Table 1. The baseline characteristics in ERGs, NERGs, CSGs, and NCSGs.
| Variables | Dietary energy reduction | Calcium supplementation | ||||
| ERGs | NERGs | P-value | CSGs | NCSGs | P-value | |
| Age (years) | 51.4 (9.4) | 49.0 (8.9) | 0.011 | 50.1 (9.4) | 50.1 (9.2) | 0.934 |
| Male [n (%)] | 232 (45.5) | 212 (41.5) | 0.433 | 221 (36.9) | 251 (59.3) | <0.001 |
| Smoking [n (%)] | 94 (18.4) | 97 (19.0) | 0.900 | 88 (14.8) | 121 (28.6) | 0.004 |
| Drinking [n (%)] | 168 (33.0) | 212 (41.4) | 0.264 | 211 (35.3) | 190 (45.0) | 0.219 |
| Regular exercise [n (%)] | 192 (37.8) | 259 (50.5) | 0.011 | 247 (41.3) | 217 (51.2) | 0.067 |
| Energy intake (kcal/d) | 2165 (984) | 2076 (774) | 0.529 | 2116 (931) | 2261 (943) | 0.150 |
| Ca_dietary (mg/d) | 549 (285) | 551 (279) | 0.961 | 544 (280) | 565 (285) | 0.481 |
| Ca2+_serum (mmol/L) | 2.24 (0.01) | 2.27 (0.01) | 0.102 | 2.25 (0.01) | 2.26 (0.01) | 0.449 |
| 25(OH)D3 (ng/ml) | 17.26(4.33) | 16.84(4.04) | 0.300 | 16.91(3.76) | 17.38(5.08) | 0.353 |
| BMI (kg/m²) | 27.7 (0.18) | 27.4 (0.18) | 0.295 | 27.5 (0.15) | 27.6 (0.23) | 0.740 |
| FSG (mmol/L) | 4.79 (0.06) | 4.57 (0.06) | 0.010 | 4.67 (0.05) | 4.74 (0.08) | 0.453 |
| 2h-glucose (mmol/L) | 6.13 (0.11) | 6.20 (0.11) | 0.671 | 6.10 (0.09) | 6.36 (0.14) | 0.120 |
| Fasting insulin (μ U/L) | 9.52 (0.44) | 9.31 (0.46) | 0.744 | 9.69 (0.36) | 8.81 (0.55) | 0.190 |
| 2h-insulin (μ U/L) | 54.5 (3.5) | 53.5 (3.6) | 0.846 | 54.3 (2.8) | 53.4 (4.3) | 0.863 |
| HbA1c (%) | 5.56 (0.03) | 5.60 (0.03) | 0.394 | 5.61 (0.03) | 5.51 (0.04) | 0.071 |
Note: Data are presented as mean (Standard deviation) with adjustment for age and gender.