J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://jocmr.elmerjournals.com

Original Article

Volume 17, Number 3, March 2025, pages 164-173

Predictive Factors for Diagnosing Diabetic Ketoacidosis or Simple Hyperglycemia in Adults With High Blood Glucose: The “1-DKA Alert” Study

↓ Figure 3. Calibration plot for predicted and observed probabilities of diabetic ketoacidosis. CI: confidence interval.

↓ **Table 1.** Baseline Characteristics of Patients With Diabetic Ketoacidosis and Simple Hyperglycemia
Baseline characteristics	Missing	Diabetic ketoacidosis (n = 56), mean ± SD	Simple hyperglycemia (n = 218), mean ± SD	P value
SD: standard deviation; bpm: beats per minute; SpO₂: peripheral capillary oxygen saturation; Cr: Creatinine; eGFR: estimated glomerular filtration rate; CKD: chronic kidney disease.
Female, n (%)	0	31 (55.4)	114 (52.3)	0.765
Age (years)	0	52.9 ± 18.5	60.4 ± 13.7	0.001
Body mass index (kg/m²)	4	22.4 ± 4.6	23.4 ± 5.0	0.209
Symptoms, n (%)	0	54 (96.4)	124 (56.9)	< 0.001
Dyspnea	0	42 (75.0)	74 (33.9)	< 0.001
Gastrointestinal/hepatobiliary	0	23 (41.1)	55 (25.2)	0.030
Fever	0	18 (32.1)	55 (25.2)	0.312
Vital signs
Temperature (°C)	0	36.7 ± 1.0	36.8 ± 1.1	0.613
Respiratory rate	0	27.4 ± 8.7	22.1 ± 5.6	< 0.001
Systolic blood pressure (mm Hg)	0	124.8 ± 34.3	138.3 ± 31.9	0.006
Diastolic blood pressure (mm Hg)	0	74.7 ± 20.5	78.4 ± 18.6	0.199
Mean arterial pressure (mm Hg)	0	91.4 ± 24.1	98.3 ± 21.3	0.035
Pulse rate (bpm)	0	112.4 ± 22.3	95.6 ± 21.8	< 0.001
SpO₂ (%)	0	96.5 ± 6.0	97.1 ± 3.5	0.348
Initial capillary blood glucose (mg/dL)	0	495.3 ± 117.0	420.7 ± 108.5	< 0.001
Initial blood glucose (mg/dL)	0	594.8 ± 299.5	431.3 ± 147.7	< 0.001
Hemoglobin A1c (prior visit) (%)	95	10.1 ± 3.4	9.3 ± 3.0	0.173
Hemoglobin A1c (latest visit) (%)	115	12.2 ± 3.1	10.5 ± 2.9	0.001
Cr (prior visit) (mg/dL) median (IQR)	46	0.87 (0.70, 1.28)	0.94 (0.7, 1.43)	0.330
eGFR (prior visit) (mL/min/1.73 m²), median (IQR)	46	87.26 (54.86, 107.21)	78.76 (46.75, 101.26)	0.135
Cr (latest visit) (mg/dL), median (IQR)	0	1.35 (0.67, 2.76)	1.11 (0.75, 1.70)	0.263
eGFR (latest visit) (mL/min/1.73 m²), median (IQR)	0	56.24 (21.60, 104.55)	63.64 (41.13, 94.71)	0.604
Urine ketone, median (IQR)	0	3 (2, 4)	0 (0, 0)	< 0.001
Suspected infection, n (%)	0	46 (82.1)	104 (47.7)	< 0.001
Presumed source of infection, n (%)
No infection	0	11 (19.6)	113 (51.8)	< 0.001
Pneumonia	0	15 (26.8)	24 (11.0)
Urinary tract infection	0	13 (23.2)	31 (14.2)
Septicemia	0	9 (16.1)	16 (7.3)
Gastrointestinal/hepatobiliary infection	0	1 (1.8)	5 (2.4)
Infected wound	0	0 (0)	16 (7.3)
Other	0	7 (12.5)	13 (6.0)
First diagnosis: hyperglycemia, n (%)	0	2 (3.6)	22 (10.1)	0.183
Previous diabetic ketoacidosis, n (%)	0	14 (25.0)	9 (4.1)	< 0.001
Diabetes mellitus, n (%)	0	54 (96.4)	196 (89.9)	0.183
Type of diabetes mellitus (DM), n (%)
Undiagnosed DM	0	2 (3.6)	22 (10.1)	< 0.001
Type 1 DM	0	8 (14.3)	3 (1.4)
Type 2 DM	0	46 (82.1)	193 (88.5)
CKD stages 3 - 5, n (%)	0	18 (32.1)	81 (37.2)	0.535
Hypertension, n (%)	0	33 (58.9)	154 (70.6)	0.108
Dyslipidemia, n (%)	0	24 (42.9)	120 (55.1)	0.133
Insulin usage, n (%)	0	39 (69.6)	64 (29.4)	< 0.001
Type of insulin, n (%)
Multiple dose regular insulin	169	6 (15.4)	12 (18.2)	0.794
Isophane insulin	170	9 (23.1)	14 (21.5)	1
Mixtard insulin	170	31 (79.5)	41 (63.1)	0.124
Oral hypoglycemic agent used, n (%)	0	25 (44.6)	138 (63.3)	0.014
Type of oral hypoglycemic agents, n (%)
Sulfonylureas (glipizide)	110	9 (36.0)	69 (49.6)	0.277
Biguanides (metformin)	110	24 (96.0)	112 (80.6)	0.081
Thiazolidinediones (pioglitazone)	110	13 (52.0)	45 (32.4)	0.071
Diet control alone, n (%)	0	2 (3.6)	21 (9.6)	0.183
Poor compliance, n (%)	0	42 (75.0)	97 (44.5)	< 0.001

