Delay in Diagnosis Leads Majority with Prediabetes to Remain Unaware
A number of studies have established that most cases of Type 2 Diabetes can be prevented or delayed with lifestyle modification or pharmaceutical intervention in patients with prediabetes, also called impaired fasting glucose. Due to a delay in diagnosis by physicians, only about 7% of Americans are aware they have the condition and are therefore not being appropriately treated.
Prediabetes risk awareness is very low in the United States.
Before people develop Type 2 Diabetes, they almost always have an asymptomatic condition called prediabetes. Whereas diabetes is formally diagnosed as having a fasting plasma glucose level of greater than 126 mg/dl on two or more separate blood tests, prediabetes is confirmed when glucose levels are between 100 and 125 mg/dl.
Using data from the Fourth National Health and Nutrition Examination Survey (NHANES IV), researchers assessed the proportion of 1547 adults who met the criteria for impaired fasting glucose (IFG) or impaired glucose intolerance (ITG). Patients were asked if they had received a formal diagnosis from their physicians, were advised on measures to take to bring blood sugar back to normal, and if they were actively implementing those measures.
Only about 3.4% of the study sample reported receiving a diagnosis of IFG, IGT, borderline diabetes, or prediabetes, but 38% actually had one of these conditions. None of the individuals reported receiving oral anti-hyperglycemic medications, but 31.7% received counseling for exercise and 33.4% received diet advice.
Adherence to counseling was relatively high. 86% of those who had received a recommendation to control their diet or their weight reported that they had made lifestyle changes. About 70% of those who received exercise recommendations were following the advice.
One reason diagnosis rates may be so low is that the usual tests performed, which include a fasting plasma glucose test (FPG) and an oral glucose tolerance test, require a patient to return on a separate day after an overnight fast and they must remain in the office for 2-3 hours for the test to be completed.
Ronald Ackerman, MD MPH of Indiana University suggests using a different test for the diagnosis of prediabetes and diabetes – the Hemoglobin A1C or HbA1c. This test requires only one blood draw and gives an average measure of glucose for the previous three months. A range of 5.5% to 6.5% indicates the patient is prediabetic; higher numbers indicate full-blown Type 2 Diabetes.
Dr. Ackerman and his team found that just by using HbA1c, physicians could better identify 41.3% of patients at risk for diabetes and 13.3% of those at risk for heart disease. The team concludes that HbA1c measurement “should be considered a means of identifying greater numbers of patients at risk for diabetes and heart disease" -- especially because "of its practical nature and wide availability."
For those who do have impaired fasting glucose levels, a separate study presented in the British Medical Journal found that increasing the number of steps a person takes each day can improve their sensitivity to insulin and therefore bring blood levels closer to normal. If a sedentary individual would just increase his or her daily step count so they walk an extra 2,000 steps per day (about one mile), they could expect to decrease body mass index by about 0.16 kg/m2 and increase insulin sensitivity by 2.76 units. Reaching a total of 10,000 steps per day (about 5 miles) would further increase the benefits, reducing BMI by almost a full point (0.83 kg/m2) and boost insulin sensitivity by 13.85 units.
Ackerman RT, et al "Identifying adults at high risk for diabetes and cardiovascular disease using hemoglobin A1c" Am J Prev Med 2011; 40(1): 11–17.
Diabetes Care 2010;33:2355-2359
Dwyer T, et al "Association of change in daily step count over five years with insulin sensitivity and adiposity: population based cohort study" BMJ 2010; 341: c7249.