News · Heart & Metabolic
Weight lost early in prediabetes still counted 34 years on
The Da Qing study followed 540 Chinese adults with impaired glucose tolerance for 34 years. Those who lost at least 5% of their weight in the first six years later had a third fewer deaths and half as many heart failure admissions.
- About 1 in 3 adults has prediabetes, and most advice about it aims at preventing diabetes.
- This asked a longer question: does early weight loss change how long you live?
- Losing 5% or more in six years: 33% fewer deaths (HR 0.67) over the next three decades.
- Cardiovascular deaths fell 44% and heart failure admissions 52% in the same group.
- Death from any cause arrived a median 2.1 years later, cardiovascular death 6.5 years later.
Prediabetes is usually framed as a warning about diabetes. Lose some weight, move more, and you may delay or avoid the diagnosis.
That framing has a horizon of a few years. A new analysis in Diabetes Care extends it to 34, using a Chinese cohort that has been followed since 1986, and asks a blunter question: did the weight people lost in the first six years change when they died?
It did, by a margin most short trials would never be able to see.
What impaired glucose tolerance and prediabetes are
Prediabetes means that your blood glucose, or blood sugar, levels are higher than normal but not high enough to be called diabetes. Impaired glucose tolerance is one way of defining it, based on how far blood sugar rises after a glucose drink.
It is not rare. About 1 out of every 3 adults has prediabetes, and if you have prediabetes, you are more likely to develop type 2 diabetes, heart disease, and stroke.
The standard response is behavioral: losing weight, if you are overweight, getting regular physical activity, and following a healthy, reduced-calorie eating plan. Those changes may be able to delay or prevent type 2 diabetes.
Whether they also change how long someone lives has been much harder to establish, because it requires waiting.
Why the Da Qing cohort could follow weight for 34 years
In 1986, 577 adults with impaired glucose tolerance in Da Qing, China were randomly assigned by clinic to a control group or one of three interventions (diet, exercise, or diet plus exercise) for six years. They have been followed ever since.
By the 30-year mark, that trial had already produced a striking result: the intervention group, compared with controls, had a median delay of 3.96 years in diabetes onset, with 26% fewer cardiovascular events, along with continuing reduction in mortality, leading to a significant increase in life expectancy. Significant there means the difference survived the statistical test, rather than that it was large.
This new analysis asks a different question of the same people. Not which arm they were assigned to, but what actually happened to their weight.
How the weight groups were defined
In the Da Qing Diabetes Prevention Study, 540 adults with IGT, or impaired glucose tolerance, were categorized into three groups based on their weight change from baseline to the end of a 6-year lifestyle intervention trial: non-weight loss (n = 200), low weight loss (<5%, n = 163), and high weight loss (>=5%, n = 177).
Participants were followed for 34 years to assess all-cause mortality, cardiovascular disease (CVD) mortality, and CVD events.
Five percent is a modest target. For someone at 80 kg it is about 4 kg, held over six years rather than lost in a rush.
What 34 years of follow-up showed
Weight loss during the initial 6 years following IGT diagnosis was associated with reduced long-term risks of CVD events and mortality.
The group that lost 5% or more did best on every outcome. Compared with participants without weight loss, those with weight loss of at least 5% had significantly lower risks of CVD death, CVD events, hospitalized heart failure, and all-cause death after adjustment.
In plainer terms: roughly a third fewer deaths from any cause, about 44% fewer cardiovascular deaths, and around half as many admissions for heart failure.
Then the framing that makes it concrete. The high weight loss group showed delays in the median time to all-cause mortality and CVD mortality of 2.1 years and 6.5 years, respectively. The events still came. They came later.
What this weight study cannot separate
This analysis sorts people by what happened to their weight, not by what they were assigned to do, which makes it observational despite sitting inside a randomized trial.
That matters, because people who lose weight and keep it off differ from people who do not, in motivation, in illness, in circumstances no adjustment captures. Some weight loss over six years is also unintentional and a sign of something wrong, which pulls the other way.
The cohort is 540 Chinese adults recruited in 1986, all with impaired glucose tolerance. Diets, body sizes and medical care have changed since, and none of this was tested in people with normal blood sugar.
The paper is paywalled, so the authors’ own limitations section was not available for this piece.
What to do if you have prediabetes
Nothing here changes the advice, which was already to lose modest weight and move more. What it changes is the reason to bother.
Most of the argument for acting on prediabetes has been about avoiding a diagnosis. This adds a longer one: on these data, the weight lost in the first few years tracked with dying later, decades on, whether or not diabetes eventually arrived.
The authors put it as an argument about timing, suggesting the critical importance of early weight management in individuals with prediabetes for improving long-term survival and cardiovascular health.
Five percent, held for a few years, is a small enough target to be worth discussing with a doctor.
People also ask
What is impaired glucose tolerance?
One of the ways prediabetes is defined: blood sugar that rises too far after a glucose drink, without reaching the level that counts as diabetes. Prediabetes means that your blood glucose, or blood sugar, levels are higher than normal but not high enough to be called diabetes, and about 1 out of every 3 adults has prediabetes. If you have prediabetes, you are more likely to develop type 2 diabetes, heart disease, and stroke.
What did the study find?
Compared with participants without weight loss, those with weight loss of 5% or more had significantly lower risks of cardiovascular death (HR 0.56; 95% CI 0.35-0.89), cardiovascular events (HR 0.71; 0.52-0.99), hospitalized heart failure (HR 0.48; 0.26-0.88), and all-cause death (HR 0.67; 0.48-0.95), after adjusting for age, sex, baseline weight and other covariates.
How much later did people die?
The high weight loss group showed delays in the median time to all-cause mortality and cardiovascular mortality of 2.1 years and 6.5 years respectively. That framing is more useful than a hazard ratio for most people: the events still happened, and on average they happened later.
How was weight loss measured?
As the change from baseline to the end of a six-year lifestyle intervention trial. The 540 adults were sorted into three groups: non-weight loss (200 people), low weight loss of under 5% (163), and high weight loss of 5% or more (177). So the exposure is what happened in the first six years, and the outcomes are what happened over the following 28.
Was the weight loss caused by the trial?
Partly. Da Qing randomly assigned clinics to diet, exercise, diet plus exercise, or control for six years. This analysis ignores which arm people were in and sorts them by what actually happened to their weight, which is a more useful question and a weaker design: people who lost weight differ from people who did not in ways beyond the intervention.
Is 5% a lot of weight?
It is a common clinical threshold and a modest amount in practice: around 4 kg for someone weighing 80 kg. Nothing here required dramatic loss, and the comparison group that lost under 5% did not show the same benefits, which is what makes the threshold interesting rather than arbitrary.
What should someone with prediabetes do?
The standard advice already covers it: losing weight, if you are overweight, getting regular physical activity, and following a healthy, reduced-calorie eating plan. This is general information rather than medical advice. What this study adds is a reason to treat the first few years as the ones that count, and to raise the target with a doctor rather than waiting to see whether diabetes arrives.
References
- He, S., Yu, L., Wang, J., et al. Early Weight Loss in Impaired Glucose Tolerance Is Associated With Reduced Long-term Mortality and Cardiovascular Risk: The Da Qing Diabetes Prevention Outcome Study. Diabetes Care, 2026.
- Gong, Q., Zhang, P., Wang, J., et al. Morbidity and mortality after lifestyle intervention for people with impaired glucose tolerance: 30-year results of the Da Qing Diabetes Prevention Outcome Study. The Lancet Diabetes & Endocrinology, 2019.
- MedlinePlus. Prediabetes. US National Library of Medicine.