U-shaped association of sleep duration with metabolic syndrome and insulin resistance in patients with type 2 diabetes: the Fukuoka Diabetes Registry.

OBJECTIVE: Sleep duration is suggested to be associated with adverse health outcomes. However, few studies are available on the impact of sleep duration on metabolic syndrome in patients with diabetes, who were at high risk for cardiovascular diseases (CVD). The objective of the present study was to examine the associations of sleep duration with metabolic syndrome and insulin resistance, a major pathophysiologic feature of metabolic syndrome, in patients with type 2 diabetes. MATERIALS/METHODS: A total of 4402 Japanese patients with type 2 diabetes aged ≥20years were divided into 5 groups according to self-reported sleep duration: less than 5.5h, 5.5-6.4h, 6.5-7.4h, 7.5-8.4h, and more than 8.5h. The associations of sleep duration with metabolic syndrome and other cardiovascular risk factors were examined cross-sectionally. RESULTS: The proportions of patients who had metabolic syndrome increased significantly in both patients with shorter and longer sleep duration compared with those with 6.5-7.4h of sleep (P for quadratic trend <0.001). This U-shaped association remained significant after adjustment for potential confounders, including total energy intake, current smoking, current drinking and depressive symptoms. Each component of metabolic syndrome also showed similar trends. Furthermore, sleep duration had a quadratic association with homeostasis model assessment of insulin resistance and high sensitivity C-reactive protein. CONCLUSIONS: Sleep duration was shown to have a U-shaped relationship with metabolic syndrome and insulin resistance, independent of potential confounders, and therefore may be an important modifiable risk factor for CVD prevention in patients with type 2 diabetes.

Impact of dietary fiber intake on glycemic control, cardiovascular risk factors and chronic kidney disease in Japanese patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry.

BACKGROUND: Dietary fiber is beneficial for the treatment of type 2 diabetes mellitus, although it is consumed differently in ethnic foods around the world. We investigated the association between dietary fiber intake and obesity, glycemic control, cardiovascular risk factors and chronic kidney disease in Japanese type 2 diabetic patients. METHODS: A total of 4,399 patients were assessed for dietary fiber intake using a brief self-administered diet history questionnaire. The associations between dietary fiber intake and various cardiovascular risk factors were investigated cross-sectionally. RESULTS: Body mass index, fasting plasma glucose, HbA1c, triglyceride and high-sensitivity C-reactive protein negatively associated with dietary fiber intake after adjusting for age, sex, duration of diabetes, current smoking, current drinking, total energy intake, fat intake, saturated fatty acid intake, leisure-time physical activity and use of oral hypoglycemic agents or insulin. The homeostasis model assessment insulin sensitivity and HDL cholesterol positively associated with dietary fiber intake. Dietary fiber intake was associated with reduced prevalence of abdominal obesity, hypertension and metabolic syndrome after multivariate adjustments including obesity. Furthermore, dietary fiber intake was associated with lower prevalence of albuminuria, low estimated glomerular filtration rate and chronic kidney disease after multivariate adjustments including protein intake. Additional adjustments for obesity, hypertension or metabolic syndrome did not change these associations. CONCLUSION: We demonstrated that increased dietary fiber intake was associated with better glycemic control and more favorable cardiovascular disease risk factors including chronic kidney disease in Japanese type 2 diabetic patients. Diabetic patients should be encouraged to consume more dietary fiber in daily life.

Association between sleep duration and urinary albumin excretion in patients with type 2 diabetes: the Fukuoka diabetes registry.

OBJECTIVE: Few studies have so far investigated the impact of sleep duration on chronic kidney disease in diabetic patients. The objective of the present study was to examine the relationship between sleep duration and albuminuria in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: A total of 4,870 Japanese type 2 diabetic patients ≥20 years of age were divided into six groups according to self-reported sleep duration: less than 4.5 hours, 4.5-5.4 hours, 5.5-6.4 hours, 6.5-7.4 hours, 7.5-8.4 hours and more than 8.5 hours. The association between sleep duration and urinary albumin-creatinine ratio (UACR) was examined cross-sectionally. RESULTS: Both short and long sleep durations were significantly associated with higher UACR levels and higher proportions of patients with albuminuria (≥30 mg/g) and macroalbuminuria (≥300 mg/g) compared with a sleep duration of 6.5-7.4 hours (P for quadratic trend <0.001). A U-shaped association between sleep duration and UACR remained significant even after adjustment for potential confounders, including age, sex, duration of diabetes, current smoking habits, former smoking habits, current drinking habits, regular exercise habits, total energy intake, total protein intake, hypnotic use and estimated glomerular filtration rate. Furthermore, the association remained substantially unchanged after additional adjustment for body mass index, hemoglobin A1c, systolic blood pressure, renin-angiotensin system inhibitor use and depressive symptoms. CONCLUSIONS: Our findings suggest that sleep duration has a U-shaped association with the UACR levels in type 2 diabetic patients, independent of potential confounders.