Measurement of hepatic functional mass by means of 13C-methacetin and 13C-phenylalanine breath tests in chronic liver disease: Comparison with Child-Pugh score and serum bile acid levels

Table 1 Patient characteristics.

	CTR n = 40	CH n = 50	LCA n = 30	LCB n = 30	LCC n = 30
Gender male/female	25/15	27/23	23/7	20/10	22/8
Age mean (range)	50 (30-80)	57 (38-78)	60 (33-80)	63 (32-80)	59 (39-76)
BSA Mean	1.76	1.75	1.78	1.74	1.72
Etiology Viral/Alcoholic	0	50/0	22/8	25/5	24/6
Child score Mean (range)	0	0	5.38 (5-6)	8.0 (7-9)	10.54 (10-15)

CTR: Controls; CH: Chronic hepatitis; LCA: Child A cirrhosis; LCB: Child B; LCC: Child C; BSA: Body surface area.

Table 2 ¹³CO₂-peak and area under the curve (AUC) of ¹³CO₂ maximal scores in all groups of subjects studied.

Tests	CTR Mean (95% CI)	CH Mean (95% CI)	LCA Mean (95% CI)	LCB Mean (95% CI)	LCC Mean (95% CI)
13C- phenylalanine
13CO2-peak	12.68 (10.94-14.42)	16.11 (13.58-18.63)	11.85 (9.41-14.29)	10.45 (8.07- 12.83)	7.11 (2.74-11.47)
AUC13CO2max	5.40 (2.32-7.62)	6.85 (2.83-12.80)	5.81 (2.64-10.36)	4.60 (2.13-9.25)	5.40 (2.77-10.65)
13C-methacetin
13CO2-peak	31.03b (25.61-36.46)	22.80d (20.74-24.85)	19.19f (15.60-22.77)	10.18 (8.52-11.83)	7.02 (5.03-9.00)
AUC13CO2 max	16.76h (7.35-28.04)	14.69d (5.41-31.27)	9.44e (2.76-29.01)	4.91 (3.13-8.83)	5.32 (2.87-7.17)

CTR: Controls, CH: Chronic hepatitis, LCA: Child A cirrhosis, LCB: Child B, LCC: Child C ^bP<0.001 vs All groups ^dP<0.001 vs Child B,C. ^fP<0.01 vs Child B,C. ^hP<0.001 vs Child A,B,C. ^eP<0.05 vs Child B.

Table 3 Areas under receiver operating characteristic (ROC) curves for phenylalanine breath test (PBT) and methacetin breath test (MBT) in chronic hepatitis and cirrhotic patients.

PBT collecting time	Area	SE	MBT collecting time	Area	SE
10 min	0.45	0.07	10 min	0.83	0.04
20 min	0.54	0.07	20 min	0.86	0.04
30 min	0.59	0.07	30 min	0.89	0.03
40 min	0.64	0.06	40 min	0.91	0.03
50 min	0.69	0.06	50 min	0.92	0.03
60 min	0.72	0.05	60 min	0.93	0.03
70 min	0.7	0.06	70 min	0.93	0.02
80 min	0.7	0.06	80 min	0.93	0.02
90 min	0.7	0.06	90 min	0.93	0.02
100 min	0.71	0.05	100 min	0.93	0.02
110 min	0.72	0.06	110 min	0.92	0.03
120 min	0.72	0.05	120 min	0.92	0.03

Table 4 Comparison between area under the receiver operating characteristic (ROC) curves for methacetin breath test (MBT) and phenylalanine breath test (PBT).

Group	Time (min)	MBT		PBT		χ2
		Area	SE	Area	SE
CTR vs all patient	60	0.86	0.04	0.73	0.04	0.02
CH vs C	60	0.89	0.03	0.69	0.05	0.003
CTR vs CH	60	0.67	0.07	0.56	0.008	ns
CH vs C-Child A	60	0.79	0.05	0.6	0.07	0.02

CTR : Controls; CH: Chronic hepatitis; C: Cirrhosis (Child A,B,C).

Table 5 Multiple regression analysis of ¹³C-methacetin breath test, serum levels of cholic acid ( CCA) and chenodeoxycholic acid (CDCA) conjugates.

Variable	Beta	P
13C-methacetin (60 min % oxidation)	-0.544	0
CCA	0.576	0.0016
CDCA	0.855	0.001

r² = 0.660.

Table 6 Multiple regression analysis of ¹³C-phenylalanine breath test, serum levels of cholic acid (CCA) and chenodeoxycholic acid (CDCA) conjugates.

Variable	Beta	P
13C-phenylalanine (60 min % oxidation)	-0.252	0.057
CCA	0.487	0.07
CDCA	1.01	0

r² = 0.545.