Table 3 Model Statistics assessing the association between Fibromyalgia (FMS) and blood serum C-reactive Protein (CRP) quartile adjusting for BMI and Comorbidity index in a US adult population, 2005–2006 (N = 52,535)

CRP level (mg/L)

3.79 (7.22)

5.54 (9.77)

3.75 (7.15)

1.02 (1.01–1.02) (<.0001^*)

1.01 (1.00–1.01) (.004^*)

1.01 (1.00–1.01) (.059)

1.00 (.997–1.01) (.267)

1.00 (.997–1.01) (.279)

CRP Quartile 1^a (ref)

14,516 (27.6%)

192 (17.1%)

14,324 (27.9%)

—

—

—

—

—

 Quartile 2^b

12,221 (23.3%)

214 (19.0%)

12,007 (23.4%)

1.33 (1.09–1.62) (.004^*)

1.13 (0.92–1.38) (.243)

1.07 (0.88–1.32) (.473)

1.04 (0.85–1.28) (.686)

1.03 (0.84–1.27) (.750)

 Quartile 3^c

12,755 (24.3%)

297 (26.4%)

12,458 (24.2%)

1.78 (1.48–2.14) (<.0001^*)

1.23 (1.02–1.48) (.032^*)

1.12 (0.92–1.37) (.244)

1.08 (0.89–1.30) (.452)

1.06 (0.87–1.29) (.576)

 Quartile 4^d

13,043 (24.8%)

422 (37.5%)

12,621 (24.6%)

2.50 (2.10–2.97) (<.0001^*)

1.35 (1.13–1.62) (.0009^*)

1.17 (0.96–1.42) (.120)

1.10 (0.92–1.32) (.310)

1.07 (0.88–1.30) (.510)

Wald X², p for trend^t

118.42, (<.0001*)

17.48, (<.0001*)

4.02, (.045*)

3.44, (.064)

1.23, (.269)