Risk factors for acute kidney injury (AKI) in infants with melamine-associated urolithiasis and follow-up: a multi-center retrospective analysis

Figures & data

Table 1. General data.

Risk factor		AKI (%) (n = 47)	Control (%) (n = 572)	Odds ratio (95% CI)		p Values
Gender	M	34 (72.3)	374 (65.4)	1.39 (0.71–2.68)	0.97	0.33
	F	13 (27.7)	198 (34.6)	1.00
Age (month)	–	10.83 ± 5.11	16.77 ± 11.37	–	–	0.000
PIT (month)	–	9.30 ± 3.89	11.31 ± 8.05	–	–	0.008
SanLu® powder	Y	46 (97.9)	401 (70.1)	19.62 (2.68–143.39)	24.08	0.000^a
	N	1 (2.1)	171 (29.9)	1.00
Diarrhea	Y	23 (48.9)	10 (1.7)	53.86 (23.08–125.68)	91.80	0.000^a
	N	24 (51.1)	562 (98.3)	1.00
Dehydration	Y	16 (34.0)	1 (0.2)	294.71 (37.85–2294.69)	80.78	0.000^a
	N	31 (66.0)	571 (99.8)	1.00
Fever	Y	18 (38.3)	18 (3.1)	19.10 (9.00–40.54)	32.23	0.000^a
	N	29 (61.7)	554 (96.9)	1.00
URTI	Y	15 (31.9)	25 (4.4)	10.26 (4.93–21.34)	52.17	0.000^a
	N	32 (68.1)	547 (95.6)	1.00

Note: ^aContinuity corrected Chi-square tests.

Table 2. Regression analysis of age, powder-intake time and AKI occurrence in infants.

					95% CI
		AKI group (%)	Control group (%)	Odds ratio	95% lower	95% upper	p Value
Age (months)  = 25.82, p < 0.01	<6 m	1 (2.1)	37 (6.5)	3.76	0.23	61.50	0.35
	6 ∼ 11 m	27 (57.4)	172 (30.1)	9.22	3.17	26.84	0.000
	12 ∼ 17 m	16 (34.0)	165 (28.8)	5.70	1.87	17.35	0.002
	18 ∼ 23 m	2 (4.3)	59 (10.3)	2.98	0.41	21.65	0.28
	24 m ∼	1 (2.1)	139 (24.3)	1	–	–
PIT(month)  = 5.66, p = 0.017	12 m ∼	12 (25.5)	217 (37.9)	0.968	0.353	2.650	0.968
	6 ∼ 11m	29 (61.7)	250 (43.7)	2.075	1.127	3.822	0.019
	3 ∼ 5m	4 (8.5)	71 (12.4)	0.958	0.167	5.489	0.958
	<3 m	2 (4.3)	34 (5.9)	1	–	–	–

Table 3. Correlation matrix of presenting symptoms.

	Fever	Diarrhea	Dehydration	URTI
Fever	1.000	0.433	0.338	0.524
Diarrhea	–	1.000	0.708	0.259
Dehydration	–	–	1.000	0.277
URTI	–	–	–	1.000

Note: All p value < 0.01.

Table 4. Correlation between symptom frequency and AKI.

				95% CI
Frequency	AKI (%)	Control (%)	Odds ratio	95% Lower	95% Upper
4	5 (10.6)	1 (0.2)	178.000	19.576	1618.541
3	7 (14.9)	1 (0.2)	249.200	28.819	2154.814
2	11 (23.4)	11 (1.9)	35.600	13.352	94.919
1	9 (19.1)	25 (4.4)	12.816	5.115	32.113
0	15 (31.9)	534 (93.4)	1	–	–

Note:  = 113.85, p = 0.000.

Table 5. Logistic regression analysis on AKI caused by melamine-associated urolithiasis.

						95% CI
	B	Standard error	Wald	p Value	Odds ratio	95% Lower	95% Upper
Constant	–6.848	1.123
Symptoms Frequency (1)	1.455	0.457	10.155	.001	4.29	1.75	10.49
Sanlu® milk powder	2.982	1.020	8.550	0.003	19.73	2.67	145.66
6 ∼ 11 m	2.260	0.553	16.727	0.000	9.59	3.25	28.33
12 ∼ 17 m	1.620	0.575	7.952	0.005	5.06	1.64	15.59