Serum Adiponectin Levels, Neuroimaging, and Cognition in the Mayo Clinic Study of Aging

Background: Adiponectin, a protein involved in inflammatory pathways, may impact the development and progression of Alzheimer's disease (AD). Adiponectin levels have been associated with mild cognitive impairment (MCI) and AD; however, its association with Alzheimer-associated neuroimaging and cognitive outcomes is unknown. Objective: Determine the cross-sectional association between plasma adiponectin and neuroimaging and cognitive outcomes in an older population-based sample. Methods: Multivariable adjusted regression models were used to investigate the association between plasma adiponectin and hippocampal volume (HVa), PiB-PET, FDG PET, cortical thickness, MCI diagnosis, and neuropsychological test performance. Analyses included 535 non-demented participants aged 70 and older enrolled in the Mayo Clinic Study of Aging. Results: Women had higher adiponectin than men (12,631ng/mL versus 8,908ng/mL, p<0.001). Among women, higher adiponectin was associated with smaller HVa (B=-0.595; 95 CI -1.19, -0.005), poorer performance in language (B=-0.676; 95 CI -1.23, -0.121), and global cognition (B=-0.459; 95 CI -0.915, -0.002), and greater odds of a MCI diagnosis (OR=6.23; 95 CI 1.20, 32.43). In analyses stratified by sex and elevated amyloid (PiB-PET SUVR >1.4), among women with elevated amyloid, higher adiponectin was associated with smaller HVa (B=-0.723; 95 CI -1.43, -0.014), poorer performance in memory (B=-1.02; 95 CI -1.73, -0.312), language (B=-0.896; 95 CI -1.58, -0.212), global cognition (B=-0.650; 95 CI -1.18, -0.116), and greater odds of MCI (OR=19.34; 95 CI 2.72, 137.34). Conclusion: Higher plasma adiponectin was associated with neuroimaging and cognitive outcomes among women. Longitudinal analyses are necessary to determine whether higher adiponectin predicts neurodegeneration and cognitive decline.