Association of Biological Markers of Alcohol Consumption and Self-Reported Drinking with Hippocampal Volume in a Population-Based Sample of Adults

Aims: The current study examined a large community cohort to understand relationships between indicators of alcohol consumption and hippocampal volume. Short summary: Alcohol use measures were not associated with hippocampal volume in a population-based sample. However, alcohol consumption was associated with hippocampal volume reduction in subsets of the sample including subjects aged >= 50 years old, and those with none to moderate levels of depressive symptoms. Methods: A total of 1848 adults with magnetic resonance imaging (MRI) and alcohol consumption data were included. Multiple linear regressions were performed with left or right hippocampal volume as dependent variables, and age, gender, race, education, body mass index, Quick Inventory of Depressive Symptomatology (QIDS-SR) scores, drinks per week (DPW), aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT, gamma-glutamyl transferase and mean corpuscular volume (MCV) as independent variables. Post hoc analyses were conducted to assess interactions of demographic factors and variables of interest (DPW, AST, ALT, AST/ALT, GGT and MCV). For statistically significant interactions, analyses were conducted in groups split by gender, depression (QIDS-SR scores >= 11 and <11) and age (>= 50 and <50 years). Results: Average alcohol consumption in the population was low (mu = 2.95 +/- 6.7 DPW). Alcohol consumption measures were not significantly associated with hippocampal volume in the primary analysis. Exploratory analyses revealed significant associations between DPW and right hippocampal volume in participants with QIDS-SR scores <11 (B = -3.75, P = 0.02, CI = -6.97, -0.52) and in those aged >= 50 years (B = -4.844, P = 0.023 CI = -9.023 to -0.664). AST/ALT was significantly associated with right (B = -93.66, P = 0.022, CI = -173.64 to -13.68) and left hippocampal volume (B = -109.79 P = 0.008, CI = -190.97 to -28.61) in participants aged >= 50 but not <50 years. Gender differences were not observed. Conclusions: The findings suggest a relationship between alcohol use indicators and right hippocampal volume in non-depressed and older adults.