Study Reveals Strong Link Between Elevated HbA1c and Increased Hypertension Risk

"HbA1c levels are strongly linked to an increased risk of hypertension, with individuals exhibiting 22% higher odds of developing HTN compared to those with lower HbA1c levels. Additionally, the risk of isolated systolic hypertension (ISH) was 30% greater in those with elevated HbA1c," the researchers reported in BMC Cardiovascular Disorders. The study also found that the risk of HTN escalates significantly as HbA1c approaches 5.5%, highlighting the importance of monitoring blood sugar levels to mitigate the risk of developing hypertension.

HbA1c, a key marker of long-term blood glucose control, is widely used to monitor and manage diabetes. Given that hypertension and diabetes often coexist, monitoring HbA1c levels becomes crucial not only for managing diabetes but also for assessing the risk of developing hypertension, a common comorbidity in diabetic patients. Considering this, Wenbo Xu, Department of Laboratory, People’s Hospital of Yuxi City, Yuxi City, Yunnan Province, P.R. China, and colleagues seek to clarify the relationship between HTN and HbA1c, as well as the links between different types of hypertension and HbA1c levels.

For this purpose, the researchers analyzed data from the NHANES 2011–2018, which included anthropometric measurements and biochemical tests. Participants were categorized based on their HbA1c levels into groups of diabetes, prediabetes, and no diabetes. Logistic regression analyses were conducted to examine the correlations between HbA1c levels and the risks of HTN, ISH, and isolated diastolic hypertension (IDH). A fitting curve was also created to illustrate the relationship between HTN and HbA1c.

The study revealed the following findings:

• Among the 10,503 participants, the prevalence of hypertension (HTN) increased significantly with higher HbA1c levels.
• In the adjusted model, compared to the lowest HbA1c group, the odds ratio (OR) for the highest HbA1c group was 1.22.
• The risk of isolated systolic hypertension (ISH) increased significantly with higher HbA1c levels in group 3 compared to group 1 (OR: 1.3).
• The adjusted model showed no significant association between HbA1c levels and the risk of isolated diastolic hypertension.

The study highlights the independent role of HbA1c in increasing the risk of hypertension among adults in the United States, emphasizing the common occurrence of both abnormal glucose metabolism and HTN.

"The findings particularly show that the risk of developing HTN rises most sharply when HbA1c levels near 5.5%," the researchers concluded.

Reference:

Luo, B., Xu, W., Luo, F. et al. Association between elevated glycosylated hemoglobin levels and hypertension among US adults: NHANES 2011–2018. BMC Cardiovasc Disord 25, 58 (2025). https://doi.org/10.1186/s12872-025-04503-3