Type 2 diabetes mellitus in Mexican municipalities: A spatial analysis

Type 2 diabetes mellitus (T2DM) is a growing health concern worldwide. In 2021, an estimated 537 million individuals aged 20–79 years were living with diabetes globally, with projections indicating that this number will rise to 783 million by 2045. The rise will predominantly occur in middle- and low-income nations, such as Mexico, where resources for treating the disease and its complications are limited. The main T2DM complications are cardiovascular disease, blindness, kidney failure, and lower limb amputation. The prevalence increase stems from several factors, such as the aging population, which will increase the percentage of individuals over 60 living with T2DM, higher rates of obesity and overweight due to lifestyle changes (such as increased calorie intake and decreased physical activity), and improved medical treatments, leading to higher survival rates among those with T2DM. Excluding the mortality risks associated with COVID-19, it is estimated that approximately 6.7 million individuals aged 20 to 79 years died worldwide from T2DM or its complications in 2021. This accounted for approximately 12.2% of the total deaths in these age groups.

In 2021, Mexico ranked seventh globally for the highest number of individuals living with T2DM, totaling around 14.1 million adults aged 20 to 79, indicating that one out of every six Mexican adults is affected by this condition. The number is projected to rise to 21.2 million by 2045 (IDF, 2021), largely driven by the high prevalence of obesity and physical inactivity that are characteristic of the Mexican population. In 2020, T2DM was ranked as the third leading cause of death in the country, following cardiovascular diseases and COVID-19, with 151,019 recorded deaths. Over the past three decades, mortality associated with T2DM has surged by 77% (Gutierrez-Leon et al., 2022). Mortality related to T2DM is associated with sociodemographic and economic inequalities (Gutierrez-Leon et al., 2022), which have been exacerbated by the COVID-19 pandemic. There was an estimated 41% increase in T2DM-related deaths in 2020 compared to the preceding period from 2017-2019, reflecting the significant impact the pandemic has had in Mexico (Bello-Chavolla et al., 2022).

Analyzing the geographic distribution of T2DM mortality facilitates the identification of geographic areas with higher mortality rates (Kouchaki et al., 2023). The risk factors for T2DM can vary significantly between regions. Thus, by studying diabetes at the municipal level, we can gain deeper insights into the determinants of health, highlighting disparities in healthcare access, socioeconomic factors, and environmental influences that contribute to differential disease burdens. Consequently, examining type 2 diabetes at this level provides valuable insights into the local disease burden, informing targeted strategies for prevention, public health planning, resource allocation, and policy development (Hill-Briggs et al., 2021). Therefore, the main objective of this study is to examine the spatial patterns of mortality from T2DM across municipalities in Mexico and to investigate the main contextual factors linked to this cause of death in 2020. For this purpose, we used a spatial Bayesian hierarchical regression model based on the Integrated Nested Laplace Approximation (INLA) (Rue et al., 2009).