Trajectories of healthy lifestyle index and prediabetes risk of adult workers in Japan.

Abstract

Background: The relationship between health-related lifestyle trajectories and prediabetes risk among adults with normoglycemia remains unclear. We investigated this issue using data from a cohort of working individuals.

Methods: This cohort study included 10,773 workers (8986 men) aged 30-64 years in Japan, with normoglycemia in 2009, followed until 2017 using annual health checkup data. The trajectories of health-related lifestyles were identified during 2006-2009 using group-based trajectory modeling; we calculated the health-related lifestyle index in each year using five lifestyle factors: smoking, alcohol use, exercise, sleep duration, and body weight control (0-5 points; higher score indicated healthier lifestyles). Prediabetes was defined by fasting plasma glucose and hemoglobin A1c based on the American Diabetes Association criteria; the onset was assessed from 2009 to 2017. Cox regression with adjustment for demographic, health-related, and work-related factors was used to evaluate the association of lifestyle trajectories and prediabetes risk.

Results: Five trajectories of health-related lifestyles are identified. Maintaining or improving health-related lifestyles are linked to lower prediabetes risks. Compared with a persistently very unhealthy pattern, the adjusted hazard ratios (95% confidence intervals) are 0.92 (0.84, 0.99), 0.82 (0.71, 0.95), 0.83 (0.76, 0.90), and 0.74 (0.67, 0.83) for "persistently very unhealthy", "persistently unhealthy", "improved from unhealthy to moderately healthy", "persistently moderately healthy", and "persistently mostly healthy" trajectories, respectively.

Conclusions: Participants with healthier lifestyle trajectories tend to have a lower risk of developing prediabetes. The prediabetes risk at the trajectory of improved from unhealthy lifestyles is lower than that of persistently unhealthy lifestyles.