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Table 1 Characteristics of all included controls, and pre-symptomatic individuals, also separated by gender

From: Vitamin D in individuals before onset of rheumatoid arthritis - relation to vitamin D binding protein and its associated genetic variants

  All Male Female
Controls (n = 267) Pre-symptomatic individuals (n = 515) p a Controls (n = 79) Pre-symptomatic individuals (n = 150) p a Controls (n = 188) Pre-symptomatic individuals (n = 365) p a
Gender, female n (%) 188 (70.4) 365 (70.9) 0.89
Age at sample donation, years, mean (SD) 53.3 (9.3) 52.2 (9.4) 0.14 52.3 (8.7) 51.6 (9.3) 0.59 53.7 (9.5) 52.5 (9.5) 0.15
Time between sampling and onset of symptoms, years (SD) 6.2 (4.3) 6.3 (4.2) 6.2 (4.3)
BMI, mean (S.D.) 25.4 (3.8) 26.3 (4.3) 0.01 25.8 (2.6) 26.9 (3.9) 0.03 25.2 (4.2) 26 (4.4) 0.10
Ever smoker, n (%) 103/242 (42.6) 324/514 (63.0) < 0.001 42/76 (55.3) 103/150 (68.7) < 0.05 61/166 (36.7) 221/364 (60.7) < 0.001
Education levelb, n (%) 173/224 (77.2) 377/453 (83.2) 0.06 55/72 (76.4) 133/149 (89.3) 0.01 118/152 (77.6) 244/304 (80.3) 0.51
Season at time of sample collectionc, n (%) 124/267 (46.4) 266/515 (51.7) 0.61 48/79 (60.8) 75/150 (50.0) 0.12 93/188 (49.5) 174/365 (47.7) 0.68
Total 25(OH)D nmol/L, mean (SD) 54.5 (17.4) 53.8 (17.7) 0.56 53.7 (17.7) 55.5 (17.6) 0.45 54.9 (17.3) 53.1 (17.7) 0.24
DBP mg/L, mean (SD) 278 (117.8) 279.2 (117.6) 0.89 265.4 (122.8) 249.1 (111.3) 0.31 283.3 (115.5) 291.6 (118) 0.43
Total 25(OH)D:DBP molar ratiod, mean (SD) 14.1 (8.8) 13.9 (9.8) 0.77 15.4 (10.4) 16.3 (10.6) 0.51 13.5 (8) 12.9 (9.2) 0.39
  1. aCalculated with Mann-Whitney U test for continuous variables or Pearson Chi-Square for dichotomous variables
  2. bPresented as having no academic education/university
  3. cPresented as light time of year, including sampling time between March and September
  4. dProxy for free vitamin D concentration
  5. The significant p-values are shown in bold