Interaction between Mean Arterial Pressure and HbA1c in Prediction of Cardiovascular Disease Hospitalisation: A Population-Based Case-Control Study

Objective. To explore the relationship between mean arterial pressure (MAP), HbA1c, and cardiovascular (CV) hospitalisation risk in type 2 diabetes. Design. Population-based case-control study. Settings. Primary and secondary care level in Cambridgeshire, United Kingdom. Participants. 588 patients with type 2 diabetes from 18 English general practices recording a CV hospitalisation in 2009-2011 were included. Risk-set sampling was used to select 2920 gender, age, and practice matched control type 2 diabetes patients. Main Outcome Measure. Conditional logistic regression was used to explore further dose-response relationships between MAP, HbA1c, and CV hospitalisation risk. Results. The relationship between MAP and CV hospitalisation was nonlinear (P < 0.001 for linearity test). The MAP associated with the lowest CV hospitalisation risk was 97 (95% CI: 93-101) mmHg. An interaction between MAP and HbA1c for increased risk of cardiovascular hospitalisation was observed among those with HbA1c < 7% (53 mmol/mol) and MAP < 97 mmHg. Conclusions. In type 2 diabetes, MAP is a good predictor of CV hospitalisation risk. CV hospitalisation is lowest with a MAP between 93 and 101 mmHg. CV hospitalisation was particularly high among those with both a low MAP and a lower HbA1c.