Effects of lifestyle and physical exercise on impaired glucose tolerance in middle-aged men

The rapid lifestyle changes in China correlate with alarming rise of diabetes mellitus (DM) and its comorbidities such as cardiovascular disease. Impaired glucose intolerance (IGT) is one of the risk factors associated with DM onset. We investigated the relation between lifestyle such as meat and carbohydrate intake, smoking and alcohol and physical exercise on IGT in 349 middle-aged (age range 41 to 59 years) Chinese men with no history of DM or any related treatments.

After being assessed for glucose tolerance, study participants were classified into the IGT (N.=172) and NGT (N.=177) group. Using a questionnaire they were assessed for daily meat and carbohydrate intake, smoking and alcohol drinking habits and physical exercise. Associations were analyzed with a single-factor ANOVA and regression and controlled for body mass index (BMI).

Significant differences between IGT and NGT groups were found for high appetite intake (>400 g/day: 91.9% vs. 41.8%, respectively, P<0.01), high meat intake (>100 g/day: 62.2% vs. 40.7%, P<0.01), frequent smoking (20 cigarettes/day during more than 2 years: 51.2% vs. 9.05%, P<0.01) and frequent physical exercise (≥ 3 times/week: 15.1% vs. 65.5%, respectively, P<0.01).

Our study found that high carbohydrate and meat intake, frequent smoking and low physical exercise associate with IGT in middle-aged men. Further studies are needed to assess whether diminishing or eliminating these risk factors could reverse IGT in middle age, both in men and women.