Men: baseline characteristics and the onset of impaired fasting glucose^* according to fasting plasma glucose levels.

Values are expressed as mean ± standard deviation.

Quartile 1: fasting plasma glucose <5 mM; quartile 2: fasting plasma glucose 5–5.22 mM; quartile 3: fasting plasma glucose 5.23–5.49 mM; quartile 4: fasting plasma glucose 5.55–6.10 mM.

For continuous values, differences among groups were assessed using one-way analysis of variance. The chi-square test was employed for comparisons of prevalence. The Cochran–Armitage test was used to assess the trend in the incidence rates of impaired fasting glucose onset according to the fasting plasma glucose groups.

*Onset of impaired fasting glucose was defined as a fasting plasma glucose level ≥6.11 mM.

Men: baseline characteristics and the onset of impaired fasting glucose^* according to fasting plasma glucose levels.