Table 4

Frequency of the IL-6 G-G-G diplotypes, by the DIP OA status (n = 533 to 535)

Condition

Diplotypes

Condition absent

Condition present

Odds ratio (95% confidence interval)

n

Percentage

n

Percentage

Crude

Adjusted

DIP OA

Total n

309

224

other/other

117

37.9

74

33.0

1.00

1.00

G-G-G/other

148

47.9

107

47.8

1.14 (0.78–1.68)

1.17 (0.77–1.76)

G-G-G/G-G-G

44

14.2

43

19.2

1.54 (0.93–2.58)

1.48 (0.86–2.55)

G-G-G carriage

192

62.1

150

67.0

1.23 (0.86–1.77)

1.24 (0.85–1.83)

G-G-G frequency

236

38.2

193

43.1

1.22 (0.96–1.57)

1.20 (0.92–1.56)

Symmetrical DIP OA

Total n

329

205

other/other

127

38.6

64

31.2

1.00

1.00

G-G-G/other

155

47.1

101

49.3

1.29 (0.87–1.91)

1.35 (0.89–2.04)

G-G-G/G-G-G

47

14.3

40

19.5

1.69 (1.01–2.83)

1.65 (0.95–2.84)

G-G-G carriage

202

61.4

141

68.8

1.38 (0.96–2.00)

1.42 (0.96–2.10)

G-G-G frequency

229

35.9

181

42.1

1.30 (1.01–1.67)^a

1.29 (0.99–1.68)

Symptomatic DIP OA

Total n

487

48

other/other

185

38.0

6

35.7

1.00

1.00

G-G-G/other

223

45.8

34

70.8

4.70 (1.93–11.44)^a

5.03 (2.02–12.51)^a

G-G-G/G-G-G

79

16.2

8

16.7

3.12 (1.05–9.29)

3.01 (0.98–9.22)

G-G-G carriage

302

62.0

42

87.5

4.29 (1.79–10.28)^a

4.45 (1.82–10.88)^a

G-G-G frequency

381

39.1

50

51.0

1.83 (1.19–2.81)^a

1.62 (1.07–2.45)^a

Distal interphalangeal osteoarthritis (DIP OA) was defined by the presence of radiographic findings of grade 2 or more in at least two DIP joints. Symmetrical DIP OA was defined by the presence of radiographic findings of grade 2 or more in at least one symmetrical pair of the DIP joints. Symptomatic DIP OA was defined by the presence of both radiographic findings of grade 2 or more and symptoms in at least two DIP joints.

^aP value remained statistically significant after correcting for multiple testing.

Kämäräinen et al. Arthritis Research & Therapy 2008 10:R21   doi:10.1186/ar2374