Delirium may be a red flag for dementia in older people

In hospitalized older adults with acute illness, the incidence of delirium carries a twofold greater odds of developing dementia postdischarge, a retrospective study has found.

Researchers reviewed the medical records of 309 acutely ill elderly patients (mean age, 78 years; 60 percent female). None of the patients showed cognitive decline on admission.

Delirium was detected in 66 patients (21 percent). These patients were more likely to be totally dependent for activities of daily living (44 percent vs 14 percent; p<0.001), malnourished (36 percent vs 24 percent; p<0.001), have higher levels of C-reactive protein (78 vs 51 g/dL; p=0.005) and lower levels of serum albumin on admission (3.04 vs 3.35 mg/dL; p=0.001).

After a median follow-up of 24 months, 21 patients (32 percent) who had experienced delirium developed dementia, while only 38 patients (16 percent) of those without delirium had the same outcome (p=0.003).

Multivariate competing-risk proportional-hazard models showed delirium to be independently associated with postdischarge dementia, yielding a subhazard ratio of 1.94 (95 percent CI, 1.10–3.44; p=0.022).

The findings suggest that delirium is as an independent and potentially preventable risk factor for cognitive decline, highlighting the importance of systematic initiatives to fight the syndrome, according to the researchers. Additional studies on the possible biomarkers and neuropathologic substrata of the delirium-to-dementia pathway, as well as clinical trials exploring whether delirium prevention effectively reduces incident dementia, are needed.