Increased leisure-time physical activity associated with lower onset of diabetes in 44 828 adults with impaired fasting glucose: a population-based prospective cohort study.

Aims: To evaluate the effects of habitual leisure-time physical activity (LTPA) on incident type 2 diabetes in a prospective cohort of Chinese adults with impaired fasting glucose (IFG).

Methods: 44 828 Chinese adults aged 20-80 years with newly detected IFG but free from cardiovascular and cerebrovascular disease were recruited and followed up from 1996 to 2014. Incident type 2 diabetes was identified by fasting plasma glucose ≥7 mmol/L. The participants were classified into four categories based on their self-reported weekly LTPA: inactive, low, moderate, or high. Hazard ratios (HRs) and population attributable fractions (PAFs) were estimated with adjustment for established diabetic risk factor.

Results: After 214 148 person-years of follow-up, we observed an inverse dose-response relationship between LTPA and diabetes risk. Compared with inactive participants, diabetes risk in individuals reporting low, moderate and high volume LTPA were reduced by 12% (HR 0.88, 95% CI 0.80 to 0.99; P=0.015), 20% (HR 0.80, 95% CI 0.71 to 0.90; P<0.001), and 25% (HR 0.75, 95% CI 0.67 to 0.83; P<0.001), respectively. At least 19.2% (PAF 19.2%, 95% CI 5.9% to 30.6%) of incident diabetes cases could be avoided if the inactive participants had engaged in WHO recommendation levels of LTPA. This would correspond to a potential reduction of at least 7 million diabetic patients in the Greater China area.

Conclusions: Our results show higher levels of LTPA are associated with a lower risk of diabetes in IFG subjects. These data emphasise the urgent need for promoting physical activity as a preventive strategy against diabetes to offset the impact of population ageing and the growing obesity epidemic.