Bone mineral density and body composition in patients with airflow obstruction--the role of inhaled steroid therapy, disease and lifestyle

Fat mass to fat-free mass ratio and its associations with clinical characteristics in asthma

BACKGROUND

Fat mass to fat-free mass ratio (FM/FFM) assesses the combined effect of the balance between fat mass and fat-free mass.

AIMS

to evaluate the associations beetween FM/FFM and clinical outcomes in asthma and to compare clinical characteristics between individuals with higher and lower FM/FFM.

METHODS

128 participants with asthma underwent anthropometric, spirometry and bioelectrical impedance assessments. Physical activity in daily life (PADL) was assessed by the Actigraph for 7 days. Daily dose of inhaled medication, steps of pharmacological treatment, Asthma Control Questionnaire, Asthma Quality of Life Questionnaire and Hospital Anxiety and Depression Scale were also assessed. Participants were classified into two groups according to the 50th percentile of reference values for FM/FFM.

RESULTS

Individuals with higher FM/FFM (n=75) used higher daily doses of inhaled corticosteroids, had worse lung function and fewer steps/day when compared to those with lower FM/FFM (n=53) (P≤0.021). Associations were found between absolute values of FM/FFM with lung function (FEV₁ and FVC [liters]): R²=0.207 and 0.364;P<0.0001), and between the categories of lower or higher FM/FFM with steps of medication treatment (Cramer's V=0.218;P=0.016) and level of PADL (Cramer's V=0.236;P=0.009). The highest FM/FFM was a determining factor of physical inactivity (OR: 3.21;95%CI:1.17-8.78) and highest steps of pharmacological treatment (OR: 8.89;95%CI:1.23-64.08).

CONCLUSION

Higher FM/FFM is significantly associated with worse clinical characteristics in individuals with asthma, such as higher doses of inhaled corticosteroids, worse lung function and fewer steps/day. Moreover, higher FM/FFM is a determining factor of physical inactivity and the highest steps of pharmacological treatment for asthma.

A longitudinal assessment of the effect of inhaled fluticasone propionate therapy on adrenal function and growth in young children with asthma

OBJECTIVE

Fluticasone proprionate (FP) is increasingly used to treat very young children with asthma. Its safety in terms of effects on the hypothalamic pituitary axis (HPA) and growth in this age group is uncertain.

PATIENTS AND METHODS

Eleven children (median (range) age 10 (5.6-24.3) months) presenting with recurrent wheeze and family history of asthma were studied prospectively for a period of 18 months. Children received daily-inhaled FP 250 microg via a spacer device. No other corticosteroid therapy was administered prior to or during the study. A Short Standard Synacthen Test (SST) (125 microg) was performed pretreatment, and after 6 and 18 months. Weight (Wt), height (Ht), and body mass index (BMI) were measured at 3-6 monthly intervals.

RESULTS

Fasting early morning and peak cortisol levels remained within the normal reference range with therapy. There were no changes in Ht SDS, whereas both Wt SDS (baseline 0.05 (-2.17 to 0.52) vs. +18 months 0.68 (-0.5 to 1.36) P < 0.02) and BMI SDS (-0.22 (-1.73 to 0.75) vs. 0.86 (0.03 to 1.99) P < 0.005) increased after 18 months of treatment.

CONCLUSION

Daily treatment with inhaled FP 250 microg in young children with asthma appears to have no adverse effects on the HPA or on linear growth, however, treatment is associated with increases in body Wt and BMI in young children.

The determinants of bone mineral density in Chinese men--results from Mr. Os (Hong Kong), the first cohort study on osteoporosis in Asian men

Mr. Os (Hong Kong) is the first study to address the risk factors for osteoporosis in Asian men. A standardized, structured interview and dual X-ray densitometry (DEXA) were performed on 2,000 Chinese men aged 65-92. By multiple regression, the following factors were found to be positively associated with BMD at both the total hip and the spine: body weight, grip strength and a history of diabetes mellitus. The following factors were found to be negatively associated with BMD at both the total hip and spine: cigarette smoking, a history of gastrectomy or bowel resection, current use of inhaled steroid and a history of fracture after 50 years. Moreover, a history of chronic obstructive pulmonary disease (COPD) was negatively associated with BMD at the total hip, and age, the use of an alpha-blocker, thiazide diuretic and nitrate were associated with a higher BMD at the spine. A total of 21.8% of the variance in total hip and 31.5% of the variance in total spine BMD was accounted for in the multivariate analysis.

