Comparison of fatty liver index with noninvasive methods for steatosis detection and quantification

Table 1 Characteristics of the study sample, distribution of steatosis as predicted by different methods, and comparison between subjects with fatty liver index ≥ 60 and < 60

Characteristics/method	Range	Total (n = 338)	FLI < 60 (n = 259)	FLI≥60 (n = 79)	P value
Age (yr)		50.8 ± 10.4	50.0 ± 10.4	53.3 ± 10.0	0.01
Male %		53.0	48.3	68.4	0.002
BMI (kg/m2)		27.2 ± 4.4	25.6 ± 3.2	32.4 ± 3.9	< 0.001
ALT (U/L)	5-39	22.1 ± 9.6	20.6 ± 7.4	26.9 ± 13.5	< 0.001
AST (U/L)	5-40	23.0 ± 5.5	22.5 ± 4.8	24.7 ± 7.0	0.008
GGT (U/L)	6-28	16.0 ± 12.1	13.9 ± 11.1	22.7 ± 12.7	< 0.001
Glucose (mg/dL)	70-110	90.8 ± 19.8	87.6 ± 16.2	101.0 ± 26.1	< 0.001
Insulin (μU/mL)	5-25	22.3 ± 11.7	19.5 ± 10.0	31.5 ± 12.3	< 0.001
Triglycerides (mg/dL)	50-175	116.8 ± 60.4	100.2 ± 44.4	170.9 ± 73.3	< 0.001
Ferritin (ng/mL)	7.1-151	72.7 ± 60.1	64.6 ± 55.3	100.1 ± 67.5	< 0.001
FL on AUS % (n = 338)		31.1	18.5	72.2	< 0.001
HRI (n = 331)		1.3 ± 0.4	1.2 ± 0.3	1.6 ± 0.4	< 0.001
HRI ≥ 1.50 (FL) %		24.2	13.9	57.0	< 0.001
SteatoTest (n = 338)		0.3 ± 0.2	0.2 ± 0.1	0.6 ± 0.1	< 0.001
S ≥ 2 (FL) %		20.4	3.9	74.7	< 0.001
S0 %		66.9	84.2	10.1	< 0.001
S1 %	1-5	12.7	12.0	15.2	0.45
S2 %	6-33	13.0	3.9	43.0	< 0.001
S3-S4 %	34-100	7.4	0	31.6	< 0.001
FLI (n = 338)		36.7 ± 27.7	24.2 ± 17.1	77.8 ± 11.1	< 0.001
FLI ≥ 60 (FL) %		23.4	NA	NA	NA
FLI < 30 %		48.8	NA	NA	NA

Data are mean ± SD or proportion. BMI: Body mass index; ALT: Alanine amino transferase; AST: Abstract syntax tree; GGT: Gamma-glutamyl transpeptidase; FL: Fatty liver; FLI: Fatty liver index; AUS: Abdominal ultrasound; HRI: Hepatorenal ultrasound index; NA: Not avaliable.

Table 2 Diagnostic value of fatty liver index for predicting steatosis vs SteatoTest or hepatorenal ultrasound index or abdominal ultrasound

FLI≥60 vs	Sensitivity %	Specificity %	PPV %	NPV %	κ
SteatoTest ≥ S2 (n = 338)	85.5	92.6	74.7	96.1	0.74
HRI ≥ 1.50 (n = 331)	56.3	86.5	57	86.1	0.43
Abdominal ultrasound fatty liver (n = 244)	80.3	87.3	72.2	91.5	0.65

HRI: Hepatorenal ultrasound index; FLI: Fatty liver index; PPV: Positive predictive value; NPV: Negative predictive value.