Improving and maintaining healthy lifestyles are associated with a lower risk of diabetes: a large cohort study

Background It is well known that healthy lifestyles measured at one time-point are inversely associated with diabetes risk. The impact of transitions in combined lifestyles in real settings remains unknown. Methods We identified the trajectory patterns of combined lifestyles over three years using group-based trajectory modeling in 26,647 adults in Japan. We developed two types of indices (not having the unhealthy lifestyle [easy goal] and having healthiest lifestyles [challenging goal]) using five lifestyle factors: smoking, alcohol consumption, exercise, sleep duration, and body weight control. This index was calculated using the yearly total score (0-5; higher score indicated healthier lifestyles). Diabetes was defined by high plasma glucose level, high hemoglobin A1c level, and self-report. Results Five trajectory patterns were identified for each index and showed that healthier patterns are associated with a lower risk of type 2 diabetes during 6.6 years of average follow-up. For example, with a challenging-goal, compared with a persistently very unhealthy pattern, the adjusted hazard ratios (95% confidence intervals) were 0.65 (0.59, 0.73), 0.50 (0.39, 0.64), 0.43 (0.38, 0.48), and 0.33 (0.27, 0.41) for "persistently unhealthy", "improved from unhealthy to moderately healthy", "persistently moderately healthy", and "persistently mostly healthy" patterns, respectively. Conclusion Our data reinforce the importance of improving and maintaining health-related lifestyles to prevent diabetes.