By Felicia Bamgbose 23l
A study analyzing peripheral neuropathy in people living with HIV has found links to both new and known variables, including advanced age, longer duration of HIV infection, exposure to neurotoxic antiretroviral drugs, and other chronic conditions. Dr. Wei Tu's research team at the University of Alberta discovered that the factors associated with peripheral neuropathy in those diagnosed with HIV more than 15 years ago differed from those diagnosed less than 15 years ago.
Peripheral neuropathy is a common condition associated with HIV, affecting 21% of those in this study, a rate similar to that found in other studies worldwide. Peripheral neuropathy refers to nerve damage, primarily in the feet or hands, but it can also affect the legs and arms. Symptoms can range from mild tingling and numbness to severe pain and difficulty walking. Multiple types of damage can occur, making it difficult to pinpoint the specific causes of peripheral neuropathy. However, the resulting chronic pain and disability can significantly impair a person's quality of life and ability to function, making peripheral neuropathy a major concern.
This study, published in AIDS , allowed for a better understanding of the variables associated with different types of peripheral neuropathy. Understanding these variables could lead to improved ways of diagnosing, preventing, and treating peripheral neuropathy in people living with HIV.
People living with HIV at the Southern Alberta Clinic in Canada were regularly screened for neurological disorders during their routine clinical appointments. A total of 519 participants were enrolled between 2013 and 2019. The participants' demographic and clinical data were then analyzed using univariate and multivariate methods and compared using machine learning analysis.
Overall, 111 (21%) had some type of peripheral neuropathy, which was divided into two groups: those with damage to multiple nerves affecting their sensation (17%) and those with damage to specific individual nerves (4%). Damage to multiple nerves included those with more generalized burning or stabbing pain, loss of sensation, and weakness. Specific nerves were identified by those with symptoms consistent with conditions such as carpal tunnel syndrome, which affects a nerve in the hand.
Univariate analysis indicated that peripheral neuropathy was associated with 28 different variables, including age, diabetes, substance misuse, and exposure to antiretroviral therapy that could damage nerves. The antiretrovirals known to cause peripheral neuropathy were the “d drugs” didanosine (ddI), zalcitabine (ddC), and stavudine (d4T), which are no longer in use. However, prior use affected the likelihood of peripheral neuropathy in this study, despite not being evident in some earlier studies. Links were also found with higher peak viral loads, lower CD4 counts, and less sleep.
For people living with HIV for more than 15 years, the associations included diabetes, syphilis, cardiovascular disease, increased viral load, and use of nerve-damaging antiretroviral drugs. A longer duration of HIV infection increased the likelihood of peripheral neuropathy regardless of the analysis model used. There was a higher prevalence of nerve damage (40%) in people living with HIV for more than 15 years compared to those living with HIV for less than 15 years (11%). The analysis showed that the risk factors associated with peripheral neuropathy differed for those diagnosed more than 15 years ago compared to those diagnosed more recently.
For those diagnosed less than fifteen years prior, associated variables included worse self-assessment scores on mental health questionnaires, cigarette smoking, fewer hours of sleep, and lower levels of education. Medications such as vincristine (used in chemotherapy) and nitroglycerin (often used for cardiovascular diseases) were also linked to peripheral neuropathy in this group.
Neuropathic pain, the use of more than five medications (excluding antiretrovirals), and exposure to a drug used to treat neuropathic pain (pregabalin) were associated with peripheral neuropathy regardless of the time since HIV diagnosis.
While peripheral neuropathy can affect anyone and is linked to many conditions, it is a common condition for people living with HIV and contributes to significant disability and pain. Researchers noted that "a deeper understanding of both the pathogenesis and the clinical factors that define peripheral neuropathy is required to address this problem."
References
Wei T et al. Predictive variables of peripheral neuropathy in treated HIV-1 infection revealed by machine learning. AIDS.