Effect of Age on Wound Healing in Healthy Human Beings

Background: Although the elderly clinically have a higher rate of wound complications, the physiologic effect of age on wound healing in human beings is unknown.

Methods: Healthy young (18 to 55 years of age) and elderly (more than 65 years of age) human volunteers had a 2 x 2 cm, superficial, split-thickness wound created on the anterior aspect of the thigh, and the rate of epithelialization was assessed. For studies of fibroplasia, similar groups underwent subcutaneous implantation of polytetrafluoroethylene catheters, which were removed after 14 days. Biochemical analyses of the catheters included determinations of hydroxyproline, total alpha-amino nitrogen, and DNA.

Results: The elderly volunteers had a significant delay of 1.9 days in epithelialization. Analyses of the subcutaneously implanted catheters showed no difference in DNA content or hydroxyproline-accumulation; however, the young volunteers had a significantly higher amount of total alpha-amino nitrogen.

Conclusions: In healthy humans, aging leads to delayed epithelialization. No effect of age on collagen synthesis was noted, although accumulation of wound noncollagenous protein was decreased. This decrease may impair the mechanical properties of scarring in aged human beings.