Cardiovascular disease risk in Black African females and the efficacy of a walking programme on blood pressure in a sub-sample

The purpose of the study was to investigate the cardiovascular disease (CVD) risk profile of black African females in the Makana region, Eastern Cape, South Africa. Baseline measures from 40 participants, who met the criteria, were compared against the 2003 South African Demographic and Health Survey (SADHS) and the 2013 South African National Health and Nutritional Examination Survey (SANHANES-1). The risk factors measured were anthropometric (stature, body mass and body mass index (BMI)), morphological (waist circumference (WC), fat mass and lean mass), cardiovascular (heart rate and blood pressure (BP)), physical activity (step count and energy expenditure), biochemical (glycated haemoglobin and full blood lipid profile) and behavioural (alcohol and tobacco use). Results showed significantly higher (p≤0.05) values for overweight/obesity (BMI 37.60 kg.m⁻²; WC 1130.58 mm; fat mass 45.23%) and high BP (130/88 mmHg) compared to the previous national surveys, highlighting these CVD risk factors as problematic. The subsequent sub-study aimed to assess the efficacy of a pedometer-based walking intervention on high BP. The walking programme (n=25) was based on individual step goals to be completed at a moderate-intensity on five days.week⁻¹ for 12 weeks. The same measurements were taken at monthly intervals, Week 0, Week 4, Week 8 and Week 12, with the addition of dietary intake and fitness level, and the exclusion of the behavioural variables. There were no significant differences (p≤0.05) in systolic and diastolic BP with the exercise intervention, although there was a strong, negative relationship with time for diastolic BP (r²=0.9857). This trend suggests that the lack of significance may be a result of poor compliance and/or the small sample size. Individual results, however, showed no compliance-result relationship for the two risk factors of interest: overweight/obesity and high BP. Future recommendations include supervised or group-based exercise interventions to improve compliance, and the addition of resistance training to the aerobic programme