Medial temporal lobe is vulnerable to vascular risk factors in men: a population-based study.

BACKGROUND AND
PURPOSE: Vascular risk factors (VRFs) are known to cause cerebral microvascular disease, but evidence supporting an effect of VRFs on regional brain atrophy is mixed. We investigate whether an aggregation of VRFs is associated with volume of hippocampus and entorhinal cortex in elderly people living in the community.
METHODS: This cross-sectional study consists of 523 participants (age ≥60 years, 59.3% women) of the SNAC-K Study in central Stockholm, Sweden, who were free of clinical stroke and cognitive impairment. We collected data on VRFs through interviews, clinical examination and inpatient register system. Hippocampal and entorhinal cortex volume was manually measured on magnetic resonance images. Data were analysed with general linear regression models controlling for demographics and total intracranial volume.
RESULTS: In men, high total cholesterol and diabetes were significantly or marginally associated with smaller hippocampus and entorhinal cortex; when current smoking, binge alcohol drinking, high cholesterol and diabetes were aggregated, an increasing number of VRFs were significantly associated with decreasing volume of hippocampus and entorhinal cortex (P for linear trend <0.01). In women, none of individual VRFs or their aggregation was significantly associated with the volume of these brain regions, except former smoking that was significantly associated with a larger volume of these regions.
CONCLUSIONS: Aggregation of VRFs is associated with reduced hippocampal and entorhinal cortex volume in apparently healthy elderly men, but not in women. This implies that in men, the medial temporal lobe is vulnerable to cardiovascular risk factors.