Knowledge Transfer

In this study, some cardiovascular disease risk factors were identified to be prevalent in the HIV infected population compared to the control population. These include physical inactivity, significant alchohol intake, smoking, increased waist-hip ratio, impaired glucose tolerance, dyslipideamia, hypertension, metabolic syndrome and left ventricular hypertrophy. The Human Immune-deficiency Virus is known to possess an intrinsic metabolic and cardio-pathogenic action that may be detected even in the early stages of the disease^11-13. This in addition to adverse lifestyle predisposes the HIV infected subjects to increased risks for cardiovascular disease.

The difference in social class of subjects and controls in this study did not attain statistical significance p>0.05. This shows that differences in the cardiovascular abnormalities found may have been due to the virus and its associated factors. Some studies have identified extremes of social class as a risk factor for cardiovascular diseases in the general population79,82,83,85. However in HIV infected persons, low socio-economic class have been identified as a significant predictor of increased cardiovascular disease risk score and actual cardiovascular disease10,16,35,57. In a large multicentre study involving 931 men and 1455 women with HIV infection in the United states.

98 Robert Kaplan et al concluded that having a low socio-economic class (income less than 10,000 dollars/year) was associated with increased prevalence of moderate-high coronary heart disease risk scores in the subjects⁵⁷. Infact, among the factors considered; belonging to a lower socio-economic class was the strongest risk factor identified to having a moderate-high coronary heart disease risk score (OR 2.32, 95%CI 1.51-3.36)⁵⁷. Similar findings have been obtained by several other studies on risk factors for cardiovascular abnormalities in HIV infected persons16,20,38,80.

A significant number of the subjects smoke (21.3%), take alchohol in significant quantities (31.3%) and do not engage in physical exercises (97.0%). Among the controls, only 2.0% smoke and 6.0%

take alchohol in significant quantities; this is comparable to results obtained in other studies which report that risky lifestyle is commoner in HIV infected persons^16,80,138. These habits significantly promote cardiovascular diseases and are commoner in those who experience stigma^16-18,80. Recent evidences also suggest that smoking and alchoholism reduces immunity and the efficacy of anti-retroviral therapy^16-18. They also promote vascular disease and hypertension and have been shown to increase all cause mortality in HIV infected persons^16-18. Physical inactivity was prevalent in the subjects; this may be due to the chronicity and debilitating nature of the disease. HIV infection predisposes its victim to long periods of physical inactivity with its attendant consequences.

Physical inactivity has been shown to have an adverse impact on blood glucose levels, blood pressure and lipid profiles; it also raises the risk of a cardiovascular event by two-fold⁷⁸.

Obesity (BMI>25) was found in 26.7% of the subjects and 32.0% had increased waist circumference. The controls however had higher mean values of weight and BMI; this may be due to the fact that HIV is a chronic infection which results in progressive weight loss especially in those not yet on ART. Among the subjects, those on ART had statistically significant higher mean values of weight, body mass index, waist circumference and waist-hip ratio compared to those not on ART. A recent study in fact found that being overweight or obese is now more prevalent than wasting in HIV infected population^55,56. Increased mortality rates have been identified as an

99 exponential function of increasing body weight58,59,64,65. The risk of coronary heart disease doubles with BMI greater than 25 and increases nearly fourfold when it is above 29^64,65. The risk of developing type 2 diabetes also increases with increasing weight such that individuals with a BMI above 35 have a 40-fold higher risk of developing diabetes when compared to non-obese individuals58,59,64,65.

In people with normal BMI, increased waist circumference has a positive correlation with abdominal fat content. Fat located in the abdominal region is associated with a greater health risk than peripheral fat58,59,64,65. This study also found that increased wait-hip ratio is commoner in the HIV infected population compared to uninfected controls. Some studies on cardiovascular risk factors in HIV infected persons have found evidence of increased alteration of body shape and size in HIV infected persons55,56,70,71-75.

A significant number of the HIV infected subjects (28.0%) had impaired glucose tolerance compared to only 2.0% of the controls, p<0.001. This occurred mostly in those on ART and showed a strong statistically significant difference when compared to those not on ART. Some studies had reported the prevalence of type 2 diabetes mellitus among patients with HIV to range from 6.0% to 18.0% ^60-61. Reasons that have been reported to predispose the subjects to diabetes are exposure to anti-retroviral therapy particularly protease inhibitors, changes in body shape and size and hepatitis C co-infection among others^60-63.

Dyslipideamia is a significant predictor of endothelial dysfunction and atherosclerosis in the general population. It was found in more than 60.0% of the subjects but only 6.0% of the controls.

Literature search revealed a prevalence that ranges from 28.0%-80.0% in patients receiving anti-retroviral therapy52-54,62,63,71.In general, use of protease inhibitors have been associated with more adverse lipid changes than use of other classes of anti-retroviral drugs^52-54,62. In addition, adverse dietary habits and even untreated HIV infection is associated with dyslipideamia in infected persons^52-54. Dietary modification may therefore be needed as part of management modalities⁵⁴.

100 Hypertension was found in 56.0% of the subjects on anti-retroviral therapy, 30.0% of those not on treatment but only 10.0% of the uninfected controls. This finding is in agreement to that obtained from other studies which show that hypertension is generally increased in HIV infected persons compared to uninfected controls16,17,44-49. It is known that the impact of hypertension on cardiovascular morbidity and overall mortality rate is much higher among persons living with HIV than the general population^14,35,45. Generally, patients with hypertension will often develop other cardiovascular risk factors such that hypertension is regarded as central in management of cardiovascular disease risk factors^39-41. Experts in resource poor setting like ours must take advantage of this peculiarity to manage cardiovascular health as a whole; particularly as hypertension can be is easily diagnosed.

In addition, about 25% of the study subjects had at least 4 identified cardiovascular disease risk factors. This was considerably more in those on anti-retroviral therapy. Metabolic syndrome using the IDF criteria was found in almost 27% of the subjects, majority of who were on anti-retroviral therapy. Although the exact prevalence is not known in persons infected with HIV, some have estimated it as high as 32%44-49,66,67. The presence of metabolic syndrome is known to increase cardiovascular risk exponentially39,41,64,65 and so should be identified early and managed aggressively in all populations especially the HIV infected persons who already have increased cardiovascular risk burden .

In this study, the subjects had significantly higher mean values of Framingham risk scores (FRS) compared to the controls, the difference was statistically significant. Likewise those on anti-retroviral therapy had higher FRS mean values of compared to those not on therapy with statistically significant difference. Among the subjects on ART, those on protease inhibitor based therapy had higher mean values of FRS compared to those not on protease inhibitor based therapy.

This findings are in keeping with reports mostly from outside Africa by other authors16-21,44-49,52-74. The Data on Adverse Effects of Antiretroviral therapy survey reported similar findings of increased

101 cardiovascular risk in persons on ART especially the PI based one^17,19,35. Reasons suggested for this is that HIV and ART may have an additional influence on traditional CHD risk factors³⁵. However, it is generally agreed that knowing the CHD risk and acting on it is imperative to long term survival in HIV infected persons.