Association between health literacy and glycemic control in elderly patients with type 2 diabetes and modifying effect of social support.

Objective: To investigate the association between inadequate functional health literacy, considering the Short Assessment of Health Literacy for Portuguese-speaking Adults, and glycemic control in elderly patients with type 2 diabetes, and to examine this association in low social support settings, according to Medical Outcomes Study .

Methods: Cross-sectional study conducted at the diabetes referral center of a university hospital. Participants were recruited among type 2 diabetes patients aged 60 years or older, between May 2013 and November 2014. The primary outcome was the most recent glycated hemoglobin value measured within the last 6 months.

Results: A total of 398 elderly patients with type 2 diabetes were evaluated. Of these, 232 were not eligible to participate. The final sample comprised 166 participants. Hierarchical multiple linear regression was performed. The following variables were entered in three blocks: sociodemographic characteristics, clinical variables and health literacy scores. Regression analysis of the interaction between health literacy and social support as a determinant of glycemic control was also performed. Mean age of subjects was 68.0 years (standard deviation of 5.9). Mean glycated hemoglobin value was 8.5% (standard deviation of 1.4). Short assessment of health literacy for Portuguese speaking adults score was independently associated with glycated hemoglobin (B=-0.059; p=0.043). The interaction between social support and health literacy score (p=0.003) was a determinant of glycemic control.

Conclusion: Health literacy is associated with glycemic control. Social support may modify the relation between health literacy and glycemic control.