erythropoiesis (impaired RBC production), excessive RBC destruction, and blood loss Blood loss can be either acute or chronic Acute blood loss usually results from bleeding due to accident or injuries Many chronic diseases such as malignancies, gastrointestinal tract lesions, gynecologic disturbances, etc cause chronic blood loss Deficient erythropoiesis and excessive RBC destruction (hemolysis) result from many causes While ID results in deficient erythropoiesis, inherited Hb disorders (thalassemia & hemoglobinopathies)

can result in either deficient erythropoiesis or excessive hemolysis depending on the number and types of abnormal genes inherited [2,15]

Anemia may occur at any age But it can be found commonly in preschool – age children, pregnant women and non – pregnant women of reproductive age [1] Individuals with anemia may have several unpleasant clinical symptoms depending on its cause and severity Signs and symptoms of anemia may include headache, dizziness, weakness and fatigue, shortness of breath, chest pain, and irregular heartbeat Anemia may also result in slowed growth development, poor cognitive performance and behavioral disturbance in young children [16-18] For pregnant women, many poor maternal outcomes such as risk of perinatal mortality and morbidity have been reported [19-21] For non-pregnant women of reproductive age and other groups of population, anemia usually results in reduced work performance When anemia becomes severe, other serious health consequences could occur and may lead to heart attack or failure [2]

2 Iron deficiency (ID) and iron deficiency anemia (IDA)

ID is the most common nutritional deficiency worldwide It results from a long-term of negative iron balance The early stage of ID starts with a depletion of iron stores, and it does not cause physiological impairment At this stage, the iron storage is reduced but serum iron remains normal Without iron replacement, deficient erythropoiesis occurs, leading to anemia, so-called iron deficiency anemia (IDA) As a result, Hb level as well as mean cell volume (MCV) and mean cell hemoglobin (MCH) reduce significantly Therefore, a reduction in Hb, MCV and MCH values is used widely as indicator of IDA [2] A definite diagnosis of ID requires measurement of iron stores, serum ferritin (SF) In an absence of infection or inflammation, SF is considered as the most reliable biomarker for detecting iron deficiency According to the WHO, anemic individuals with SF < 15 ng/ml are diagnosed as having IDA [22] However, it is suggested that this marker should be used in an area where the incidence of malaria and parasitic infestation is low

Causes of IDA can be categorized into 3 main groups, i.e increased iron requirements, insufficient intake, and impaired iron absorption (Table 2) While the high risk groups like young children and pregnant women require more iron for growth development (for themselves and the

developing fetus), non-pregnant women of reproductive age requires more iron for compensation

of blood loss via menstruation

Table 2: Causes of iron deficiency [23]

Increased iron requirements

Part II: Related research

1 Prevalence and risk factors for anemia in Vietnam

In Vietnam, the prevalence of anemia has improved over time The prevalence of anemia varies greatly depending on study population and areas Data on anemia prevalence collected before 2009 have shown a high prevalence of anemia in the country, ranging from 20-62% [24] The prevalence was particularly high among population living in rural areas

A large survey representing the burden of anemia in the country had been conducted in

1995 by Nguyen et al [25] The authors conducted a cross-sectional survey for anemia in rural areas of 53 provinces Children, pregnant and non-pregnant women as well as men were recruited from 9,500 households A high prevalence of anemia of 60% was found in young children aged under 2 years Anemia prevalence among pregnant and non-pregnant women of

reproductive was 53% and 40%, respectively They also found that 16% of men were anemic The strongest factor associated with anemia was found to be hookworm infection Risk factors associated with anemia among children and women included living in different ecological zones, eating < 1 serving of meat/ week, and farming Additional risk factors for women were having >

