Longitudinal analysis of blood pressure control and influencing factors among 32 701 primary care hypertensive patients with or without diabetes: a prospective cohort study in Jianye District, China

Background: We aimed to explore the variation in blood pressure (BP) control in primary care hypertensive patients with or without diabetes, and investigate potential factors associated with inadequate BP control during follow-up. Methods: Primary care hypertensive patients with and without diabetes were recruited in 2020 from Jianye District of Nanjing and prospectively followed up until 2023. Effective BP control was measured in terms of consistent normal readings of systolic BP <140 mmHg and of diastolic BP <90 mmHg based on the most recent assessment during the follow-up period. We used the negative binomial model with total person-years as an offset to evaluate whether the study population would achieve BP control after the 3-y follow-up period in terms of rate ratio (RR) and 95% CI. We further conducted subgroup analysis based on the absence or presence of clinically confirmed diabetes and BP stability at baseline. Results: Of a total of 32 701 patients with hypertension, compared with those without comorbid diabetes and stable BP at baseline, patients with comorbid diabetes and unstable BP at baseline were less likely to have effective BP control at follow-up (adjusted RR=2.01, 95% CI 1.89 to 2.15). We observed an elevated risk of ineffective BP control at follow-up in those aged 60-70 y (1.69; 95% CI 1.56 to 1.83) or >= 70 y (1.73; 95% CI 1.59 to 1.88), females (1.09; 95% CI 1.03 to 1.16), those with a higher waist-to-height ratio (1.25; 95% CI 1.17 to 1.34), overweight/obese in terms of body mass index (1.16; 95% CI 1.09 to 1.23) or regularly consuming alcohol (1.26; 95% CI 1.16 to 1.37). Higher educational attainment indicated a reduced risk of ineffective BP control at follow-up (0.68; 95% CI 0.63 to 0.75). Conclusions: Achieving effective BP control remains a persistent challenge, especially for patients with comorbid hypertension and diabetes. In the absence of any novel strategies for hypertension care, the existing multidisciplinary care approaches could be repurposed and integrated for effective management of the aforementioned comorbid conditions in primary care settings.