Table 2

Association of classic risk factors and RA characteristics with insulin sensitivity and β-cell function in patients and controls

RA and controls (n = 200)

RA patients (n = 101)

Unadjusted model

Adjusted model


β coefficient (95% CI)

P

β coefficient (95% CI)

P

β coefficient (95% CI)

P

Insulin resistance (logHOMA-IR)


RA versus controls (β 95% CI for RA, 101, and controls, 99)

0.40 (0.20-0.59)

0.00

GC-RA versus controls (β 95% CI for RA, 56, and controls, 99)

0.14 (0.05-0.24)

0.00

GC+RA versus controls (β 95% CI for RA, 55, and controls, 99)

0.17 (0.10-0.24)

0.00

RA features


Disease duration

-0.02 (-0.06-0.01)

0.19

-0.01 (-0.05-0.03)

0.59

RF positivity

0.00 (-0.39-0.39)

0.99

-0.15 (-0.54-0.24)

0.86

ESR

-0.00 (-0.01-0.01)

0.66

-0.01 (-0.02-0.00)

0.26

CRP

-0.01 (-0.02-0.00)

0.05

-0.01 (-0.02-0.00)

0.07

Current prednisone

0.23 (-0.14-0.60)

0.22

0.04 (-0.32-0.40)

0.81

Prednisone, mg/day/previous 3 months

0.01 (-0.18-0.20)

0.94

-0.23 (-0.46-0.01)

0.47

HAQ

-0.01 (-0.30-0.29)

0.97

0.12 (-0.18-0.41)

0.44

DAS28

-0.00 (-0.14-0.13)

0.95

-0.05 (-0.17-0.07)

0.40

Current nonbiologic DMARD

-0.28 (-1.35-0.79)

0.60

0.08 (-0.67-0.82)

0.83

Classic IR risk factors


Sex

-0.24 (-0.76-0.27)

0.35

Age

0.00 (-0.02-0.02)

0.83

BMI

0.06 (0.03-0.10)

0.0a

Waist circumference

0.02 (0.01-0.03)

0.00a

Triglycerides

0.00 (0.00-0.01)

0.07

Hypertension

0.48 (0.11-0.86)

0.01a

β-cell function (logHOMA%B)


RA versus controls (β 95% CI for RA, 101, and controls, 99)

22 (5-39)

0.01

GC-RA versus controls (β 95% CI for RA, 56, and controls, 99)

11 (2-19)

0.02

GC+RA versus controls (β 95% CI for RA, 55, and controls, 99)

8 (0-15)

0.05

RA features


Disease duration

2 (-1-4)

0.27

1 (-2-4)

0.40

RF positivity

10 (21-42)

0.52

11 (-19-41)

0.46

ESR

0 (-1-1)

0.52

0 (-1-1)

0.61

CRP

1 (-2-1)

0.32

0 (-1-1)

0.40

Current prednisone

1 (-28-31)

0.93

3 (-26-32)

0.85

Prednisone, mg/day/previous 3 months

2 (-15-18)

0.83

10 (-8-21)

0.36

HAQ

-3 (-27-21)

0.83

3 (-20-26)

0.81

DAS28

-1 (-12-10)

0.81

-0 (-11-10)

0.95

Current nonbiologic DMARD

-16 (110-79)

0.74

-15 (-100-71)

0.73

Classic IR risk factors


Sex

-52 (-92--12)

0.0a

Age

-1 (-3-0)

0.06

BMI

2 (-1-5)

0.16

Waist circumference

0 (-1-1)

0.67

Triglycerides

0 (-0-0)

0.90

Hypertension

10 (-21-41)

0.53


HOMA-IR and HOMA%B are considered dependent variables and were log transformed. β-coefficients are expressed log transformed. Β-coefficient refers to changes in insulin resistance (IR) or β-cell function (%B) outcome per unit increase in the indicated characteristic. Sex refers to the change from female to male; current prednisone to the change from not taking corticoids to taking corticosteroids treatment, and RF positivity, to the change from negative to positive rheumatoid factor. Adjusted model represents a model in which RA features are adjusted for the classic risk factors of the previous model with P < 20 (BMI, and hypertension in the IR model; and sex, age, and BMI for the %B model). See Table 1 for abbreviations and units. Significant associations (P < 0.05) are depicted in bold

Ferraz-Amaro et al. Arthritis Research & Therapy 2013 15:R17   doi:10.1186/ar4149

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