BACKGROUND:Some studies have shown that the hounsfield units(HU)value based on lumbar CT can be used to screen osteoporosis.At present,the number of patients with pulmonary infection has increased;the number of patients with pulmonary infection and type 2 diabetes is also increasing,which increases the utilization rate of chest CT. OBJECTIVE:To investigate the role of lumbar 1 vertebral body HU value based on chest CT in the screening of type 2 diabetes mellitus osteoporosis. METHODS:The clinical data of 244 patients with type 2 diabetes mellitus treated in the First Affiliated Hospital of Chengdu Medical College from June 2020 to June 2022 were analyzed retrospectively.The bone mineral density was obtained by dual-energy X-ray absorptiometry.According to WHO's diagnostic criteria for osteoporosis,the subjects were divided into the non-osteoporosis group(n=120)and the osteoporosis group(n=124).The general condition,T value and HU value of lumbar 1 vertebra in chest CT were compared,and the relationship between the HU value and T value of each position was analyzed and the accuracy of type 2 diabetes mellitus osteoporosis was evaluated. RESULTS AND CONCLUSION:(1)There was no significant difference in sex,age,body mass index,glycosylated hemoglobin,mean blood glucose,calcium(Ca),phosphorus(P),time of type 2 diabetes mellitus,history of hypertension and history of hyperlipidemia between the two groups(P>0.05).(2)The HU value was positively correlated with the lowest T value of the hip(r=0.619,P<0.01);the HU value was positively correlated with the hip T value(r=0.584,P<0.01),and the HU value was positively correlated with the femoral neck T value(r=0.641,P<0.01).When the HU value was 98,the prediction of type 2 diabetes mellitus osteoporosis had good accuracy,and the sensitivity was 70.8%.(3)It is concluded that the HU value of the lumbar 1 vertebra based on chest CT examination is of good value for osteoporosis screening in patients with type 2 diabetes mellitus,and may be an opportunistic and cost-free supplementary screening method for type 2 diabetes mellitus osteoporosis.