Opportunistic measurement of sagittal abdominal diameter with bone densitometry predicts death and cardiovascular events

Supine sagittal abdominal diameter (SAD), also known as abdominal height, has been proposed as a simple measure for assessing abdominal adiposity. We aimed to determine whether SAD from DXA performed for osteoporosis assessment predicts major adverse cardiovascular events (MACEs) using the population-based DXA registry for the Province of Manitoba, Canada. The study population comprised 72 974 individuals aged 40 yr and older with baseline DXA assessment between February 1999 and March 2018. Incident MACE (composite of all-cause mortality, acute myocardial infarction [MI], non-hemorrhagic stroke) was ascertained from linked healthcare databases. During mean 8.4 yr follow-up (611 862 person-years), 14 457 (18.8%) individuals experienced incident MACE. Risk stratification was greatest with SAD/weight ratio, with area under the curve (AUC) for MACE and its components ranging from 0.582 for acute MI to 0.620 for death (all <i>p</i> < .001), all significantly better than with BMI (<i>p</i> < .001). In multivariable-adjusted models, each SD increase in SAD/weight was associated with increased risk for MACE (hazards ratio [HR] 1.20, 95% CI 1.18-1.22), death (HR 1.22, 95% CI 1.20-1.25), acute MI (HR 1.19, 95% CI 1.14-1.24), and stroke (HR 1.17, 95% CI 1.12-1.22). A linear gradient was seen across SAD/weight quintiles (all <i>p</i>-trend < .001), with adjusted HR for MACE 1.61 (95% CI 1.50-1.72) for highest vs lowest quintile. Results were similar when further adjusted for BMI in non-obese and obese individuals (<i>p</i>-interaction for obesity = .141) and in both women and men (<i>p</i>-interaction for sex = .471). In conclusion, SAD measured opportunistically at the time of DXA testing is predictive of death and major cardiovascular events in individuals undergoing osteoporosis assessment.