Bidirectional Associations Between Blood Glucose and Blood Pressure: A Data-Driven Causal Analysis Using Structural...

Area of Science:

• Cardiovascular epidemiology
• Metabolic disease research
• Causal inference in health sciences

Background:

• The causal relationship between hyperglycemia and hypertension is complex and unresolved.
• Shared metabolic drivers may underlie both conditions.
• Understanding the directionality is crucial for clinical management.

Purpose of the Study:

• To quantify the bidirectional causal effects between glycaemic status and blood pressure.
• To determine the magnitude and robustness of these effects.
• To assess the impact of unmeasured confounding.

Main Methods:

• Analysis of 55,386 adults from NHANES (1999-2023) and replication in Framingham Heart Study (n=4240).
• Application of a triangulated causal inference framework including DAGs, SEM, PSM, IPW, and AIPW.
• Sensitivity analyses using E-value and Rosenbaum Gamma.

Main Results:

• Bidirectional causal effects were confirmed across all methods.
• Hypertension increased fasting glucose (6.55 mg/dL), while hyperglycemia increased systolic BP (1.76 mmHg), with a dominant BP → glucose pathway.
• Sensitivity analyses indicated moderate robustness to unmeasured confounding (RR ≥ 1.40-1.64).

Conclusions:

• The blood pressure to glucose pathway is the primary causal direction.
• Prioritizing hypertension control may offer significant benefits for glycaemic regulation.
• Findings support integrated management strategies for cardiometabolic health.