Patients with ulcerative colitis (UC) have reduced bone mineral density (BMD), regardless of steroid use, according to results from a meta-analysis published in Clinical and Translational Medicine.
In order to assess the relationship between UC and BMD, the investigators collected data from 13 cross-sectional studies published before August 2019 by searching PubMed, EMBASE, and the Cochrane Library. The meta-analysis comprised 570 patients with UC and 584 control individuals.
The included studies, when pooled, indicated a decrease in BMD in patients with UC on the basis of a standard mean difference (SMD) in BMD T-score of -0.24 (95% CI, -0.44 to -0.04; I2 =61.7%) compared with the control group, with an odds ratio of 6.41 (95% CI, 2.59-15.87; I2 =56.8%) for low BMD in patients with UC.
Four of the studies provided data from patients with UC who had never been introduced to steroid therapy. The investigators reported that among these steroid-free patients, the SMD in T-score for BMD was -0.55 (95% CI, -0.85 to -0.25; I2 =0.0%) compared with control individuals, indicating reduced BMD despite a lack of steroid use.
The investigators reported some discrepancies between subgroups compared with the control group, specifically with regard to geographic location, patient body mass index (BMI), and age. They reported lower BMD in Europeans with UC (SMD, -0.25; 95% CI, -0.47 to -0.04) than in Americans with UC (SMD, -0.03; 95% CI, -0.64 to 0.58). Patients with a BMI <25 kg/m2 had a lower BMD (SMD, -0.24; 95% CI, -0.56 to 0.08), whereas patients with a higher BMI exhibited higher BMD (SMD, -0.08; 95% CI, -0.31 to 0.14). Patients younger than 45 years had a higher BMD (SMD, -0.16; 95% CI, -0.39 to 0.07) than older patients (SMD, -0.52; 95% CI, -0.83 to -0.22). Taken together, the investigators observed that the most susceptible group to osteoporosis were older European patients with UC who had low BMI.
A limitation to this study was the high amount of heterogeneity observed between studies. Moreover, all of the observed differences between subgroups of patients were not explained by the subgroup analysis, indicating that additional factors like genetic predisposition or exposure to bisphosphonates were possible confounding factors not accounted for in the statistical analysis.
The study authors concluded that their results indicated a potential association between UC and a decrease in BMD and that clinicians should monitor BMD levels in all patients with UC regardless of steroid use.
Zhou T, Pan J, Lai B, et al. Bone mineral density is negatively correlated with ulcerative colitis: a systematic review and meta-analysis. Clin Trans Med. 2020;9(1);18.