ORIGINAL ARTICLE Sleep abnormalities in type 2 diabetes may be associated with glycemic control M. Trento Æ F. Broglio Æ F. Riganti Æ M. Basile Æ E. Borgo Æ C. Kucich Æ P. Passera Æ P. Tibaldi Æ M. Tomelini Æ F. Cavallo Æ E. Ghigo Æ M. Porta Received: 1 January 2008 / Accepted: 11 July 2008 / Published online: 7 August 2008 Ó Springer-Verlag 2008 Abstract Sleep disturbances may be associated with impaired glucose metabolism. The aim of this study was to evaluate sleep duration and quality in relation to glycemic control in patients with type 2 diabetes. In a cross-sectional study, sleep duration and quality were assessed in 47 mid- dle-aged patients with type 2 diabetes treated with oral agents and without sleep disturbing complications and 23 healthy control subjects similar by age, sex, body mass index, occupation and schooling. Sleep was recorded by wrist-actigraphy for three consecutive days under free-liv- ing conditions. Univariate analysis showed lower sleep maintenance (P = 0.002) and sleep efficiency (P = 0.005), and higher fragmentation index (P \ 0.0001), total activity score (P = 0.05) and moving time (P \ 0.0001) in patients with type 2 diabetes. After adjusting for age, gender and schooling, fragmentation index and moving time remained significantly higher in the patients with diabetes (P \ 0.05, both). HbA1c correlated inversely with sleep efficiency (r =-0.29; P = 0.047) and positively with moving time (r = 0.31; P = 0.031). These findings suggest that type 2 diabetes is associated with sleep disruptions even in the absence of complications or obesity. The relevance of sleep abnormalities to metabolic control and possible strategies to improve sleep quality in type 2 diabetes deserve further investigation. Keywords Type 2 diabetes Á Sleep disturbances Á Actigraphy Introduction Diabetes remains a critical public health challenge. Its prevalence continues to increase and it now affects an estimated 180 million people worldwide [1, 2]. Patients with diabetes require frequent contacts with the health care system for effective management and pre- vention of complications, and are at increased risk for premature mortality and hospitalization for cardiovascular and kidney disease. Although lifestyle changes such as healthy eating, weight loss and increased physical activity are the cornerstones of diabetes prevention and treatment, efforts are needed to better understand other determinants of this disease and to develop additional intervention strategies. Understanding the link between diabetes and sleep may represent one important part of that effort [3, 4]. Sleep loss is a common condition in modern society [3, 4]. In the USA, nearly one-third of adults report sleeping less than 6 h per night [5]. Factors responsible for sleep curtailment are likely to be similar in all industrialized countries and include increases in environmental light, longer working days/commuting time, an increase in shift and night work, and the advent of television, radio, and the internet [6]. Abnormal sleep duration, either excessively long or excessively short, has been shown [7], together with self- reported poor sleep quality, to be a predictor of overall M. Trento (&) Á M. Basile Á E. Borgo Á C. Kucich Á P. Passera Á P. Tibaldi Á M. Porta Department of Internal Medicine, Laboratory of Clinical Pedagogy, University of Turin, Corso AM Dogliotti 14, 10126 Turin, Italy e-mail: marina.trento@unito.it F. Broglio Á F. Riganti Á M. Tomelini Á E. Ghigo Department of Internal Medicine, University of Turin, Corso AM Dogliotti 14, 10126 Turin, Italy F. Cavallo Department of Public Health and Microbiology, University of Turin, Corso AM Dogliotti 14, 10126 Turin, Italy 123 Acta Diabetol (2008) 45:225–229 DOI 10.1007/s00592-008-0047-6