Twelve-year nationwide cohort study identifying risk factors for conversion from mild cognitive impairment to Alzheimer’s disease

Mild cognitive impairment (MCI) is a pre-dementia stage that precedes dementia of the Alzheimer’s type (DAT). Although many studies have explored factors affecting the progression from MCI to DAT, their results remain inconsistent. A study examined the incidence of conversion from MCI to DAT and the risk factors that contribute to DAT conversion in Korean patients with MCI.
A 12-year nationwide retrospective study was carried out. Researchers enrolled patients aged 40 years or older with MCI between 2009 and 2015 and followed them until 2020. The incidence of DAT conversion, based on age at MCI diagnosis and its risk factors, was analysed.
The conversion rate of DAT in patients with MCI increased between the ages of 70 and 90 years, then levelled off near age 100 years. Being underweight (hazard ratio [HR] 1.279, 95% confidence interval [CI] 1.223–1.338) was linked to a higher risk of DAT conversion. Cardiometabolic diseases (diabetes, HR 1.373, 95% CI 1.342–1.406; coronary heart disease, HR 1.047, 95% CI 1.015–1.079; and haemorrhagic stroke, HR 1.342, 95% CI 1.296–1.390) increased the risk of DAT conversion, while hypertension, ischaemic stroke, and dyslipidaemia did not. Depression (HR 1.736, 95% CI 1.700–1.773) and physical inactivity (HR 1.193, 95% CI 1.161–1.227) were associated with increased risk. Mild (hr 0.860, 95% CI 0.830- 0.891) to moderate (hr 0.880, 95% CI 0.837- 0.926) alcohol consumption, higher income (hr 0.947, 95% CI 0.925- 0.970), and urban residence (hr 0.889, 95% CI 0.872- 0.907) were linked to a reduced risk of DAT conversion.
Several modifiable risk factors were strongly linked to a higher likelihood of DAT conversion. Our findings may assist in developing preventative strategies to reduce the risk of DAT conversion in patients with MCI.
Source: Baik, K., Kang, M., Park, Y.J., et al. (2025). Twelve-year nationwide cohort study identifying risk factors for conversion from mild cognitive impairment to Alzheimer's disease. Science Reports, 15(1):35418.