Lung Capacity Declines Faster With Diabetes

FRIDAY, March 28 (HealthDay News) -- Diabetes, the leading cause
of heart disease, stroke, blindness, kidney failure and non-traumatic
amputations, can also cause the lungs to deteriorate quicker than they
normally do with age, a new study shows.

Although everyone experiences a decline in lung function as they grow
older, research published in the April issue of Diabetes Care
concluded that the lungs of people with type 2 diabetes deteriorate more
quickly than normal.

The Johns Hopkins team that conducted the research, part of a larger
investigation known as the Atherosclerosis Risk in Communities (ARIC)
study, found in previous research that reduced lung function predicted and
preceded the development of type 2 diabetes.

In this latest study, there was an average difference of 6 millimeters
more decline per year in forced vital capacity (FVC), a measure of how
well the lungs fill with air, said study author Hsin-Chieh Jessica
Yeh.

The scientists suggest the accelerated reduction in forced vital
capacity (FVC) found in people with diabetes could be the result of high
blood sugar levels stiffening lung tissue or fatty tissue in the chest and
abdomen restricting the lungs.

The ARIC is a prospective cohort study of 15,792 adults from four U.S.
communities. The present analysis, which looked at 1,100 diabetics and
10,162 non-diabetics, was based on three years of follow-up.

"This study confirms the results of five previous studies, which
demonstrated lower lung function in diabetic subjects compared with their
non-diabetic counterparts," said Dr. Guillermo E. Umpierrez, an associate
professor of medicine at Emory University and section head of Diabetes and
Endocrinology at the Grady Health System, both in Atlanta. "These studies
also demonstrated a higher annual rate of lung function decline in the
diabetic compared with the non-diabetic population. Although the
information is not novel, this report enhances recognition of the lung as
a target of diabetic injury."

Most of the diabetic participants in the current study had type 2
diabetes, so the scientists were not able to look at decreases in lung
function among type 1 diabetics, who have to use insulin on a daily
basis.

"On the other hand, we found diabetes severity, as indicated by
intensity of anti-diabetic treatment, was associated with greater rate of
FVC decline. Patients on insulin treatment, alone or with oral
medications, had the greatest decline in forced vital capacity compared to
their non-diabetic counterparts," Yeh explained.

In an accompanying editorial, Dr. Connie Hsia, of the University of
Texas Southwestern Medical Center, cautioned that using inhaled insulin
might trigger or exacerbate the pulmonary dysfunction found in people with
diabetes.

"However, since none of our study participants were on inhaled insulin,
our study did not have direct implications on the use or absorption of
inhaled insulin," Yeh said.

Umpierrez pointed out that the use of inhaled insulin needs more study.
"The future of inhaled insulin for treatment of diabetes is uncertain;
however, some pharmaceutical companies continue to investigate the safety
and efficacy of inhaled insulin as an alternative of insulin injections,"
he noted.

Diminished lung capacity may lead to lower oxygen delivery to all body
tissues, he noted, although the drop in lung function among diabetics in
this study appears to be small. However, in elderly patients with
long-standing diabetes, impairment of lung capacity could worsen the risks
of adverse outcomes should the elderly diabetic develop pneumonia, heart
failure, volume overload or vascular complications, he added.

"Traditionally, the lung is not treated as a target organ for diabetes
complication. Based on the current study, we suggest physicians add lung
function on the watch list as they care for their diabetes patients," Yeh
said.

More information

For more on diabetes, visit the American Diabetes
Association.