Public health interventions to manage the future risks of type 2 diabetes and cancer in people with prediabetes should be tailored to the age of prediabetes diagnosis, findings from a 20-year observational study suggest.
Writing in the Lancet Diabetes & Endocrinology, a University of Leicester-led research team said higher than normal glucose concentrations had been linked to an increased risk of cancer in previous studies.
But research had not previously mapped the complete clinical trajectory from prediabetes to cancer and accounted for the potential progression to type 2 diabetes and the risk of death.
To fill this data gap, they used linked English primary care, hospital and mortality records to identify 328,049 individuals aged 18-100 years who had been diagnosed with prediabetes between 1 January 1998 and 30 November 2018.
Follow-up was from prediabetes diagnosis until death or 30 November 2018, with two intermediate outcomes of type 2 diabetes and cancer.
Type 2 diabetes and cancer probability
Some 10 years after the diagnosis of prediabetes, the likelihood of remaining in the prediabetes state was much higher for those diagnosed at a younger age (72.1% for men aged <55 years at diagnosis compared with 23.2% for men aged ≥75 years at diagnosis).
Among men diagnosed with prediabetes, the probability of developing cancer and remaining in this state ranged from 1.9% for men aged <55 years at diagnosis to 7.8% for men aged ≥65 to <75 years.
The likelihood of developing type 2 diabetes and remaining in this state, ranged from 7.9% for men aged ≥75 years at prediabetes diagnosis to 24.0% for women aged <55 years.
Meanwhile, the probability of death following prediabetes diagnosis ranged from 1.2% for women aged <55 years at diagnosis up to 38.7% for women aged ≥75 years at diagnosis.
The analysis showed smoking, socioeconomic status, ethnicity and body mass index had independent but small associations with different trajectories of disease.
Cancer incidence rates were only slightly higher in people who developed type 2 diabetes compared with those with prediabetes, the researchers noted, which suggested mechanisms linking type 2 diabetes to cancer could unfold before type 2 diabetes was clinically diagnosed.
‘The trajectories of type 2 diabetes and cancer following a diagnosis of prediabetes varied substantially by age at prediabetes diagnosis and, to a lesser extent, other sociodemographic and lifestyle factors, with most younger individuals (aged <55 years) remaining in the prediabetes state,’ they concluded.
‘These figures clearly indicate that for any strategy aimed at reducing the risk of death, type 2 diabetes, or cancer in individuals with prediabetes to be cost-effective and yield a net health benefit, it should account for the age of prediabetes diagnosis, as the absolute risks of these three possible outcomes vary substantially with age.’
The need for clinical intervention
Study lead author Dr Francesco Zaccardi, honorary consultant in cardiometabolic medicine and associate professor in clinical epidemiology and health data science at the University of Leicester, said the findings highlighted the importance of age when looking at prediabetic patients and determining the risk of progression to type 2 diabetes or cancer.
‘Importantly, proactive lifestyle and clinical interventions can help individuals maintain stable glucose level or even revert from prediabetes state to normal glucose levels,’ he said.
Study senior author Professor Kamlesh Khunti, director of the Leicester Real World Evidence Unit and professor of primary care diabetes and vascular medicine at the University of Leicester, said the findings revealed a striking age-related difference in how prediabetes progresses.
‘This highlights the importance of targeted strategies to support people at different stages of life and manage their long-term health risks,’ he said.
The research was funded by the National Institute for Health and Care Research Applied Research Collaboration East Midlands, for which Professor Khunti is the director, the NIHR Leicester Biomedical Research Centre and Hope Against Cancer.