Background Patients with both diabetes and hypertension could face more health risks than those with either condition alone, and less attention has been paid to their management outcomes, so this study may be the first to specifically address this problem. We aimed to examine the management outcomes of blood pressure (BP) in hypertensive patients with/without diabetes and fasting plasma glucose (FPG) in diabetic patients with/without hypertension. Methods Follow-up data were obtained from the National Basic Public Health Service Project in Sanming (2017–2021). A total of 25,795 adults with hypertension only, 4111 adults with diabetes only, and 5729 comorbid adults (namely, hypertensive patients with diabetes) were included. Generalized estimating equations were applied. Results Systolic blood pressure (SBP) and diastolic blood pressure (DBP) in patients with hypertension only both dropped significantly (Coef. = −0.00088, P < 0.001; Coef. = −0.00081, P < 0.001). DBP in comorbid patients decreased considerably (Coef. = −0.00033, P < 0.001). Pulse pressure in comorbid patients grew rapidly (Coef. = 0.00044, P < 0.001). BP control rate in patients with hypertension only increased significantly (OR = 1.00039, P < 0.001). FPG control rates in diabetic patients with/without hypertension grew markedly (OR = 1.00013, P < 0.001; OR = 1.00020, P < 0.001). Comorbid patients had lower baseline SBP and DBP but higher latest SBP than patients with hypertension only (Coef. = −1.18872, P < 0.001; Coef. = −1.16049, P < 0.001; Coef. = 1.0634, P < 0.001). Comorbid patients had lower baseline BP and FPG control rates than those with either condition alone, and differences were greater at the latest follow-up (OR = 0.28086, P < 0.001; OR = 0.91012, P = 0.049; OR = 0.04020, P < 0.001; OR = 0.69465, P < 0.001). Conclusion BP and FPG management outcomes have achieved progress. Comorbid patients have poorer performance than patients with either disease alone in BP levels especially the SBP level and control rates of SBP, DBP, and FPG. Future studies should be conducted using national data and include more confounding factors.