Dose-response relationship for risk of non-vertebral fracture with inhaled corticosteroids

Developments in the field of allergy in 2008 through the eyes of Clinical & Experimental Allergy

In 2008, many thousands of articles were published on the subject of allergic disease with over 200 reviews, editorials and original papers in Clinical & Experimental Allergy alone. These represent a considerable amount of data and even the most avid reader could only hope to assimilate a small fraction of this knowledge. There is therefore a pressing need for the key messages that emerge from a journal such as Clinical & Experimental Allergy to be summarized by experts in the field in a form that highlights the significance of the developments and sets them in the context of important findings in the field published in other journals. This also has the advantage of making connections between new data in conditions such as asthma, where articles often appear in different sections of the journal. As can be seen from this review, the body of work is diverse both in terms of the disease of interest and the discipline that has been used to investigate it. However, taken as a whole, we hope that the reader will gain a flavour of where the field is mature, where there remain controversies and where the cutting edge is leading.

Dose-response relationship of inhaled corticosteroids and cataracts: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The risk of cataracts associated with the long-term use of inhaled corticosteroids (ICS) is poorly recognized, yet may be of major public health importance. The aim of this study was to determine the dose-response relationship of ICS use and risk of cataracts in adults.

METHODS

A systematic review and meta-analysis was performed of case-control studies of cataracts and ICS use, which included at least two doses of ICS and in which the number of cases and controls using each dose of ICS was reported. The primary outcome variable was risk of cataracts.

RESULTS

Four case-control studies were identified, with a total of 46 638 cases and 146 378 controls. There was a significant relationship between the risk of cataracts and ICS dose, with a random effects pooled odds ratio for risk of cataracts per 1000 microg increase in daily beclomethasone dipropionate dose of 1.25 (95% CI: 1.14-1.37).

CONCLUSIONS

The risk of cataracts was increased by approximately 25% for each 1000 microg per day increase in the dose of beclomethasone dipropionate or equivalent. These findings reinforce the importance of prescribing within the therapeutic dose-response range for ICS in asthma and the need to determine the dose-response relationship for the efficacy of ICS in COPD. Screening for the presence of cataracts could usefully be undertaken in older subjects with asthma and COPD, particularly current or ex-smokers.

Long-term therapy in COPD: any evidence of adverse effect on bone?

Patients with COPD have high risk for osteoporosis and fractures. Hip and vertebral fractures might impair mobility, and vertebral fractures further reduce lung function. This review discusses the evidence of bone loss due to medical treatment opposed to disease severity and risk factors for COPD, and therapeutic options for the prevention and treatment of osteoporosis in these patients. A review of the English-language literature was conducted using the MEDLINE database until June 2009. Currently used bronchodilators probably lack adverse effect on bone. Oral corticosteroids (OCS) increase bone resorption and decrease bone formation in a dose response relationship, but the fracture risk is increased more than reflected by bone densitometry. Inhaled corticosteroids (ICS) have been associated with both increased bone loss and fracture risk. This might be a result of confounding by disease severity, but high doses of ICS have similar effects as equipotent doses of OCS. The life-style factors should be modified, use of regular OCS avoided and use of ICS restricted to those with evidenced effect and probably kept at moderate doses. The health care should actively reveal risk factors, include bone densitometry in fracture risk evaluation, and give adequate prevention and treatment for osteoporosis.

Inhaled corticosteroids in patients with stable chronic obstructive pulmonary disease: a systematic review and meta-analysis

CONTEXT

Recent studies of inhaled corticosteroid (ICS) therapy for managing stable chronic obstructive pulmonary disease (COPD) have yielded conflicting results regarding survival and risk of adverse events.

OBJECTIVE

To systematically review and quantitatively synthesize the effects of ICS therapy on mortality and adverse events in patients with stable COPD.

DATA SOURCES

Search of MEDLINE, CENTRAL, EMBASE, CINAHL, Web of Science, and PsychInfo through February 9, 2008.

STUDY SELECTION

Eligible studies were double-blind, randomized controlled trials comparing ICS therapy for 6 or more months with nonsteroid inhaled therapy in patients with COPD.

DATA EXTRACTION

Two authors independently abstracted data including study characteristics, all-cause mortality, pneumonia, and bone fractures. The I(2) statistic was used to assess heterogeneity. Study-level data were pooled using a random-effects model (when I(2) > or = 50%) or a fixed-effects model (when I(2) < 50%). For the primary outcome of all-cause mortality at 1 year, our meta-analysis was powered to detect a 1.0% absolute difference in mortality, assuming a 2-sided alpha of .05 and power of 0.80.

RESULTS

Eleven eligible randomized controlled trials (14,426 participants) were included. In trials with mortality data, no difference was observed in 1-year all-cause mortality (128 deaths among 4636 patients in the treatment group and 148 deaths among 4597 patients in the control group; relative risk [RR], 0.86; 95% confidence interval [CI], 0.68-1.09; P = .20; I(2) = 0%). In the trials with data on pneumonia, ICS therapy was associated with a significantly higher incidence of pneumonia (777 cases among 5405 patients in the treatment group and 561 cases among 5371 patients in the control group; RR, 1.34; 95% CI, 1.03-1.75; P = .03; I(2) = 72%). Subgroup analyses indicated an increased risk of pneumonia in the following subgroups: highest ICS dose (RR, 1.46; 95% CI, 1.10-1.92; P = .008; I(2) = 78%), shorter duration of ICS use (RR, 2.12; 95% CI, 1.47-3.05; P < .001; I(2) = 0%), lowest baseline forced expiratory volume in the first second of expiration (RR, 1.90; 95% CI, 1.26-2.85; P = .002; I(2) = 0%), and combined ICS and bronchodilator therapy (RR, 1.57; 95% CI, 1.35-1.82; P < .001; I(2) = 24%).

CONCLUSIONS

Among patients with COPD, ICS therapy does not affect 1-year all-cause mortality. ICS therapy is associated with a higher risk of pneumonia. Future studies should determine whether specific subsets of patients with COPD benefit from ICS therapy.