TABLE 2.
Baseline characteristics of ovarian cancer patients by tertiles of dietary copper/zinc ratio (N = 701).
| Characteristics | All patients | Tertiles of dietary copper/zinc ratio |
P-value* | ||
| I | II | III | |||
| Range (mg/d) | <0.18 | 0.18–0.26 | >0.26 | ||
| No. of patients/deaths | 701/130 | 233/46 | 233/48 | 235/36 | 0.29 |
| Mean (SD) age at diagnosis (years) | 53.60 (9.44) | 54.34 (9.20) | 52.80 (9.34) | 53.65 (9.74) | 0.25 |
| Mean (SD) body mass index (kg/m2) | 32.79 (16.54) | 23.17 (3.33) | 23.16 (3.29) | 23.40 (4.09) | 0.94 |
| Mean (SD) physical activity (MET h/d) | 15.78 (11.25) | 15.77 (11.41) | 15.80 (10.89) | 15.74 (11.50) | 0.95 |
| Ever cigarette smoking | 68 (9.70) | 25 (10.73) | 21 (9.01) | 22 (9.36) | 0.80 |
| Ever alcohol drinking | 149 (21.26) | 50 (21.46) | 50 (21.46) | 49 (20.85) | 0.98 |
| Ever menopause | 506 (72.18) | 172 (73.82) | 165 (70.82) | 169 (71.91) | 0.76 |
| Ever diet change before diagnosis | 168 (23.97) | 49 (21.03) | 55 (23.61) | 64 (27.23) | 0.29 |
| Parity | 0.32 | ||||
| ≤1 | 504 (71.90) | 160 (68.67) | 168 (72.10) | 176 (74.89) | |
| ≥2 | 197 (28.10) | 73 (31.33) | 65 (27.90) | 59 (25.11) | |
| Menarche age | 0.61 | ||||
| ≤16 | 591 (84.31) | 198 (84.98) | 192 (82.40) | 201 (85.53) | |
| >16 | 110 (15.69) | 35 (15.02) | 41 (17.60) | 34 (14.47) | |
| Educational level | 0.44 | ||||
| Junior secondary or below | 373 (53.21) | 133 (57.08) | 119 (51.07) | 121 (51.49) | |
| Senior high school/technical secondary school | 147 (20.97) | 49 (21.03) | 52 (22.32) | 46 (19.57) | |
| Junior college/university or above | 181 (25.82) | 51 (21.89) | 62 (26.61) | 68 (28.94) | |
| Income per month (Yuan) | 0.11 | ||||
| <5,000 | 420 (59.91) | 141 (60.52) | 141 (60.52) | 138 (58.72) | |
| 5,000– < 10,000 | 193 (27.53) | 71 (30.47) | 54 (23.18) | 68 (28.94) | |
| ≥ 10,000 | 88 (12.56) | 21 (9.01) | 38 (16.30) | 29 (12.34) | |
| Mean (SD) total energy intake (kcal/d) | 1456.93 (552.98) | 1253.53 (464.72) | 1424.92 (471.72) | 1690.33 (618.93) | <0.05 |
| Mean (SD) protein intake (g/d) | 58.51 (24.79) | 47.21 (20.26) | 56.40 (19.61) | 71.82 (27.22) | <0.05 |
| Mean (SD) total fiber intake (g/d) | 17.53 (8.62) | 12.27 (5.32) | 17.04 (6.99) | 23.23 (9.22) | <0.05 |
| Mean (SD) calcium intake (mg/d) | 454.47 (248.46) | 333.55 (194.16) | 427.52 (182.69) | 601.07 (278.09) | <0.05 |
| Mean (SD) iron intake (mg/d) | 18.92 (7.98) | 15.00 (5.61) | 18.28 (6.71) | 23.43 (8.86) | <0.05 |
Values are numbers (percentages) unless stated otherwise. MET, metabolic equivalents of task; SD, standard deviation. *P-values were determined with one-way ANOVA or the Kruskal-Wallis test for continuous variables and the chi-square test for categorical variable.