Review for 10.1186/1471-230X-12-47 (2012)

Reviewer's report
Title:Vertebral fractures in patients with inflammatory bowel disease compared
with healthy population
Version: 1Date:3 December 2011
Reviewer: Ashwin N Ananthakrishnan
Reviewer's report:
Disordered bone metabolism and its consequences therein are an important
concern in patients with IBD. Literature on fracture risk has been inconsistent in
demonstrating an association with CD or UC. In addition, the association
between low bone mass and fractures has also yielded varying effects. In this
study by Vazquez and colleagues, 107 patients with IBD and 51 healthy subjects
underwent evaluation for the prevalence of morphometric vertebral crush
fractures. The authors find that a diagnosis of IBD was associated with a four fold
increase in risk of such fractures. There was no specific association with BMD ,
vitamin D status, or corticosteroid use.
Overall, I think it is a well-done study. The manuscript is also well written and
conclusions consistent with the results presented. I have a few comments.
Major compulsory
1) Given the association between age, gender and bone mass – were the cases
and controls matched by any criteria? How were the controls selected? No
details are provided. However, this is of key importance in any case-control
analysis.
2) Was the assessment for the presence of morphometric fractures done in a
blinded fashion? Could there be the possibility of a reader bias with increased
diagnosis of fractures in those who carry a diagnosis of IBD?
3) It is important to provide some information regarding the disease
characteristics of the IBD patients included. What was the mean duration of
disease? Disease location? Disease behavior? Current and past treatments
other than steroids?
4) I’m interested in hearing the authors’ thoughts on why there is the higher
incidence of fractures in their cohort compared to most prior studies? Also, do
they have any thoughts on why they see such a strong association in their study
in comparison to other large studies which have not demonstrated an association
between IBD and fractures.
5) Is the prevalence of morphometric fractures in their controls consistent with
findings from other cohorts? It would be useful if the authors reference this in
their discussion as well.
6) The discussion is overtly long and needs to be more focused. There is a lot of
repetition (for example Page 12 and Page 14 both present fracture rates in the
present study IBD population and prior IBD studies).
Minor essential
7) In their introduction, particularly for gastroenterology readers who may not be
familiar with the various measures of fracture risk, it may be worth commenting
on what the consequences of morphometric fractures are. Have they been
associated with increased risk of overt fractures or other relevant health
outcomes?
8) I would suggest re-ordering some of the results as it is somewhat difficult to
follow in its present setting. A more ordered approach – initially establishing IBD
as a risk factor for such fractures, and then comparing risk factors for fractures in
the IBD and non-IBD cohorts, followed by the secondary outcomes may be
easier to follow.
9) More careful attention should be made to language. For example, in the
results, Page 9 (just before the subheading bone mineral density) – it is stated
that bone mass and other variables were shown to be independent. Perhaps they
mean that the other variables were not significant?
Discretionary
1) Page 10, under subheading “biochemical parameters” – the authors refer to
“the pathological group”. I’m not sure what this refers to.
Level of interest: An article of importance in its field
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests