Systematic review of the prevalence and development of osteoporosis or low bone mineral density and its risk factors in patients with inflammatory bowel disease

Table 4 Overview of the most relevant risk factors for change in bone mineral density over time

Risk factors for change in BMD	CD	CD + UC	Comments
General risk factors
Gender[8,9,11,12]	No data	+/-	No difference was found between genders in one study cohort[8,9,12], whilst another cohort[11] found a greater incidence of osteoporosis in women than in men.
Age[8,9,11,12]	No data	+/-
Weight[9,11]	No data	+
BMI[7,9,11]	+	+
Steroid treatment[7-9,11]	-	+/-
Smoking[7]	-	No data
Serum 25-OH D[7,8,11]	+	+/-
Disease-specific risk factors
Diagnosis[9,11,12]	Not relevant	+1, -	One[13] out of three studies found CD to be associated with an increased risk of osteoporosis. The others found no associations.
Disease location[7]	-	No data
Disease activity[11]	No data	-

¹Only in Crohn’s disease. CD: Crohn’s disease; UC: Ulcerative colitis; +: Positive association; -: No association; +/-: Significant association and no association were found, depending on the study and/or statistical analysis carried out. A plus sign means that a significant association was found and a minus sign means that no association was found. If studies found different results, both signs are present. Follow-up time for the respective studies was as follows: Jahnsen et al[16]: 2 yr; Leslie et al[19]: 2.3 ± 0.3 yr; Leslie et al[20]: 2.3 ± 0.3 yr; Targownik et al[3]: 4.3 ± 0.3 yr; Tsai et al[18]: 6.49 ± 3.09 yr.