Overweight and obesity in axial spondyloarthritis is common and has a negative impact on disease activity, registry data shows.
Lead author and rheumatology registrar Gillian Fitzgerald, from the St James’s hospital in Dublin, Ireland, told ACR 2017 delegates there was a general perception that people with axial spondyloarthritis (axSpA) had a ‘normal’ BMI.
But her analysis of data from the Ankylosing Spondylitis Registry of Ireland found that, on the contrary, over two-thirds (67%) of the 683 registry participants were classified as overweight or obese (BMI over 25).
These patients tended to be older, have longer disease duration, and more comorbidities such as hypertension and hyperlipidaemia, compared to normal weight patients.
Higher BMI and obesity were associated with higher BASDAI, ASQoL, BASMI and HAQ scores.
| Dependent variable | Predicting variable | Univariable analysis, B (95% CI) | P | Multivariable analysis, B (95% CI) | P |
| BASDAI | BMI | 0.089 (0.01-0.08) | 0.02 | 0.07 (0-0.07) | 0.1 |
| Obesity | 0.13 (0.29-1.1) | <0.01 | 0.13 (0.25-1.1) | <0.01 | |
| ASQoL | BMI | 0.14 (0.07-0.23) | <0.01 | 0.14 (0.06-0.23) | <0.01 |
| Obesity | 0.16 (1.1-2.9) | <0.01 | 0.17 (1.14-3.08) | <0.01 | |
| BASMI | BMI | 0.26 (0.09-0.16) | <0.01 | 0.17 (0.05-0.11) | <0.01 |
| Obesity | 0.22 (0.8-1.63) | <0.01 | 0.18 (0.62-1.38) | <0.01 | |
| BASFI | BMI | 0.24 (0.08-.16) | <0.01 | 0.17 (0.05-0.12) | <0.01 |
| Obesity | 0.21 (0.78-1.66) | <0.01 | 0.17 (0.58-1.45) | <0.01 | |
| HAQ | BMI | 0.14 (0.01-0.02) | <0.01 | 0.1 (0-0.02) | 0.02 |
| Obesity | 0.16 (0.1-0.28) | <0.01 | -0.15 (0.09-0.27) | <0.01 |
Table: Linear regression analysis of association between BMI and obesity with clinical outcome.
“In regression analysis being overweight remained an independent predictor of worse function however being obese independently predicted worse outcomes across all disease measures,” she said.
“When devising treatment plans for axSpA patients this study provides rheumatologists with a strong rationale to include strategies to actively control weight,” Dr Fitzgerald said.
There were still some unanswered questions such as whether losing weight would have an effect on disease outcomes, she added.
See abstract here