Half of China Has Prediabetes

World Diabetes Day 世界糖尿病日
World Diabetes Day 世界糖尿病日

My family medicine colleagues and I recently have noticed an alarming increase in our patients’ blood sugar levels testing high for diabetes and prediabetes, so much so that we figured it must be a lab error. But our lab confirmed these indeed were accurate, and now a recent paper published in the esteemed Journal of the American Medical Association confirms the frightening reality in China: more than half of all persons in China now are prediabetic. Even worse, 11.2% have diabetes, giving China the dubious and unwanted distinction of having the highest prevalence of diabetes in the world. This is now higher than in the USA, an extraordinary statement given the far higher rate of obesity in the USA. As November 14th is World Diabetes Day, I felt a timely urgency to share my advice on how to avoid this disease – or at least to slow it down.

It helps to think of diabetes as a modern lifestyle disease, mostly caused by all developing countries’ gains in weight, less physical activity, and changes in diet. Diabetes now is a global pandemic. Tens of millions of people have diabetes, and many people are undiagnosed because they’ve never been tested. There are two types of diabetes, and type 2 diabetes accounts for 90 to 95 percent of diagnosed diabetes in adults.

Diabetes is a disease caused by your body losing the ability to properly digest and use sugars and starches in your foods, thus leading to high levels in your blood. Too much glucose floating around your bloodstream for many years can cause many toxic problems to your organs if not treated — especially with your eyes, kidneys and lower legs. For example, diabetes is the leading cause of kidney failure, non-traumatic lower-limb amputation and new cases of blindness among adults in much of the world. Diabetes also raises your risk of heart disease and some cancers.

Prediabetes concerns us doctors because it means you are at extremely high risk of developing diabetes in the next few years. Studies show that a prediabetic person has a 25% risk of developing diabetes within three years, and a majority within ten years. The greatest risk factor by far is overweight and obesity. Having a BMI under 23 is ideal, and a BMI of 25 increases your lifetime risk of diabetes by 600%. A BMI of 30 increases your risk by 4,000% — that’s 40 times the risk!

The crucially important message for everyone is that you have great control over whether or not you develop full diabetes. You should think of prediabetes as an early warning sign by your body, a major wake up call that whatever you’ve been doing to your body isn’t too healthy. Most people with prediabetes fit one or more of these three major risk factors: body mass index (BMI) over 25; lack of enough exercise; and unhealthy food choices as well as portion sizes.

So let’s say that you’re one of the half of China who has prediabetes: what can you do right now to help? If you follow the three lifestyle steps below, you can lower your risk more than half! One of the most important public health research studies ever, the Diabetes Prevention Program, proved that lifestyle changes worked better than pills. Lifestyle changes lowered a prediabetic person’s risk by 58% over three years — much better than the 31% improvement with a daily pill. The three most important lifestyle tips are:

  1. Lose weight. Weight gain and obesity are the top causes of type 2 diabetes, and losing weight is now proven to be the most effective prevention. In the DPP study, the goal was to lose at least 7% of your body weight. Your goal should be to lose 5-10% of your body weight.
  2. Exercise. Exercise may not directly cause much weight loss, but exercising muscles absorb sugars much more effectively. This is why exercising is crucial to help control sugars, both in a prediabetic as well as in diabetics. How much exercise is enough? We usually recommend 150 minutes a week of moderate exercise, but any amount is better than nothing. Also, as I mentioned in an earlier New York Times column, shorter, more intense workouts also can help.
  3. Proper diet. Healthy food choices also are crucial to control your sugars. One of the most common misperceptions about diabetes and prediabetes is that it’s “a sugar problem” and you must cut down on sweets and desserts. The bigger culprit are total starches — pastas, breads, rice and potatoes. In all these cases, processed versions are never as healthy as the originals.

Here are a few quick tips on nutrition:

  • Brown is always better than white: Processed white bread and flour have lost all the nutritious fiber which helps regulate your bowels as well as your sugar spikes after a meal. If you love your carbs, at least try to switch to whole wheat pastas, breads and rice.
  • Portion control: Total calories are also important, as most likely you are taking in a bit more than you realize. These extra calories will get deposited as fat, which leads to more risk of diabetes.
  • Cut back on sodas, beer and juices: All of these are empty calories, full of processed sugars which stress out your liver and pancreas. These unhealthy carbs, especially in sodas, are a major cause of obesity and diabetes in both children and adults.

Type 2 diabetes is partly genetic, so no matter how healthy you are, it still may be inevitable. But these above steps are always good advice for all of us. Another great thing about these healthy life changes is that they also dramatically reduce your risk of heart disease, many cancers, and early deaths from all causes.

Don’t get discouraged with this prediabetes diagnosis — you have control over the next steps! Even if you already have diabetes, you could maybe avoid that second or third medicine, especially insulin injections, if you followed those above lifestyle steps and especially lost 5-10% of your weight.