3 children and having a child < 24 months old

Similarly high prevalence of anemia among the three high risk groups, i.e children, pregnant and non-pregnant women of reproductive-age, was also reported by several groups of investigators Nhien et al [26, 27] reported the anemia prevalence of 45% among primary school children, and 56% among young children aged 12 to 72 months, whereas Le et al [28] reported a relatively lower anemia prevalence of 25% among school children residing in Tam Nong district For adolescent school girls, the occurrence of anemia appeared to be lower than young children with a prevalence of 20% [29] In pregnant women, anemia prevalence of 43-53% has been reported [30,31] Studies conducting in non-pregnant women of reproductive-age demonstrated a high prevalence of 54% in 2007 [31], and reduced to 38% in 2008 and 2009 [32, 33] In addition

to ID and hookworm infection, micronutrient deficiencies including selenium, zinc, copper, and vitamin A were shown to be associated with anemia [12-14, 28, 32, 34] The association between ethnicity and anemia has also been demonstrated in a cohort study conducting in a minority community, in which ID and malaria were found to be potential factors associated with anemia within the study population [34]

After 2010, the reported prevalence of anemia in Vietnam reduced dramatically Laillou

et al [35] reported an unexpectedly low prevalence of 9-12% for anemia, and 13-14% for ID in two study groups, reproductive-age females and children aged 6-75 months Later, a study conducted in pregnant women residing in Thua Thien Hue reported a prevalence of 19% for anemia, 20% for ID, and 6% for IDA [36] Similarly, a prevalence of anemia of 22% and 20% was reported by Tran et al in 2014 [37], and by Nguyen et al in 2016 [38] More recently, a study conducted in children aged 6-11 years also showed unexpectedly low prevalence of 11% for anemia, 6% for ID and 0.4% for IDA [39] These results indicate an improvement of anemia burden within the country However, it is noticeable that information on the health burden among the ethnic minority groups is limited

A summary of anemia prevalence in Vietnam is shown in Table 3

Table 3 Prevalence of anemia in Vietnam

Adolescent girls (age: 11 – 17

Reproductive age women (age:

15 – 45 years)

province

*Age of women was not specified

2 Prevalence of thalassemia and hemoglobinopathies in Vietnam

A few community-based surveys for thalassemia had been conducted in Vietnam A large survey was conducted in 2010 by O’Riordan et al [8] The investigators reported the results of thalassemia screening in > 9000 individuals with different ethnicity in South Vietnam They found that the gene frequencies of thalassemia among ethnic minority groups (including Tay, Dao, Nung, S’Tieng, M’Nong, Rac Lay and E De) varied considerably, ranging from 0-9.5% for β-thal, and 0-58% for Hb E The proportions of α0

-thal investigated among the 3 minority groups, i.e Tay, Nung, and S’Tieng, ranged from 5.5- 6.9% The prevalence among the Kinh, the majority group of Vietnamese, was 3.4% for α0-thal, 1.6% for β-thal and 3.4% for Hb E Later, similar prevalence of α0-thal (3.4%) and β-thal (1.5%) with slightly lower prevalence of β-thal (2.1%) was reported among the Kinh pregnant women who attended antenatal care service at

40 health commune centers in Thua Thien Hue [9]

Previous studies surveying thalassemia among 2 ethnic minority groups, the Co-Tu and Ta-Oi, in Central Vietnam, reported the remarkably high prevalence of Hb CS of around 25%, which was the highest prevalence reported so far [10, 11] A carrier frequency of Hb E of approximately 15% was observed in both groups Interestingly, none of α0-thal was identified

A summary of the three clinically significant thalassemia in Vietnam is shown in Table 4

Table 4 Prevalence of the three clinically significant thalassemia in Vietnam

Tay southern and central southern Vietnam 5.5 7.6 2.8 [8]

Nung southern and central southern Vietnam 6.8 8.1 2.0 [8]

Dao southern and central southern Vietnam NA 9.5 0 [8]

*The most prevalent thalassemia among the Co-Tu and Ta-Oi was Hb CS with a carrier frequency of around 25%

Conceptual framework

Based on the literature reviews, the conceptual framework of this study is shown below

Independent variable Dependent variable

Food consumption practices

CHAPTER III RESEARCH METHODOLOGY

1 Study design

The cross-sectional survey was conducted at Thai Nguyen University of Medicine and Pharmacy (TUMP), Thai Nguyen province, Vietnam

