Original article Risk factors for decreased bone mineral density in inflammatory bowel disease: A cross-sectional study Yasuyo Wada a, b , Tadakazu Hisamatsu a, * , Makoto Naganuma c , Katsuyoshi Matsuoka a , Susumu Okamoto a , Nagamu Inoue c , Tomoharu Yajima a , Keisuke Kouyama e , Yasushi Iwao d , Haruhiko Ogata c , Toshifumi Hibi f , Takayuki Abe e , Takanori Kanai a a Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan b Center for Human Nutrition, The University of Texas Southwestern Medical Center, Dallas, TX, USA c Center for Diagnostic and Therapeutic Endoscopy, School of Medicine, Keio University, Tokyo, Japan d Center for Preventive Medicine, School of Medicine, Keio University, Tokyo, Japan e Center for Clinical Research, School of Medicine, Keio University, Tokyo, Japan f Center for Advanced IBD Research and Treatment, Kitasato University Kitasato Institute Hospital, Tokyo, Japan article info Article history: Received 4 June 2014 Accepted 4 January 2015 Keywords: Osteoporosis Crohn's disease Ulcerative colitis Inflammatory bowel disease Body mass index Japanese summary Background & aim: Although inflammatory bowel disease (IBD) patients are at risk for metabolic bone disease, studies analyzing this correlation have identified various risk factors, including disease phenotype, age, sex and steroid therapy. Furthermore, few studies have assessed risk factors for bone loss in Japanese IBD patients. This study analyzed risk factors for metabolic bone disease in Japanese IBD patients. Methods: This cross-sectional study assessed 388 patients with IBD aged 20e50 years, including 232 with ulcerative colitis (UC) and 156 with Crohn's disease (CD). Bone mineral density of the femoral neck, total femur and lumbar spine was quantified by dual-energy X-ray absorptiometry. The blood concen- trations of bone metabolism markers were measured. History of smoking and bone fracture, and nutritional intake were assessed using questionnaires. Results: Of the 388 patients with IBD, 78 (20.1%; UC,17.2%; CD, 24.4%) had osteopenia and 17 (4.4%; UC, 3.4%; CD, 5.8%) had osteoporosis, as assessed by T-score. Bone mineral density of the lumbar vertebrae was lower in males than in females. Multivariate regression analysis showed that risk factors for bone loss in UC patients were male sex, low body mass index (BMI), high steroid dose and disease location. Risk factors for bone loss in CD patients were male sex and low BMI. Conclusion: Among Japanese patients with IBD, male sex and low BMI were associated with increased risk for metabolic bone disease. In addition, Steroid therapy shouldn't be indiscriminate in UC patients. These findings may help identify patients at particularly high risk of metabolic bone disease and may help implement appropriate therapies in a timely manner and improve long-term quality of life. © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. 1. Introduction Metabolic bone diseases such as osteopenia and osteoporosis increase the risk of bone fracture and negatively affect quality of life and independent living in aging individuals. Patients with inflam- matory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), have been shown to be at increased risk of metabolic bone disease [1e3]. Factors associated with the patho- genesis of osteoporosis in patients with IBD include age [4,5], fe- male sex [6], menopausal status in women, treatment with corticosteroids [7,8], malnutrition, calcium and vitamin D Abbreviations: BMI, body mass index; BMD, bone mineral density; CD, Crohn's disease; CDAI, Crohn's disease activity index; CI, confidence interval; CRP, C-reactive protein; DEXA, dual-energy X-ray absorptiometry; IBD, inflammatory bowel dis- ease; IL, interleukin; NTX, amino-terminal collagen type-I telopeptide; TNF, tumor necrosis factor; UC, ulcerative colitis; YAM, young adult mean. * Corresponding author. Division of Gastroenterology and Hepatology, Depart- ment of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Tel.: þ81 3 3353 1211x62384; fax: þ81 3 3357 2778. E-mail address: hisamachi@a7.keio.jp (T. Hisamatsu). Contents lists available at ScienceDirect Clinical Nutrition journal homepage: http://www.elsevier.com/locate/clnu http://dx.doi.org/10.1016/j.clnu.2015.01.003 0261-5614/© 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. Clinical Nutrition xxx (2015) 1e8 Please cite this article in press as: Wada Y, et al., Risk factors for decreased bone mineral density in inflammatory bowel disease: A cross- sectional study, Clinical Nutrition (2015), http://dx.doi.org/10.1016/j.clnu.2015.01.003