Double Trouble: New Zealand’s First Look at Blood Pressure and Blood Glucose Together
For the first time in Aotearoa, Pūtahi Manawa researchers are turning their focus to the combined impact of high blood pressure and high blood glucose (‘Sweet Pressure’)—two silent threats that often go hand in hand but have rarely been studied together.
High blood pressure (hypertension) affects around 25% of adults in Aotearoa, with even higher rates among Māori and Pacific Peoples—about half of people with high blood pressure show impaired glucose tolerance, which can lead to diabetes.
Meanwhile, diabetes continues to rise, with 5% of New Zealanders predicted to have diabetes under the current NZ definition by 2044. A person with diabetes is about twice as likely to have high blood pressure as someone who doesn’t have diabetes. On their own, each condition increases the risk of heart disease and kidney failure—but when they occur together, the danger multiplies.
The Sweet Pressure IRM is uncovering how these two common conditions interact to shape long-term health outcomes. By studying them in tandem, scientists hope to identify earlier warning signs, sharpen prevention strategies, and better support the communities most at risk. It’s a shift that could reshape how we think about and respond to long-term conditions.
Before this investigation, there was no data on how ‘sweet pressure’ shows up in New Zealanders. In 2024, renowned epidemiologist Professor Rod Jackson, Associate Professor Katrina Poppe, and University of Auckland doctoral student Jingyuan Liang used Jackson’s PREDICT (2021) primary care dataset tool (30-79 years) to determine how much of an issue this is. Preliminary findings show a prevalence of 13% in women, higher in Pacific women (28%), Māori (17%), and Indian (20%), and 12% in men, higher in Pacific men (20%), Māori (16%) and Indian (16%).
The PREDICT tool uses algorithms based on primary care data to predict the risk of cardiovascular disease. PREDICT is an ongoing, open cohort study for the NZ population and is embedded into primary practice software systems nationwide, covering at least a third of the country’s residents. Not only does this provide access to robust data, but Sweet Pressure research can have immediate societal impact.
Finding the sweet spot
Participants were identified as having “sweet pressure” if they had records showing a history of high blood pressure plus a history of diabetes. Ms Liang said that they defined ‘sweet pressure’ for the first time for their research project.
“For “sweet pressure”, high blood pressure was defined lower than the standard clinical definition because when one person has both high blood pressure and high blood sugar, the associated risks are heightened compared to having one condition on its own.”
In New Zealand, people with an HbA1c of 50 mmol/mol or greater are diagnosed with diabetes, and those in the 41-49 mmol/mol range can be diagnosed with pre-diabetes. Ms Liang said they used the lower HbA1c cutoff of ≥48 mmol/mol to identify people with a history of diabetes for the study, to align with the World Health Organisation’s recommendations and the international trend to use the lower cutoff.