You can tell if you are at high risk for diabetes if you store fat primarily in your belly. Pinch your belly; if you can pinch an more than an inch of fat under the skin there, you are at increased risk and should get a blood test called HBA1C. Having high blood levels of triglycerides and low levels of the good HDL cholesterol that helps prevent heart attacks also increases your risk for diabetes.
When you eat sugar or flour, your blood sugar rises too high. This causes your pancreas to release insulin that converts sugar to triglycerides, which are poured into your bloodstream. Then the good HDL cholesterol tries to remove triglycerides by carrying them back into the liver, so having high blood levels of triglycerides and low blood levels of the good HDL cholesterol are both individual risk factors for diabetes.
High blood levels of insulin constrict arteries to raise blood pressure, so many people who have high blood pressure are also prediabetic. High insulin levels also constrict the arteries leading to your heart to cause heart attacks directly. People with insulin resistance have an increase in small, dense, low-density lipoprotein (LDL) cholesterol, which is more likely to cause heart attacks than the large, buoyant regular LDL cholesterol. High levels of insulin also cause clotting to increase your risk for heart attacks.
A study from Sweden showed that many people discover that they are diabetic only after they have had a heart attack. Researchers recorded blood sugar levels in men who had had heart attacks and then did sugar tolerance tests at discharge and three months later. They found that 40 percent had impaired sugar tolerance tests three months later. This suggests that 40 percent of people who have heart attacks are diabetic, even though they may not know it. The authors recommend that all people with heart attacks be tested for diabetes (Lancet, 2002; 359:2140-44).
You can help to prevent diabetes and heart attacks by avoiding sugar and flour, exercising and eating lots of vegetables. See Treating insulin resistance