Even when several risk factors for heart disease including cholesterol and diabetes are well controlled, people with HIV remain at higher risk of heart attacks, strokes or heart failure than people without HIV, a large study of people receiving medical care in California has found.
The study, published in Clinical Infectious Diseases, also showed that unhealthy levels of alcohol consumption place people with HIV at substantially higher risk of heart disease than people without HIV.
People with HIV have a higher risk of cardiovascular disease, including heart attack, stroke and heart failure than the rest of the population in high-income countries. It’s unclear to what extent modifiable risk factors like smoking, poorly controlled blood sugar, lipids and blood pressure, or alcohol use might affect the risk of heart disease. How much impact would a greater focus on improving management of these risk factors have on heart disease in people with HIV?
To answer this question, Dr Michael Silverberg and colleagues in US medical schools and health systems looked at people receiving care through the Kaiser Permanente Northern California, which provides medical care in San Francisco and northern California.
The study population consisted of all those who attended primary care visits between 2013 and 2017 and provided information on smoking and alcohol use (227,600 people without HIV and 8285 people with HIV matched in the ratio 20:1 to people with HV by age, sex, race or ethnicity and baseline year).
People with HIV had a mean age of 47 years, 91% were male, 55% were White non-Hispanic, 15% Black non-Hispanic and 19% Hispanic. There were few substantive differences between people with HIV and the control group in risk factors for heart disease such as hypertension, dyslipidaemia and diabetes. People with HIV were less likely to be overweight than the control group (59% vs 78%), more likely to have depression (31% vs 12%), alcohol use disorder (10% vs 7%) and to smoke (10% vs 8%). They attended twice as many primary care visits during follow-up (14 vs 7).
In the first stage of their analysis, the researchers calculated a disease management index for each of six markers, based on the extent of control of blood pressure, total and LDL cholesterol, triglycerides and diabetes in people who had been diagnosed with high blood pressure, dyslipidaemia or diabetes. A 100% percent score on the disease management score meant that although the condition had been diagnosed previously, the condition or marker was below the threshold and fully controlled throughout the follow-up period.
Disease Management Index scores for blood pressure and cholesterol were similar for people with HIV and the control group (above 90% for blood pressure and LDL cholesterol, 86% for total cholesterol), after adjustment for demographic factors, depression, weight, smoking, alcohol use and insurance status.
Disease Management Index scores for triglycerides were lower for people with HIV than the rest of the population (79% vs 86%) but HbA1c scores for diabetes control were higher (70% vs 62%), showing that people with HIV were more likely to have well controlled diabetes than the rest of the population.
During the four-year follow-up period, people with HIV had an 18% higher risk of a cardiovascular event (8% vs 6.8% four-year risk). The risks were similar for heart attack and stroke.
In people with 100% control of LDL cholesterol, total cholesterol, triglycerides or diabetes, there was no difference in the risk of a cardiovascular event between people with or without HIV. But people with HIV who had been diagnosed with hypertension and subsequently achieved targets for blood pressure control throughout the follow-up period had a 19% to 24% higher risk, depending on whether blood pressure control was measured by diastolic or systolic pressure.
But HIV did not add to the risk of cardiovascular disease in people with 80% or less control of blood pressure, lipids or blood sugar – except for total cholesterol, where having poorly controlled cholesterol 20% of the time was associated with a 22% higher risk of cardiovascular disease in people with HIV.
Among people with HIV who had never been diagnosed with a condition monitored in this study, the risk of cardiovascular disease remained 19-25% higher than in the control group. An elevated risk of cardiovascular disease in people with HIV compared to the control group was also evident among people who did not drink alcohol (22% higher), in those who reported frequent unhealthy alcohol use (213% higher), in non-smokers (21%) and in people who were not overweight or obese (32%). In other words, when all other risk factors are removed, living with HIV moderately increases the risk of heart disease.
But the additional risk associated with HIV disappeared when people with HIV and people without HIV who had cardiovascular risk factors were compared. The investigators say that this finding suggests that in people with other cardiovascular risk factors, the “HIV-specific risk factors may only have marginal effects”. So, inflammation caused by HIV contributes much less than high blood pressure, high cholesterol or uncontrolled diabetes to the risk of heart disease in people with those risk factors.
But the study did find that HIV exacerbated the impact of one risk factor in particular – unhealthy alcohol use.
Unhealthy alcohol use was reported by 10.5% of people with HIV. The definition was based on heavy drinking days (4-5 US drinks or 8-10 UK units, what UK alcohol guidelines define as binge drinking). People who had between one and four heavy drinking days in the past 90 days had 'infrequent unhealthy alcohol use' while those with more than five heavy drinking days had 'frequent unhealthy alcohol use'.
People with HIV who reported frequent unhealthy alcohol use were twice as likely as people without HIV to experience a heart attack, stroke or heart failure during the follow-up period, after adjusting for smoking and other cardiovascular risk factors.
They study authors note that they are not the first group to observe this increased risk in US cohorts. Studies of both the Veterans Affairs and Multicenter AIDS Cohorts have also reported an increased risk of heart disease in people with HIV with unhealthy alcohol use.
“These findings suggest that alcohol use may be particularly harmful for people with HIV,” the study authors conclude. However, the study also found that people with HIV who were moderate drinkers or infrequent unhealthy drinkers did not have a raised risk of heart disease, suggesting that the focus of advice and intervention should be people with HIV who regularly drink more than guidelines indicate is healthy.
Silverberg MJ et al. Cardiovascular disease risk factor control in people with and without human immunodeficiency virus. Clinical Infectious Diseases, published online 18 January 2024.