Healing function of sweat glands declines with age

A group of scientists and dermatologists are studying the role sweat

glands play in how aging skin recovers from wounds. The goal of the

researchers is to learn more about aging skin and gain insight into how to

better treat and slow the aging process.

The study, published online in the journal Aging Cell (May 17, 2016),

compared the skin of 18 elderly subjects to the skin of 18 young adults,

to determine how each group healed skin lesions. The lesions were

created by the researchers, smaller than the diameter of a pencil eraser

and performed under local anesthesia.

“We’ve identified, for the first time, the cellular mechanisms of altered

skin wound repair in elderly patients,” said first author Laure Rittié, PhD,

research assistant professor in the University of Michigan’s Department

of Dermatology, in a press release.

Beyond the underarm

The researchers had already determined eccrine sweat glands, located

throughout the body, are important for wound closure. The eccrine sweat

glands are major contributors of new cells that replace the cells lost due

to injury. This finding led to a new research question.

“Since we know elderly people tend to sweat less than young adults, we

concentrated on this healing function of sweat glands,” said Dr. Rittié.

In young people, they discovered sweat glands contributed more cells to

wound closure than in aged adults. The cells in aged skin were not as

cohesive, either. Fewer cells participating, spaced further apart, can

create a delay in wound closure and, once repaired, a thinner epidermis in

aged versus young skin.

It was not that the sweat glands were less active in older people, rather,

that the environment in the aging skin had been slowly degraded, making

the skin structures less able to support the new cells that were generated,

noted the press release.

“This tells us that, beyond the frustrating appearance, skin aging also

negatively impacts the ability of the skin to repair itself,” Dr. Rittié

explained.

Clinical implications

The elderly especially would benefit from improved skin healing, and Dr.

Rittié and her team plan to continue the research with that target.

“Limiting skin damage during the aging process is likely to limit the

negative impact of aging on wound repair,” she said. “This study teaches

us that poor wound healing and wrinkling and sagging that occur in aging

skin share similar mechanisms. Chronic sun exposure is an important

factor that damages skin structures that normally support sweat glands.

This is another good reason to wear sunscreen.”