1373-P: Longitudinal Associations of Dietary Exposures and Hypothalamic Gliosis in the Framingham Heart Study

Introduction: Hypothalamic gliosis is linked to obesity and is known to be induced by dietary factors in rodent models including high-fat, fructose-rich, and sucrose-enriched diet. This longitudinal analysis evaluated whether dietary exposures are associated with the degree of hypothalamic gliosis as assessed at MRI examinations obtained 5-8 years later.

Methods: Dietary exposures and brain MRI images were collected from 867 adults. Self-reported food frequency questionnaires were obtained and daily consumption of % total fat, % total carbohydrates, % total protein, % saturated fat, % fructose, and % sucrose of total energy intake were calculated and used as dietary exposures. To calculate the primary outcome, MRI T2 signal intensities were extracted to calculate a ratio of mediobasal hypothalamus (MBH)/amygdala (AMY), a greater ratio suggesting evidence of gliosis; a positive control ratio of MBH/putamen (PUT); and a negative control ratio of PUT/AMY. Linear regression evaluated the association between each dietary exposure and the outcomes of T2 signal ratios adjusting for age, sex, and BMI.

Results: The average age was 54.9±8.8 y (54.9% female). There were no statistically significant associations between % total fat, % saturated fat, % fructose, % sucrose, % total carbohydrates, and % total protein with the degree of MBH gliosis (MBH/AMY) as assessed at MRI examinations obtained 5-8y later (P = 0.89, 0.79, 0.42, 0.90, 0.71, 0.63, respectively). No associations were found between the dietary exposures and the positive or negative control ratio.

Conclusion: We did not find evidence of prospective associations between self-reported diet and MRI evidence of MBH gliosis. However, further research is warranted given the limitations of self-reported diet data and the extended time interval between the dietary exposure and MRI measurements.