If prediabetes is found (blood sugar high but not yet diabetes), push diabetes back by eating less, losing weight and moving more, and recheck your blood sugar every 6 months

Cost

Free, and eating less may even save a little. Do at least 150 minutes a week of moderate activity such as brisk walking, which works out to about twenty minutes a day. Eat 400 to 500 kcal less a day than before. The hard part is keeping it up, and keeping the weight off once it comes down. Recheck by a blood draw every 6 months; a fasting glucose test costs a dozen or so CNY.

What you get

The Da Qing study was a randomized trial in Daqing, Heilongjiang, assigned by clinic. 577 adults with impaired glucose tolerance were placed in a control group or one of three intervention groups: diet only, exercise only, or both. The intervention lasted 6 years. The cumulative share who got diabetes within 6 years was 67.7% in the control group. It was 43.8% in the diet group, 41.1% in the exercise group, and 46.0% in the diet plus exercise group. After accounting for differences in body mass index and fasting blood sugar, the risk of getting diabetes in the three groups was about 31%, 46% and 42% lower. Lean and overweight people (body mass index 25 as the dividing line) saw similar reductions. At 23 years of follow-up, cardiovascular death in the intervention groups was about 41% lower (HR 0.59, 95% CI 0.36–0.96, the plausible range). Total death was about 29% lower (HR 0.71, 0.51–0.99). Getting diabetes was about 45% lower (HR 0.55, 0.40–0.76). At 30 years of follow-up, the median time to diabetes in the intervention groups was delayed by 3.96 years. Cardiovascular events were about 26% lower (HR 0.74, 0.59–0.92). Severe small-vessel complications of the eyes, kidneys and nerves were about 35% lower (HR 0.65, 0.45–0.95). Cardiovascular death was about 33% lower (HR 0.67, 0.48–0.94). Total death was about 26% lower (HR 0.74, 0.61–0.89). People lived 1.44 years longer on average (0.20–2.68). The U.S. DPP trial randomized 3234 people with high blood sugar. The lifestyle group's goals were to lose at least 7% of body weight and be active at least 150 minutes a week. Followed for 2.8 years on average, the lifestyle group's risk of getting diabetes was 58% lower than the placebo group's (95% CI 48%–66%). The group taking metformin was 31% lower (17%–43%), which was worse than changing lifestyle. At an average of 15 years of follow-up, the lifestyle group was still 27% lower (HR 0.73, 0.65–0.83), but the gap narrowed year by year. At a median of 21 years, total mortality in the lifestyle group did not differ from the placebo group (HR 1.02, 0.81–1.28). Cardiovascular death did not differ either (HR 1.18, 0.77–1.81). The Finnish DPS trial randomly assigned 522 overweight people with impaired glucose tolerance. Cumulative diabetes at 4 years was 11% in the intervention group and 23% in the control group. The risk during the trial was 58% lower. After one-on-one counseling stopped, follow-up continued, and at a median of 7 years it was still 43% lower. At an average of 10.6 years of follow-up, total death was not clearly different (HR 0.57, 0.21–1.58). Neither was cardiovascular disease (HR 1.04, 0.72–1.51). The cutoffs given by the Healthy China Action (健康中国行动) are: a fasting blood sugar of 6.1 to 7.0 mmol/L (not including 7.0) counts as prediabetes. So does a blood sugar of 7.8 to 11.1 mmol/L (not including 11.1) 2 hours after a sugar drink. It advises people who are overweight or obese to bring their body mass index to or near 24, or to lose at least 7% of body weight. Daily food energy should be at least 400 to 500 kcal lower, with moderate-intensity activity at least 150 minutes a week. Check fasting blood sugar or 2-hour after-meal blood sugar every 6 months.

Notes

Dispute. All three trials saw fewer people getting diabetes and getting it later. But whether people died less was seen only in the Da Qing trial. Da Qing had only 577 people, and the authors themselves say the number is small, because the trial was designed to look at diabetes. After the U.S. DPP trial ended, everyone was invited to a modified lifestyle course, the placebo group included. The authors of the Finnish trial write that the numbers may have been too few to see small differences. So delaying diabetes is certain, and extending life is not settled. The people in the U.S. and Finnish trials had an average body mass index above 30. The Da Qing people averaged only 25.7, only those with a body mass index over 25 were urged to lose weight, and not much weight was lost; the authors think the effect came mainly from changing how they ate and moving more. So people who are not heavy should still change how they eat and move more. Stop sugary drinks first; see §2.7 (don't drink sugary drinks). To check whether your activity is enough, compare with §2.11 (walk 7000–8000 steps a day). For where your weight should end up, compare with §2.32 (keep your BMI between 20 and 25). For how to find it out, see §1.8 (get one fasting blood sugar test). Metformin can also reduce getting diabetes, but not as well as changing lifestyle, and whether to take it is the doctor's call. The size of the benefit is set at large based on Da Qing's total mortality about 26% lower, but the U.S. and Finnish trials did not repeat it. The beneficiary of this item is mainly you.

Evidence grade

A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.

Sources

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8. Lindström J, Ilanne-Parikka P, Peltonen M, 等 (2006). Sustained reduction in the incidence of type 2 diabetes by lifestyle intervention: follow-up of the Finnish Diabetes Prevention Study. Lancet, 368(9548), 1673-1679. https://doi.org/10.1016/S0140-6736(06)69701-8
9. Uusitupa M, Peltonen M, Lindström J, 等 (2009). Ten-year mortality and cardiovascular morbidity in the Finnish Diabetes Prevention Study—secondary analysis of the randomized trial. PLoS ONE, 4(5), e5656. https://doi.org/10.1371/journal.pone.0005656（争议方）
10. 健康中国行动推进委员会 (2019). 健康中国行动（2019—2030年），（十四）糖尿病防治行动（湖南省卫生健康委员会转载）. https://wjw.hunan.gov.cn/wjw/ztzl/knowledge/tzggzcfg/202003/t20200303_11359594.html

Translated from the Chinese original. Original book, section 2, tip 45. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer