Hearing-impaired adults may ACHIEVE cognitive benefit from hearing aids

Findings from the ACHIEVE* study suggest that older adults who are at increased risk for cognitive decline and dementia and who have hearing loss may benefit the most from hearing intervention within 3 years.

“Hearing loss intervention could reduce the cognitive load of processing degraded sound, provide increased brain stimulation, and improve social engagement,” said coprimary investigator Dr Frank Lin from Johns Hopkins University, Baltimore, Maryland, US, at AAIC 2023. “This [implies] that hearing loss is a potentially modifiable risk factor for cognitive decline and dementia.”

“In our study, the hearing intervention had a significant effect on reducing cognitive change within 3 years in older adults who are at increased risk for cognitive decline,” he continued.

The researchers recruited 977 adults (mean age 76.8 years, 53 percent female) who had untreated hearing loss and intact cognition from the ARIC** study (n=238) and a group of healthy de novo volunteers (n=739). They were randomized 1:1 to a hearing intervention (HI) or health education (control). In the HI group, audiologic counselling and hearing aids were provided, while the control intervention involved sessions with a health educator to cover healthy ageing topics. [AAIC 2023, abstract 83084]

In the primary analysis combining the ARIC and de novo groups, 3-year cognitive change (global cognition) was not significantly different between HI and control (difference in SD units, 0.002; p=0.96). On prespecified analyses however, the difference between the ARIC and de novo groups became significant (p_interaction=0.01).

In the ARIC group, HI was associated with a 48-percent reduction in global cognition vs control (difference, 0.191; p=0.027). “This effect was carried across the three different cognitive domains [ie, executive function, language, and memory] and all trended towards favouring HI,” said Lin. Conversely, the difference was not significant in the de novo group (–0.061; p=0.18).

These strong differences may have been driven by the differences between the control groups of each cohort, Lin pointed out. “Looking at the ARIC control, they declined by nearly half (–0.402) a standard deviation (SD) over 3 years. In the de novo group, they declined by 0.15 SD. Hence, there was almost a threefold faster rate of cognitive decline over 3 years in the ARIC vs de novo group.”

This aligns with the fact that ARIC patients were more at risk for cognitive decline and had lower baseline cognitive scores than de novo patients. “This represents a true random sample as opposed to the de novo group. You cannot slow something that is already going really slow. In ARIC, there was a much steeper rate of cognitive decline over 3 years. You can slow something down that is steeply declining,” he continued.

Self-reported outcomes

At baseline, there were similar proportions of participants in the HI and control groups with self-perceived communicative impairment (HHIE-S*** ≥10; 68 percent vs 69 percent) but over time, this dropped significantly across all timepoints (p<0.001 for 6 months and at 1, 2, and 3 years). The corresponding percentages at year 3 were 34 percent vs 74 percent.

Satisfaction rates were higher with HI vs control. Nearly half of HI recipients reported that their lives had been ‘very much better’ after 3 years, and about 74 percent shared that the hearing aids were ‘very much worth it’.

An important public health target

“Hearing loss is very treatable in later life, which makes it an important public health target to reduce risk of cognitive decline and dementia, along with other dementia risk factors such as less education in early life, high blood pressure, social isolation and physical inactivity,” Lin said.

“Until we know more, we recommend for general health and well-being that older adults have their hearing checked regularly and any hearing issues properly addressed,” he added.