The combined role of diabetes and obesity in susceptibility to musculoskeletal disorders and its subtypes in older men and women in India.

Background and aims: In later life, diabetes and obesity can cause a change in musculoskeletal systems that can lead to aching joints and a myriad of other musculoskeletal disorders such as arthritis, osteoporosis, rheumatism, bone fractures etc., resulting in significant morbidity including pain and disability. There is a paucity of research to know how comorbidity of diabetes and obesity increase musculoskeletal disorders among older people. Therefore, the present study used nationally representative data to examine the interaction of diabetes and obesity on musculoskeletal disorders and its subtypes including arthritis, osteoporosis, and rheumatism among older men and women in India.

Methods: Data were extracted from the first wave of the nationally representative survey Longitudinal Aging Study in India (LASI) conducted in 2017-18. The final sample includes 31,464 people aged 60 years or above. Primary outcome variable was any listed musculoskeletal disorders and secondary outcomes were its subtypes including arthritis, osteoporosis, and rheumatism based on self-reported questions. Diabetes and obesity based on anthropometric index of weight and height (i.e., body mass index (BMI) with a standard cut-off of 30 kg/m² or over) were considered as explanatory variables of interest. Logistic regression was used to assess the relationship between diabetes and musculoskeletal disorders. Interaction analysis was performed by both additive and multiplicative scales.

Results: Comparing older people without diabetes, the prevalence of musculoskeletal disorders and its subtypes were higher among those with diabetes, particularly arthritis disorders in older women. Diabetes was significantly correlated with the risk of musculoskeletal disorders and its subtypes including arthritis and osteoporosis even after controlling potential factors. The combination of diabetes and obesity was significantly and positively associated with musculoskeletal disorders (aOR: 4.14; p-value < 0.0001; 95% CI: 1.96 to 8.74) and its subtype only arthritis (aOR: 4.36; p-value < 0.0001; 95% CI: 1.76 to 10.8) comparing to those without both the conditions. However, the association was strong for older women as compared to older men. Notwithstanding, multiplicative scale interaction showed statistically significant for musculoskeletal disorders and its three subtypes among older women, however it was not significant for osteoporosis and rheumatism disorders among older men. When we analyzed interaction on additive scale, we found it only for arthritis disorder among older women suggesting the risk from obesity (relative excess risk due to interaction (RERI): -0.83, 95% CI: -1.44 to -0.22, attributable proportion due to interaction (AP): -0.54, 95% CI: -1.05 to -0.03, synergy index (S): 0.39, 95% CI: 0.16 to 0.93) was additive to the risk from diabetes.

Conclusions: This study suggests an elevated risk of musculoskeletal disorders among Indian older adults with diabetes. The result of this study also suggests an interactive association of diabetes and obesity with musculoskeletal disorders, particularly with arthritis disorder. There is a need to pay attention to the BMI level while treating diabetes in Indian older population.