Does vascular burden contribute to the progression of mild cognitive impairment to dementia?

Aims: To investigate the contribution of vascular risk factors (VRFs), vascular diseases (VDs) and white matter lesions (WMLs) to the progression of mild cognitive impairment (MCI) to dementia and Alzheimer's disease (AD). Methods: Two hundred forty-five consecutive subjects with MCI (age 74.09 ± 6.92 years) were followed for an average of 2.4 years. The Hachinski Ischemic Score and the Framingham Stroke Risk Profile were used to summarize VRFs and VDs. WMLs were graded using the Age-Related White Matter Changes Scale. Results: One hundred twenty-nine (52.6%) out of 245 subjects at risk converted to dementia, including 87 cases of AD. When hypertension occurred in MCI with deep WMLs, a 1.8-fold increased risk of dementia was observed (95% CI = 1.0-3.4). When deep WMLs occurred in MCI with high scores (≥4) on the Hachinski scale, a 3.5-fold (95% CI = 1.6-7.4) and 3.8-fold (95% CI = 1.2-11.5) risk of progression to dementia and AD was observed, respectively. Analogously, the joint effect of WMLs and high scores (≥14) on the Framingham scale nearly doubled the risk of dementia (hazard ratio = 1.9, 95% CI = 1.1-3.3). Conclusions: Accelerated progression of MCI to dementia and AD is to be expected when VRFs and VDs occur together with WMLs.