CARDIOVASCULAR ANTHROPOMETRY: WHAT IS BEST SUITED FOR LARGE SCALE POPULATION SCREENING IN SUB-SAHARAN AFRICA

Principal-Investigator/Mentee

Dr. Hadiza A Agbo, M.B; B.S., FWACP Consultant Public Health Physician Department of Community Medicine

University of Jos/Jos University Teaching Hospital, Jos, Plateau State

Nigeria  dragboha@yahoo.com

Abstract

Obesity as a disease contributes substantially to cardiovascular morbidity and premature death. Obesity is common-place in the United States of America (USA), as well as among some sub- Saharan native groups; and is actually on the rise in sub-Saharan Africa as a result of the ongoing epidemiological transition. Several studies have established differences in the prevalence of CVD among groups (rural/urban, sex, age, social status etc). In Tanzania, researchers have observed elevated lipid profiles among adults over 35 years of age, with women being affected more than men. In North Catalonia, CVD prevalence was 22.0% and more frequent in men.The danger of obesity arises largely from its cardio-metabolic consequences; as it is known to contribute significantly to hypertension and type 2 diabetes mellitus among others. These two components of the metabolic syndrome are also linked to cardiovascular disease (CVD). The body mass index (BMI) is the standard measure of overweight and obesity, which has recently been found to miss subjects whose cardio-metabolic risk factors are related to increased adiposity. Africans are among those in whom the current BMI definition of obesity may not be appropriate.

In a pilot study in Jos, the case for the utility of the abdominal height (AH) determined by a new tool – the abdominometer, as a useful cardiovascular anthropometric index in an African cohort was made. There is the need therefore to see how AH measured with the abdominometer compares with the old World Health Organization (WHO) standard – BMI and other commonly used anthropometric indices in predicting hypertension and diabetes mellitus; the 2 major components of metabolic syndrome involved in CVD, and to determine which is best suited for large scale epidemiological studies in our environment . The finding if confirmed would result in a paradigm shift in cardiovascular anthropometry.

Project Narrative

The abdominometer a new innovative tool made out of the concept of appropriate technology will be used to detect adiposity in individuals which are often missed if assessed only with the BMI in our locality. It is an innovation currently in use in most developed setting which has not gained significant acceptability and use in a country like Nigeria particularly as a screening device in community and clinical based assessment of abdominal height.

Its use has not being established as a validation tool in developing country such as Nigeria which may be as a result of its non availability. However, it will be good to establish this innovation and validate this with sliding beam caliper using the kappa’s ratio (which will be appropriate if it is

>7.0).

Research Plan

1. Specific Aims

• • To measure the abdominal height with the abdominometer among male and female adults in rural community
  • To determine the BMI, glycosylated haemoglobin and C-reactive protein among male and female adults in our local population
  • To compare the accuracy of abdominometer versus body mass index as a predictive measure of cardio-metabolic disease risk in our local population

2. Background and Significance

Obesity is a disease of affluence which is on the rise and fuels galloping prevalence of cardiometabolic diseases. In developing countries, maternal underweight is the leading risk factor for preventable deaths and diseases. In North Catalonia, the prevalence of selected cardiovascular risk factor for hypertension was 74.5% and dyslipidemia 77.7% among others. In Nigeria, about 17.3 % of the adult population is obese by BMI classification and 18.5% by percentage body fat classification. Hypertension the main cardiometabolic consequence of obesity is up to 48.9% prevalent in some Nigerian studies. The prevalence of cardiovascular risk factors among staff of Ladoke Akintola University of Technology, Ogbomoso, Nigeria was 42.7% in females and 38.5% in males. The WHO standard of measurement is said to wrongly classify disease risks in certain populations, Africans inclusive. The measurement of abdominal height rather than BMI has been recommended for use, however, the appropriate tool for its applicability particularly in resource limited setting like Nigeria is still at a rudimentary level, and it is opined that the use of this innovative approach to detect, screen and facilitate the care for cardiovascular disease among at-risk individuals with obesity especially among women are urgently needed which will further establish its usefulness particularly where there is a growing prevalence of cardiovascular related morbidity and mortality. We propose to use the abdominometer which is a new device made out of the concept of appropriate technology to aid the early and proper detection of individuals with increased adiposity which are often missed if assessed only with the BMI.

3. Preliminary Data

The abdominometer conceptualized by the Mentor, have in a small pilot study among women in a tertiary health center in North Central Nigeria, shown good promise as an effective predictor of cardiometabolic disease risk when compared with BMI.

4. Experimental Design and Methods

This will be a comparative descriptive cross sectional study between male and female adults in a rural community in Mangu Local Government Area (LGA) of Plateau state.

