**2. Methods and materials**

#### **2.1 Sample**

The study constituted of 624 young adults (306 males; 318 females) aged 18 to 29 years old from the Ellisras Longitudinal Study (ELS) in Lephalale, Limpopo province in South Africa. The details of ELS are explained elsewhere [15]. The study was approved by the Ethics Committee at the University of Limpopo prior to the study commencing. Consent forms were also signed by the participants.

Participants with factors that could influence the reliability of the study including pregnancy and chronic diseases or hospitalization were excluded.

#### **2.2 Blood pressure measurements**

Prior to being measured the participants rested for approximately 5 minutes. Afterwards, three blood pressure (BP) readings of systolic blood pressure (SBP) And diastolic blood pressure (DBP) were measured five minutes apart in both the left and right arms using an electronic Micronta monitoring kit, [16, 17]. Average BP was calculated for both arms. Then the difference between the average SBP and DBP in the left and right arms was calculated.

#### **2.3 Cardiovascular risk factor measurements**

All participants underwent height and weight measurements according to the standard procedures [18]. The weight and height were then used to determine the body mass index (BMI) [18].

There was fasting of between 8–10 hours before the collection of blood samples. All blood sample collections were carried out in schools by qualified nurses from the

**101**

*Inter Arm Blood Pressure and Cardiovascular Risk in Young Adults at Ellisras*

transported, and analyzed according to standard procedures [14].

≥7.8 mmol/L while obesity was defined as BMI (kg/m2) ≥25 kg/m2

Chemistry System from Beckman Coulter (Brea, Calif).

Medical Science Unit at University of Limpopo.

**2.4 Statistical analysis**

significant.

**3. Results**

than the ≥10 mmHg (0–16.7%).

Witpoort Hospital at Ellisras in the morning. The samples were collected, stored,

Blood glucose (fasting) was drained into fluoride tubes and measured using an Accu-chek [19]. The total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) levels were both measured using standard procedure that utilizes spectrophotometry. The Friedewald equation was then used to determine low density lipoprotein cholesterol (LDL-C) (LDL-C = TC - HDL-C - TG/2.2) [20]. Triglycerides (TG) measurement was done through standard enzyme-based colorimetric technique. These measurements were all accomplished using an AU480

All apparatuses underwent calibration based on standard procedures. These blood analysis was carried out by workers in the Department of Pathology and

The cut-off points were as follows: hypertension was defined as systolic and diastolic blood pressure ≥ 140/90 mmHg. Diabetes was defined as elevated FBG

Inter arm systolic blood pressure difference (IASBPD) and inter arm diastolic blood pressure difference (IADBPD) were described as the absolute value of the left arm SBP/DBP minus the right arm SBP/DBP respectively. Both the IASBPD and IADBPD were grouped into two categories based on a cut-off point: <10 mmHg which is normal and ≥ 10 mmHg which is the category increasing cardiovascular risk [22]. Continuous variables were articulated as mean ± standard deviation while categorical variables were articulated as frequencies and percentages. Moreover comparisons of the variables were performed between the two cut-off groups using independent *t* test for continuous variables, and chi-square test for categorical variables. A multivariate logistic regression model was used to analyze the association between IASBPD and IADBPD, height, weight, BMI, SBP, DBP, fasting glucose, TC, TG, HDL-C, LDL-C, diabetes and hypertension. All analyses were performed using SPSS software version 14.0 and P-value of ≤0.05 was considered statistically

**Table 1** represents the Descriptive statistics of the general characteristics. There was significant (p ≤ 0.05) mean difference of diastolic blood pressure of the <10 mmHg and ≥ 10 mmHg groups. The prevalence of obesity, diabetes and hypertension was insignificantly (p > 0.05) higher in the <10 mmHg group (1.8–30.9%)

**Table 2** shows the association between risk factors and inter arm differences in systolic blood pressure among Ellisras young adults. There was a positive significant association between IASBPD and hypertension (B = 5.331; 95%CI = 12.260–23.183; P = 0.026). There was also a positive significant association found between gender

**Table 3** shows the association between risk factors and interarm differences in diastolic blood pressure among Ellisras young adults. There was a positive significant association found between SBP and IADBPD (B = 1.003; 95%CI = 0.967–1.041; P = 0.001) while there was no significant association found between DBP and

and IASBPD (B = 1.998; 95%CI = 0.022–3.903; P = 0.043).

IADBPD (B = 1.081; 95%CI = 1.032–1.131; P = 0.920).

[21].

*DOI: http://dx.doi.org/10.5772/intechopen.96704*

#### *Inter Arm Blood Pressure and Cardiovascular Risk in Young Adults at Ellisras DOI: http://dx.doi.org/10.5772/intechopen.96704*

Witpoort Hospital at Ellisras in the morning. The samples were collected, stored, transported, and analyzed according to standard procedures [14].

Blood glucose (fasting) was drained into fluoride tubes and measured using an Accu-chek [19]. The total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) levels were both measured using standard procedure that utilizes spectrophotometry. The Friedewald equation was then used to determine low density lipoprotein cholesterol (LDL-C) (LDL-C = TC - HDL-C - TG/2.2) [20]. Triglycerides (TG) measurement was done through standard enzyme-based colorimetric technique. These measurements were all accomplished using an AU480 Chemistry System from Beckman Coulter (Brea, Calif).

All apparatuses underwent calibration based on standard procedures. These blood analysis was carried out by workers in the Department of Pathology and Medical Science Unit at University of Limpopo.

The cut-off points were as follows: hypertension was defined as systolic and diastolic blood pressure ≥ 140/90 mmHg. Diabetes was defined as elevated FBG ≥7.8 mmol/L while obesity was defined as BMI (kg/m2) ≥25 kg/m2 [21].
