Machine learning-based comparison of factors influencing estimated glomerular filtration rate in Chinese women with or without non-alcoholic fatty liver

Table 1 Participant descriptive statistics and risk factors, percentage and mean (± SD)

Characteristics	None	Fatty liver	P value
N number	34, 335	31, 200
Age (yr)	36.75 ± 12.33	47.52 ± 12.8	< 0.001
Income	2.04 ± 1.47	1.61 ± 1.57	< 0.001
Body fat (%)	26.66 ± 5.55	35.96 ± 6.83	< 0.001
Systolic blood pressure (mmHg)	111.83 ± 16.07	124.52 ± 19.68	< 0.001
Diastolic blood pressure (mmHg)	66.81 ± 10.21	73.8 ± 11.69	< 0.001
Leukocyte (× 103/μL)	5.93 ± 1.73	6.45 ± 1.73	< 0.001
Hemoglobin (× 106/μL)	13.09 ± 1.14	13.36 ± 1.18	< 0.001
Platelets (× 103/μL)	248.96 ± 57.74	264.39 ± 63.31	< 0.001
Fasting plasma glucose (mg/dL)	92.75 ± 10.64	103.7 ± 25.6	< 0.001
Total bilirubin (mg/dL)	0.77 ± 0.32	0.73 ± 0.33	< 0.001
Albumin (mg/dL)	4.5 ± 0.26	4.45 ± 0.24	< 0.001
Globulin (mg/dL)	3.08 ± 0.36	3.15 ± 0.36	< 0.001
Alkaline Phosphatase (IU/L)	101.86 ± 49.29	110.72 ± 59.94	< 0.001
Serum glutamic oxaloacetic transaminase (mg/dL)	19.88 ± 11.71	24.61 ± 17.56	< 0.001
Serum glutamic pyruvic transaminase (IU/L)	17.68 ± 18.62	28.72 ± 27.22	< 0.001
Serum γ-glutamyl transpeptidase (IU/L)	14.22 ± 13.94	25.3 ± 30.09	< 0.001
Lactate dehydrogenase (IU/L)	241.42 ± 84.03	246.65 ± 92.63	< 0.001
Estimated glomerular filtration rate (mL/min/1.73 m2)	89.6 ± 76.89	84.33 ± 72.4	< 0.001
Uric acid (mg/dL)	4.88 ± 1.09	5.67 ± 1.34	< 0.001
Triglyceride (mg/dL)	78.81 ± 42.95	139.02 ± 101.03	< 0.001
High density lipoprotein cholesterol (mg/dL)	61.73 ± 14.8	54.17 ± 13.47	< 0.001
Low density lipoprotein cholesterol (mg/dL)	107.97 ± 30.48	125.76 ± 34.09	< 0.001
Calcium (mg/dL)	9.2 ± 0.39	9.29 ± 0.41	< 0.001
Phosphorus (mg/dL)	3.72 ± 0.44	3.7 ± 0.46	< 0.001
Thyroid stimulating hormone (IU/mL)	1.75 ± 3.25	1.94 ± 3.64	< 0.001
C-reactive protein (mg/dL)	0.19 ± 0.45	0.3 ± 0.51	< 0.001
Forced expiratory volume in one second (L)	2.2 ± 0.46	1.96 ± 0.53	< 0.001
Drink area	0.97 ± 6.5	1.38 ± 8.72	< 0.001
Smoke area	1.5 ± 7.15	1.57 ± 7.89	< 0.001
Betel nut area	0 ± 0	0.02 ± 1.2	< 0.001
Sport area	3.32 ± 5.99	3.96 ± 6.19	< 0.001
Sleep time	2.91 ± 0.59	2.87 ± 0.72	0.25
Marriage, n (%)
Unmarried	13 (458)	8 (438)	< 0.001
Married	19 (939)	2 (1545)

Table 2 Comparison with SMAPE, RAE, RRSE, and RMSE between multiple linear regression and machine learning methods

NAFLD+ group with age	MAPE	SMAPE	RAE	RRSE	RMSE
Linear	0.139	0.132	0.845	0.842	13.959
SGB	0.138	0.131	0.841	0.834	13.825
XGBoost	0.139	0.132	0.845	0.842	13.946
Elasticnet	0.139	0.132	0.845	0.842	13.954
NAFLD- group with age
Linear	0.133	0.128	0.868	0.862	14.671
SGB	0.132	0.126	0.855	0.857	14.59
XGboost	0.132	0.126	0.853	0.857	14.58
Elasticnet	0.134	0.128	0.868	0.862	14.673
NAFLD+ group without age
Linear	0.154	0.14	0.872	0.897	15.606
SGB	0.153	0.139	0.865	0.888	15.444
XGboost	0.153	0.14	0.869	0.891	15.49
Elasticnet	0.154	0.14	0.872	0.897	15.596
NAFLD- group without age
Linear	0.134	0.13	0.905	0.906	15.149
SGB	0.133	0.129	0.895	0.892	14.915
XGboost	0.133	0.129	0.895	0.893	14.916
Elasticnet	0.134	0.13	0.904	0.905	15.119

Data showed as mean; SGB: stochastic gradient boosting, XGBoost: eXtreme gradient boosting; RAE: Relative Absolute Error; RRSE: Root Relative Squared Error; RMSE: Root Mean Squared Error; NAFLD: Non-alcoholic fatty liver.