Reduced bone mineral density in male Severe Acute Respiratory Syndrome (SARS) patients in Hong Kong

During the Severe Acute Respiratory Syndrome (SARS) outbreak in Hong Kong in 2003, patients were treated with very high doses of corticosteroid and ribavirin. The detrimental effects of such treatment on the bone mineral density (BMD) of SARS patients are unknown. To compare the BMD of SARS patients with normal range data, a cross-sectional survey was conducted. The bone mineral density of 224 patients with SARS, who were treated with an average of 2753 mg (SD = 2152 mg) prednisolone and 29,344 mg (SD = 15,849 mg) of ribavirin was compared to normal data. Six percent of men had a hip BMD Z score of < or =-2 (P = 0.057 for testing the hypothesis that >2.5% of subjects should have a Z score of < or =-2). Moreover, there was a negative association (r = -0.25, P = 0.023) between the duration of steroid therapy and BMD in men. We conclude that male SARS patients had lower BMD at the hip than normal controls, and this could be attributed to prolonged steroid therapy.

Osteoporosis associated with excess glucocorticoids

Excess glucocorticoids, whether endogenous or exogenous, can cause osteoporosis and fractures. Even low doses of oral glucocorticoids and mild endogenous hypercortisolism may be associated with bone loss. Patients treated with glucocorticoids, however, often are not evaluated and treated for this problem. Patients on chronic glucocorticoids or initiating these drugs should have their bone density measured and appropriate laboratory studies. They should be treated with adequate calcium and vitamin D, and antiresorptive therapy (particularly bisphosphonates) should be considered.

Inhaled corticosteroids, bone mineral density and fracture in older people

The efficacy of inhaled corticosteroids in the treatment of asthma has been firmly established in a variety of settings. The majority of asthma management plans now recommend the use of inhaled corticosteroids at an early stage. This means that most patients with asthma will be prescribed an inhaled corticosteroid at some point in time and many patients with asthma will use these drugs for several years. Inhaled corticosteroids are also used in the treatment of other conditions, particularly chronic obstructive pulmonary disease (COPD). Since inhaled corticosteroids are absorbed into the systemic circulation, they can have systemic adverse effects, such as suppression of the hypothalamic-pituitary-adrenal axis and increasing the risk of bruising. However, perhaps the greatest concern for patients is whether the regular use of inhaled corticosteroids has an adverse impact on the bone mineral density and increases the risk of fracture. There is now accumulating evidence from epidemiological studies that the use of inhaled corticosteroids is inversely related to bone mineral density in a dose-dependent fashion. However, data from two clinical trials of moderately high doses of inhaled corticosteroids in patients with COPD have produced conflicting results and while the larger study of triamcinolone found a significant impact of this drug on bone mineral density, a smaller study of budesonide found no effect. Epidemiological research into the relationship between inhaled corticosteroids and fracture is at an early stage. To date, only three studies in this area have been reported, all of which have used different approaches to try to minimise the impact of bias and confounding. There is a lack of consistency between the final estimates of the impact of inhaled corticosteroids on fracture risk. However, taken together these data suggest that the short to medium term use of inhaled corticosteroids is associated with a small adverse effect on bone. Doctors and patients need to be aware of this risk and balance it against the known beneficial effects of inhaled corticosteroids.

Hormone replacement therapy and obstructive airway diseases

Controversy exists as to the role of female reproductive hormones in asthma and COPD and, specifically, the effect of hormone replacement therapy (HRT) on these disorders. The differential incidence of asthma over the menstrual life cycle suggests an effect of female reproductive hormones on asthma; less data are available for COPD. Estrogen and progesterone have protean effects at the cellular level, consistent with potentially harmful and beneficial effects in lung disease. Large epidemiologic studies show an increased risk of development of asthma with the use of HRT but no consistent effects on COPD. Clinical and epidemiologic studies of exacerbations are limited, but suggest either a harmful effect or no effect of HRT on exacerbations of asthma and COPD. HRT appears to increase the risk of development of asthma but is not associated with the loss of lung function characteristic of COPD. Because the development of asthma is rare in postmenopausal women, the absolute increase in risk among women without asthma is modest. Physicians may wish to avoid HRT therapy in patients with difficult to control asthma and COPD. Clinical decisions to start or continue HRT among women without asthma or COPD should be based on the effects of HRT on more common diseases such as cardiovascular disease, breast cancer and osteoporosis, non-vertebral fractures and colon cancer.

Vitamin D deficiency, bone mineral density and weight in patients with advanced pulmonary disease

OBJECTIVE

To study the influence of underweight, body composition and vitamin D deficiency on bone mineral density in patients with advanced pulmonary disease.

DESIGN

Cross-sectional study with time span for inclusion set at 5 years.