The research was conducted through 2 subsequent steps

Step 1: Face to face interview

Face-to-face interview using questionnaires was applied to collect basic information including age, weight, height, ethnicity, educational background, family income, iron supplementation, and medical history (i.e history of blood loss, chronic disease and/or other infection or inflammation, as well as family history of thalassemia)

Step2: Blood collection

Venipuncture was performed to collect blood samples for investigation of anemia, ID and thalassemia

2 Study population

The study population included apparently healthy female students of any ethnic minority group studying at Thai Nguyen University of Medicine and Pharmacy Only females aged 18-35 years were recruited Participation was voluntary Pregnant females were excluded

Where, 95% confident interval (Zα/2) = 1.96

Prevalence of anemia in student (P) = 0 37 [32]

Precision of estimation (e) = 0.05

A total number of female ethnic minority students (N) studying at TUMP = 829

4 Data collection & tools

Basic information was collected by interviewing using questionnaires This process was done by well-trained research assistants Details of questionnaires are show in Appendix I

After interviewing, blood sample was collected by staff of Thai Nguyen Institute of Hematology and Blood Transfusion Three milliliters (ml) of venous blood sample anticoagulated with EDTA was taken from all participants After collection, all blood samples were kept at 2-6oC and sent to Thai Nguyen Institute of Hematology and Blood Transfusion to determine anemia and other hematologic parameters using an automated hematology analyzer (Unicel DxH 800, Beckman Coulter, USA) Portions of blood samples were sent on ice to the Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Khon Kaen University, Khon Kaen, Thailand, for diagnosis of thalassemia and hemoglobinopathies

Anemia was defined according to the WHO criteria (Hb < 12.0 g/dl) [1] Blood samples

of anemic cases were investigated further for serum ferritin using the latex agglutination reagent

kit (Beckman Coulter Inc., CA, USA) Anemic individual with SF < 15 ng/ml was diagnosed as IDA [22]

Approach to diagnosis of thalassemia

At CMDL, all blood samples were screened for Hb E using the KKU-DCIP-Clear reagent kit (PCL Holdings, Bangkok, Thailand) Cellulose acetate electrophoresis (Helela Laboratories, Beaumont, Texas, USA) was initially performed to identify Hb types Then, blood samples with normal Hb-type (A2A) together with either MCV < 80 fl or MCH < 27 pg were selected for further determination of Hb A2 level Individual with Hb A2 > 3.5% was concluded as β-thalassemia trait Identification of α0-thal was performed in all samples using a multiplex gap-PCR for SEA and THAI deletions [40]

5 Statistical analysis

Data were analyzed using SPSS for Windows program (version 20.0, SPSS, Chicago, IL, USA) Prevalence of anemia, IDA, and the clinically significant thalassemia was summarized as percentage with 95% confidence interval (95% CI) Normally distributed continuous variables including hematological parameters were presented as mean with standard deviation The association between anemia and selected factors (including socio-economic information, food consumption behavior, health status and history of blood loss, as well as thalassemia types) was tested with Chi-square test To demonstrate the effect of different types of thalassemia on anemia, all ID and homozygous Hb E cases were excluded Multiple logistic regression was then applied to calculate the odd ratio (OR) and 95% CI P-value < 0.05 was considered statistically significant for all analyses

6 Ethical consideration

This study was approved by the Ethics Committee of Khon Kaen University and TUMP Written informed consent was obtained prior to blood collection

7 Scope and limitation of the study

This study was a cross-sectional study aiming to determine the prevalence of anemia and its risk factors among reproductive-age females of ethnic minorities The investigated risk factors

comprised socioeconomic status and the promising factors, including history of blood loss as well as consumption behavior Consumption behavior focused on certain types of foods and drinks that are most likely to be associated with ID; i.e meat, tea and coffee Serum ferritin, an indicator of iron deficiency, were determined in anemic females Only three forms of thalassemia including α0-thal, β-thal and Hb E were investigated All information on socio-economic and health status was based on interview