Table 3 The average of the importance of risk factors derived from stochastic gradient boosting, random forest and extreme gradient boost, in NAFLD+ (Model 1, including age)

Variables	SGB	XGBoost	Elasticnet	Average	Rank
Age	100	100	15.08	71.69	1
Income	0.14	0	0	0.05
Body fat	3.94	1.9	3.27	3.04
Systolic blood pressure	1.37	0.67	1.01	1.02
Diastolic blood pressure	2.67	0.67	1.8	1.71
Leukocyte	0.72	0.33	4.32	1.79
Hemoglobin	1	0	0	0.33
Platelets	3.64	1.62	0.31	1.86
Fasting plasma glucose	2.92	1.18	0.66	1.59
Total bilirubin	6.86	2.29	40.24	16.46	6
Albumin	1.84	0.54	49.85	17.41	5
Globulin	0.28	0.29	17.83	6.13
Alkaline Phosphatase	0.99	0.15	0	0.38
Serum glutamic oxaloacetic transaminase	1.63	0.36	0	0.66
Serum glutamic pyruvic transaminase	3.83	1.94	0.82	2.20
Serum γ-glutamyl transpeptidase	1.89	1.33	0.48	1.23
Lactate dehydrogenase	23.21	23.25	0.86	15.77
Uric acid	27.03	24.05	60.42	37.17	2
Triglyceride	0.84	0	0.02	0.29
High density lipoprotein cholesterol	1.99	0.8	1.16	1.32
Low density lipoprotein cholesterol	1.78	0.14	0.1	0.67
Calcium	3.97	2.87	65	23.95	4
Phosphorus	0.79	0.36	0	0.38
Thyroid stimulating hormone	6.92	3.99	4.91	5.27
C-reactive protein	0.61	0.22	6.99	2.61
Forced expiratory volume in one second	6.63	3.41	100	36.68	3
Drink area	0.11	0	0.07	0.06
Smoke area	0.25	0	0	0.08
Betel nut area	0	0	0	0.00
Sport area	0.45	0.2	0.28	0.31
Sleep time	0.14	0	0	0.05
Marriage	0	0	1.99	0.66

SGB: Stochastic gradient boosting; XGBoost: eXtreme gradient boosting; NAFLD: Non-alcoholic fatty liver.

Table 4 The average of the importance of risk factors derived from stochastic gradient boosting, random forest and extreme gradient boost, in NAFLD- (Model 1, including age)

Variables	SGB	XGBoost	Elasticnet	Average	Rank
Age	100	100	15.19	71.73	1
Income	0	0	1.41	0.47
Body fat	3.69	1.05	4.15	2.96
Systolic blood pressure	0.46	0.09	0.75	0.43
Diastolic blood pressure	4.19	3.09	2.96	3.41
Leukocyte	1.21	0.34	4.52	2.02
Hemoglobin	4.81	1	11.57	5.79
Platelets	2.61	1.06	0.2	1.29
Fasting plasma glucose	0.42	0.21	0.17	0.27
Total bilirubin	3.11	1.84	19.24	8.06
Albumin	2.28	1.34	69.53	24.38	4
Globulin	0.42	0.12	3.03	1.19
Alkaline Phosphatase	1.84	0.22	0.04	0.70
Serum glutamic oxaloacetic transaminase	0.52	0	0	0.17
Serum glutamic pyruvic transaminase	3.79	1.94	1.12	2.28
Serum γ-glutamyl transpeptidase	1.16	0	0.38	0.51
Lactate dehydrogenase	21.99	18.24	0.97	13.73	5
Uric acid	26.62	22.99	76.35	41.99	2
Triglyceride	1.59	0.31	0	0.63
High density lipoprotein cholesterol	1.4	0.25	0.65	0.77
Low density lipoprotein cholesterol	2.37	0.26	0.18	0.94
Calcium	1.66	0.64	29.96	10.75	6
Phosphorus	2.05	2.07	10.98	5.03
Thyroid stimulating hormone	11.86	8.69	5.02	8.52
C-reactive protein	0.42	0	2.73	1.05
Forced expiratory volume in one second	5.06	3.01	100	36.02	3
Drink area	0	0.25	0	0.08
Smoke area	0.37	0.17	0.79	0.44
Betel nut area	0	0	0	0.00
Sport area	1.13	0.65	1.55	1.11
Sleep time	0	0	0	0.00
Marriage	0.13	0	5.51	1.88

SGB: Stochastic gradient boosting; XGBoost: eXtreme gradient boosting; NAFLD: Non-alcoholic fatty liver.

