You Don't Have to be Diabetic to Check Your Blood Sugar

Health Professional

Checking your blood sugar (glucose) has become an easy and relatively inexpensive tool that just about anybody can incorporate into health habits. More often than not, it can provide you with some unexpected insights about your response to diet.

You and I can now purchase our own blood glucose monitor at stores like Walmart and Walgreens for $10-20. (You will also need to purchase the fingerstick lancets and test strips; the test strips are the most costly part of the picture, usually running $0.50 to $1.00 per test strip. But since people without diabetes check their blood sugar only occasionally, the cost of the test strips is, over time, modest.)

If you're not a diabetic, why bother checking blood sugar? New studies are documenting the fact that increased levels of blood sugar below the diabetic range are associated with increased risk for cardiovascular disease. In the 22,000-participant DECODE study, for example, risk for heart attack and death from heart disease increased statistically beginning at a fasting blood sugar ≥110 mg/dl.

Even more than fasting blood sugars, after-eating,or postprandial, blood sugars are proving to be a powerful predictor of heart attack. In other words, the increase in blood sugar that occurs in the 1-2 hours after a meal has been associated with greater risk for heart disease: the higher the blood sugar after a meal, the greater the risk for heart disease. While it is not clear where begins to increase, but long-term risk for heart disease is 30-60% greater at 140 mg/dl.

What does blood sugar have to do with heart disease? It is becoming clear that surges in blood sugar that occur after a meal (or after soft drinks, cookies, or other snacks) injures arteries, triggering inflammatory and antioxidative responses. Even a single surge in blood sugar is sufficient to provoke these phenomena.

Blood glucose levels in people with diabetes are usually checked first thing in the morning, then before meals; this helps diabetics manage their blood sugars with medications and insulin. In people without diabetes, we can use blood sugar assessment a little differently: We use blood sugars to assess our response to various foods. We can identify which foods provoke high blood sugars, which foods don't provoke high blood sugars. Since most people don't eat a single food per meal, but a mix of foods, it also allows you to assess the combined blood sugar effect of an entire meal.

Knowing your blood sugar response can help you individualize diet choices. Keep in mind that only carbohydrates increase blood sugar substantially; proteins and fats do not.

For people without diabetes, we use: 1) glucose just prior to a meal, and 2) glucose one-hour after a meal. The one-hour glucose after a meal reveals the effect of a specific food or meal on blood glucose and provides feedback on its blood sugar-increasing effects.

For example, say you want to test your blood glucose response to a breakfast of stone-ground oatmeal in skim milk with raisins and walnuts. Blood glucose prior to meal: 102 mg/dl; blood glucose one-hour after the meal: 157 mg/dl-far too high and sufficient to add to coronary risk.

Is this high blood sugar response common? Yes, it is far more common than you'd think. The last 40 years of American diet habits have created a population who, having overindulged in carbohydrates like breads, pasta, and breakfast cereals, are excessively sensitive to carbohydrate foods. The party cannot last forever.

What are ideal blood sugar levels? We currently aim to keep fasting blood sugars 90 mg/dl or less; one-hour after-eating, 120 mg/dl or less. If you check your fasting and after-eating blood sugars and they are too high, it means cutting back on carbohydrates, exercising, getting adequate sleep, and losing weight. More on that in future posts.