The Woolcock Institute of Medical Research

Results from SURMOUNT-OSA, a landmark international clinical trial for which the Woolcock was a flagship recruitment centre, are changing the way we look at sleep and metabolic health. The study revealed that treating both obesity and obstructive sleep apnea (OSA) with the weight-loss medication tirzepatide may significantly reduce the risk of diabetes and cardiovascular disease — conditions that commonly affect people living with severe sleep apnea. Importantly, the research provides compelling evidence that addressing weight and sleep-disordered breathing together delivers greater health benefits than targeting either condition alone.

OSA an estimated 38 percent of Australians. It is strongly linked to obesity and substantially increases the risk of Type 2 diabetes, high blood pressure, heart attack and stroke. Traditional treatments such as continuous positive airway pressure (CPAP) machines help keep the airway open at night. However, while CPAP improves breathing and sleep quality, it has not consistently been shown to reduce the long-term risk of diabetes or cardiovascular disease.

KEY TRIAL FINDINGS

Participants receiving tirzepatide in the SURMOUNT-OSA trial experienced significant weight loss, reduced severity of sleep apnea, lower markers of inflammation, improved pre-diabetes indicators, reduced triglycerides and lower levels of LDL (“bad”) cholesterol. While weight loss produced substantial benefits, the combination of weight reduction and improved OSA control delivered the greatest improvements in cardiometabolic health.

Professor Grunstein described the findings as evidence that “a holistic approach is vital for patients struggling with both obstructive sleep apnea and obesity,” adding that targeting both conditions may significantly reduce cardiovascular disease burden in this vulnerable population.

SHIFT TO METABOLIC CARE

The findings reinforce the strong connection between sleep health and metabolic health. Rather than treating OSA and obesity separately, future care models may increasingly combine pharmacological weight-loss strategies with sleep-focused therapies to optimise heart health outcomes.

This integrated approach could represent a major shift in how clinicians manage patients at high risk of diabetes and cardiovascular disease.

NEW TRIALS

Building on these promising findings, researchers at the Woolcock Institute of Medical Research are now recruiting participants for clinical trials known as MARITIME-OSA.

MARITIME-OSA are clinical research studies looking at an investigational weight loss drug which is administered monthly by injection. These studies will assess whether the drug can improve quality of life for people living with moderate to severe OSA and obesity or overweight.

These studies may be suitable for you if you are aged 18 years or over, have obesity or are overweight with a BMI of 27 or higher and have been diagnosed with moderate to severe OSA. They will involve five overnight sleep studies at the Woolcock Institute of Medical Research. If you use a positive airway pressure (PAP) machine, you will need to stop using it for a minimum of seven days before each sleep study. You will be assigned by chance (using a computer) to receive either the study drug or placebo, both given as an injection.

The trial is supported by Dr Claudia Harper (PhD), an Accredited Practising Dietitian who works exclusively on OSA and weight-loss clinical trials at the Woolcock Institute. She has extensive experience in dietary and pharmacological weight-loss approaches for chronic disease management, including OSA.

LOOKING AHEAD

The emergence of medications like tirzepatide signals a new era in sleep medicine. By targeting both obesity and sleep apnea together, researchers are uncovering opportunities to reduce the long-term risks of diabetes and heart disease in millions of people worldwide.

As understanding grows around the deep interconnection between sleep and metabolic health, treatment strategies may increasingly reflect this whole-person approach — improving not just sleep, but overall cardiovascular wellbeing.

For more information about the MARITIME-OSA trial, interested individuals can contact the study team at weightlossosa@woolcock.org.au.

Find out more

• Study Finds OSA Treatment May Reduce Diabetes and Heart Disease
• Our Sleep and Circadian Research Group
• Obstructive Sleep Apnea