For a study, researchers sought to determine if men and women have distinct relationships between vascular risk factors (VRF) and brain MRI measurements of brain aging and cerebral small vessel disease. The tendency of men and women to acquire stroke differs, and it was represented in gender-specific versions of the widely used Framingham Stroke Risk Prediction (FSRP) index, which offered an estimate of the 10-year risk of incident clinical stroke. However, in the data, no sex-specific relationships between the individual risk factor components of FSRP and subclinical vascular brain damage had previously been investigated.
In 1,579 stroke- and dementia-free Framingham Offspring who attended their 8th quadrennial examination (53% F; age 669 years), they linked levels of blood pressure, diabetes, current smoking, and prevalent non-stroke cardiovascular disease (CVD) to brain MRI measures of total cerebral brain, hippocampal and white matter hyperintensity volumes (TCBV, HPV, WMHV), and covert brain infarcts (CBI). In addition, they looked at age-adjusted, sex-stratified linear or logistic regression models for all VRF with a P<0.1 sex interaction.
Higher blood pressure (measured as systolic blood pressure (SBP) or JNC7-defined Stage 1 HTN (≥140/90 mm Hg or use of antihypertensive medication) had a more significant negative impact on WMHV in women than in men (SBP:β±SE: 0.009±0.002, P<0.001 versus 0.004±0.002, P<0.031; HTN:β 0.176±0.066, P=0.008 versus non-significant association, in women and men respectively). Furthermore, in males, both Stage 1 HTN and diabetes showed higher negative impacts on TCBV (β-0.309±0.141, P<0.029 and -0.853±0.177, P<0.001, respectively, compared to non-significant relationships in women).
Current levels of VRF at the time of examination were associated with a greater burden of vascular brain injury in women than in men of the same age in the cohort of young-old participants, where the majority of women were postmenopausal, whereas current VRF levels appeared to have a greater global impact on brain volumes in men. The findings showed that the increased risk of dementia seen in older women relative to men may be mostly due to modifiable vascular risk factors. More aggressively treating them in women might help close the gender gap.