↓ Table 1. Baseline Characteristics of Patients With Diabetic Ketoacidosis and Simple Hyperglycemia

Baseline characteristics

Missing

Diabetic ketoacidosis (n = 56), mean ± SD

Simple hyperglycemia (n = 218), mean ± SD

P value

SD: standard deviation; bpm: beats per minute; SpO₂: peripheral capillary oxygen saturation; Cr: Creatinine; eGFR: estimated glomerular filtration rate; CKD: chronic kidney disease.

Female, n (%)

31 (55.4)

114 (52.3)

0.765

Age (years)

52.9 ± 18.5

60.4 ± 13.7

0.001

Body mass index (kg/m²)

22.4 ± 4.6

23.4 ± 5.0

0.209

Symptoms, n (%)

54 (96.4)

124 (56.9)

< 0.001

Dyspnea

42 (75.0)

74 (33.9)

< 0.001

Gastrointestinal/hepatobiliary

23 (41.1)

55 (25.2)

0.030

Fever

18 (32.1)

55 (25.2)

0.312

Vital signs

Temperature (°C)

36.7 ± 1.0

36.8 ± 1.1

0.613

Respiratory rate

27.4 ± 8.7

22.1 ± 5.6

< 0.001

Systolic blood pressure (mm Hg)

124.8 ± 34.3

138.3 ± 31.9

0.006

Diastolic blood pressure (mm Hg)

74.7 ± 20.5

78.4 ± 18.6

0.199

Mean arterial pressure (mm Hg)

91.4 ± 24.1

98.3 ± 21.3

0.035

Pulse rate (bpm)

112.4 ± 22.3

95.6 ± 21.8

< 0.001

SpO₂ (%)

96.5 ± 6.0

97.1 ± 3.5

0.348

Initial capillary blood glucose (mg/dL)

495.3 ± 117.0

420.7 ± 108.5

< 0.001

Initial blood glucose (mg/dL)

594.8 ± 299.5

431.3 ± 147.7

< 0.001

Hemoglobin A1c (prior visit) (%)

