Epidemiology of Diabetes Mellitus in Adults and Seniors in Rio Branco, Acre, Western Brazilian Amazon

(1) Background: To analyze the prevalence and factors associated with diabetes mellitus in adults and the elderly in Rio Branco, Acre, Western Brazilian Amazon. (2) Methods: The R software version 4.0.5 was used for estimating the prevalence of diabetes mellitus, odds ratios, and 95% confidence intervals. Multiple analysis was conducted through hierarchical variable selection. (3) Results: 1.095 individuals aged 18 years and older participated in this study, with 6.4% of the respondents showing prevalence of diabetes mellitus. The prevalence of diabetes mellitus was positively associated with a prior medical diagnosis of obesity (OR: 3.2; 95% CI: 1.67–6.12), dyslipidemia (OR: 4.17; 95% CI: 2.08–8.36), and increasing age (OR: 1.07; 95% CI: 1.05–1.09). Conversely, an inverse association was observed with higher education (12 or more years of study; OR: 0.20; 95% CI: 0.07–0.61). (4) Conclusions: The prevalence of diabetes mellitus in the municipality of Rio Branco, Acre, Brazil, has significantly increased with advancing age. Education, obesity, and dyslipidemia were also identified as factors associated with diabetes mellitus in this population. Awareness campaigns regarding dietary patterns and lifestyle choices may serve as preventive and control measures.