By: Dr. Linda Anegawa
The Annals of Internal Medicine just published new guidelines from the US Preventive Services Task Force (USPSTF) that recommend broader screening for type II diabetes among those who are overweight.
This should be good news, right? Let’s take a look at the latest recommendations.
The USPSTF now advises adults with overweight or obesity to have one of three tests between the ages of 40-70: either a fasting plasma glucose, an oral glucose tolerance test, or a hemoglobin A1C test to help detect diabetes earlier.
It certainly is good news that the USPSTF feels there are enough studies to recommend broader screening than in the past. After all, diabetes is a major risk factor for cardiovascular disease, the leading cause of death in the US.
So what is the problem? There are several.
First: based on what types of patients are seen in a typical obesity medicine practice, these recommendations just don’t go far enough to protect the public.
Type II DM typically develops slowly and insidiously, and unfortunately by the time it is detected, complications such as eye and kidney disease already are present. This is especially true with many of the ethnic groups in Hawaii, who are at much higher risk than the general population of the US and at lower BMIs. That means that high risk ethnicities such as native Hawaiians, Japanese, Chinese, and those from the Philippines are at high risk even when their Body Mass Indices don’t meet the traditional “overweight” cutoff of 25 for screening! We could be missing thousands and thousands of new cases of diabetes in Hawaii, and not even know it.
Then, why is the USPSTF not recommending screening earlier in adulthood, especially in high-risk ethnicities? The American Academy of Pediatrics does: they recommend diabetes screening in children and adolescents who are overweight or obese, and have two additional risk factors such as a family history of diabetes, or are of a high risk ethnicity as defined above. So does the American Diabetes Association.
Nearly every patient we see at OSR Weight Management would meet early-screening criteria, and indeed when we test, we find diabetes or prediabetes 99% of the time. Especially in Hawaii, there are great arguments to recommend screening at lower weights and MUCH earlier in adulthood than the USPSTF recommends.
Second: based on the science of how Type II diabetes develops, the most commonly performed and the cheapest test – the fasting plasma glucose – may miss the mark in many patients. The reason is because fasting glucose is not generally a problem unless an individual makes no insulin at all (Type I diabetes). In Type II diabetes, the problem is really in how individuals process the glucose in the blood after they eat. So the fasting glucose may actually be normally, but the after-meal sugar is generally elevated. This will only be picked up by either the glucose tolerance test or the Hemoglobin A1c, which are not as commonly performed for screening.
Third: the USPSTF acknowledges that ‘evidence on the optimal rescreening interval is limited’ but then states that ‘rescreening every 3 years may be a reasonable approach.’ Unfortunately, waiting 3 years to re-screen gives diabetes plenty of time to effect major damage on the body and vastly increase the risk of cardiovascular disease.
My biggest worry is that the USPSTF’s recommendations are what guide 3rd party payers in reimbursing lab tests ordered by your doctor. So some of our patients may have to fight to get the costs of such testing covered, even though they are at high risk of morbidity and mortality from this dread disease. Why so little, so late, USPSTF?