Abstract: Objective To establish of blood beta hydroxybutyrate (βOHB) threshold for diagnosing type 2 diabetes ketoacidosis
(DKA) and explore the relationship between βOHB levels and the severity of DKA. Methods Correlation analysis was
performed between serum βOHB and [HCO3] in type 2 diabetic patients admitted in the emergency department in the past
year. Regression equation was used to calculate the concentration of βOHB corresponding to a [HCO3] level of 18.0, 15, and
10.0 mmol/L, and βOHB concentration corresponding to a [HCO3] level of 18.0 mmol/l was used as the DKA diagnostic
threshold. Results The serum βOHB level and [HCO3] concentration showed a good correlation (R2=0.7023, P<0.001). βOHB
concentrations that corresponded to a [HCO3] level of 18.0, 15, and 10.0 mmol/L were 3.0, 4.70, and 7.5 mmol/L, respectively, in
accordance with the severity of DKA. Combined with the blood glucose concentration ≥13.9 mmol/L, a blood βOHB≥3.0
mmol/L showed a sensitivity of 99%, specificity of 86%, and total effectiveness of 92.81% for diagnosing DKA. Conclusion A
serum βOHB level above 3.0 mmol/L can be used as the diagnostic threshold of DKA. βOHB can serve as an index for
assessing the severity of DKA.