title: The Association Between Trabecular Bone Score and Lumbar Spine Volumetric BMD Is Attenuated Among Older Men With High Body Mass Index.
abstract: Trabecular bone score (TBS) has been proposed as a dual-energy X-ray absorptiometry (DXA) derived measure of underlying quality of trabecular bone; however, TBS is not considered valid for those with body mass index (BMI) >37 kg/m2. Our objective was to determine the association between TBS and lumbar spine (trabecular) volumetric BMD (LS-VBMD) and to examine whether the association varied by BMI and body composition among older men below this clinical threshold. We used regression models to study 3479 men age ≥65 years enrolled in the Osteoporotic Fractures in Men (MrOS) study who had TBS from spine DXA scans, LS-VBMD from central quantitative computed tomography, measures of trunk fat and lean mass from DXA, and BMI <37 kg/m2. TBS was categorized as normal (n = 925), partially degraded (n = 1747), and degraded (n = 807). TBS was inversely related to BMI, trunk fat mass, and trunk lean mass (all p < 0.001). The relationship between TBS and LS-VBMD was nonlinear with magnitude of effect (slope of regression line using standardized variables) ranging from 0.07 (95% CI, -0.02 to 0.15) among those with degraded TBS up to 0.71 (95% CI, 0.54 to 0.89) among those with normal TBS. The relationship was still nonlinear after adjusting for age, clinical site, and either BMI, trunk lean mass, or trunk fat mass. The magnitude of effect relating TBS and LS-VBMD also decreased with increasing BMI (interaction, p = 0.090) and increasing trunk lean mass (interaction, p = 0.001), but not with increasing trunk fat mass (interaction, p = 0.224). In summary, the strength of the association between TBS and LS-VBMD among older men was variable and dependent on BMI and body composition, particularly trunk lean mass. The clinical utility of TBS among older men may be somewhat limited among men with high BMI or high trunk lean mass. © 2016 American Society for Bone and Mineral Research.
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA. langs005@umn.edu.
authors.forename: Lisa
authors.initials: L
authors.lastname: Langsetmo
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Tien N
authors.initials: TN
authors.lastname: Vo
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA.|Department of Medicine, University of Minnesota, Minneapolis, MN, USA.|Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, Minneapolis, MN, USA.
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA.|Department of Medicine, University of Minnesota, Minneapolis, MN, USA.|Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, Minneapolis, MN, USA.
authors.forename: Brent C
authors.initials: BC
authors.lastname: Taylor
authors.affiliation: California Pacific Medical Center Research Institute, San Francisco, CA, USA.|Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Cawthon
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Ann V
authors.initials: AV
authors.lastname: Schwartz
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.|Department of Medicine, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Bauer
authors.affiliation: Bone and Mineral Unit, Oregon Health Sciences University, Portland, OR, USA.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Orwoll
authors.affiliation: Department of Medicine, University of California, Davis, Davis, CA, USA.|Department of Rheumatology, University of California, Davis, Davis, CA, USA.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Lane
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
authors.affiliation: HealthPartners Institute, HealthPartners, Minneapolis, MN, USA.|Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Schousboe
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015519:Bone Density; D050723:Fractures, Bone / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000378:metabolism* / Q000473:pathology; D008297:Male; D010024:Osteoporosis / Q000378:metabolism* / Q000473:pathology
keywords: BODY MASS INDEX; BONE MINERAL DENSITY; OSTEOPOROSIS; TRABECULAR BONE SCORE