10.1 ± 3.4

9.3 ± 3.0

0.173

Hemoglobin A1c (latest visit) (%)

115

12.2 ± 3.1

10.5 ± 2.9

0.001

Cr (prior visit) (mg/dL) median (IQR)

0.87 (0.70, 1.28)

0.94 (0.7, 1.43)

0.330

eGFR (prior visit) (mL/min/1.73 m²), median (IQR)

87.26 (54.86, 107.21)

78.76 (46.75, 101.26)

0.135

Cr (latest visit) (mg/dL), median (IQR)

1.35 (0.67, 2.76)

1.11 (0.75, 1.70)

0.263

eGFR (latest visit) (mL/min/1.73 m²), median (IQR)

56.24 (21.60, 104.55)

63.64 (41.13, 94.71)

0.604

Urine ketone, median (IQR)

3 (2, 4)

0 (0, 0)

< 0.001

Suspected infection, n (%)

46 (82.1)

104 (47.7)

< 0.001

Presumed source of infection, n (%)

No infection

11 (19.6)

113 (51.8)

< 0.001

Pneumonia

15 (26.8)

24 (11.0)

Urinary tract infection

13 (23.2)

31 (14.2)

Septicemia

9 (16.1)

16 (7.3)

Gastrointestinal/hepatobiliary infection

1 (1.8)

5 (2.4)

Infected wound

0 (0)

16 (7.3)

Other

7 (12.5)

13 (6.0)

First diagnosis: hyperglycemia, n (%)

2 (3.6)

22 (10.1)

0.183

Previous diabetic ketoacidosis, n (%)

14 (25.0)

9 (4.1)

< 0.001

Diabetes mellitus, n (%)

54 (96.4)

196 (89.9)

0.183

Type of diabetes mellitus (DM), n (%)

Undiagnosed DM

2 (3.6)

22 (10.1)

< 0.001

Type 1 DM

8 (14.3)

3 (1.4)

Type 2 DM

46 (82.1)

193 (88.5)

CKD stages 3 - 5, n (%)

18 (32.1)

81 (37.2)

0.535

Hypertension, n (%)

33 (58.9)

154 (70.6)

0.108

Dyslipidemia, n (%)

24 (42.9)

120 (55.1)

0.133

Insulin usage, n (%)

39 (69.6)

64 (29.4)

< 0.001

Type of insulin, n (%)

Multiple dose regular insulin

169

6 (15.4)

12 (18.2)

0.794

Isophane insulin

170

9 (23.1)

14 (21.5)

Mixtard insulin

170

31 (79.5)

41 (63.1)

0.124

Oral hypoglycemic agent used, n (%)

25 (44.6)

138 (63.3)

0.014

Type of oral hypoglycemic agents, n (%)

Sulfonylureas (glipizide)

110

9 (36.0)

69 (49.6)

0.277

Biguanides (metformin)

110

24 (96.0)

112 (80.6)

0.081

Thiazolidinediones (pioglitazone)

110

13 (52.0)

45 (32.4)

0.071

Diet control alone, n (%)

2 (3.6)

21 (9.6)

0.183

Poor compliance, n (%)

42 (75.0)

97 (44.5)

< 0.001

↓ **Table 2.** Final multivariable risk ratio regression analysis for the predictive model
Predictors	Diabetic ketoacidosis
mRR: multivariable risk ratio; DM: diabetes mellitus; CI: confidence interval.
Initial capillary blood glucose (mg/dL)	1	1.00, 1.00	0.043
History of DM	Reference
Type 1 DM	2.93	1.00, 8.52	0.049
Type 2 DM	2.14	0.83, 5.53	0.117
Insulin usage	2.79	1.63, 4.77	< 0.001
Poor compliance	2.43	1.45, 4.05	0.001
Respiratory rate	1.04	1.01, 1.06	0.001
Suspected infection	2.51	1.32, 4.78	0.005

↓ Table 2. Final multivariable risk ratio regression analysis for the predictive model

Predictors

Diabetic ketoacidosis

mRR

95% CI

P value

mRR: multivariable risk ratio; DM: diabetes mellitus; CI: confidence interval.

