Sub studies

Magnetic Resonance imaging (MRI) of cerebral small vessel disease (CSVD)

It is known that cerebral small vessel disease (CSVD) is associated with circulating inflammatory mediators. Given that PLWH are known to have a higher risk of stroke that HIV-negative people, we wished to know whether there was an association between HIV and CSVD.

NRTI exposure, age and toxicity

The pharmacokinetics of drugs change with age. Whilst tenofovir has been shown to cause toxicity more frequently in older PLWH, data on other NRTI drugs and the potential for them to cause renal toxicity in older PLWH is lacking.  Furthermore, the clinical consequences of available findings relating to tenofovir are unclear and there are no recommendations on individual dose adjustment in the ageing populatio

Hepatic steatosis in HIV-infected patients older than 50 years of age: a sub-study of the POPPY cohort

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the general population. Whilst the prevalence of NAFLD in PLWH has been reported to be 48%, little is known about the effect of aging on the evolution of liver on this.

POPPY Muscle biopsy study

Although most people living with HIV can now expect a good life expectancy, it has been suggested that the ageing process may be accelerated.As people age, mitochondria generally become damaged - mitochondria are important in muscle, and it is known that maintenance of muscle strength is important in healthy ageing. This study will assess whether PLWH experience greater damage to their mitochondria than would be expected in normal ageing.

Measurement of retinal vessels as a biomarker of cerebrovascular ageing in older HIV positive men compared to controls

Understanding the impact of cerebrovascular disease in people with HIV is critical. However, there are few studies of cerebrovascular disease in HIV. This study compared the diameter of retinal vessels, a known biomarker of cardio- and cerebrovascular disease, in the three POPPY sub-cohorts.

POPPY Sleep: Sleep, Aging and HIV Infection Cohort Study

Objective data on sleep in people with HIV are lacking.  Therefore, this POPPY sub-study aims to characterise sleep patterns in older and younger individuals living with HIV.

COBRA: Co-morbidity in relation to HIV and AIDS

The COBRA Study is a collaboration between the investigators of the POPPY study and the AGEhiV study in the Netherlands, which provides a detailed investigation of age-associated comorbidities in people with HIV.

POPPY research themes

While pain has been identified as a prevalent and burdensome problem in PLWH, little research into it exists in the modern ART era – most of our knowledge about pain in HIV derives from an era when individuals were receiving ART drugs that are no longer currently in use.  We know very little about how prevalent pain is among individuals receiving modern ART regimens, now what the causes of pain are likely to be in this group.  Without this information, it is difficult to make recommendations for how to manage pain in this population.  

Several other studies have reported rates of frailty to be increased in people living with HIV. This may be related to the multi-morbidity, or high rates of medical problems, reported to be present in older people living with HIV.  We are determining the prevalence of frailty, using several different definitions, among participants in the POPPY study.

We have a substantial dataset on the healthcare resources used by POPPY participants which is currently being analysed. This unique dataset will allow us to investigate the types of healthcare resources that are used by individuals with various clinical conditions and to assess whether HIV infection has an impact on healthcare resource use.

We currently know very little about the impact of HIV on the health of older women living with HIV.  It has been speculated that the menopause may occur at an earlier age in women living with HIV, but the evidence to support this hypothesis is weak. We are therefore investigating the timing and impact of the menopause on several outcomes among women in the POPPY study.

It is known that several lifestyle factors, including tobacco, alcohol and recreational drug use, are common in PLWH.  Previous analyses of the general population have demonstrated a strong association between these lifestyle factors and condomless sex in young people.  Higher risk sexual activity has also been reported in men who have sex with men living with HIV.  However, it is not known if or how these factors cluster together within older PLWH.

Drug concentrations may be affected by aging and this is clinically relevant for life-long treatment like antiretroviral therapy.  One of the major objectives of POPPY is to evaluate associations between antiretroviral drug concentrations and age, and to assess the potential impact of age on drug efficacy, drug-drug interactions and co-morbidities. 

Several studies have reported that PLWH are more likely to experience fractures than similarly aged people without HIV.  It has been proposed that some ART drugs. as well as HIV infection, may contribute by leading to a loss of bone density.  We also know that as people age their bones start to lose strength and that there are other factors (e.g. some recreational drugs, hepatitis C virus coinfection, smoking etc.) which may also contribute to weakened bones.  Thus, the increased fracture rate that has been seen in other studies may simply be a reflection of these factors.

Completed core Poppy sub-studies

Concentration difficulties have been widely reported by many research teams, in otherwise well treated persons living with HIV. However actual rates of cognitive impairment, or mild dementia, in people living with HIV are difficult to determine due to differences in definitions used and differences in the characteristics of the people living with HIV in different parts of the world.