Weight Loss Induced by Anti-obesity Medications and All-cause Mortality Among Patients with Knee or Hip Osteoarthritis

Jie Wei¹, david Hunter², Nancy Lane³, Jing Wu⁴, Chao Zeng⁵, Guanghua Lei⁵ and Yuqing Zhang⁶, ¹Health Management Center, Xiangya Hospital Central South University, Changsha, China, ²Sydney Musculoskeletal Health, University of Sydney, St. Leonards, Australia, ³University of California, Hillsborough, CA, ⁴Key Laboratory of Aging-related Bone and Joint Diseases Prevention and Treatment, Ministry of Education, Xiangya Hospital, Central South University, Changsha, China, ⁵Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China, ⁶Division of Rheumatology, Allergy, and Immunology, Department of Medicine, Massachusetts General Hospital, Boston, MA

Meeting: ACR Convergence 2023

Keywords: Epidemiology, longitudinal studies, Mortality, obesity, Osteoarthritis

Session Information

Date: Tuesday, November 14, 2023

Title: (1977–1995) Osteoarthritis – Clinical Poster III

Session Type: Poster Session C

Session Time: 9:00AM-11:00AM

Background/Purpose: The current international guidelines recommend weight loss for pain relief and functional improvement in overweight or obese patients with knee or hip osteoarthritis; however, there is a paucity of data on the relation of weight loss to all-cause mortality among patients with osteoarthritis. We aimed to examine the relation of the rate of weight loss induced by anti-obesity medications over 1-year to all-cause mortality among overweight/obese patients with knee or hip osteoarthritis.

Methods: Using IQVIA Medical Research Database in the United Kingdom, we identified overweight/obese people aged 40 years or older with knee or hip osteoarthritis. We emulated analyses of a hypothetical target trial using a “cloning, censoring, and weighting” approach to assess the effect of slow-to-moderate (2-10%) or fast (≥10%) weight loss induced by the initiation of anti-obesity medications (i.e., orlistat, sibutramine, and rimonabant) within 1-year on all-cause mortality and several secondary outcomes (i.e., incident hypertension, type 2 diabetes, venous thromboembolism, cardiovascular disease, and any cancer) over 5-year follow-up, respectively (Figure 1).

Results: Among 6,524 participants initiating anti-obesity medications, the 5-year all-cause mortality was 5.3%, 4.0%, and 5.4% for “weight gain/stable”, “slow-to-moderate weight loss” and “fast weight loss” arms, respectively. Compared with the “weight gain/stable” arm, hazard ratios (HRs) of all-cause mortality were 0.72 (95% confidence interval [CI]: 0.56-0.92) for the “slow-to-moderate weight loss” arm and 0.99 (95%CI: 0.67-1.44) for the “fast weight loss” arm, respectively. In addition, we found dose-response protective effects of weight loss on incident hypertension, type 2 diabetes, and venous thromboembolism. However, a slightly higher risk of cardiovascular disease, albeit non-statistically significant, was observed in the “fast rate of weight loss” arm compared with the “weight gain/stable” arm (HR=1.20, 95%CI: 0.81-1.78). No apparent difference in the risk of cancer was observed between the “fast rate of weight loss” arm and the “weight gain/stable” arm (HR=1.04, 95%CI: 0.74-1.45) (Table 1).

Conclusion: In this population-based study, a slow-to-moderate, but not fast, rate of weight loss induced by anti-obesity medications within 1-year is associated with a lower risk of all-cause mortality in overweight/obese people with knee or hip osteoarthritis. Our findings that gradual weight loss by anti-obesity medications lower all-cause mortality, if confirmed by future studies, could guide policy-making, and improve the well-being of overweight/obese patients with knee or hip OA.

Figure 1. Study design of a hypothetical randomized controlled trial (“target trial”) on which we modeled our observational data analysis (A); Cloning and censoring in five hypothetical patients (B). Patient A lost ≥ 10% weight within one year after anti-obesity medications initiation. At time zero, 3 copies of the patient are made and they are randomly allocated to three groups. Patient A lost ≥ 10% weight within one year after anti-obesity medications initiation. The copy assigned to the “fast rate of weight loss” group is adhered with his/her assignment and will not be censored. However, the other two copies assigned to the “weight gain/stable” group and “slow-to-moderate rate of weight loss” group are violated with their assignment, and thus be censored at the time.

Table 1. Relations of weight reduction induced by anti-obesity medications within 1-year to all-cause mortality, incident hypertension, T2DM, VTE, CVD and cancer in overweight or obese knee or hip OA patients

Disclosures: J. Wei: None; d. Hunter: None; N. Lane: None; J. Wu: None; C. Zeng: None; G. Lei: None; Y. Zhang: None.

To cite this abstract in AMA style:

Wei J, Hunter d, Lane N, Wu J, Zeng C, Lei G, Zhang Y. Weight Loss Induced by Anti-obesity Medications and All-cause Mortality Among Patients with Knee or Hip Osteoarthritis [abstract]. Arthritis Rheumatol. 2023; 75 (suppl 9). https://acrabstracts.org/abstract/weight-loss-induced-by-anti-obesity-medications-and-all-cause-mortality-among-patients-with-knee-or-hip-osteoarthritis/. Accessed .

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