Table 1 Baseline characteristics of the study groups

Demographics

 Age (years)

50.17 ± 10.68

58.30 ± 9.89

< 0.01^†

 Sex (% male)

161 (81.3%)

259(90.9%)

< 0.01^†

 Hypertension (%)

29 (14.6%)

58 (20.5%)

0.16

 Diabetes mellitus (%)

18 (9.1%)

35 (12.4%)

0.42

 Dyslipidemia (%)

35 (17.7%)

45 (15.9%)

0.61

 T4 stage (%)

58 (29.7%)

99 (35.6%)

0.18

 Advanced T (T3/T4) stages (%)

109 (55.9%)

167 (60.1%)

0.37

 Smoking (%)

76 (38.3%)

162 (57.2%)

< 0.01^†

 Betel quid chewing (%)

28 (14.2%)

123 (43.4%)

< 0.01^†

 RT dose (centi-grays)

6996 (6996, 6996)

6600 (6600, 6996)

< 0.01^†#

 Proton beam therapy (%)

86 (43.4%)

46 (16.1%)

< 0.01^†

 Re-irradiation

11 (5.6%)

19 (6.7%)

0.63

Cancer types

–

 NPC

198 (100%)

0 (0%)

 Oral cavity/oropharyngeal cancer

0 (0%)

199 (69.8%)

 Laryngeal cancer

0 (0%)

23 (8.1%)

 Hypopharyngeal cancer

0 (0%)

56 (19.6%)

 Others

0 (0%)

7 (2.5%)

Laboratory data

 Glycated hemoglobin (%)

5.66 ± 0.54

6.31 ± 0.69

0.28

 Creatinine (mg/dL)

1.02 ± 1.08

1.04 ± 1.04

0.91

 Homocysteine

12.05 ± 5.90

12.69 ± 4.83

0.31

 High-sensitivity CRP

3.25 ± 6.51

10.84 ± 54.50

0.07

 Uric acid (mg/dL)

6.79 ± 9.39

7.60 ± 13.25

0.51

 Triglyceride (mg/dL)

129.39 ± 93.59

147.03 ± 95.69

0.07

 Free T4

1.25 ± 3.69

1.38 ± 6.78

0.83

 Time from RT to the last follow-up (months)

35 (21, 46)

30 (18, 42)

0.03^†#