Loss of lean body mass affects low bone mineral density in patients with rheumatoid arthritis – results from the TOMORROW study

Abstract

Objectives: Osteoporosis is one of the complications for patients with rheumatoid arthritis (RA). Rheumatoid cachexia, the loss of lean body mass, is another. However, the relationship between decreased lean body mass and reduced bone mineral density (BMD) in patients with RA has not been well studied.

Methods: This study included 413 participants, comprising 208 patients with RA and 205 age- and sex-matched healthy volunteers. Clinical data, BMD, bone metabolic markers (BMM) and body composition, such as lean body mass and percent fat, were collected. Risk factors for osteoporosis in patients with RA including the relationship BMD and body composition were analyzed.

Results: Patients with RA showed low BMD and high BMM compared with controls. Moreover, lean body mass was lower and percent fat was higher in patients with RA. Lean body mass correlated positively and percent fat negatively with BMD. Lean body mass was a positive and disease duration was a negative independent factor for BMD in multivariate statistical analysis.

Conclusion: BMD and lean body mass were significantly lower in patients with RA compared to healthy controls. Lean body mass correlated positively with BMD and decreased lean body mass and disease duration affected low BMD in patients with RA.

Trial Registration: [UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/, UMIN000003876].

Keywords:

• Body composition
• bone mineral density
• bone metabolic marker
• rheumatoid arthritis
• rheumatoid cachexia

Acknowledgements

We wish to thank Atsuko Kamiyama and the members of the Center for Drug and Food Clinical Evaluation, Department of Radiology and Department of Central Clinical Laboratory in Osaka City University Hospital for their special efforts in recruiting subjects, collecting data, and managing the quality of data.

Conflict of interest

Dr. Okano received speaking fees from AbbVie. Prof. Koike has received research fees, consulting fees, or other remuneration from AbbVie, Astellas Pharma Inc., Bristol-Myers Squibb, Chugai Pharmaceutical, Eisai, Janssen, Lilly, Mitsubishi Tanabe Pharma Corporation, MSD, Ono Pharmaceutical, Pfizer, Roche, Takeda Pharmaceutical, Teijin Pharma, and UCB. Prof. Inui has received research grants and/or speaking fees from Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Astellas Pharma Inc., AbbVie, Eisai Co., Ltd., MSD K.K., Bristol-Myers K.K., Takeda Pharmaceutical Co., Ltd. and Janssen Pharmaceutical K.K. Prof. Nakamura has received research grants and/or speaking fees from Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Nippon Zoki Pharmaceutical Co., Ltd., Daiichi Sankyo Co., Ltd., Eisai Co.,Ltd., Takeda Pharmaceutical Co., Ltd., Hisamitsu Pharmaceutical Co., Inc., Ono Pharmaceutical Co., Ltd., Osteopharma Inc., Teijin Pharma Ltd., Asahi Kasei Pharma Co., Taisho Toyama Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Pfizer Japan Inc. and Janssen Pharmaceutical K.K. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding

The authors received no financial support for the research, authorship, or publication of this article.