Table 3.
Clinical associations with serial body mass index (BMI) measurements over 24 months.
| Variable | Univariable | Full Multivariable Model | |||
|---|---|---|---|---|---|
| Est. (95%CI) | p Value | Est. (95%CI) | p Value | ||
| Time | Repeated measures over 24 m | 0.43 [0.21, 0.65] | <0.0001 | 0.08 [−0.08, 0.24] | 0.28 |
| Demographics | Age at study entry | 0.24 [0.15, 0.33] | <0.0001 | 0.021 [−0.004, 0.046] | 0.08 |
| Gender (Male vs. female) |
0.0 [−2.0, 2.0] | 0.99 | 0.38 [−0.18, 0.95] | 0.17 | |
| IBD-related factors | IBD phenotype (Ulcerative colitis vs. Crohn’s disease) | −0.7 [−2.9, 1.5] | 0.52 | −0.04 [−0.46, 0.38] | 0.86 |
| IBD disease duration | 0.014 [0.005, 0.022] | 0.002 | 0.0003 [−0.0020, 0.0026] | 0.78 | |
| Faecal calprotectin (μg/g) | −0.0015 [−0.0025, 0.004] | 0.007 | 0.00021 [−0.00044, 0.00086] | 0.48 | |
| C-reactive protein (mg/L) | −0.011 [−0.027, 0.006] | 0.19 | 0.001 [−0.009, 0.011] | 0.85 | |
| Current corticosteroid use | −0.4 [−1.0, 0.2] | 0.22 | −0.10 [−0.49, 0.29] | 0.55 | |
| Biologic therapy | 0.25 [−0.31, 0.81] | 0.38 | 0.04 [−0.18, 0.25] | 0.69 | |
| Immunomodulator therapy | 0.42 [−0.03, 0.88] | 0.06 | 0.11 [−0.02, 0.23] | 0.08 | |
| Lifestyle and nutritional factors | Smoking status Current vs. never Ex vs. never |
0.8 [−1.9, 3.4] 2.0 [−0.4, 4.4] |
0.23 | −0.24 [−0.75, 0.28] 0.34 [−0.11, 0.78] |
0.07 |
| Excess alcohol intake ^ | 0.2 [−4.9, 5.3] | 0.95 | 0.8 [−0.1, 1.8] | 0.06 | |
| Vitamin D level (nmol/mL) | 0.006 [−0.005, 0.017] | 0.25 | 0.006 [0.000, 0.011] | 0.03 | |
| Habitual exercise (IPAQ score, continuous) § | 0.002 [−0.036, 0.041] | 0.91 | 0.009 [−0.011, 0.029] | 0.36 | |
| Albumin (g/dL) | 0.06 [−0.02, 0.13] | 0.16 | 0.008 [−0.034, 0.049] | 0.76 | |
| Body composition factors | Fat mass index (FMI) | 1.1 [1.0, 1.2] | <0.0001 | 1.0 [1.0, 1.1] | <0.0001 |
| Appendicular skeletal muscle index (ASMI) | 2.1 [1.8, 2.5] | <0.0001 | 1.3 [1.1, 1.5] | <0.0001 | |
| Functional sarcopenia ¶ | −1.5 [−2.5, −0.4] | 0.0006 | 0.11 [−0.41, 0.62] | 0.65 | |
| Grip strength (pounds per square inch, PSI) | 0.024 [−0.024, 0.072] | 0.32 | 0.028 [0.008, 0.049] | 0.006 | |
^ Data log-transformed prior to analysis: ^ VAT, visceral adipose tissue; ^ VAT:SAT, visceral adipose tissue: subcutaneous adipose tissue ratio; VHI, visceral adipose tissue area (cm3) divided by height (m2); ¶ Low ASMI and grip strength ≥1 standard deviation below mean. ^ Excess alcohol use defined according to the Australian Healthy Drinking Guidelines; § IPAQ, International Physical Active Questionnaire; FMI, fat mass index (kg/height m2); ASMI, appendicular skeletal muscle index (kg/height m2); Linear mixed effects regression models with missing data imputed with cohort means.