AIMS: Post-hoc evaluation of relationships between first-year change in glycaemic control (HbA(1c) ) and change in patient-reported outcomes among ACCORD health-related quality of life (HRQoL) substudy participants. METHODS: Data from 2053 glycaemia-trial subjects were analysed. We assessed physical and mental health status (36-Item Short Form Health Survey, Version-2), symptom count and severity (Diabetes Symptoms Distress Checklist) and treatment satisfaction (Diabetes Treatment Satisfaction Questionnaire). Linear mixed models were used to test relationships between 1-year changes in HbA(1c) and patient reported outcomes sequentially adjusting for correlates (baseline characteristics, baseline patient reported outcomes, treatment assignment, frequency of clinical contact and post-randomization weight change plus new complications). RESULTS: Poorer baseline control of HbA(1c) and cardiovascular disease risk factors predicted greater one-year improvements in treatment satisfaction. Similarly, poorer baseline patient reported outcome scores all individually predicted greater 1-year improvement in that same outcome. Accounting for baseline and post-randomization characteristics and treatment arm, 1-year change in HbA(1c) was unrelated to changes in overall physical or mental health; however, every one percentage-point (10.9 mmol/mol) reduction in HbA(1c) was associated with lower symptom count (beta = 0.599; P = 0.012), lower symptom distress (beta = 0.051; P = 0.001), and higher treatment satisfaction (beta = -2.514; P < 0.001). CONCLUSIONS: Independent of all relevant covariates, better glycaemic control over 1 year was associated with reduced patient-reported diabetes symptoms and symptom distress, and increased treatment satisfaction, but not overall physical and mental health. Further investigation is required to understand the specific psychosocial mechanisms that affect how patients value health and treatments.