Prevalence and determinants of subclinical brain infarction

Abstract

Objective-Risk factors for subclinical brain infarcts (SBI) have not been well studied, especially in Hispanics and blacks who may be at higher risk for vascular disease. We examined the prevalence and determinants of SBI in a multi-ethnic community cohort. Methods-TheNorthern Manhattan Study (NOMAS) includes 892 stroke-free participants who underwent brain magnetic resonance imaging (MRI). Baseline demographic and vascular risk factor data were collected. The presence of SBI was determined from the size, location, and imaging characteristics of the lesion based on FLAIR, T1 and T2, and proton density MRI sequences. We calculated the prevalence of SBI and cross-sectional associations with socio-demographic and vascular risk factors, using logistic regression to adjust for relevant covariates.Results-Among 892 subjects (mean age 71.3 years), 158 (17.7%) had SBI (13.5% had 1 lesion, 4.3% had > 1 lesion). Of the total 216 infarcts, most were small (< 1 cm, 82.4%) and subcortical (82.9). SBI prevalence increased with age (< 65: 9.7%; 65-75: 16.4%; > 75: 26.1%), was increased among men (21.3% vs. 15.2% in women) and blacks (24.0% vs. 18.1% in whites and 15.8% in Hispanics). The presence of SBI was independently associated with older age (per year: OR 1.06, 95% CI 1.04-1.09), male sex (OR 1.79, 95% CI 1.22-2.61), and hypertension (OR 2.08, 95% CI 1.35-3.22) adjusting for age, sex, race-ethnicity, and vascular risk factors. A significant interaction (P = 0.002) between race and age was observed such that younger blacks had greater odds of having SBI.Conclusions-SBI were detected in nearly 18% of subjects in a multi-ethnic community-based cohort. Age, male sex, and hypertension were independently associated with SBI. Subclinical cerebral infarcts are more prevalent than symptomatic infarcts and may increase the true public health burden of stroke.

Quality of life declines after first ischemic stroke

“…32 In the Northern Manhattan population, 18% of 892 participants free of clinical stroke had subclinical infarcts. 33 Silent infarcts have been associated with cognitive function, 34 and cerebral leukoaraiosis with QOL in previous studies. 35 Accumulation of additional subclinical infarcts and leukoariosis over time may therefore account for the decline in QOL over time after stroke, and this effect may be most prominent in those with limited access to health care resources.…”

Ideal Cardiovascular Health and Biomarkers of Subclinical Brain Aging: The Northern Manhattan Study

“…Methods to identify and classify MRI‐defined infarcts have been described in detail 21. Two independent raters used a superimposed image of the subtraction, proton density, and T2‐weighted images at 3× magnified view for interpretation of lesion characteristics.…”

Sex differences in the risk profile and male predominance in silent brain infarction in community-dwelling elderly subjects: the Sefuri brain MRI study

“…We found a male predominance of SBI (15.0% in men vs. 8.9% in women), which was similar to the North Manhattan Study (21.3% in men vs. 15.2% in women). 7 However, male sex was not significantly associated with SBI after adjustment for other vascular risk factors. In other words, higher prevalence of risk factors such as alcohol and smoking in men produced male predominance of SBI in this study.…”

“…However, the male predominance of silent brain infarction (SBI) was inconsistent in the earlier studies. [7][8][9][10][11] With regard to SBI, the North Manhattan Study found that male sex was independently associated with SBI on a multivariable logistic regression model. 7 Although the Rotterdam Scan Study reported a higher prevalence of SBI among women than men, the sex difference was no longer statistically significant when adjusted for other risk factors.…”

“…[7][8][9][10][11] With regard to SBI, the North Manhattan Study found that male sex was independently associated with SBI on a multivariable logistic regression model. 7 Although the Rotterdam Scan Study reported a higher prevalence of SBI among women than men, the sex difference was no longer statistically significant when adjusted for other risk factors. 8 In a population-based consecutive autopsy series of residents (the Hisayama Study), SBI tended to be more frequent (non-significant on multivariate analysis) in female among 713 subjects without clinical stroke: 16.2% of 390 men and 19.2% of 323 women with a mean age at death of 78.3 years.…”