The sample size was determined using the formula below;

𝑛 = (𝑍^𝛼 + 𝑍^𝛽)2𝑋 2 𝑋 𝑝(1 − 𝑝)/𝑑²

Where n = Minimum sample size

Za= Standard normal deviate at 95% confidence level=1.96

Zb= Power to detect a true difference at 20% B error (80% power) =0.84

P= Estimates from studies showed an overall prevalence ranging from 17.5% to 51.6% in urban areas and 4.6% to 43% in rural areas.

A prevalence of 43% will be used.

d= Expected precision of cardiovascular risk in rural community is 7.5% N= (1.96 +0.84)² x 2x 0.43 (1- 0.43)/ (0.075)²

N= (2.8)² x 2 x 0.43 x 0.57 /0.005625

N= 683.23

Adding 5% to make up for incomplete and poor responses

 683 x 5 = 34.15

100

683.23 +34.15 = 717.38 ≈ 717

Therefore, a minimum number of 717 male and female adult each will be studied in the rural population.

This will be a comparative descriptive cross sectional community study among all consented male and female adults above 18 years of age, a minimum number of 717 male and female adults each will be studied each from the population.

Preparation for data collection

Prior to commencement, advocacy shall be made to the community leaders and other relevant stake holders in the chosen community by the Principal investigator and the mentor to seek for permission.

The research assistants shall comprise of four trained Community Health Officers and two laboratory scientists working and residing in/in the vicinity of the Primary Health Care facilities in the rural community who shall be trained on the tools (interviewer administered questionnaire, abdominometer application/measurement and collection of blood samples for the measurements of glycosylated haemoglobin and C-reactive protein) to ensure standardization and uniformity. They will be trained and all members of the research team

to be involved with data collection will be expected to have two measurements for each subject, in order to minimize error as much as possible. Other members will be regularly supervised by the Principal Investigator and the Mentor to ensure good conduct of research.

The research shall be carried out over twelve months (52 weeks) comprising of on-the- field data collection, data entry, analysis and presentation of results.

Week 1 to 6:

1. Application for and obtaining of Ethical clearance for study from the Ethical Committee of the Jos University Teaching Hospital, Jos. Nigeria.
2. Advocacy visits to community leader and other stake holders in the selected community, Chairman of the selected Local Government Area (LGA) in Mangu LGA of Plateau state Nigeria.

Week 7 to 9:

• • Purchase of research instruments (needle and syringe, syphnomanometer, methylated spirit, cotton wool, safety boxes, latex gloves, hand sanitizers, black colour coded polythene bags for non- infectious wastes)
  • Design and printing of questionnaires for a population of 717 x 2 participants)
  • Construction of six abdominometers (to minimize time wasting when measuring the abdominal heights community)

Week 10 to 12:

• • Screening/recruitment of research assistants
  • Training of research assistants

Week 13 to 14:

• • Advocacy to selected communities for mobilization of participants
  • Selection of conducive site in the communities

Week 15 to 19:

• • Data collection simultaneously from the two communities

Week 20 to 45:

• • Data Collation
  • Data entry and cleaning
  • Data analysis

Week 46 to 52:

• • Data presentation
  • Feedback to relevant stake holders in the communities
  • Publication of results

Tools for data collection

• Interviewer administered Questionnaire This shall comprise on four sections:

1. Socio-demographic characteristics and presence/absence of the cardiovascular risk factors of the participants
2. Values of the measured abdominal height, weight, glycosylated haemoglobin and C- reactive protein, blood pressure
3. Measurements of associated parameters (abdominal height, weight, glycosylated haemoglobin and C-reactive protein, blood pressure)

Data generated will be entered into Microsoft word Excel which will be used for data entry and cleaning. Statistical software SPSS (Statistical Package for Social Sciences) Version 20.0 shall be used for data analysis.

5. Future directions:

Research findings will be published and plans will be made to replicate the research among persons under 18 years of age due to the observed growing cases of obesity in children. The abdominometer if comparative in this larger study as it was recorded in the pilot study would be greatly beneficial in health planning for the purposes of initiating preventive and therapeutic actions to curb the menace of cardiovascular disease morbidity and mortality among adults with increased adiposity.

6. Plan for Protection of Human Subjects:

The research will provide an opportunity for the early detection of cardiometabolic diseases risk among the black adults especially in the rural communities and to establish the sex difference if any among rural dwellers.

Informed consent shall and sought and obtained from all the study participants after duly educating them on the details of the research and the quantity blood sample to be collected. The confidentiality shall be strictly adhered to and no name will be written on the questionnaire. Participants will be free to opt out of the study at any stage if they so wish without any penalty. Information will be used strictly for the purpose of this research only.

7. Project Mentor:

Prof Okeahialam Basil (Professor of Cardiology, University of Jos, Nigeria)

8. Pending IRB Approval:

Ethical Clearance will be sought and obtained from the Human Research Ethics Committee of the Jos University Teaching Hospital, Jos. Nigeria.

Budget

A. Equipments

1.   Six Abdominometer @₦18,000.00 each                                                        ₦108,000.00

Budget Justification