Category: Bone Densitometry or Body Composition

16 - Association of Visceral Adipose Tissue Measured on DXA with Incident Atherosclerotic Cardiovascular Disease Events in Older Men

Purposes/Aims: To estimate the associations of DXA-VAT and the proportion of central vs peripheral adipose tissue (measured as Android-Gynoid fat mass ratio on DXA) with incident ASCVD (myocardial infarction, coronary heart disease death, or fatal or non-fatal stroke) among older men.

Rationale/Conceptual Basis/Background: VAT and a high proportion of central vs peripheral adipose tissue have been postulated to be important predictors of incident ASCVD events. DXA can accurately measure VAT compared to computed tomography and magnetic resonance imaging. No study to date has estimated the associations of DXA-VAT or Android-Gynoid fat mass ratio on DXA with incident ASCVD.


Methods:
2,654 older men (mean [SD] age 76.1 [5.4] years) were enrolled in the Sleep Substudy of the Osteoporotic Fractures in Men (MrOS) study, had valid baseline measures of VAT on DXA body composition studies (Hologic QDR4500A), complete covariate data, and rigorous adjudication of incident ASCVD events.. Participants were surveyed by questionnaire every 4 months for any potential ASCVD events, and two physician experts reviewed all relevant medical records to determine if an event had occurred. We used proportional hazards models to estimate the hazard ratios (HR) for incident ASCVD events per SD increase of VAT or Android-Gynoid fat mass ratio, adjusted for age, race, education, systolic blood pressure, smoking status, oxidized LDL level, treatment for hypertension, statin use, aspirin use, and presence of diabetes mellitus. Analyses were repeated for subsets of men with normal body mass index (BMI 18.5 to 24.9 kg/m2) and overweight BMI (25.0 to 29.9 kg/m2).


Results:
Over a mean (SD) follow-up time period of 8.2 (3.3) years, 371 men (14.0%) had an incident ASCVD event. Neither DXA-VAT nor Android-Gynoid fat mass ratios were associated with incident ASCVD events after multivariable adjustment, with the possible exception of a weak association for DXA-VAT among men with normal BMI (table).

Implications: DXA measures of VAT or central adipose tissue should not be used for ASCVD risk assessment among older men. However, these results are not generalizable to women or middle-aged individuals, and further investigations among those populations are warranted.

Kristine Ensrud

Principal Investigator, Epidemiologist
University of Minnesota
Minneapolis, Minnesota

Allyson Kats

Data analyst and statistician
University of Minnesota
Minneapolis, Minnesota

Lisa Langsetmo

Epidemiologist and Statistician
University of Minnesota
MInneapolis, Minnesota

Brent Taylor

Epidemiologist and Statistician
MInneapolis Veterans Administration Medical Center
Minneapolis, Minnesota

Tien Vo

Data analyst and statistician
Univeristy of Minnesota
Minneapolis, Minnesota

John T. Schousboe

Director, Park Nicollet Osteoporosis Center; Research Investigator
Park Nicollet Clinic and HealthPartners Institute, HealthPartners, Minneapolis, MN
Minneapolis, Minnesota

John Schousboe is a rheumatologist, health services researcher, and expert in the diagnosis and management of osteoporosis. He is the Director of the Osteoporosis Center at Park Nicollet Clinic, a subsidiary of HeatlhPartners. His research interests are in the areas of vertebral fracture epidemiology and assessment, abdominal aortic calcification, fracture risk assessment, health care costs attributable to fractures, and cost-effectiveness of diagnostic procedures for osteoporosis and fracture prevention interventions.