Table 1.
Characteristics of 196 patients with recent onset IP and in those with and without IR
| Variable at baseline | All pts n = 196 |
IR (HOMA IR ≥ 2.29) n = 118 (60%) |
No IR HOMA IR < 2.29 n = 78 (40%) |
P-value |
|---|---|---|---|---|
| Age when first seen (years) † | 49 (40 to 57) | 49 (41 to 56) | 48 (37 to 57) | 0.49 |
| Male gender | 59 (30%) | 38 (32%) | 21 (27%) | 0.43 |
| Current smoker | 50 (26%) | 27 (23%) | 23 (29%) | 0.30 |
| Obese (BMI ≥ 30) | 57 (30%) | 46 (40%) | 11 (15%) | < 0.001 |
| On treatment for or diagnosed with DM | 26 (13%) | 16 (14%) | 10 (13%) | 0.88 |
| Fasting blood glucose (mmol/L) * | 4.7 (4.4 to 5.0) | 4.8 (4.5 to 5.1) | 4.5 (4.3 to 4.8) | < 0.001 |
| Fasting insulin (μU) | 12.7 (8.9 to 18.1) | 16.7 (13.2 to 21.6) | 8.2 (6.0 to 9.4) | < 0.001 |
| HOMA-IR | 2.7 (1.8 to 3.9) | 3.5 (2.8 to 4.8) | 1.6 (1.2 to 1.9) | < 0.001 |
| SBP (mmHg) * | 132 (17) | 135 (17) | 129 (15) | 0.04 |
| DBP (mmHg) * | 81 (10) | 83 (10) | 79 (9) | 0.01 |
| On treatment for hypertension | 19 (10%) | 13 (11%) | 6 (8%) | 0.44 |
| TG (mmol/L) * | 1.4 (0.6) | 1.6 (0.6) | 1.1 (0.5) | < 0.001 |
| T.Chol (mmol/L) * | 5.4 (1.1) | 5.5 (1.1) | 5.2 (1.1) | 0.24 |
| HDL (mmol/L) * | 1.5 (0.4) | 1.5 (0.5) | 1.6 (0.4) | 0.03 |
| LDL (mmol/L) * | 3.2 (0.9) | 3.3 (0.9) | 3.1 (0.9) | 0.43 |
| On statin treatment | 11 (6%) | 5 (4%) | 6 (8%) | 0.30 |
| IP symptom duration (months)† | 6.7 (4.6 to 10.7) | 6.5 (4.5 to 9.9) | 7.0 (4.7 to 11.8) | 0.28 |
| Age at IP symptom onset | 48 (40 to 56) | 48 (40 to 55) | 48 (36 to 57) | 0.42 |
| RF positive | 90 (47%) | 63 (55%) | 27 (35%) | 0.01 |
| ACPA positive | 66 (34%) | 50 (44%) | 16 (21%) | < 0.001 |
| Fulfil ACR criteria for RA | 87 (44%) | 58 (49%) | 29 (37%) | 0.10 |
| Swollen joint count (/51)† | 4 (1 to 7) | 4 (2 to 9) | 4 (1 to 7) | 0.44 |
| Tender joint count (/51)† | 8 (2 to 18) | 8 (2 to 18) | 9 (3 to 17) | 0.87 |
| Both swollen & tender (/51)† | 2 (0 to 6) | 2 (0 to 6) | 2 (0 to 5) | 0.96 |
| CRP (mg/L)† | 10 (7 to 17) | 11 (5 to 21) | 9 (7 to 13) | 0.21 |
| DAS28CRP † | 3.9 (3.0 to 4.8) | 3.9 (3.0 to 4.9) | 3.9 (3.1 to 4.7) | 0.73 |
| HAQ† | 0.88 (0.38 to 1.38) | 0.88 (0.38 to 1.68) | 0.88 (0.38 to 1.38) | 0.26 |
| On steroids prior to baseline assessment |
43 (22%) | 24 (20%) | 19 (24%) | 0.51 |
| On DMARDs prior to baseline assessment |
105 (54%) | 67 (57%) | 38 (49%) | 0.27 |
| On MTX prior to baseline assessment | 60 (31%) | 36 (31%) | 24 (31%) | 0.97 |
| On HCQ prior to baseline assessment | 11 (6%) | 6 (5%) | 5 (6%) | 0.69 |
All data are presented as n (%) except where we indicate that either median (IQR) † or mean (SD) * were used.
ACPA, anti-CCP antibody; ACR, American College of Rheumatology; CRP, C-reactive protein; DAS 28CRP , Disease Activity Score calculated using CRP; DBP, diastolic blood pressure; DM, diabetes mellitus; HAQ, Health Assessment Questionnaire; HCQ, hydroxychloroquine; HDL, high density lipoprotein; HOMA-IR, Homeostatic Model Assessment for Insulin Resistance; IP, inflammatory polyarthritis; LDL, low density lipoprotein; MTX, methotrexate; RF, rheumatoid factor; SBP, systolic blood pressure;
T.chol, total cholesterol; TG, triglycerides