AimsTo assess longitudinal changes in blood pressure (BP) and fasting plasma glucose (FPG) in primary care patients with concomitant hypertension and type 2 diabetes mellitus (T2DM), and to explore factors associated with patients' inability to improve BP and FPG at follow-up.MethodsWe constructed a closed cohort in the context of the national basic public health (BPH) service provision in an urbanised township in southern China. Primary care patients who had concomitant hypertension and T2DM were retrospectively followed up from 2016 to 2019. Data were retrieved electronically from the computerised BPH platform. Patient-level risk factors were explored using multivariable logistic regression analysis.ResultsWe included 5,398 patients (mean age 66 years; range 28.9 to 96.1 years). At baseline, almost half [48.3% (2,608/5,398)] of patients had uncontrolled BP or FPG. During follow-up, more than one-fourth [27.2% (1,467/5,398)] of patients had no improvement in both BP and FPG. Among all patients, we observed significant increases in systolic BP [2.31 mmHg, 95% confidence interval (CI): 2.04 to 2.59, p