Adapted from Steve Freed’s article in Diabetes in Control Spring 2020
Elevated blood glucose levels indicative of prediabetes appear to be associated with increased risks for retinopathy, peripheral neuropathy, and also diabetic nephropathy, according to Emanuelsson et al. (p.894).
As a result, they suggest that screening for micro- and macrovascular complications should be recommended for individuals with raised blood glucose or prediabetes.
In total, about 820,000 individuals were considered in the analysis. The authors found that, on an observational level, increasing glucose levels were associated with higher risks for both micro and macrovascular complications. Validation in the cohorts further confirmed the associations with retinopathy, neuropathy, nephropathy, and myocardial infarction but not peripheral arterial disease or kidney disease. This risk is present at glucose levels within what is currently considered the normal or prediabetic range.
The American Diabetes Association recommends screening for prediabetes in adults with obesity or overweight and with risk factors for diabetes. However, this screening does not include examinations for microvascular complications.
Screening for retinopathy, neuropathy, diabetic nephropathy and additional risk factors such as obesity, hyperlipidemia, and hypertension might be indicated in individuals with prediabetes.
The finding of a stepwise increase in the risk of vascular disease with increasing glucose levels within the normoglycemic range or higher support the idea that an elevated glucose level has a causal role in the pathogenesis of the microvascular disease, as do levels below the diabetes cut off. This is in line with the general understanding of the natural history of type 2 diabetes as a continuous process of declining β-cell function and increasing relative insulin deficiency, leading to a continuous increase in glucose that is initiated years before the diabetes threshold is reached.
Randomized controlled trials have shown that lifestyle changes and treatment with glucose-lowering drugs can reduce the progression from prediabetes to diabetes.
Recent 30-year follow-up data from a study of 577 Chinese individuals showed that lifestyle interventions in individuals with prediabetes reduce long-term risks of diabetes, a composite of microvascular complications, cardiovascular disease, cardiovascular mortality, and all-cause mortality.
The effects of lifestyle intervention are not likely to be due to glucose-lowering alone but to several beneficial metabolic effects. The findings highlight the importance of early detection of glycemia and screening for prediabetes in asymptomatic individuals through the use of risk assessment tools—such as the one currently provided by the American Diabetes Association
- Having blood glucose in the prediabetes range considered normal has shown to begin the complications of diabetes much earlier than thought.
- We need to be more proactive at the first signs of prediabetes. That means any fasting glucose reading above 100mg (5.5 mmol/l) or a random reading of above 139mg/dL(7.8 mmol/l).
- These findings suggest that elevated glucose levels should be identified as an essential risk factor for micro- and macrovascular disease in the general population and that screening for microvascular disease may be recommended, along with screening for additional cardiovascular risk factors, in individuals with prediabetes.
- Maybe it is time to just call prediabetes, diabetes, which would provide for much earlier treatment.
Reference for “Prediabetes Equals Diabetes”:
Diabetes Care 2020 Apr; 43(4): 894-902.https://doi.org/10.2337/dc19-1850