Comparing radiopaque markers and ¹³C-labelled breath test in diabetic gastroparesis diagnostics

Figures & data

Figure 1 Study protocol.

Abbreviations: PAGI-SYM, Patient assessment of upper gastrointestinal symptom severity index; GEBT, ¹³Carbon-labelled gastric emptying breath test of solids; ROM, [gastric emptying of] radiopaque markers.

Figure 2 Inclusion flow chart.

Abbreviations: ROM, [gastric emptying of] radiopaque markers; GEBT, ¹³Carbon-labelled gastric emptying breath test of solids.

Table 1 Clinical characteristics

Variables	Patients
n	45
Gender (♀/♂), n	30/15
Diabetes type (1/2), n	40/5
Age, years	45 (34–53)
Diabetes duration, years	24 (18–32)
Late complications (0/1/≥2), n	9/12/24
HbA1c, mmol/mol	76 (63–76)
GCSI (mean, SD)	3.00 (0.87)
PAGI-SYM (mean, SD)	2.78 (0.87)

Note: Data are given as median and quartiles unless otherwise indicated.

Abbreviations: HbA1c, glycated hemoglobin; GCSI, Gastroparesis Cardinal Symptom Index; PAGI-SYM, Patient Assessment of Upper Gastrointestinal Symptom Severity Index.

Figure 3 ROC curve for a positive ROM test compared to GEBT. Area under curve for the ROC was 0.63 (95% CI 0.48–0.70).

Abbreviations: ROC, receiver operating characteristics; AUC, area under curve; ROM, [gastric emptying of] radiopaque markers; GEBT, ¹³Carbon-labelled gastric emptying breath test of solids.

Figure 4 Inter-rater reliability testing showed a strong correlation of r=0.97, P<0.0001.

Abbreviation: ROM, [gastric emptying of] radiopaque markers.

Table 2 Glycated hemoglobin (HbA1c) levels by test results

Variables	ROM	GEBT
HbA1c (negative GE test), mmol/mol	72 (16)	72 (22)
HbA1c (positive GE test), mmol/mol	83 (26)	77 (25)
Difference between groups	S (P=0.04)	NS (P=0.08)
Association gastric retention vs HbA1c (r)	NS (P=0.21)	0.41 (P=0.008)

Note: Data are given as median and interquartile range unless otherwise indicated.

Abbreviations: ROM, [gastric emptying of] radiopaque markers; GEBT, ¹³Carbon-labelled gastric emptying breath test of solids; S, significant; NS, non-significant; GE, gastric emptying.

Table 3 Symptom scores by test results

Variables	Neg. GE	ROMPos. GE	P-value	Neg. GE	GEBTPos. GE	P-value
1) Nausea/vomiting	3.00 (2)	2.00 (2)	0.44	2.84 (3)	2.17 (2)	0.63
2) Fullness/early satiety	3.75 (2)	2.50 (1)	0.07	3.50 (2)	2.75 (2)	0.42
3) Bloating	4.00 (3)	3.50 (2)	0.34	3.25 (2)	3.75 (2)	0.28
4) Upper abdominal pain	3.00 (4)	3.00 (2)	0.93	3.00 (4)	3.50 (2)	0.29
5) Lower abdominal pain	3.00 (2)	3.00 (3)	0.46	3.00 (2)	3.00 (3)	0.42
6) Heartburn/regurgitation	1.86 (3)	2.08 (2)	0.84	1.86 (3)	1.86 (2)	0.94
GCSI (mean, SD)	3.19 (0.97)	2.76 (0.68)	0.12	2.89 (0.84)	2.91 (0.83)	0.92
PAGI-SYM (mean, SD)	2.89 (1.03)	2.64 (0.60)	0.32	2.65 (0.84)	2.70 (0.82)	0.86

Note: Data are given as median and interquartile range unless otherwise indicated.

Abbreviations: ROM, [gastric emptying of] radiopaque markers; GEBT, ¹³Carbon-labelled gastric emptying breath test of solids; Neg. GE, negative gastric emptying test; Pos. GE, positive gastric emptying test; GCSI, Gastroparesis Cardinal Symptom Index; PAGI-SYM, Patient Assessment of Upper Gastrointestinal Symptom Severity Index.

Table 4 Late complications of diabetes mellitus by test results

Late complication	ROM (total retention, %)			GEBT (T ½, min.)
	-	+	P-value	-	+	P-value
Retinopathy	11.5 (31)	59 (77)	0.014	154 (40)	150 (53)	0.49
Nephropathy	22 (51)	59 (63)	0.062	150 (40)	152.5 (66)	0.70
Polyneuropathy	31 (60)	40.5 (69)	0.09	135 (42)	157.5 (51)	0.014
Diabetic wounds	31.5 (67)	56 (79)	0.29	137 (48)	165 (38)	0.004
Coronary heart disease	34 (77)	53 (68)	0.69	150 (47)	158 (67)	0.25
Any late complications (≥1)	3 (33)	47 (75)	0.028	133 (25)	152 (51)	0.29

Note: Data are given as median and interquartile range unless otherwise indicated.

Abbreviations: T ½, half-time; (-), patients without the specified complication; (+), patients with the specified complication.

Figure 5 Abdominal radiograph taken after four hours in a patient undergoing ROM testing. As indicated by the red arrow, ROM can be hard to distinguish from the underlying spine, as they have almost identical X-ray opacity.

Abbreviation: ROM, [gastric emptying of] radiopaque markers.