Objective: We investigated the association between metabolic syndrome risk factors and brain tissue integrity, as assessed by magnetic resonance imaging.
Research design and methods: From the Leiden Longevity Study, which is a community-based study of long-lived subjects, their offspring, and partners thereof, 130 subjects (61 men; mean age 66 years) were included. A metabolic syndrome score was computed by summing the individual number of components according to the Adult Treatment Panel III criteria. We performed linear and logistic regression analysis and used standardized β-values to assess the association between metabolic syndrome and brain macrostructure (brain volume and white matter lesion load, lacunar infarcts, and cerebral microbleeds) and microstructure (mean magnetization transfer ratio [MTR], MTR histogram peak height, fractional anisotropy, and mean diffusivity [MD]). Linear and stepwise regression analysis was performed to identify the individual contribution of one metabolic syndrome parameter adjusting for the four other parameters. Models were adjusted for age, sex, and relation to long-lived family.
Results: Brain macrostructure was not associated with metabolic syndrome. In contrast, metabolic syndrome was associated with decreased gray (β = -0.3 P = 0.001) and white matter peak height (β = -0.3, P = 0.002) and increased gray matter MD (β = 0.2, P = 0.01, P = 0.01). Serum HDL cholesterol (β = 0.22, P = 0.012), triglycerides (β =-0.25, P = 0.002), BMI (β =-0.2, P = 0.014), and diastolic blood pressure (β = -0.17, P = 0.047, and β = -0.23, P = 0.009, for gray and white matter, respectively) were independent factors in these changes in brain microstructure.
Conclusions: In early manifest metabolic syndrome, brain tissue decline can be detected. Serum HDL cholesterol, triglycerides, BMI, and diastolic blood pressure were independent factors in brain tissue integrity.