title: Low sit-to-stand performance is associated with low femoral neck bone mineral density in healthy women.
abstract: Bone mass may be adjusted to control the strains produced by muscular activity. We assessed the relationship between maximum rising strength (MRS), a new measurement of sit-to-stand performance, and femoral neck (FN) bone mineral density (BMD), taking into account possible confounding variables. The study population consisted of 249 healthy women aged 18-76. We measured MRS with a dynamometer fixed on the ground and connected by an adjustable nonelastic cord to a padded belt. FN BMD was measured by dual X-ray absorptiometry. Women in the first quartile of FN BMD (<0.702 g/cm(2)) had significantly lower values of MRS, body weight, height, lean mass, past 5-year physical activity expenditures, blood 17 beta estradiol (E2), 25-hydroxyvitamin D (25(OH)D), dehydroepiandrosterone sulfate (DHEAS), and insulin like growth factor 1, and higher values of age and parathyroid hormone than other women. In the logistic regression model, FN BMD values in the lowest quartile were associated with age (adjusted odds ratio [OR(a)] per 10-year increase = 1.84, 95% confidence interval [95% CI] = 1.33-2.54, P < 0.001), body weight (OR(a) per 10-kg decrease = 3.67, 95% CI = 2.08-6.47, P < 0.001), MRS (OR(a) per 20-kg decrease = 1.17, 95% CI = 1.02-1.34, P = 0.03), serum DHEAS (OR(a) < 0.5 mg/ml vs > or =0.5 mg/ml = 2.83, 95% CI = 1.3-6.12, P = 0. 01), and serum E2 (OR(a) per 10-pmol/l decrease = 1.02, 95% CI = 1.01-1.03, P = 0.03). The present study suggests a significant association between low FN BMD and low sit-to-stand performance in healthy women, independent of possible confounding variables.
authors.affiliation: Department of Internal Medicine and Geriatrics, University Hospital, University Montpellier 1, Montpellier, France. h-blain@chu-montpellier.fr
authors.forename: Hubert
authors.initials: H
authors.lastname: Blain
authors.forename: Audrey
authors.initials: A
authors.lastname: Jaussent
authors.forename: Eric
authors.initials: E
authors.lastname: Thomas
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Micallef
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Dupuy
authors.forename: Pierrick
authors.initials: P
authors.lastname: Bernard
authors.forename: Denis
authors.initials: D
authors.lastname: Mariano-Goulart
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Cristol
authors.forename: Charles
authors.initials: C
authors.lastname: Sultan
authors.forename: Michel
authors.initials: M
authors.lastname: Rossi
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Picot
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000368:Aged; D015519:Bone Density; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging*; D005602:France / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D010024:Osteoporosis / Q000453:epidemiology*; D011187:Posture; D018570:Risk Assessment; D013647:Task Performance and Analysis; D055815:Young Adult