Association of Body Mass Index and Fracture Risk Varied by Affected Bones in Patients with Diabetes: A Nationwide Cohort Study (Diabetes Metab J 2023;47:242-54)

Article information

Diabetes Metab J. 2023;47(3):439-440
Publication date (electronic) : 2023 May 26
doi : https://doi.org/10.4093/dmj.2023.0104
1Department of Orthopedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea
2Department of Orthopedic Surgery, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
3Department of Statistics and Actuarial Science, Soongsil University, Seoul, Korea
4Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
5Department of Internal Medicine, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
Corresponding authors: Kyungdo Han https://orcid.org/0000-0002-6096-1263 Department of Statistics and Actuarial Science, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul 06978, Korea E-mail: hkd917@naver.com
Hyuk-Sang Kwon https://orcid.org/0000-0003-4026-4572 Department of Internal Medicine, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 10 63-ro, Yeongdeungpo-gu, Seoul 07345, Korea E-mail: drkwon@catholic.ac.kr

We appreciate the interest of Dr. So Young Park in our published article, “Association of body mass index and fracture risk varied by affected bones in patients with diabetes: a nationwide cohort study,” [1] and are grateful for the opportunity to further discuss our work. We agree with Dr. Park’s comments on our study findings. Type 1 diabetes mellitus is linked to lower bone mineral density and increased risk of hip fracture [2,3], while the association between type 2 diabetes mellitus (T2DM) and hip fracture remains unclear. However, recent studies have suggested a relationship between T2DM and hip fracture, and one study has suggested that even prediabetic conditions may increase the risk of hip fracture [4].

Our study demonstrated that the impact of body mass index (BMI) on fracture varies by anatomical location [1]. Regarding our study’s analysis of fracture risk according to BMI and affected skeletal sites, underweight individuals with T2DM had increased risk of total, vertebral, and hip fractures, while obesity and morbid obesity were associated with decreased risk of these fractures. Of note, hip fracture showed the largest change by BMI, and limb fracture was least affected.

Our subgroup analysis revealed higher risk of fracture in the underweight group in men than in women, unlike other studies [4]. Our plausible explanation for the disparity in fracture risk by sex is that men have larger bones and less adipose tissue than women [5]. Since the weight of bone remains relatively constant compared to muscle or fat tissue, the effect of low BMI on fracture risk may be more significant in males. Dr. Park commented that this might explain the difference better by including body composition (bone, muscle, fat, and so on) in the analysis.

This study has the advantage of being the largest-scale nationwide population study conducted on patients with T2DM (n =2,086,187) and a long follow-up period greater than 6 years. However, our study had limitations of a retrospective analysis using only National Health Insurance System claim data and did not consider important fracture risk factors, such as bone mineral density, history of falls, and drugs and diseases related to secondary osteoporosis.

Although being overweight may decrease the risk of fracture, it is not desirable due to its well-known association with T2DM [6]. On the other hand, being underweight may increase the risk of fracture. Thus, as noted by Dr. Park, our findings emphasize the importance of maintaining an appropriate weight through healthy diet and exercise habits. Further research considering other important fracture risk factors is needed.

Once more, we thank Dr. Park for her comprehensive review and valuable comments on our work.

Notes

CONFLICTS OF INTEREST

No potential conflict of interest relevant to this article was reported.

References

1. Lee SW, Han K, Kwon HS. Association of body mass index and fracture risk varied by affected bones in patients with diabetes: a nationwide cohort study. Diabetes Metab J 2023;47:242–54.
2. Chen C, Chen Q, Nie B, Zhang H, Zhai H, Zhao L, et al. Trends in bone mineral density, osteoporosis, and osteopenia among U.S. adults with prediabetes, 2005-2014. Diabetes Care 2020;43:1008–15.
3. Vestergaard P. Discrepancies in bone mineral density and fracture risk in patients with type 1 and type 2 diabetes: a meta-analysis. Osteoporos Int 2007;18:427–44.
4. Park HY, Han K, Kim Y, Kim YH, Sur YJ. The risk of hip fractures in individuals over 50 years old with prediabetes and type 2 diabetes: a longitudinal nationwide population-based study. Bone 2021;142:115691.
5. Nieves JW, Formica C, Ruffing J, Zion M, Garrett P, Lindsay R, et al. Males have larger skeletal size and bone mass than females, despite comparable body size. J Bone Miner Res 2005;20:529–35.
6. World Health Organization. A healthy lifestyle-WHO recommendations. Body mass index–BMI. Available from: http://www.euro.who.int/en/health-topics/disease-prevention/nutrition/a-healthy-lifestyle/body-mass-index-bmi(cited 2023 Apr 13).

Article information Continued