Abdominal fat from spine dual-energy x-ray absorptiometry and risk for subsequent diabetes

Abdominal obesity is a major risk factor for diabetes. Dual-energy x-ray absorptiometry (DXA) of the lumbar spine provides an index of abdominal fat.

Our objective was to examine the hypothesis that DXA-derived abdominal fat measurement in women undergoing osteoporosis investigation predicts risk for subsequent diagnosis of diabetes.

This historical cohort study was derived from the Manitoba Bone Density Program Database for the Province of Manitoba, Canada.

30,252 nondiabetic women aged 40 yr and older were referred for baseline osteoporosis assessment with DXA between January 1990 and March 2007.

Each woman's longitudinal provincial health service record was assessed for the presence of diabetes diagnosis codes after DXA testing.

During 5.2 + or - 2.6 yr of observation, 1252 (4.1%) women met the case definition for diabetes. A greater proportion of abdominal fat from spine DXA was strongly related to subsequent diabetes diagnosis in models adjusted for age, body mass index, and other comorbidities. Those in the highest quintile had 3.56 (95% confidence interval = 2.67-4.75) times the risk for subsequent diabetes diagnosis compared with those in the lowest (reference) quintile. Fat from hip DXA was not predictive of subsequent diabetes after adjustment for the same variables (1.00, 95% confidence interval = 0.79-1.26).

Predictive information about diabetes risk can be obtained from spine DXA scans performed for osteoporosis risk assessment. This is consistent with evidence linking abdominal fat with insulin resistance and the metabolic syndrome.