Physical Activity and Risk Factors Screening for Ischaemic Heart Disease in South African Individuals Living with HIV

People living with HIV (PLWH) are at risk of developing chronic lifestyle diseases such as ischaemic heart disease (IHD). Physical inactivity is a modifiable risk factor for IHD. The level of ambulation physical activity in individuals living with HIV in a South African context is unknown. The aim of this study was to assess the physical activity levels and other risk factors for IHD in PLWH on antiretroviral therapy (ARV). An observational study was conducted from October 2010 to June 2012 at an outpatient clinic in Johannesburg, South Africa. Two hundred and five individuals who were on ARV for 6-12 months were screened. Physical activity was measured with the Yamax SW200 pedometer over a seven day period. Physical activity of the sample was reduced at 7673.2 (±4017.7) steps/ day with women walking less than men [6993.3 (±3462.6) and 10076.3 (±4885.6)]respectively. Body mass index was increased to 25.6 (±5.4) kg/m with women noted to be overweight [26.6 (±5.5) kg/m]. Independent predictors of being overweight were systolic blood pressure, waist and hip circumference, CD4 count and daily fruit and vegetable intake. Smoking was less common in the study population with 16.1% of the sample being current smokers and 25.9% former smokers. Individuals ’ mean perceived stress levels were 19.9 (±7.8) on the Cohen’s Perceived Stress Scale. The ambulation physical activity level of individuals living with HIV requires modification to assist with reducing risk factors of IHD. DOI : 10.14302/issn.2324-7339.jcrhap-13-255 Corresponding author: Ronel Roos, Telephone: 00 27 11 7173723, Fax: 00 27 86 570 3644, E-mail address: ronel.roos@wits.ac.za

Chronic lifestyle diseases are of concern as mortality in individuals living with HIV is slowly shifting to non-aids related illnesses such as cardiovascular disease [6,7]. This shift could partially be explained by the prevalence of known risk factors of IHD such as smoking and obesity [8,9] and specific HIV sequelae such as chronic inflammation, dyslipidemia and lipodystrophy [10][11][12]. Independent of IHD risk factors, HIV replication (Plasma HIV-1 RNA levels > 50 copies/mL) is also associated with an elevated risk of myocardial infarction (odds ratio 1.51 [95% confidence interval, 1.09-2.10]) [13].
Physical inactivity is a known modifiable risk factor for IHD and is estimated to account for 6% of the burden of disease related to IHD internationally [14]. In the South African context this burden is noted to be much higher at an estimated value of 30% in the general population [15]. Walking, as a form of exercise, is often suggested as a means of lowering and managing an individuals' risk for heart disease as it does not have cost implications or require specific skills. PLWH are encouraged to do regular exercise to manage their disease. Physical activity and ambulation behaviour have been well researched in the general population but is still poorly understood in an HIV population. This paucity in studies may be attributed to different measuring instruments being used to evaluate physical activity and researchers defining physical activity differently [16].
Considering the potential burden of IHD in a South African HIV context, it seems prudent to evaluate the level of physical activity and risk factors for IHD at a primary health care level. Such screening may inform the type of intervention programmes needed to influence the risk factors for IHD in this population. Therefore the aim of this study was to evaluate the ambulation physical management and all participants gave informed consent prior to participating in the study.
The sample size was calculated at 195 participants using the prevalence rate for hypertension in the South African context as guide as no prevalence rates for IHD in South Africa were available at the start of the study [17]. The alpha level was set at 5% and power at 80%. The sample was increased with a factor of 100/95 to allow for any loss to follow-up of participants accounting for a final sample size of 205.
Since completion of the current study, prevalence rates for IHD in individuals living with HIV in South Africa were published and indicated that the disease itself is still at a low prevalence level in this population [18].
The following risk factors for IHD were screened using a questionnaire and body measurements: smoking history (current and former), diet (vegetable and fruit intake), physical activity levels (walking behaviour), resting heart rate and blood pressure, self-reported hypertension and diabetes, body mass index (BMI), waist-and hip circumference and waist: hip ratio (WHR).
The study participants' perception regarding their body shape and weight changes in the last six months was documented.
Physical activity was assessed using the Yamax SW200 pedometer to provide information on walking behaviour (daily step count). Participants were asked to wear a hip-mounted pedometer for seven consecutive days from getting up in the morning until going to bed at night and to document their daily steps on a physical activity log sheet. They were encouraged not to alter their normal physical activity routine. Reactivity related to the physical activity assessment was calculated following the pilot study. No significant alteration (p = 0.4) in physical activity level was observed between the first and last day of assessment in participants when wearing the hip-mounted pedometer and documenting their findings on a log sheet during the pilot study.
The participants' perceived stress levels were evaluated with the Cohen's Perceived Stress Scale-10 (PSS). The PSS is an instrument that measures the degree to which a person perceives their life as being stressful. The instrument consists of 10 questions that are rated on a 5-point Likert scale and range from "0 = never" to "4 = very often". Total PSS score is computed by summing across all ten questions. Scores range from 0 to 40 where a higher score reflects a higher degree of perceived stress [19][20][21]. The PSS has been used in South Africa [22] and in a HIV population [23,24]. In the current study, the Cronbach's α for the PSS was 0.82 as evaluated during the pilot study.
Resting heart rate and blood pressure were

Results
Two hundred and ninety six participants who were on ARV treatment for six to twelve months indicated interest in participating in the study. Fourteen individuals were excluded due to not meeting all the inclusion criteria. Two hundred and eighty two participants consented to participate in the study.
Seventy seven individuals recruited did not attend their first scheduled session due to work obligations, financial difficulties, travelling outside the Gauteng province and/ or were not able to be contacted telephonically. Two hundred and five participants attended their first session and eleven of these individuals did not attend their second session due to the same barriers identified following recruitment. One hundred and ninety four individuals' data were complete and used during data analysis. Physical activity data for 195 participants were available for analysis due to the following reasons: three participants' data were excluded during analysis due to not completing seven days of pedometer assessment, seven participants did not attend their second visit or return their pedometer and pedometer log sheet and three participants send a friend/family member to return their pedometer and physical activity log sheet if they could not attend their second session.      This was a rather interesting finding as one would anticipate the opposite to be true. Body mass index provides information regarding the general nutritional status of individuals and could therefore indicate that participants that fell into the overweight/obese category had sufficient nutrition that allowed them to also partake in daily fruit and vegetable intake. The focus of the study was to screen diet as risk factor for IHD and not general diet. It is reported that a daily diet low in fruit and vegetable is considered a risk factor for IHD [42]; hence the inclusion of investigation of fruit and vegetable intake in the current study. The majority of participants were unable to partake in daily fruit and