Does health literacy predict cardiometabolic marker trajectories among people with diabetes? A longitudinal mixed-effect analysis

AIMS: To assess trajectories in cardiometabolic markers among people with type 1 and type 2 diabetes with varying health literacy levels.

METHODS: Survey data assessing self-reported health literacy among 1401 people with type 1 diabetes and 910 people with type 2 diabetes were linked to prospective clinical data. Mixed effects modelling was used to identify the impact of three health literacy domains on trajectories of systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), and glycated hemoglobin (HbA1c).

RESULTS: High health literacy scores in some domains were associated with attenuated HbA1c trajectories, while associations with LDL-C and SBP were weak or absent, particularly among participants with type 2 diabetes. The domain "Ability to Actively Manage Health" had the strongest association with HbA1c (P < 0.001). Exponential changes over time were not observed. Differences in the estimated progression of cardiometabolic markers by health literacy levels did not reach statistical significance.

CONCLUSION: Low health literacy was associated with suboptimal glycaemic levels in type 1 and type 2 diabetes. There was inconclusive evidence of associations between health literacy, BP, and LDL-C. Development in cardiometabolic markers did not indicate faster diabetes progression among people with low health literacy.