BackgroundProperly understanding the health information of people with type 2 diabetes mellitus (T2DM) is the basis for better risk factor management, which also positively affects their quality of life. The aim of this study was to investigate diabetes health literacy (HL), self-efficacy, and self-care behaviors associated with glycemic control among older adults with T2DM in northern Thai communities.MethodsA cross-sectional study was conducted among 414 older adults over the age of 60 diagnosed with T2DM. The study was conducted in Phayao Province from January to May 2022. Simple random sampling of the patient list for the Java Health Center Information System program was used. Questionnaires were used to collect data on diabetes HL, self-efficacy, and self-care behaviors. Blood samples were tested for estimated glomerular filtration rate (eGFR) and glycemic controls, such as fasting blood sugar (FBS) and glycated hemoglobin (HbA1c).ResultsThe mean age of participants was 67.1 years. FBS (mean ± SD = 108.5 ± 29.5 mg/dL) and HbA1c (mean ± SD = 6.6 ± 1.2%) levels were found to be abnormal in 50.5% (≥ 126 mg/dL) and 17.4% (≥ 6.5%) of the subjects, respectively. There was a strong correlation between HL and self-efficacy (r = 0.78), HL and self-care behaviors (r = 0.76), and self-efficacy and self-care behaviors (r = 0.84). The eGFR was significantly correlated with diabetes HL (r = 0.23), self-efficacy (r = 0.14), self-care behaviors (r = 0.16), and HbA1c (r = -0.16) scores. Linear regression after adjusting for sex, age, education, DM duration, smoking, and drinking alcohol showed that FBS level was inversely associated with diabetes HL (Beta = -0.21, R2= 11.0%), self-efficacy (Beta = -0.43, R2= 22.2%), and self-care behavior (Beta = -0.35, R2= 17.8%), whereas HbA1C level was negatively associated with diabetes HL (Beta = -0.52, R2= 23.8%), self-efficacy (Beta = -0.39, R2= 19.1%), and self-care behavior (Beta = -0.42, R2= 20.7%).ConclusionDiabetes HL was related to self-efficacy and self-care behaviors in elderly T2DM patients and was shown to influence their health, including glycemic control. These findings suggest that implementing HL programs to build competence in self-efficacy expectations is important for contributing to improvements in diabetes preventive care behaviors and HbA1c control.