Silent lacunar infarction and incident cognitive impairment in older adults: a five-year ambispective cohort study

Silent lacunar infarction (SLI) is common in older adults but is often overlooked in clinical practice because patients lack focal neurological deficits. However, its long‑term impact on cognitive function remains unclear. This ambispective cohort study aimed to determine the impact of SLI on incident cognitive impairment and identify associated risk factors. We retrospectively enrolled 215 inpatients and outpatients who underwent brain magnetic resonance imaging (MRI) at the Department of Neurology, Shihezi People’s Hospital, from January to December 2016. Based on MRI findings, 105 patients with SLI were assigned to the exposure group, whereas 110 patients without lacunar infarction constituted the control group. Participants had no cognitive impairment at baseline and were followed for 5‑year. We collected clinical data, laboratory indices, and scores from the Chinese version of the Mini-Mental State Examination (CMMSE). Cognitive impairment was defined as a CMMSE score < 27. Cox proportional hazards models were used to determine independent predictors of cognitive impairment. Of the 215 enrolled participants, 186 completed the 5-year follow-up, of whom 57 (30.6%) developed cognitive impairment. In multivariable Cox proportional hazards analysis, SLI was associated with a substantially increased risk of incident cognitive impairment (HR 4.18, 95% CI 2.20–7.93). Smoking, Alcohol consumption, hypertension, higher Hcy levels, and white matter lesions were also associated with increased risk. Among participants who developed cognitive impairment, those with SLI had lower CMMSE scores for attention and calculation, than those without SLI ( p < 0.001); No significant between-group differences were observed in orientation, memory, delayed recall, or language scores (all p > 0.05). SLI was associated with an increased risk of incident cognitive impairment in older adults. Smoking, alcohol consumption, hypertension, higher Hcy levels, and white matter lesions were also associated with an increased risk of cognitive impairment. Among participants who developed cognitive impairment, those with SLI showed poorer performance in attention and calculation. Early identification of SLI and management of modifiable vascular and lifestyle risk factors may help reduce or delay cognitive decline in this vulnerable population.