 


This is a revised update from my recent article; a Chinese version will be published in my regular column in the New York Times Chinese edition


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2 thoughts on “Half of China Has Prediabetes”

  1. Here’s one possible explanation:
    Air pollution appears to foster diabetes
    Findings confirm previously published animal data
    By Janet Raloff
    Web edition : Monday, October 4th, 2010

    A pair of new studies — one in the United States, another in Germany — reports strong evidence that diabetes rates climb with increasing air pollution in the form of of tiny airborne particles.
    “Although previous studies had hinted at this possibility, the data were mostly from small studies or from animals exposed to high levels of particulate matter,” notes Aruni Bhatnagar, a cardiovascular researcher at the University of Louisville in Kentucky who did not take part in either study. He says the new data provide important and more rigorous evidence that real-world pollution may be tampering with blood sugar control in a large and growing number of people.
    Both new studies focused on tiny airborne motes spewed primarily by traffic, coal-fired power plants and industrial boilers.
    The new findings are particularly disturbing when set against “an exploding pandemic, if you will, of type 2 diabetes, particularly in urbanized areas around the world,” adds cardiologist Sanjay Rajagopalan of the Ohio State University College of Medicine in Columbus, who is also unaffiliated with either new study. “The traditional explanation for this pandemic,” he says, “has been changes in lifestyle — diet and exercise — and increasing obesity.”
    Particulate pollution is emerging as another potentially important candidate for causing obesity, he says, owing to its ability to trigger chronic, low-grade inflammation — initially in the lung but also in a host of other tissues, including fat.
    Last year, Rajagopalan’s team published data from mice that for the first time demonstrated that fine particulate pollution can conspire with obesity to promote metabolic disease. The researchers exposed animals for half a year to what’s known as PM-2.5, airborne particulate matter 2.5 micrometers in diameter or smaller. All the animals ate a high-fat diet and became obese.
    Compared with fat mice breathing clean, filtered air, those that inhaled high but real-world concentrations of PM-2.5 developed chronic inflammation, insulin resistance, a propensity to deposit their fat around the belly and a host of other prediabetic changes. The study’s findings appeared in the Feb. 3 Circulation in 2009.
    The next step was to look for signs that PM-2.5 promotes diabetes in people, and the new studies tackle that question, Rajagopalan contends.
    For the U.S. study, John Pearson of Children’s Hospital Boston and his coworkers compared Environmental Protection Agency measurements of fine particulates in counties across the nation against county-by-county diabetes prevalence numbers that had been collected by the federal Centers for Disease Control and Prevention.
    They found that for every 10 micrograms per cubic meter increase in average PM-2.5, diabetes prevalence climbed — in absolute terms — by about 1.15 percent. (For instance, the incidence in a county whose average particulate concentration was 15 µg/m3 might be 7 percent of all adults, versus 5.85 percent in a county where the average PM-2.5 level was just 5 µg/m3.) The probability that the observed associations are due solely to chance is less than one in 1,000, Pearson’s team reports in the October Diabetes Care.
    Even after accounting for a host of known diabetes risk factors including obesity, diet, exercise and a community’s population density, air pollution’s link to the disease held, Pearson says. To further test the link his team reran its analyses, taking out areas of the country with high average pollution readings or eliminating data for ethnic groups known to be at especially high diabetes risk. “And no matter how we analyzed it, the association remained strong,” he says.
    In the second study, epidemiologist Wolfgang Rathmann of the German Diabetes Center in Düsseldorf and his colleagues tallied new cases of the metabolic disease between 1990 and 2006 among 1,775 middle-age women. All were taking part in a study probing air pollution’s links to lung disease, inflammation and aging. In all, 187 of the participants developed diabetes.
    Because PM-2.5 measurements were unavailable, the researchers used proximity to roads — where vehicles would be a major pollution source — as a proxy for exposure to fine particulates. Women who developed diabetes were more likely to have lived nearest to heavily trafficked roads, Rathmann reports.
    Compared to the 25 percent of women living farthest from busy roads, the relative risk of developing diabetes was 15 percent higher for the 25 percent of women living closest to major roadways. The findings appear in the September Environmental Health Perspectives. That diabetes risk associated with PM-2.5 in this study was similar to what Pearson’s group measured in comparing the quarter of counties with the highest PM-2.5 values to the 25 percent of counties with the least fine-particulate pollution — about a 20 percent difference.
    “There is a growing body of literature suggesting that people with diabetes may be more susceptible to the harmful effects of air pollution,” notes Gregory Wellenius of Brown University in Providence, R.I. These new studies suggest this hypothesis is worth investigating further, he says. However, the epidemiologist cautions, while such studies are useful in generating hypotheses, they can’t establish causation. He says additional studies with exposure values for individuals will be needed to confirm or refute these apparent links.
    The big U.S. analysis is particularly interesting, Bhatnagar says, because it’s the first to show “in such a large and comprehensive study that air pollution is associated with diabetes.” But it does not address a perplexing trend, he notes: From 1994 to 2004, U.S. particulate pollution fell somewhat, while the prevalence of diabetes increased by between 4 and 6 percent.

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