Vitamin D may halt weakening of asthmatics' lung function

Washington, May 21 (ANI): Researchers at the University of Pennsylvania have found that vitamin D may slow the progressive decline in asthmatics' ability to breathe as a result of human airway smooth muscle (HASM) proliferation.

In their study, the researchers found that calcitriol, a form of vitamin D synthesized within the body, reduced growth-factor-induced HASM proliferation in cells isolated from both persons with asthma and from persons without the disease.

The proliferation is a part of process called airway remodeling, which occurs in many people with asthma, and leads to reduced lung function over time.

According to researchers, by slowing airway remodeling, the decline in breathing that leaves many asthmatics even more vulnerable when they suffer an asthma attack can be prevented.

"Calcitriol has recently earned prominence for its anti-inflammatory effects. But our study is the first to reveal the potent role of calcitriol in inhibiting ASM proliferation," said Gautam Damera, Ph.D

The studies were carried out with cells from 12 subjects, and the researchers compared calcitriol with dexmethasone, a corticosteroid prescribed widely for the treatment of asthma.

Although, dexmethasone is also a powerful anti-inflammatory agent, the researchers found that it had little effect on HASM growth.

Damera and his colleagues found calcitriol inhibits HASM in a dose-dependent manner.

They also conducted experiments to determine the mechanism by which calcitriol retards HASM proliferation.

They believe the vitamin works by inhibiting activation of distinct set of proteins responsible for cell-cycle progression.

The study has been presented at the American Thoracic Society's 105th International Conference in San Diego on Wednesday, May 20. (ANI)