Influence of inhaled glucocorticoids on bone mineral density and bone metabolism in asthmatic women

Tong WANG; Kaisheng YIN; Lihua BAO; Jundi CHEN

ABSTRACT

BACKGROUND:

Inhaled glucocorticoids(IGC) are powerful anti_inflammatory agents used in the treatment of asthma. But it is still uncertain whether long-term use of the IGC affects bone metabolism in asthmatic patients, especially women.

OBJECTIVE:

To investigate if the prolonged treatment with IGC to Chinese asthmatic woman has a detrimental effect on bone mass and metabolism.

DESIGN:

A matched controlled study based on the patients

SETTING:

Clinical Laboratory and the Department of Respiratory Medicine, First Affiliated Hospital, Nanjing Medical University.

PARTICIPANTS:

From February 1998 to February 2002, forty female Chinese patients with bronchial asthma, regularly followed up at our outpatient clinic, all in the Nanjing area, none of them having a history of chronic systemic GC use, agreed to take part in the study, were selected and divided into two groups therapeutic group (IGC group) 20 asthmatic women, aged 18-63 years, 5 menopausals, received IGC therapy regularly for at least 5 months; Control group 20 asthmatic women, aged 18-60 years, 5 menopausals, never received IGC received conventional bronchodilators . They were matched individually for sex, age and menopausal status.

METHODS:

Bone mineral density (BMD) at the lumbar spine (2-4),femoral neck, trochanter, ward's triangle and total body of femur were measured by dual energy X-ray absorptiometry, BMD were expressed as a absolute value and a T score considered as a SD from peak bone mass respectively. Meanwhile, BMD was also expressed as a percentage (%), which was defined by comparing the BMD absolute value of subjects and BMD normal value of isosexual age cohorts. Osteocalcin and some other markers of bone metabolism were measured by radio immunoassay in two groups.daily dose and accumulative total dose of IGC and BMD in the IGC group.

RESULTS:

There were no significant difference between two groups in BMD and T score (including the lumbar spine (2-4), femoral neck,trochanter, ward' s triangle and total body of femur) (P ＞ 0.05). There were also no significant correlation between daily dose of IGC and BMD of above 5 parts in the IGC group (r=-0.325 to -0.1102, P ＞ 0.05). But,there were significantly negative correlation between the accumulative total dose of IGC and BMD at lumbar spine2-4,femoral neck and ward's triangle(r=-0.495 ,-0.517,-0.531 ,P ＜ 0.05).There were no significant correlation between the accumulative total dose of IGC and T score of above 5 parts in the IGC group (r=0.443to 0.295 ,P ＞ 0.05). There was negative correlation between the age and the BMD at ward's triangle in the IGC group(r=-0.506,P ＜ 0.05). However ,BMD at 5 locus were not correlated with the age in control group (r=-0.079 to 0.326, P ＞ 0.05).Osteocalcin and some other markers of bone metabolism were no significant difference between two groups (P ＞ 0.05).

CONCLUSION:

The data suggests that there is no significant influence of IGC on bone mineral density and bone metabolism in asthmatic women,but if continuing exposures to high doses over many years,there may be a detrimental effect on bone mass and metabolism in women, especially elder or postmenopausal asthmatic women treated with IGC who may be more susceptible to any bone mineral loss caused by IGC.