It is known that the sugar metabolism in the body starts going haywire 10–15 years before the diabetes is diagnosed. This is known as the Natural History of type II diabetes. Read here: The evolution of type II diabetes.
It is hypothesized that the insulin resistance starts moving up at least 12 years before the diagnosis of diabetes, and a few years before the diagnosis of pre-diabetes. So, how early can one sense the onset of diabetes?
A recent Japanese study published in The Journal of the Endocrine Society found that the early signs of the onset of type 2 diabetes can be detected as early as 20 years before the final diagnosis.
The scientists tracked 27,392 healthy, non-diabetic adults for their fasting blood sugar, body mass index (BMI), and insulin sensitivity.
During the 11 year period of following them, 18% of them developed pre-diabetes and 4% developed type 2 diabetes.
Diagnosis of diabetes was made when the fasting blood glucose crossed 125 mg/dL. Those who had their fasting blood sugar between 100 and 125 mg/dL, were said to be having pre–diabetes. Those who had fasting blood sugar below 100 mg/dL were considered normal.
Those who did not develop diabetes maintained their fasting blood sugar at an average of 94 mg/dL throughout the study period.
Those who developed diabetes had their fasting blood glucose at an average of 101.5 mg/dL ten years before the diabetes diagnosis. This average crept upwards slowly reaching 110 mg/dL one year before the diagnosis. The levels shot up thereafter to cross the diabetes diagnosis cutoff point, 125 mg/dL.
Those who developed prediabetes also had higher fasting blood sugar ten years before prediabetes diagnosis than those who did not develop prediabetes. Their fasting blood sugar also had a similar increase for a decade but to a lower extent than in the patients who ended up getting diabetes.
Insulin resistance and BMI (a marker for obesity) followed similar trends to fasting blood sugar.
Discussion about the results
Thus, people who ended up as prediabetics showed early signs at least 10 years before the diagnosis, through fasting blood sugar, insulin resistance and obesity. Even 10 years prior to diagnosis, their numbers for these three were different from the numbers of people who did not develop prediabetes.
Similarly, diabetes showed its early signs at least 10 years before the diagnosis, through fasting blood sugar, insulin resistance and obesity. Even 10 years prior to be diagnosed as diabetics, their values for these three were different from the values of those who did not develop diabetes.
So, prediabetics were discernible from normal people at least 10 years before. And diabetics were distinguishable from prediabetics, as well as normal people, at least 10 years before.
Combining the two, the authors concluded that the signs of diabetes can be seen in fasting blood sugar, insulin resistance, and obesity more than 20 years before the actual diagnosis of diabetes.
The converse is not true: If the early signs of glucose dysregulation, such as fasting blood sugar, are normal, it does not mean that one is 20 years away from getting diabetes. The progression can be faster.
So the right way to use these results to look for a change in the above markers, and once we spot them, we act on bringing them in control. Twenty years is a warning long enough.
Glucose dysregulation starts at least 20 years before the diagnosis of diabetes.
Watch for rising fasting blood sugar levels above 95 mg/dL.
Make healthy lifestyle choices as you age, or gain weight.
First published on: 26th April, 2018