单选题 About 79 million Americans have pre-diabetes（糖尿病前期）。That means they have blood sugarthat's higher than normal but not high enough to be diagnosed（诊断）with type 2-at least not yet.One long-term study reposed by the American Diabetes Association found that 11% of people withpre-diabetes develop the full-blown disease each year.Another study shows that pre-diabetes willprobably become type 2 in 10 years or less. 

Yet，that process is not inevitable.Last year，scientists in Colorado found that people withpre-diabetes who lowered their blood sugar to normal levels--even briefly--were 56%less likely toreach type 2 levels. 

If you have pre-diabetes.here are four steps to help prevent or delay a diabetes diagnosis： 

Lose 7% of your body weight.That is about l5 pounds for the persons who weigh 200.Drop-ping that small percentage has been shown to lower the risk of developing type 2 by close to 60%.

Exercise 30 minutes five days a week.Whether you do the 30 minutes in one shot or in three10一minute sessions，the benefit is the same.Choose certain exercises，such as fast walkin9，playingtennis or lifting weights.Physical activity such as sweeping floors works，too. 

Turn to your doctor.In some cases，pre-diabetes raises the risk of heart disease and stroke by50%.Your doctor may use some medicine to control your glucose（葡萄糖）levels and keep yourblood pressure in check. 

Know your numbers.To see if your pre-diabetes is improvin9，have your blood sugar checkedregularly.A fasting blood sugar of 100 to 125 mg/dI suggests pre-diabetes;126 mg/dI or above isdiabetes;and below 100 is normal.Other tests，including glucose tolerance and AIC，also are used tomonitor blood sugar. 

What do we learn from the two studies mentioned in Paragraph 1 ？