High-Normal Adolescent Fasting Plasma Glucose Is Associated With Poorer Midlife Brain Health: Bogalusa Heart Study

It is unclear how adolescent glycemic status relates to brain health in adulthood.

To assess the association between adolescent fasting plasma glucose (FPG) and MRI-based brain measures in midlife.

Between 1973 and 1992, the Bogalusa Heart Study (BHS) collected FPG from children, 3 to 18 years old, and followed up between 1992 and 2018. Cognitive tests and brain MRI were collected in 2013 to 2016 and 2018.

Observational longitudinal cohort study.

Of 1298 contacted BHS participants, 74 completed screening, and 50 completed MRI.

Mean FPG per participant at ages <20, 20 to 40, and over 40 years old; brain white matter hyperintensity (WMH) volume, gray matter volume, and functional MRI (fMRI) activation to a Stroop task; tests of logical and working memory, executive function, and semantic fluency.

At MRI, participants were middle aged (51.3 ± 4.4 years) and predominantly female (74%) and white (74%). Mean FPG was impaired for zero, two, and nine participants in pre-20, 20 to 40, and over-40 periods. The pre-20 mean FPG above the pre-20 median value (i.e., above 83.5 mg/dL) was associated with greater WMH volume [mean difference: 0.029% of total cranial volume, CI: (0.0059, 0.052), P = 0.015] and less fMRI activation [-1.41 units (-2.78, -0.05), P = 0.043] on midlife MRI compared with below-median mean FPG. In controlling for over-40 mean FPG status did not substantially modify the associations. Cognitive scores did not differ by pre-20 mean FPG.

High-normal adolescent FPG may be associated with preclinical brain changes in midlife.