Diabetes Risks Develop 20 Years Before Diagnosis

Screening, treatment delay may hasten or increase cardiovascular disease risk.

A study was done to describe trajectories for metabolic risk factors for type 2 diabetes (T2D) up to 25 years prior to diagnosis and to estimate the absolute 20-year risk for T2D based on a simple set of commonly measured key risk factors.

Håkan Malmström, from the Karolinska Institutet in Stockholm, and colleagues assessed data from the Swedish AMORIS cohort and included about 300,000 individuals with data on fasting glucose obtained in health examinations during 1985–1996 (baseline period). All had a fasting glucose from a health exam during the baseline period and followed until 2012 for development of incident T2D. The 20‐year T2D risk based on age, sex, body mass index (BMI), fasting glucose and triglycerides was estimated. Trajectories for biomedical risk factors of T2D starting from >20 years before diagnosis and including fasting glucose, triglycerides, and BMI were evaluated according to yearly means for cases and controls.

Subjects who had excessive weight and obesity, and those with elevated fasting glucose (fGlu) and triglycerides (TG) had a substantially increased risk among both men and women. More than 20 years before diagnosis, T2D cases had higher mean body mass index, fGlu, and TG vs controls. The difference in fGlu between those who developed T2D and controls increased over time.

“This suggests that diabetogenic processes tied to chronic insulin resistance operate for decades prior to the development of T2D,” the authors write.

They identified 28, 244 new T2D cases during the study period, with an average 20-year risk of 8.1%. This risk was substantially increased in both participants with excessive weight and obesity and in those with elevated fasting glucose and triglyceride levels, in both men and women. T2D cases had higher mean BMI and fasting glucose and triglyceride levels compared with controls >20 years before diagnosis and the difference in fasting glucose levels increased over time. Microalbumin can also be present as a risk factor.

Overall, abnormalities related to chronic insulin resistance are in play for decades prior to the development of type 2 diabetes, and using risk classification can help identify individuals at increased risk.

Development of T2D is associated with subtle elevations in glucose and lipid levels >20 years before diagnosis. This suggests that diabetogenic processes tied to chronic insulin resistance operate for decades prior to the development of T2D. A simple risk classification can help in early identification of individuals who are at increased risk.

In another study they found that early detection and treatment of type 2 diabetes may be more beneficial than even aggressive control of blood glucose, blood pressure, and cholesterol.

Screening to identify type 2 diabetes followed by early treatment with just a change in nutrition and physical activity could result in substantial health benefits currently and into the future, according to new research that combined large scale clinical observations and innovative computer modelling.

This study, led by researchers at the University of Michigan Medical School and the MRC Epidemiology Unit, University of Cambridge, used data from the ADDITION-Europe study of diabetes screening and treatment, which it combined with a computer simulation model of diabetes progression.

This approach revealed that screening followed by treatment led to a reduced risk of cardiovascular disease or death within a five-year follow-up period when compared to patients having no screening.

“Diabetes can be debilitating for patients and costly for healthcare,” says William Herman, M.D., lead author of the paper and a professor at the University of Michigan Medical School. “This research shows that the early identification of diabetes has major health benefits, and supports the introduction of measures such as screening to reduce the time between development of type 2 diabetes and its treatment.”

At 10 years after baseline, the simulations predicted that with a delay of three years in diagnosis and treatment, 22.4 percent of those with type 2 diabetes would experience a cardiovascular disease event, such as stroke or heart bypass surgery. This rose to 25.9 percent with a diagnosis delay of six years.

However, if screening and routine care had been implemented, the simulation predicted only 18.4 percent would experience a cardiovascular disease event at 10 years after baseline. The simulated incidence of all-cause mortality was 16.4 percent with a delay of three years and 18.2 percent with a delay of six years, compared to 14.6 percent for screening and treatment.

This means that over 10 years, the model predicts that for people with undiagnosed type 2 diabetes, screening would be associated with a 29 percent reduction in relative risk of a cardiovascular disease event, compared with a delay of six years in diagnosis and treatment.

This amounts to a 7.5 percent reduction in the absolute risk of adverse cardiovascular outcome in this population. The comparable change in all-cause mortality was 20 percent relative risk and 3.6 percent absolute risk reduction.

The researchers concluded that there are substantial health benefits of early identification of type 2 diabetes plus the major benefit of reducing cost.

Practice Pearls:

• Development of T2D is associated with subtle elevations in glucose and lipid levels >20 years before diagnosis.
• Early diagnosis and proper treatment of type 2 diabetes are likely to confer health benefits.
• Aggressive control of blood glucose, blood pressure and cholesterol after diagnosis of type 2 diabetes may be less important than early screening.
• Delaying in screening and treatment for type 2 diabetes may hasten and/or increase the risk for developing cardiovascular diseases.

References:

Diabetes Obes Metab. 2018 Feb 5. doi: 10.1111/dom.13241. [Epub ahead of print]

Early Detection of Type 2 Diabetes Reduces Death Caused by Cardiovascular Disease  Diabetesincontrol