CHAPTER IV RESULTS

`1 General characteristics of the study population

Table 5 shows the socio-demographic characteristics of the study participants Mean age of participants was 22.8±1.8 years Ethnic groups of participants included Tay (42.2%), Nung (17.8%), Muong (16.7%), Thai (5.5%), Dao (4.7%), San Diu (4.7%), Mong (2.6%), San Chi (1.8%), Cao Lan (1.5%), Pa Di (0.7%), Tho (0.7), Giay (0.4%), Hoa (0.46%), Ngan (0.4%) Approximately 90% of participants’ families lived in rural area Around 60% of participants were senior students (4rd-6th year) 3-Most of them (94.5%) were single Around 60% of participants had high income

Basic information regarding health status of participants is shown in Table 6 Underweight accounted for 29.8% of participants whereas only 3.3% were overweight The majority of participants (88%) reported no any chronic illness but around 16% had peptic ulcer Approximately 80% of women reported duration of menstruation within 5 days All women were not vegetarians, and 67% of them did not drink or coffee

2 Prevalence of anemia, IDA, and thalassemia among 275 women of ethnic minorities

Prevalence of anemia, IDA, and thalassemia among 275 women of ethnic minorities is given in Table 7 Eighty- seven women (31.6%, 95% CI 26-37%) was anemic Only 7.6% of participating women had IDA (95% CI 4-11%) In total, 60 women (21.8%, 95% CI 17.1-28%) were found to be carriers of either thalassemia or structural Hb variants Identification of the 3 clinically significant thalassemia among 275 women of ethnic minorities revealed a prevalence of 11.3% for α0

-thal, 4.7% for β-thal and 6.9% for Hb E (Table 8)

Table 9 illustrates the proportions of thalassemia and ID among 87 anemic women A total

of 37 women (42.5%) had thalassemia ID was found in 15 women (17.2%) Coincidence of thalassemia with ID was observed in 7 women (8.1%), leaving 28 cases (32.2%) unexplained

3 Hematologic features among anemic and non-anemic women

Hematologic features among anemic and non-anemic women categorized by thalassemia and iron status are shown in Table 10 Although thalassemia heterozygotes resulted in anemia, some of them had no anemia Anemia became worst when coincided with ID Comparing hematologic features within the same genotype, it appears that coincident of thalassemia with ID resulted in a reduction in MCV and MCH values but increased RDW value Amongst anemic women with unknown cause (non-thal or non-clinically significant thal), normal MCV and MCH values were observed It is observed that two women with abnormal hemoglobin showed no abnormality in hematologic features

4 Factors associated with anemia among 275 women of ethnic minorities

Applying Chi-square test as crude analysis, no association between anemia and economic factors as well as health information was observed The only factor associated significantly with anemia was type of thalassemia Further analysis with multiple logistic regression revealed that β-thal had strongest effect (OR = 66.4, 95% CI = 8.3 – 533.7) Heterozygous states of α0

socio thal also associated significantly with anemia (OR = 25.3, 95% CI = 8.9 -72.5) However, no significant association was observed for Hb E trait (OR = 3.4, 95% CI = 0.9-12.5) The results of logistic regression analysis are shown in Table 11

5 Distribution of thalassemia among different ethnic groups

Table 12 illustrates the proportions of the three clinically significant thalassemia among different ethnic minority groups All these three forms of thalassemia were observed in almost all minority groups A high proportion of α0

-thal was detected in Tay (12.9%), Muong (10.9%), and Nung (12.5%) Other minority groups in which α0

-thal was identified were Thai, Cao Lan, Tho and San Dui For β-thal, a high proportion of 6% was observed in the Tay group Around 4% of the Nung women were found to be β-thal carriers Comparing with Tay and Nung, Muong women had a relatively lower proportion of β-thal (2.2%) with a significantly higher proportion of Hb E (26.1%) Women carrying β-thal and Hb E genes were also identified among other minority groups, including Thai, Hoa, Tho and San Dui