Association between low‐carbohydrate diet scores and macrovascular events or all‐cause mortality in adults with type 1 diabetes in Japan

AIMS/INTRODUCTION: The effects of lifestyle factors on macrovascular events or all-cause mortality remain unclear in type 1 diabetes. We examined the associations of diet, physical activity, and sleep with these outcomes among adults with type 1 diabetes living in Japan. MATERIALS AND METHODS: This multicenter prospective cohort included 352 adults with type 1 diabetes from the Juntendo-Aso Type 1 Diabetes cohort. Lifestyle factors were assessed by questionnaire. Dietary intake was evaluated using a brief-type self-administered diet history questionnaire, from which Total, Plant, and Animal low-carbohydrate diet scores were calculated. The primary composite outcome was the first occurrence of ischemic heart disease, cerebrovascular disease, peripheral artery disease, or all-cause mortality. Associations were analyzed using Cox proportional hazards models. RESULTS: Mean age was 51.4 ± 15.1 years, mean HbA1c was 7.9 ± 1.1%, and carbohydrate accounted for 49.3% of energy intake. During follow-up, 35 participants experienced the primary composite outcome. In multivariable Cox models, the Total LCDS (HR, 0.90; 95% CI: 0.82-0.98; P = 0.012), Plant LCDS (HR, 0.85; 95% CI: 0.76-0.94; P = 0.003), and Animal LCDS (HR, 0.93; 95% CI: 0.87-0.996; P = 0.037) were inversely associated with the outcome. CONCLUSIONS: Among adults with type 1 diabetes living in Japan, low-carbohydrate dietary patterns, particularly the Plant low-carbohydrate diet score, were inversely associated with macrovascular events or all-cause mortality.