Initial capillary blood glucose (mg/dL)

1.00, 1.00

0.043

History of DM

Reference

Type 1 DM

2.93

1.00, 8.52

0.049

Type 2 DM

2.14

0.83, 5.53

0.117

Insulin usage

2.79

1.63, 4.77

< 0.001

Poor compliance

2.43

1.45, 4.05

0.001

Respiratory rate

1.04

1.01, 1.06

0.001

Suspected infection

2.51

1.32, 4.78

0.005

↓ **Table 3.** Internal Validation Using the Bootstrap Resampling Method
Parameters	Apparent performance	Bootstrap performance
AuROC: area under the receiver operating characteristic curve; CITL: calibration-in-the-large; E:O ratio: expected-to-observed outcomes ratio.
AuROC	0.8777 (0.8294, 0.9259)	0.8770 (0.8330, 0.9310)
Slope	1.000 (0.730, 1.270)	0.991 (0.743, 1.285)
E:O ratio	1.000	1.004
CITL	0.000 (-0.367, 0.367)	0.002 (-0.386, 0.425)
Bootstrap shrinkage	-	0.991

↓ Table 3. Internal Validation Using the Bootstrap Resampling Method

Parameters

Apparent performance

Bootstrap performance

AuROC: area under the receiver operating characteristic curve; CITL: calibration-in-the-large; E:O ratio: expected-to-observed outcomes ratio.

AuROC

0.8777 (0.8294, 0.9259)

0.8770 (0.8330, 0.9310)

Slope

1.000 (0.730, 1.270)

0.991 (0.743, 1.285)

E:O ratio

1.000

1.004

CITL

0.000 (-0.367, 0.367)

0.002 (-0.386, 0.425)

Bootstrap shrinkage

0.991

↓ **Table 4.** Accuracy and Diagnostic Indices at Different Probability Cut-Points for Predicting DKA
Cut-point	DKA (n = 56)	Simple hyperglycemia (n = 218)	Total	Sensitivity	Specificity	PPV	NPV
DKA: diabetic ketoacidosis; PPV: positive predictive value; NPV: negative predictive value.
Probability > 15%	50 (18.2%)	67 (24.5%)	117	89.3%	78.1%	42.7%	96.2%
Probability ≤ 15%	6 (2.2%)	151 (55.1%)	157
Probability > 19.4%	43 (15.7%)	42 (15.3%)	85	76.8%	80.7%	50.6%	93.1%
Probability ≤ 19.4%	13 (4.7%)	176 (64.3%)	189
Probability > 25%	38 (13.9%)	25 (9.1%)	63	67.9%	88.5%	60.3%	91.5%
Probability ≤ 25%	18 (6.6%)	193 (70.4%)	211

↓ Table 4. Accuracy and Diagnostic Indices at Different Probability Cut-Points for Predicting DKA

Cut-point

DKA (n = 56)

Simple hyperglycemia (n = 218)

Total

Sensitivity

Specificity

PPV

NPV

DKA: diabetic ketoacidosis; PPV: positive predictive value; NPV: negative predictive value.

Probability > 15%

50 (18.2%)

67 (24.5%)

117

89.3%

78.1%

42.7%

96.2%

Probability ≤ 15%

6 (2.2%)

151 (55.1%)

157

Probability > 19.4%

43 (15.7%)

42 (15.3%)

76.8%

80.7%

50.6%

93.1%

Probability ≤ 19.4%

13 (4.7%)

176 (64.3%)

189

Probability > 25%

38 (13.9%)

25 (9.1%)

67.9%

88.5%

60.3%

91.5%

Probability ≤ 25%

18 (6.6%)

193 (70.4%)

211