Incidence of metabolic syndrome according to combinations of lifestyle factors among middle-aged Japanese male workers

Objective: To examine a combination of healthy lifestyles on the risk of metabolic syndrome (MetS) to inform future interventions. Methods: A total of 1897 men aged 35-60. years participated in an annual health check-up in 2002 and 2005. MetS was defined by AHA/NCEP criteria. Logistic regression analyses were used to estimate age- and BMI-adjusted odds ratios (ORs) of MetS incidence for each healthy lifestyle (regular physical activity, adherence to healthy eating behaviors, not current smoking, and maintaining a stable weight since one's mid-twenties), separately (Model 1) and simultaneously (Model 2). A points system was developed to derive 3-year risk of MetS incidence by assigning a specific point to each healthy lifestyle. Results: MetS developed in 285 (15.0%) subjects after the follow-up. The ORs of MetS for each healthy lifestyle ranged from 0.42 to 0.64 (Model 2). Three-year risk of MetS incidence was predicted to differ from 1% to 60% according to the individual point total of the points system. The population-attributable fraction of MetS in subjects whose point total was not in the highest quartile was 71%. Conclusion: Adherence to healthy lifestyles was associated with a lower risk of MetS among apparently healthy middle-aged Japanese male workers.