Hong Kong Chinese school children with elevated urine melamine levels: A prospective follow up study

BMC Public Health

Table 1 Baseline clinical and biochemical characteristics of the study sample (n = 502).

	All participants	Elevated urinary melamine level (urine melamine/creatinine ratio >7.1 ug/mmol)
Characteristics	(n = 502)	No (n = 455)	Yes (n = 47)	p-value
Sex ^ψ
Male	167 (33.3%)	153 (33.6%)	14 (29.8%)	0.595 ^a
Female	335 (66.7%)	302 (66.4%)	33 (70.2%)
Age (years)	13.2 (3.0)	13.3 (3.0)	12.0 (2.8)	0.004 ^b
Body weight (kg)	43.6 (11.8)	44.1 (11.7)	39.3 (12.1)	0.008 ^b,*
Body height (cm)	152.3 (13.6)	152.8 (13.4)	147.4 (14.6)	0.010 ^b,*
BMI (kg/m²)	18.5 (3.0)	18.6 (3.0)	17.5 (2.4)	0.026 ^b,*
Weight status ^ψ
Normal	428 (85.3%)	384 (84.4%)	44 (93.6%)	0.193 ^c
Overweight	51 (10.2%)	48 (10.5%)	3 (6.4%)
Obesity	23 (4.6%)	23 (5.1%)	0
Urine albumin-creatinine ratio (mg/mmol) ^†	0.70 (0.45 - 2.01)	0.69 (0.44 - 3.23)	0.70 (0.50 - 1.39)	0.820 ^d
Urine melamine/creatinine ratio (μg/mmol) ^†, ^§	0.76 (0.00 - 2.62)	0.52 (0.00 - 1.73)	13.21 (9.09 - 21.55)	<0.001 ^d

Data marked with ^† were presented as medians (interquartile ranges) and with ^ψ as frequencies (%), all others were presented as means (standard deviations).
^a Chi square test; ^b T-test; ^c Fisher's exact test; ^d non-parametric Mann-Whitney test.
^§Undetectable urine melamine level was set to zero.
* There was no statistically significance between the two groups on body weight, body height, BMI and waist circumference after adjusting for age.

ISSN: 1471-2458