In fifteen years' time, the clinical needs of Dutch people living with HIV will have changed substantially due to three quarters of them being over the age of 50. Overall, 84% will have at least one medical condition such as cardiovascular disease or cancer on top of their HIV, 28% will have three or more additional medical conditions and 53% will have problems with drug interactions or contraindications.
The predictions come from the most detailed analysis of likely future trends in HIV care for an ageing population of people living with HIV yet conducted, prepared by Mikaela Smit and colleagues at Imperial College London and published online last week in The Lancet Infectious Diseases. The findings are likely to be relevant to other Western countries with mature epidemics concentrated in gay men, the authors say.
Due to effective antiretroviral treatment, the life spans of people with HIV are ever longer. Previous researchers have estimated the increasing proportion of patients in their fifties or sixties and they have shown that older adults tend to have better adherence and are more likely to have an undetectable viral load than younger people.
But researchers have not calculated how patients’ increasing ages will impact the prevalence of medical conditions that are commonly experienced in older age. Managing these co-morbidities is likely to substantially complicate the delivery of HIV clinical care.
Mathematical model based on the Netherlands
Detailed data on all adults living with HIV in the Netherlands are collected in the ATHENA cohort. The researchers examined information on the age of people living with HIV, new infections, new diagnoses, deaths, use of HIV treatment, experience of co-morbidities (additional medical conditions) and medication to manage those co-morbidities.
Based on the real-life data collected up to 2010, they developed an individual-based mathematical model which makes future projections up to 2030.
The model took account of the causal pathways between diabetes, kidney disease, high blood pressure, high cholesterol, heart attacks and strokes. The model also examined trends in osteoporosis and cancers (excluding AIDS-defining cancers).
Other problems were not included due to a lack of reliable data. Of note, this includes depression, cognitive impairment, fractures and incontinence.
Data on 10,278 people living with HIV in the Netherlands were included. Of note, 1005 women who had been pregnant were excluded from the analysis, due to the way medications used during pregnancy would skew the predictions concerning drug-drug interactions.
In the examined cohort, 59% are men who have sex with men, 16% are women and 66% were born in Europe.
Changes from 2010 to 2030
The proportion of HIV-positive people over the age of 50 will jump from 28% in 2010 to 73% in 2030, with those over 60 rising from 8% to 39%. In 2030, the average age of a person with HIV will be 56 years.
Most will need medical care for a condition on top of their HIV. The proportion with at least one co-morbidity will increase from 29% to 84%. The proportion with three or more co-morbidities will go from close to zero in 2010 to 28% in 2030.
Much of this will be driven by various forms of cardiovascular disease (high blood pressure, high cholesterol, heart attacks and strokes), with 78% having at least one of these problems by 2030. In addition, 17% will have diabetes and 17% will have a cancer.
The prevalence of co-morbidities will be somewhat higher than in HIV-negative people of the same age, reflecting the contributions of HIV itself and some anti-HIV drugs to the development of these medical conditions.
Due to the co-morbidities, 54% will need to take at least one other long-term drug alongside their HIV treatment and 20% will be prescribed three or more extra drugs.
The model further predicts that this could cause an increase in complications with HIV treatment – 53% risk drug-drug interactions with currently recommended first-line regimens or will be advised to choose an alternative drug due to a co-morbidity. For example, tenofovir is not recommended for people with chronic kidney disease, while abacavir is contraindicated for people with severe cardiovascular disease.
The researchers assumed that a number of demographic and clinical factors would remain constant in the future. However, if people’s lifestyles (diet, smoking, etc.) substantially improved, if clinicians screened and treated people for co-morbidities earlier, or if better antiretrovirals with fewer contraindications were developed, then the results would be somewhat different.
The successes of HIV medicine – improved life span and quality of life – may be offset by an increased burden of age-related diseases, prescription of multiple medicines and a growing proportion of patients who have complications with their HIV treatment, the authors say. This will put new demands on health services.
“Care management for HIV-infected individuals will increasingly need to draw on a wide range of medical disciplines, including geriatric medicine, cardiology, and oncology. Evidence-based changes to screening and monitoring protocols for NCDs [non-communicable diseases] in HIV-infected patients will be important to ensure continued high-quality care,” they write.
Whereas randomised trials have frequently excluded people with co-morbidities from studies, research is needed on drug interactions, side-effects and adherence, when HIV treatment is taken alongside other medications.
New drugs may be needed. “Antiretroviral drugs with no drug-drug interactions with co-medications for the NCDs that will increase in prevalence during the next 20 years, including drugs for osteoporosis, cardiovascular diseases, and diabetes, will be particularly important,” the researchers say.
While their model is based on the Dutch epidemic, they believe that the overall patterns will be repeated in other countries in Europe, North America and Australasia.
Smit M et al. Future challenges for clinical care of an ageing population infected with HIV: a modelling study. The Lancet Infectious Diseases, 2015. (Abstract.)