Early weight loss after impaired glucose tolerance tracks with fewer heart deaths 34 years on

Design

Long-term observational follow-up of a lifestyle intervention trial

Population

540 Chinese adults with impaired glucose tolerance, followed 34 years

Primary outcome

All-cause death, cardiovascular death and cardiovascular events

Effect

≥5% vs no weight loss: CVD death HR 0.56 (0.35–0.89); all-cause death HR 0.67 (0.48–0.95)

The Da Qing study followed 540 Chinese adults with impaired glucose tolerance for 34 years. Here they were grouped by what their weight did over the first six years: no loss, under 5% loss, or 5% or more.

After adjustment for age, sex, baseline weight and other factors, those who lost at least 5% had lower risks of cardiovascular death (HR 0.56, 95% CI 0.35–0.89), cardiovascular events (HR 0.71, 0.52–0.99), heart failure admission (HR 0.48, 0.26–0.88) and death from any cause (HR 0.67, 0.48–0.95). Median time to cardiovascular death was delayed by 6.5 years.

The grouping is by achieved weight change, not by randomisation, so people who lost weight may have differed in other ways. The upper bound for cardiovascular events sits just under 1.0. Even so, the direction fits the wider prediabetes literature, and the population — Asian adults with impaired glucose tolerance — is close to many Indian clinics.

• Set a concrete early target of at least 5% weight loss when impaired glucose tolerance is diagnosed.
• Record weight at each visit in the first years after diagnosis; that window carried the association here.
• Use the long time horizon in counselling: the gains in this cohort appeared over decades, not months.
• The cohort was Chinese adults, a population closer to Indian patients than most Western prevention trials.

Why it matters

Prediabetes is often watched rather than treated, and this links early action to outcomes that only show decades later.

Don't overread it

Weight change was not randomised, so this shows an association with outcomes, not that weight loss caused them.

The statistics, in plain English

A hazard ratio of 0.56 means the rate of cardiovascular death was about 44% lower in the group that lost 5% or more. The confidence intervals do not cross 1.0, but for cardiovascular events the upper limit is 0.99, so that result is at the edge of significance.

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