New Research Redefines Blood Pressure Targets for Diabetes Patients

A substantial study involving over 80,000 patients in Singapore, led by Duke-NUS Medical School and published in the Journal of the American Heart Association, emphasizes the importance of maintaining optimal blood pressure levels for Asian adults with type 2 diabetes. The research explores how different blood pressure levels correlate with the risk of heart disease-related mortality in this population. 

The study indicates that the lowest risk is associated with a systolic (top number) blood pressure in the range of 120–129 mmHg. However, the risk sharply increases when systolic levels reach 130 mmHg or higher. For diastolic (bottom number) pressure, the lowest risk is observed around 80–89 mmHg, and levels above 90 mmHg increase risk in older adults. Interestingly, the study reveals that diastolic pressure below 70 mmHg paradoxically increases cardiovascular risk. 

Professor Tazeen Jafar, the senior author of the study, highlights that diastolic pressure below 70 mmHg could potentially be harmful in patients with diabetes, although it remains unclear if this association is directly causal. The study underscores the importance of controlling elevated systolic blood pressure to less than 130 mmHg in patients with diabetes while carefully evaluating risks if diastolic pressure drops too low. 

The findings support existing clinical guidelines recommending systolic targets below 130 mmHg in patients with diabetes to protect against heart disease and stroke. However, the study suggests caution in lowering diastolic pressure too far below 70 mmHg. Given the high and rising rates of diabetes in Asian populations, the results of this study hold particular relevance.

The study addresses conflicting results from previous research on the relationship between blood pressure and cardiovascular risk in Asian diabetic patients. Differences in age distributions, blood pressure assessment methods, follow-up periods, and confounder adjustments have left optimal blood pressure targets uncertain for this population. 

Professor Jafar emphasizes the urgent need for more effective blood pressure management in those with diabetes globally. She stresses the importance of collaborative efforts between doctors and patients to lower elevated systolic pressure through lifestyle adjustments and medications while monitoring diastolic levels and overall health. 

The study utilized data from the SingHealth Diabetes Registry, a large multi-center database. Researchers analyzed the relationship between various systolic and diastolic blood pressure levels and the risk of cardiovascular mortality over a seven-year follow-up period. The analysis considered factors such as age, gender, and existing heart disease, and sensitivity analyses confirmed the robustness of the results. 

Clinical Associate Professor Bee Yong Mong, a co-author of the study, highlights the need for research initiatives to translate evidence-based guidelines into real-world practice. The aim is to scale up strategies that enhance blood pressure control and cardiovascular risk reduction in Asian populations burdened by diabetes. 

Professor Patrick Tan, Senior Vice-Dean for Research at Duke-NUS, emphasizes the public health implications of the findings, especially with rising rates of diabetes and hypertension in many parts of Asia. The study provides crucial insights into evidence-based blood pressure targets that reduce the risk of cardiovascular mortality, supporting efforts to implement optimal hypertension management. 

Journal Reference  

Seng LL et al, Real-World Systolic and Diastolic Blood Pressure Levels and Cardiovascular Mortality in Patients with Type 2 Diabetes—Results from a Large Registry Cohort in Asia, Journal of the American Heart Association (2023). DOI: 10.1161/JAHA.123.0123456.