As individuals age, the risk of developing dementia increases, not only in the general population but also among those living with HIV in the United States. A recent study suggests that people aged over 75 with HIV may experience a higher prevalence of dementia compared to the general population, with women being the most affected.
Advancing age is the most significant factor contributing to dementia, where cognitive impairment reaches a level that impacts daily functioning. For instance, the prevalence of Alzheimer's disease and related dementia doubles every five years after the age of 65. Previous research has indicated that risk factors for dementia, such as cardiovascular disease, high blood pressure, diabetes, and social isolation, may be more common in individuals with HIV. Additionally, the population of individuals with HIV over the age of 65 is growing rapidly in the United States. However, there have been limited studies directly comparing the prevalence of dementia between people with and without HIV.
Dr. Xiaoying Yu from the University of Texas Medical Branch conducted a study to delve into this topic, utilizing data from the US Medicare system. The researchers collected information from all 50 states and examined eight groups, which comprised two genders (male and female) and four age groups (65 to 69, 70 to 74, 75 to 79, and over 80 years old). By analyzing specific diagnosis codes, the researchers assessed how the prevalence of dementia changed among these eight groups between 2007 and 2019, comparing individuals with and without HIV. The Medicare dataset included over 87,000 people with HIV and more than two million people without HIV, all of whom had been evaluated for Alzheimer's disease or other types of dementia for at least one year. The overall cohort consisted mostly of females (56%), and there were more men living with HIV than without HIV (66% versus 44%). The group of people with HIV was relatively diverse, with a mean age of 73 years at the start of the study.
After adjusting for demographics and comorbidity, there were minimal differences in dementia prevalence between participants with and without HIV in the younger age groups. For example, the adjusted prevalence for men with or without HIV in the age groups of 65 to 69 and 70 to 74 remained relatively similar, at approximately 4% and 5%, respectively. In the 75 to 79 age group, a small but statistically insignificant gap emerged, with adjusted prevalence of around 8% to 9% for men without HIV and men with HIV, respectively. However, among individuals above 80 years old, a statistically significant gap widened, with adjusted prevalence increasing from 2007 to 2019. The prevalence ranged from about 20% to 25% for men without HIV and about 20% to 30% for men living with HIV.
The increase in adjusted prevalence of dementia among women living with HIV, compared to other women, was even more pronounced in the older age categories. In the first two age groups, there were no statistically significant differences in adjusted prevalence between women with and without HIV, with values ranging from 4% to 5% (65 to 69) and 5% to 7% (70 to 74). However, in the 75 to 79 age group, a statistically significant gap emerged, with approximately 8% of women without HIV being diagnosed with dementia, compared to a range of 10% to 12% among women living with HIV. Above 80 years, the gap in adjusted prevalence of dementia between 2007 and 2019 widened significantly. It ranged from about 25% to 32% in women without HIV and from about 26% to nearly 40%
