INTRODUCTION: Long-term biochemical nonremission and long-delayed diagnosis can increase the incidence of comorbidities of acromegaly and seriously affect patients' quality of life. To identify predictors of biochemical remission and quantify the relationship between delayed diagnosis and comorbidities, we performed a retrospective study of a large, single-centre cohort. METHODS: This retrospective cohort included 1692 hospitalised patients with acromegaly seen in a single referral centre between 2012 and 2020. To account for the longitudinal data structure, generalised estimating equation (GEE) regression models were established to further evaluate the factors associated with biochemical remission. RESULTS: Overall, 1692 inpatients (55.4% females, mean age at diagnosis: 40.1 ± 12.2 years, mean age at onset: 34.4 ± 11.71 years, median diagnostic delay: 4.4 years) were included. A total of 86.8% (1306/1504) had macroadenomas, and 34.1% (486/1424) had invasive tumours. According to the international diagnostic criteria, the 5-year biochemical remission rate of this cohort was 26.4%, while the Chinese criterion was 41.4%. According to the GEE model, invasion and large adenoma influence biochemical nonremission. After age 50, comorbidities such as hypertension and hyperlipidaemia were considerably more common in females than in males. The proportion of patients with comorbidities among those with a delayed diagnosis ≥4 years was greater than among those with a delayed diagnosis <
4 years (54.9 vs. 47.9%, P=0.004). CONCLUSION: The older the age at diagnosis and the longer the delay in diagnosis, the greater the incidence of comorbidities, especially in elderly females. Appropriate treatment of acromegaly should be started early to achieve biochemical control.