SETTING

The clinical work and biochemical analyses were carried out at Rikshospitalet University Hospital, Norway. Analyses for vitamin D metabolites and bone markers were carried out at Aker University Hospital, and bone measurements at Clinic of Osteoporosis.

SUBJECTS

Seventy-one candidates for lung transplantation (63% chronic obstructive pulmonary disease, 42 underweight and 29 normal weight) were included.

MAIN OUTCOME MEASURES

Body composition, bone mineral density at lumbar spine and femur neck, serum concentration of calcidiol and vitamin D intake.

RESULTS

Subnormal calcidiol levels were present in 52% of the underweight patients and 69% of the normal-weight patients. The resulting models of linear regression showed that for the lumbar spine T scores model, the total variation of 16.7% was explained by group (underweight/normal weight), sex and age. For the femur neck T scores model, the total variation of 20.4% was explained by the interaction of underweight and vitamin D deficiency (with borderline significance) and by arm muscle circumference percentage of standard. In patients with normal calcidiol levels, the median intake of vitamin D was 17 microg in the underweight patients and 11 microg in the normal-weight patients.

CONCLUSIONS

Vitamin D deficiency was common in both underweight and normal-weight patients, but only in the underweight patients, an association between vitamin D deficiency and reduced femur neck T scores was indicated.

Effects of asthma and asthma therapies on bone mineral density

With improvements in techniques for measuring bone mass, interest and concern have increased about the effects of asthma therapies, particularly corticosteroids, on bone mineral density. Whether asthma itself causes bone loss remains unclear. Studies evaluating the effect of asthma therapies on bone mineral density are often difficult to interpret because of methodologic problems. These studies show that oral corticosteroids are associated with a reduction in bone mineral density and an increased risk of fracture. Studies evaluating the effects of inhaled corticosteroids on bone mineral density provide conflicting data, but there is increasing evidence that inhaled corticosteroids may have an adverse effect on bone. However, the benefits of inhaled corticosteroids in the treatment of asthma remain far greater than the risks. The data for the effects of other asthma therapies on bone mineral density are limited.

Alendronate for the prevention of bone loss in patients on inhaled steroid therapy

One hundred women on inhaled steroid therapy (dose range from 800 to <1600 microg per day) were randomized to receive 10 mg of oral alendronate or placebo (with 500 mg of calcium in the form of daily calcium carbonate). Bone mineral density (BMD) was measured at baseline, 6 months, and 12 months. The percentage changes in BMD were -0.80% in the placebo group and 2.99% in the alendronate group at the spine (p < 0.001 by analysis of covariance [ANCOVA]), and were -0.51% in the placebo group and 0.97% in the alendronate group at the femoral neck (p < 0.05 by ANCOVA). Five patients in the alendronate-treated group, and a similar number of patients in the placebo group, complained of mild gastric discomfort. We conclude that women on inhaled steroid therapy were at risk of accelerated bone loss, which could be prevented by a daily dose of 10 mg of alendronate.

Inhaled corticosteroid use and bone-mineral density in patients with asthma

BACKGROUND

Inhaled corticosteroids are absorbed into the systemic circulation, but the extent to which they have adverse effects on bone is uncertain. The question is important since 3% of the European population take an inhaled corticosteroid regularly and may do so for many years.

METHODS

We studied the dose-response relation between cumulative inhaled corticosteroid dose and bone-mineral density at the lumbar spine and proximal femur in 196 adults (119 women) with asthma aged 20-40 years. Patients had taken an inhaled corticosteroid regularly for at least 6 months, and had had limited exposure to systemic steroids. Cumulative dose of inhaled corticosteroid was calculated from questionnaires and computerised and written general-practice records, and its effect on bone-mineral density was estimated by multiple regression analysis.

FINDINGS

Median duration of inhaled corticosteroid treatment was 6 years (range 0.5-24), and median cumulative dose was 876 mg (87-4380). There was a negative association between cumulative dose of inhaled corticosteroid and bone-mineral density at the lumbar spine (L2-L4), femoral neck, Ward's triangle, and trochanter, both before and after adjustment for the effects of age and sex. A doubling in dose of inhaled corticosteroid was associated with a decrease in bone-mineral density at the lumbar spine of 0.16 SD (95% CI 0.04-0.28). Similar decreases were found at the femoral neck, Ward's triangle, and trochanter. Adjustment for potential confounding factors including physical activity and past oral, nasal, dermal, and parenteral corticosteroids did not weaken the associations.

INTERPRETATION

This study provides evidence of a negative relation between total cumulative dose of inhaled corticosteroid and bone-mineral density in patients with asthma.