INFLUENCE OF INHALED CORTICOSTEROIDS AND DIETARY-INTAKE AN BONE-DENSITY AND METABOLISM IN PATIENTS WITH MODERATE TO SEVERE ASTHMA

Objectives Compare the effect of high doses of inhaled corticosteroids on bone loss in subjects with moderate to severe asthma or mild asthm a, and examine the influence of dietary intake on bone metabolism. Des ign A survey on the effects of corticotherapy and nutrition on bone de nsity was conducted in 74 subjects currently being treated for asthma in the asthma clinic of Hospital Laval (Sainte-Foy, Quebec, Canada). F ifty-eight subjects completed the study (attrition rate=15%). Main out come measures In all subjects expiratory volumes were determined and u rinary analysis was conducted for hydroxyproline, calcium, phosphorus, and cortisol levels. Osteocalcin, calcium, phosphorus, cortisol, alka line phosphatase, and gamma-glutamyltransferase levels were measured i n blood samp;les. Bone density of the lumbar spine was determined by m eans of dual-energy x-ray absorptiometry. Nutrition evaluation was bas ed on a 3-day food diary analyzed using progiciel Nutri 91. The nutrit ional parameters examined were calcium; phosphorus; magnesium; zinc;vi tamins A, C, and; protein; total fiber; oxalates; energy; caffeine; an d alcohol in relation to bone density. Subjects Thirty-one patients wi th moderate to severe asthma who had been taking more than 1,000 mu g beclomethasone per day or the equivalent for more than 2 years and 27 patients with mild asthma who were taking less than 500 mu g beclometh asone per day or the equivalent. Statistical analyses performed Four-f actor analysis of variance with hierarchized interactions of four leve ls, Duncan's test, Pearson correlation coefficients. Results Blood lev els of osteocalcin and protein intake were lower in patients with mode rate to severe asthma than in those with mild asthma (P<.05). Signific ant correlations (P<.02) were observed between bone density and calciu m intake (r=.40), phosphorus intake (r=.35), protein intake (r=.30), a nd serum alkaline phosphatase level (r=-.30). Bone density was not sig nificantly different between the two groups of patients with asthma. A pplications A follow-up of patients with asthma who are taking inhaled corticosteroids is needed Co assess bone density, osteocalcin levels, and dietary intakes of calcium. Verify if osteocalcin level decreases over time in patients with moderate to severe asthma, monitor possibl e modifications in bone density, and verify if the correlation between dietary calcium and bone density is maintained.