Association strong between MCI, related comorbidities, but decreases with age

Key takeaways:

• Researchers analyzed data from more than 20,000 individuals aged 50 years and older.
• Depression, stroke/TIA and hearing loss were significant predictors of mild cognitive impairment for all age groups.

For early detection of Alzheimer’s disease in older adults, comorbidities remained strongly associated with mild cognitive impairment, but prediction decreased with age, according to a poster presentation at CTAD.

“Early identification of Alzheimer’s disease is crucial for increasing the likelihood of effective treatment outcomes,” Gang Li, PhD, senior director at Eisai Inc., a health care company based in New Jersey, and colleagues wrote. “Recently approved treatments, such as amyloid targeting drug lecanemab, are labeled for use in the mild cognitive impairment or mild dementia stage of [Alzheimer’s disease].”

Li and colleagues sought to investigate associations of mild cognitive impairment with other known comorbidities found with AD and related dementias (ADRD).

Their non-interventional retrospective cohort study collected data from the IBM MarketScan (Merative) Commercial and Medicare Supplemental Databases between January 2014 and December 2019 to include more than 20,000 individuals (those with MCI, n = 5,185; those without MCI, n = 15,555) For those with MCI, index date was that of the initial claim with valid diagnosis.

Individuals in the MCI cohort were aged 50 years or older with 2 or more years of pre-index continuous insurance enrollment at baseline and no pre-index diagnoses of either MCI or dementia, and enrollment for at least 1 year post-index. Those in the non-MCI cohort who had no prior diagnosis of either MCI or dementia were propensity score matched by age, sex, geographic region and first year in database 3:1 to those in the MCI group and assigned the index date of their matched counterpart.

Primary outcomes for the study were identifying 25 medical conditions associated with risk for AD via literature review, including cardiovascular, thyroid and metabolic diseases, and central nervous system/psychiatric disorders. Researchers employed logistic regression to identify associations between three MCI and ADRD comorbidities — depression, stroke/transient ischemic attack (TIA), hearing loss — while predictive potential of those comorbidities to discriminate the MCI group from the non-MIC group was evaluated via Bayesian logistic lasso regression. Whole sample analyses were conducted by age group: 50 to 64 years, 65 to 79 years and 80 years and older. The researchers reported that all 25 medical conditions registered significantly (P < 0.05) higher frequencies in the MCI cohort compared with the non-MCI cohort and considered MCI risk factors.

Conversely, researchers found associations between MCI and each of the three main comorbidities weakened with increasing age, with the highest odds ratio and sharpest drop among age groups in stroke/TIA (OR = 6.4, 95% CI: 5.4-7.5 in age group 50 years to 64 years; OR = 2.1, 95% CI: 1.8-2.5 in age group 80 years and older).

Depression, stroke/TIA and hearing loss remained significant predictors of MCI across all age groups in the BLLR.

“The presence of these comorbidities and other routinely collected health care information can help primary care physicians triage individuals, especially in younger age groups, by elevated risk for MCI, thereby making efficient use of time and resources,” Li and colleagues wrote.