Prediabetes

• Diabetes is preceded by a 10–15 year period of prediabetes, a condition which affects 15% of adults worldwide.

• Prediabetes is a condition in which individuals have blood glucose levels that are higher than normal, but not high enough to be classified as diabetes. Normal blood sugar is less than 100 mg/dl and diabetes is diagnosed when the blood sugar is higher than 126 mg/dl on two occasions.

• The American Diabetes Association does not recommend glucose tolerance test but this cumbersome and unnecessary test is done throughout the world to diagnose diabetes and prediabetes. A glucose level between 140 and 199 mg/dL (IGT), on a two-hour glucose tolerance test also qualifies for prediabetes.

• A third and perhaps more reliable criteria is A1C between 5.7 and 6.4 percent.  A1C is a reflection of the average blood sugar for the past 3-4 months.

• 67 million or 29% of the adult U.S. population has prediabetes (36% men and 22% women).  A new study estimates that the prevalence of prediabetes will increase to 37% by 2020 and 50% by 2050.

• In whites, 5–12% of people with prediabetes progress to develop diabetes each year.  However, the rate of progression from prediabetes to diabetes seems to be about double in South Asians.¹ Unfortunately, the progression from prediabetes to diabetes is not inevitable. ²

• Prediabetes may start damaging the body long before it becomes full-blown diabetes. Prediabetes confers a 30% risk of coronary artery disease (CAD) which increases to 200% to 400% as the person develops full-blown diabetes.^{3, 4}

• Prediabetes often coexists with prehypertension. One in 3 Americans has prehypertension; one in 10 has both of these conditions.⁵ Both of these can be diagnosed and treated, long before they develop into full-blown diseases or any cardiac catastrophe.

• Prehypertension is defined as a systolic blood pressure reading between 120 and 139 and a diastolic blood pressure of 80 to 89. Systolic blood pressure is the upper number in a blood pressure measurement and refers to the pressure when the heart beats while pumping blood. Diastolic blood pressure, the lower number, is the pressure when the heart is at rest between beats. A blood pressure reading of less than 120/80 is considered ideal.

• Each one increases the risk of heart disease and the risk is markedly increased when both conditions are present. “If you have prediabetes, it’s the fire, and prehypertension is the gasoline that’s added to the fire,” according to some experts.

• The good news is that these conditions are easily identified. Testing for prediabetes involves a finger stick test for blood glucose levels, and resting blood pressure measurement can identify those individuals with prehypertension.

• Unfortunately most doctors won’t tell the patients they have prediabetes and patients would be better of asking for the blood sugar number. If it is in the triple digits, you have a problem.

• Individuals with both these conditions are also more likely to be obese and have high insulin levels, dangerous blood fats called triglycerides, and low levels of high density lipoprotein (HDL) or “good” cholesterol, compared to their counterparts without these conditions.

• If both of your parents have diabetes, you are at high risk. Genes play a role in diabetes risk, but changing your lifestyle can help significantly forestall the seemingly inevitable.

• One needs to reduce excess carbohydrate intake, exercise, and lose weight.  Losing about 7% of your body weight and engaging in 150 minutes of exercise a week can prevent diabetes by 60%.⁶  Through these lifestyle changes, one can buy at least a decade or two from becoming a full-blown diabetic.

• In addition to lifestyle modification, pharmacological interventions have shown to substantially reduce the risk of progression to diabetes in people with prediabetes across the world.^{1, 7 6}

• Unfortunately, most people with prediabetes or prehypertension do not receive a formal diagnosis or formal recommendation for lifestyle changes from the physicians. The majority of the U.S. population with prediabetes is undiagnosed and untreated with lifestyle or medication interventions.

• Five years after a major clinical trial demonstrated that interventions could greatly reduce progression from prediabetes to diabetes. Of the 35% of Americans who have received a formal diagnosis from their physicians, only 5% have been recommended lifestyle changes.⁶  Whether this is due to physicians being unaware of the evidence, unconvinced by the evidence, or clinical inertia is unclear.⁸

Sources

 1. Ramachandran A, Snehalatha C, Mary S, Mukesh B, Bhaskar AD, Vijay V. The Indian Diabetes Prevention Programme shows that lifestyle modification and metformin prevent type 2 diabetes in Asian Indian subjects with impaired glucose tolerance (IDPP-1). Diabetologia. Feb 2006;49(2):289-297.

2. Ramachandran A, Snehalatha C. Diabetes prevention programs. Med Clin North Am. Mar 2011;95(2):353-372.

3. Huxley R, Barzi F, Woodward M. Excess risk of fatal coronary heart disease associated with diabetes in men and women: meta-analysis of 37 prospective cohort studies. BMJ. Jan 14 2006;332(7533):73-78.

4. Ford ES, Zhao G, Li C. Pre-diabetes and the risk for cardiovascular disease: a systematic review of the evidence. J Am Coll Cardiol. Mar 30 2010;55(13):1310-1317.

5.  CardioSmart. American College of Cardiology.

6. Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393-403.

7. Gillies CL, Abrams KR, Lambert PC, et al. Pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance: systematic review and meta-analysis. Bmj. Feb 10 2007;334(7588):299.

8. Karve A, Hayward RA. Prevalence, diagnosis, and treatment of impaired fasting glucose and impaired glucose tolerance in nondiabetic U.S. adults. Diabetes Care. Nov 2010;33(11):2355-2359.