The weight of the human thymus gland at necropsy.

The wet, lipid and lean dry weights of 574 thymus glands from Coroner's necropsies were examined for age-related changes. Despite enormous variation in wet and lipid weights at all ages there was a gradual decrease in wet weight with age and a significant increase in lipid weight until 40--50 years of age, with little change thereafter. There was a small decrease in lean dry weight with age, but it is not known if this reflects a change in cellularity. Multiple regression analysis showed that lower wet and lipid thymic weights were associated with long-term stressful conditions, and higher weights with deaths from asphyxia (largely in younger persons) and five groups of cardiovascular conditions. The percentage of lipid in these groups was not increased.