Background: To assess the effects of aging and gender on glomerular size and global glomerulosclerosis (GS) and evaluate the relationship between glomerular size and GS in normal Caucasian donor kidneys.
Methods: All baseline graft biopsies between 1990 and 1998 were reviewed and sections with tissues containing at least 15 glomeruli were selected for morphometric analyses using a Digital Imaging Analyzer. Glomerular volumes (GV) were measured using the maximal profile area (MPA) method. The frequency of glomeruli with totally sclerotic lesions representing degree of global GS was expressed as a percentage of total number of glomeruli counted.
Results: 102 donor specimens (M/F, 46/56; mean age, 37.4 +/- 17.3 yrs) were analyzed showing mean MPA of 27.8 +/- 6.6 (x 10(-3)mm2), mean GV of 3.6 +/- 1.2 (x 10(6)microm3) and mean GS% of 6 +/- 10%. GV was increased with increasing age (r2 = 0.32, p < 0.0001). There was a progressive increase in glomerular size between infancy and adolescence (2-18 years old). The rate of MPA growth over childhood appeared to be linear (n = 13, r2 = 0.66, p = 0.0004). However, MPA increased with age at a slower rate (n = 99, r2 = 0.66, p = 0.0004) in adults (excluding data for patients < 18 years) than in infancy and adolescence. There wasn't significant gender difference in GV. Age (r = 0.47, p < 0.0001) and MPA (r = 0.31, p < 0.05) were both positively correlated with global GS.
Conclusions: 1. Aging contributes to enlargement of glomerular size and global GS. 2. Gender had no significant effect on glomerular size. 3. Enlargement of glomerular size was associated with global GS in normal Caucasians.