High body mass index (BMI) may have modulatory effects on the immune system.
To determine the association between BMI and polymyalgia rheumatica (PMR) as well as the influence of BMI on glucocorticoid treatment duration and development of giant-cell arteritis (GCA) in patients with PMR.
The BMI of 364 patients with PMR from a population-based incidence cohort was compared to the BMI of non-PMR subjects from the same population. High and low BMI were defined as > or = 25 and < 18.5 kg/m2, respectively. The association between BMI and case status was determined. The association between BMI and the duration of glucocorticoid therapy, as well as the development of GCA after accounting for relevant variables, were also examined.
The mean BMI at index was similar in both groups (PMR: 26 +/- 5.4 kg/m2; non-PMR: 25.9 +/- 4.0 kg/m(2), P = 0.83). There was no association between BMI and the duration of glucocorticoid therapy. No significant association was found between BMI and the development of GCA in patients with PMR.
Patients with high BMI (> or = 25 kg/m2) are not more likely to develop PMR. BMI did not influence the duration of glucocorticoid therapy or the occurrence of GCA in patients with PMR.