ABSTRACT
AIMS: 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. MATERIALS AND METHODS: The trajectory patterns of combined lifestyles over three years were identified using group-based trajectory modeling in 26,647 adults in Japan. Two types of indices (not having the unhealthy lifestyle [easy goal] and having healthiest lifestyles [challenging goal]) were developed 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 it was shown 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. CONCLUSIONS: Our data reinforce the importance of improving and maintaining health-related lifestyles to prevent diabetes.