title: Low body mass index is an important risk factor for low bone mass and increased bone loss in early postmenopausal women. Early Postmenopausal Intervention Cohort (EPIC) study group.
abstract: Thinness (low percentage of body fat, low body mass index [BMI], or low body weight) was evaluated as a risk factor for low bone mineral density (BMD) or increased bone loss in a randomized trial of alendronate for prevention of osteoporosis in recently postmenopausal women with normal bone mass (n = 1609). The 2-year data from the placebo group were used (n = 417). Percentage of body fat, BMI, and body weight were correlated with baseline BMD (r = -0. 13 to -0.43, p < 0.01) and 2-year bone loss (r = -0.14 to -0.19, p < 0.01). Women in the lowest tertiles of percentage of body fat or BMI had up to 12% lower BMD at baseline and a more than 2-fold higher 2-year bone loss as compared with women in the highest tertiles (p </= 0.004). Women with a lower percentage of body fat or BMI had higher baseline levels of urine N-telopeptide cross-links (r = -0.24 to -0.31, p < 0.0001) and serum osteocalcin (r = -0.12 to -0.15, p < 0.01). To determine if the magnitude of treatment effect of alendronate was dependent on these risk factors, the group treated with 5 mg of alendronate was included (n = 403). There were no associations between fat mass parameters and response to alendronate treatment, which indicated that risk of low bone mass and increased bone loss caused by thinness could be compensated by alendronate treatment. In conclusion, thinness is an important risk factor for low bone mass and increased bone loss in postmenopausal women. Because the response to alendronate treatment is independent of fat mass parameters, prevention of postmenopausal osteoporosis can be equally achieved in thinner and heavier women.
authors.affiliation: Center for Clinical and Basic Research, Ballerup, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Ravn
authors.forename: G
authors.initials: G
authors.lastname: Cizza
authors.forename: N H
authors.initials: NH
authors.lastname: Bjarnason
authors.forename: D
authors.initials: D
authors.lastname: Thompson
authors.forename: M
authors.initials: M
authors.lastname: Daley
authors.forename: R D
authors.initials: RD
authors.lastname: Wasnich
authors.forename: M
authors.initials: M
authors.lastname: McClung
authors.forename: D
authors.initials: D
authors.lastname: Hosking
authors.forename: A J
authors.initials: AJ
authors.lastname: Yates
authors.forename: C
authors.initials: C
authors.lastname: Christiansen
mesh_terms: D019386:Alendronate / Q000627:therapeutic use; D015992:Body Mass Index; D015519:Bone Density; D003094:Collagen / Q000652:urine; D024042:Collagen Type I; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000209:etiology* / Q000517:prevention & control; D010455:Peptides / Q000652:urine; D012307:Risk Factors; D013851:Thinness / Q000150:complications
chemical_list: D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D003094:Collagen; D019386:Alendronate