CHICAGO – The first comprehensive analysis of dementia prevalence among sexual minorities has found a rate of 8% in this population.

While only marginally lower than the 9% prevalence among a heterosexual comparator group, the disorder manifested at an earlier age and occurred more often among men, Jason Flatt, PhD, said at the Alzheimer’s Association International Conference. In addition, higher education didn’t exert the protective influence seen in general populations, said Dr. Flatt of the University of California, San Francisco.

The analysis of a large California health care database is the first step in learning more about dementia in this diverse population, he said. It’s an important quest because the age-risk curve is rising just as quickly among the LGB population as it is in the heterosexual population.

“We do know there are 2-3 million people who identify as LGB [lesbian, gay, or bisexual] in the U.S., and are 60 years old or older, and with the continued aging of our entire population, we expect this number to increase to about 6 million by 2040,” he said. “Given the gaps in collection of sexual orientation and gender identification, we haven’t been able to look at this issue before.”

Sexual minorities face unique dementia risks, Dr. Flatt noted. They are less likely to marry and have children than are heterosexuals, and twice as likely to live alone. “The often have little or no caregiver support, and are likely to have experienced stigma, discrimination, trauma, and high lifelong stress.”

These experiences make the LGB population less likely to seek out medical care, he said. “All of these things impact health over the life course.”

Dr. Flatt and his colleagues drew their data from the Kaiser Permanente Research Program on Genes, Environment, and Health. The study examined dementia prevalence and comorbidities among 4,337 LGB subjects aged 60 years or older, compared with 195,264 age-matched heterosexual subjects. Dementia diagnoses occurred from 1996 to 2015, and the mean follow-up time was 9 years. A quarter of the sample identified as lesbian, 37% identified as gay men, and 38% as bisexual; among these, 48% were women. Depression was more common among the LGB group (35% vs. 28%), as was posttraumatic stress disorder (1.9% vs. 1%). Both are well documented risk factors for dementia.

However, there were no significant difference in other risk factors, including hypertension, stroke, and heart disease, Dr. Flatt noted. He and his associates did not examine midlife obesity, physical inactivity, or low educational attainment, but will do so in a future analysis.

A dementia diagnosis occurred among 343 (8%) of the LGB group and 18,060 (9.2%) of the heterosexual group. The disorder manifested earlier in the LGB group (average 69 vs. 71 years). Self-identified men were overrepresented in the sample (63% vs. 44%) – a key difference, since women are generally found to have a significantly increased risk compared with men. However, Dr. Flatt noted, the study didn’t collect information that would show biological sex, so that number could be skewed.

Higher education didn’t seem to be as protective in the LGB population, with 62% having a college education, compared with 40% of the heterosexual sample.

In a regression analysis that adjusted for age and education, Dr. Flatt reported that depression almost tripled the risk of dementia among sexual minorities (odds ratio, 2.7). Depression was also a significant dementia risk factor for heterosexual subjects (OR, 2.5).

These initial findings highlight the need for more research into this population, he said.

“We need to provide more LGB-affirming health care services, and this means training health care providers to meet these needs.” This might include improved community outreach that could result in earlier detection and treatment, as well as training medical staff to provide more culturally sensitive care.

msullivan@mdedge.com

SOURCE: Flatt J et al. AAIC 2018, Abstract P1-619.

Dementia epidemiology in LGB community examined for first time