Table 5 The average of the importance of risk factors derived from stochastic gradient boosting, random forest and extreme gradient boost, in NAFLD+ (Model 2, excluding age)

Variables	SGB	XGBoost	Elasticnet	Average	Rank
Income	12.88	15.99	8.06	12.31
Body fat	22.25	16.83	3.85	14.31	5
Systolic blood pressure	11.29	9.24	0.41	6.98
Diastolic blood pressure	9.17	6.85	1.19	5.74
Leukocyte	1.73	0.58	1.9	1.40
Hemoglobin	2.57	0.31	4.27	2.38
Platelets	17.83	14.87	0.32	11.01
Fasting plasma glucose	9.72	6.71	0.2	5.54
Total bilirubin	9.6	3.56	28.65	13.94
Albumin	12.05	9.81	100	40.62	3
Globulin	1.85	1.25	10.62	4.57
Alkaline Phosphatase	4.28	0.99	0.06	1.78
Serum glutamic oxaloacetic transaminase	3.45	3.05	1.45	2.65
Serum glutamic pyruvic transaminase	16.27	11.92	1.57	9.92
Serum γ-glutamyl transpeptidase	1.14	0.65	0.28	0.69
Lactate dehydrogenase	100	100	0.6	66.87	1
Uric acid	50.16	45.66	30.15	41.99	2
Triglyceride	6.23	3.56	0.14	3.31
High density lipoprotein cholesterol	0.86	0.82	0.05	0.58
Low density lipoprotein cholesterol	9.6	6.73	0.46	5.60
Calcium	12.48	9.07	53.48	25.01	4
Phosphorus	0.79	1.87	1.48	1.38
Thyroid stimulating hormone	16.42	11.23	2.23	9.96
C-reactive protein	0	0	2.11	0.70
Forced expiratory volume in one second	39.39	44.32	38.15	40.62	3
Drink area	0	0	0.26	0.09
Smoke area	0	0	0	0.00
Betel nut area	0	0	0	0.00
Sport area	3.95	3.83	1.49	3.09
Sleep time	0.86	0.5	4.04	1.80
Marriage	0	0	2.38	0.79

SGB: Stochastic gradient boosting; XGBoost: eXtreme gradient boosting; NAFLD: Non-alcoholic fatty liver.

Table 6 The average of the importance of risk factors derived from stochastic gradient boosting, random forest and extreme gradient boost, in NAFLD- (Model 2, excluding age)

Variables	SGB	XGBoost	Elasticnet	Average	Rank
Income	2.49	1.95	1.61	2.02
Body fat	7.57	2.68	1.48	3.91
Systolic blood pressure	28.66	30.68	0.59	19.98	6
Diastolic blood pressure	18.44	21.96	1.73	14.04
Leukocyte	9.07	5.26	6.63	6.99
Hemoglobin	12.51	1.95	3.14	5.87
Platelets	12.13	8.68	0.23	7.01
Fasting plasma glucose	6.67	4.96	0.7	4.11
Total bilirubin	9.07	5.16	3.37	5.87
Albumin	21.95	20.16	100	47.37	4
Globulin	1.32	0	0	0.44
Alkaline Phosphatase	2.75	0	0.02	0.92
Serum glutamic oxaloacetic transaminase	4.06	3.15	1.59	2.93
Serum glutamic pyruvic transaminase	9.09	6.48	1.74	5.77
Serum γ-glutamyl transpeptidase	1.11	0	0.11	0.41
Lactate dehydrogenase	100	100	0.63	66.88	1
Uric acid	66.92	63.24	36.68	55.61	2
Triglyceride	12.39	8	0.34	6.91
High density lipoprotein cholesterol	2.64	0.67	0.17	1.16
Low density lipoprotein cholesterol	14.18	10.11	0.51	8.27
Calcium	3.82	2.4	21.04	9.09
Phosphorus	5.65	6.52	0.1	4.09
Thyroid stimulating hormone	34.32	24.16	2.56	20.35	5
C-reactive protein	2.68	0	0	0.89
Forced expiratory volume in one second	61.02	64.4	26.93	50.78	3
Drink area	1.01	1.21	0	0.74
Smoke area	2.24	1.22	0.85	1.44
Betel nut area	0	0	0	0.00
Sport area	13.32	11.44	2.46	9.07
Sleep time	0.79	0.47	10.69	3.98
Marriage	8.88	7.85	30.55	15.76

SGB: Stochastic gradient boosting; XGBoost: eXtreme gradient boosting; NAFLD: Non-alcoholic fatty liver.