Objective To analyze the associations between aging and fat deposition in the pancreas, liver, kidneys, and spleen.

Methods A total of 40 subjects were enrolled in the study. Fasting venous blood was collected and abdominal 3T MRI with the six-point Dixon-VIBE subsequence was performed. Fat fraction (FF) was quantified, and biochemical indexes related to glucose metabolism, lipid metabolism and liver and kidney functions were determined. Pearson correlation analysis was used to explore the correlations among variables.

Results Pancreatic fat fraction (PFF) had an independent positive correlation with age and a non-independently positive correlation with body mass index (BMI, P＜0.05); liver fat fraction (LFF) had an independently positive correlation with BMI and a non-independent association with age (P＜0.05); kidney fat fraction (KFF) had a non-independently positive correlations with both age and BMI (P＜0.05). There were positive correlations between PFF and LFF or KFF (P＜0.05); after adjusted PFF, there was no correlation between LFF and KFF. PFF was positively correlated with fasting C-peptide (FCP) and hemoglobin A1c (HbA1c, P＜0.05); LFF was positively correlated with fasting plasma insulin (FPI) and FCP, and was negatively correlated with high-density lipoprotein cholesterol (HDL-C, P＜0.05); KFF was positively correlated with fasting plasma glucose (FPG), triglyceride (TG) and was negatively correlated with HDL-C (P＜0.05). Spleen fat fraction (SFF) had no correlation with age, BMI and either metabolic parameters.

Conclusions Aging significantly affects fat deposition in the pancreas, and may affect fat deposition in the liver and kidneys, with little effect on spleen metabolism.