**2. Methodology**

#### **2.1 Geographical area**

Ellisras, also known as Lephalale, is a relatively deep rural area located within the North- western area of Limpopo province, South Africa. The population consist of approximately 50000 people residing in 42 settlements and are adjacent to the Botswana border. Majority of residence in this population work at Iscor coal mine and Matimba electricity power station, whereas the remaining work class is involved in subsistence farming, while the minority is in civil services and education [10].

#### **2.2 Sampling and study design**

Research design and sampling method for the Ellisras Longitudinal study (ELS) have been reported elsewhere [10].

In this study, a total of 492 children (n = 296 boys; n = 196 girls) aged 6 to11 who are part of the ELS, participated in this study. Ethical approval prior to this study was obtained from Ethics Committee of the University of Limpopo. Guardians were provided with, and signed, written informed assent.

### **2.3 Anthropometry**

Anthropometric measurements were done according to the International Society for the Advancement of Kin-anthropometry (ISAK). Weight was measured on an electronic scale to the nearest 0.1 kg, and a Martin anthropometry was used to measure height to the nearest 0.1 cm. Flexible steel tape was used to measure NC and WC. Waist circumference was measured midway between the lower costal margin and iliac crest immediately after exhalation. Neck circumference was measured directly below the thyroid cartilage perpendicular to the long axis of the neck. All measurements were taken with the participants standing in an anatomical position.

Children with BMI <85th, ≥85th and ≥ 95th percentile were considered normal, overweight and obese, respectively [7]. Children with WC ≥90th percentile were considered to have abdominal obesity, and those with NC 90th ≥ were considered to have obesity [3, 11]. BMI was calculated as weight in kilograms (kg) divided by the square of height in metres (m), whereas waist to height ratio was calculated as waist circumference divided by height.

**111**

**Figure 1.**

*girls (14.3%) than in boys (11.5%).*

*Association of Anthropometric Parameters with Blood Pressure and Blood Glucose…*

To measure blood glucose, the participants were first made comfortable, by sitting on the chair for at least five minutes before measurements. From each subject at least three reading blood pressure (systolic and diastolic) measurements were taken, at an interval of five minutes apart. Blood pressures readings were taken using electronic Micronta monitoring kit. The device has a bladder which contains an electronic infrasonic transducer that monitors the blood pressure and pulse rate, thus displaying these on the screen. Hypertension was defined by systolic and diastolic blood pressure ≥ 95th percentile of age and sex adjusted reference level [6].

To measure blood glucose level all subjects were asked to do an 10 hours overnight fasting prior to the test, in the morning their capillary blood sample were obtained by a finger prick and blood was caught up in little cuvettes, which were prepared with below mentioned reagents (glucose oxidase and reagents to measure the generation of hydrogen peroxide such as non-toxic phenol red and horseradish peroxidase was bonded to filter paper). After mixing with the reagents, fasting blood glucose was measured using Hemocue® [8]. Type 2 diabetes mellitus was defined by

All the statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 25. Data comparison was done using student t-test for 2 groups. Descriptive statistics were performed for age, anthropometric parameters, fasting blood glucose and blood pressure (systolic and diastolic). The Linear regression model was used to assess the association between blood pressure (systolic and diastolic), blood glucose and anthropometric parameters after adjusting for potential confounders. The logistic regression was used to determine the risk of developing hypertension and type 2 diabetes mellitus using anthropometric parameters. Statistical significance was set at a probability level of 0.05 (**Figures 1** and **2**).

*Gender specific prevalence of obesity based on WC, BMI, WHtR and NC among Ellisras children aged 6 to 11 years. The prevalence of obesity was higher in boys measured by BMI (16.9%), WC (5.4%) and WHtR (9.6%), as compared to girls BMI (12.2%), WC (4.6%) and WHtR (6.2%) and that measured by NC was higher in* 

fasting blood glucose ≥7.1 mmol/L of sex and age adjusted reference level.

*DOI: http://dx.doi.org/10.5772/intechopen.95938*

**2.4 Blood pressure**

**2.5 Blood glucose**

**2.6 Statistical analysis**

*Association of Anthropometric Parameters with Blood Pressure and Blood Glucose… DOI: http://dx.doi.org/10.5772/intechopen.95938*

## **2.4 Blood pressure**

*Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases...*

blood pressure (DBP) to derive an estimate for diagnosis [9].

glucose levels in this population.

**2.2 Sampling and study design**

have been reported elsewhere [10].

waist circumference divided by height.

provided with, and signed, written informed assent.

**2. Methodology**

education [10].

**2.3 Anthropometry**

**2.1 Geographical area**

The diagnosis of diabetes is often based on a fasting plasma glucose, random plasma glucose, a 2-hour plasma glucose value in a 75g oral glucose tolerance test or a glycated hemoglobin (A1C) measurement, but generally on fasting plasma glucose, partly because of its better sensitivity to diagnose diabetes [5, 8]. Hypertension uses information about systolic blood pressure (SBP) and/or diastolic

In view of the burden of obesity, hypertension and diabetes and their impact on children and the scarcity of information on the relationship of blood glucose, blood pressure with anthropometric parameters in rural South African communities, more especially in Ellisras, the present study aimed to determine the relationship of blood pressure and blood glucose with anthropometric parameters among Ellisras rural children aged 6 to 11 years and to determine which of the anthropometric parameters is associated with greater odds of high blood pressure and high blood

Ellisras, also known as Lephalale, is a relatively deep rural area located within the North- western area of Limpopo province, South Africa. The population consist of approximately 50000 people residing in 42 settlements and are adjacent to the Botswana border. Majority of residence in this population work at Iscor coal mine and Matimba electricity power station, whereas the remaining work class is involved in subsistence farming, while the minority is in civil services and

Research design and sampling method for the Ellisras Longitudinal study (ELS)

In this study, a total of 492 children (n = 296 boys; n = 196 girls) aged 6 to11 who are part of the ELS, participated in this study. Ethical approval prior to this study was obtained from Ethics Committee of the University of Limpopo. Guardians were

Anthropometric measurements were done according to the International Society for the Advancement of Kin-anthropometry (ISAK). Weight was measured on an electronic scale to the nearest 0.1 kg, and a Martin anthropometry was used to measure height to the nearest 0.1 cm. Flexible steel tape was used to measure NC and WC. Waist circumference was measured midway between the lower costal margin and iliac crest immediately after exhalation. Neck circumference was measured directly below the thyroid cartilage perpendicular to the long axis of the neck. All measurements were taken with the participants standing in an anatomical position. Children with BMI <85th, ≥85th and ≥ 95th percentile were considered normal, overweight and obese, respectively [7]. Children with WC ≥90th percentile were considered to have abdominal obesity, and those with NC 90th ≥ were considered to have obesity [3, 11]. BMI was calculated as weight in kilograms (kg) divided by the square of height in metres (m), whereas waist to height ratio was calculated as

**110**

To measure blood glucose, the participants were first made comfortable, by sitting on the chair for at least five minutes before measurements. From each subject at least three reading blood pressure (systolic and diastolic) measurements were taken, at an interval of five minutes apart. Blood pressures readings were taken using electronic Micronta monitoring kit. The device has a bladder which contains an electronic infrasonic transducer that monitors the blood pressure and pulse rate, thus displaying these on the screen. Hypertension was defined by systolic and diastolic blood pressure ≥ 95th percentile of age and sex adjusted reference level [6].
