While diabetes is a serious chronic disease with devastating complications, it usually develops after years of insulin resistance, or prediabetes. Prediabetes can progress to diabetes when liver and muscle cells become more and more insulin resistant (they don't respond properly to this internal insulin signal) and have increasing problems removing sugar from the bloodstream.
The good news is that if prediabetes is recognized early, it can be reversed. Let’s check in on Gary, who we met earlier.
Gary, a 45-year-old computer engineer, had many signs of prediabetes, including excess weight, a big belt size (40 inches), blood pressure of 138/83 and blood tests showing:
- High blood sugar (glucose) level (113 mg/dL); Optimal less than 90
- Low HDL, the good cholesterol (27 mg/dL); Optimal greater than 50
- Increased triglycerides (210 mg/dL); Optimal less than 100
He came to the doctor seeking advice about how to avoid developing diabetes. Based on his doctor’s recommendations, he focused on daily exercise using his home rowing machine for 30 minutes per day. He also cut down on his craft beer intake (each 12 oz. bottle has 200-plus calories) from 12 to 4 per week and started walking daily with his wife for 30 minutes. Three months later, his body weight was down by 8 pounds, his blood pressure was 132/78 and his fasting blood sugar was below 100.
How to you know that you have prediabetes? There are two main approaches to determine if you have prediabetes or insulin resistance. The simplest is to look for a fasting blood sugar of 100-125 mg/dL. This is higher than normal, but not yet at a critical diabetes level (greater than or equal to 126 mg/dL). The body can still remove sugar from the blood, but not down to normal levels.
A more sophisticated approach is to diagnose metabolic syndrome. Related to insulin resistance, metabolic syndrome also reflects other health findings that accompany serious insulin resistance. Metabolic syndrome can be diagnosed by any three of the following:
- Increased waist circumference (greater than or equal to 35 inches in women or 40 inches in men)
- Fasting blood sugar greater than or equal to 100 mg/dL
- Blood pressure greater than or equal to 130/85
- Low good cholesterol (HDL) (less than 50 mg/dL for women or 40 for men)
- High triglycerides, a type of fat in the blood (greater than 150 mg/dL)
Gary, unfortunately, had all five of these markers.
The key to preventing prediabetes from becoming Type 2 diabetes, which isn't usually reversible, is changing behavior around weight, diet, physical activity and sleep. This isn't easy and must be an ongoing, personal process.
Weight loss: Reversing prediabetes requires no further weight gain and, if possible, a 5 percent reduction in body weight through both dietary changes and increased physical activity. Key strategies include:
- Weighing yourself once a week
- Learning to tolerate a small amount of hunger
- Avoiding high calorie foods, especially sweets
- Seeking support from friends, family members and, ideally, a health professional
Dietary practices: There are several key long-term goals for reversing prediabetes. They include:
- Avoid sweets and sugar-containing beverages
- Increase fibrous vegetables and whole grains
- Reduce white starches
- Reduce animal fats
These goals can most easily be achieved by eating a diet dominated by unprocessed, plant-based foods. Eating this way can help with weight loss, but can also independently keep insulin resistance from worsening.
Physical activity: Gradually increase physical activity to 60 minutes day (about 8,000 steps). Exercise helps with weight loss, but also trains muscles to become better at removing sugar from the bloodstream.
Sleep: Getting at least seven hours of high quality sleep per night can help reverse prediabetes. Sleep deprivation has been shown to increase insulin resistance.
Medication: In addition to lifestyle changes, the drug metformin may help reverse prediabetes. It helps with weight loss and lessens insulin resistance. Use of this diabetes medication in prediabetes is controversial and should be combined with lifestyle changes.
While prediabetes often turns into Type 2 diabetes, this isn't inevitable. The proven strategies of physical activity, dietary changes, weight loss, and better sleep can stop this transition.
This is the second in a series of blog posts discussing prediabetes and Type 2 diabetes. The first installment examined what happens inside the body in prediabetes. The next blog post will focus on why diabetes treatment is often inadequate despite its high cost.
Randall Stafford, MD, PhD, a professor of medicine and director of the Program on Prevention Outcomes and Practices, practices primary care internal medicine at Stanford. He is developing practical strategies to improve how physicians and consumers approach chronic disease treatment and prevention.
Image by GDJ