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.