ORIGINAL ARTICLE Epidemiology of sleep-related complaints associated with obstructive sleep apnea, insomnia and non-restorative sleep in an at-risk population in Granada, Spain Marie Carmen VALENZA, 1 Gerad VALENZA, 1 Tomás MUÑOZ-CASAUBON, 3 Miguel BOTELLA-LÓPEZ, 2 Emilio J PUENTEDURA, 5 Manuel ARROYO-MORALES 1 and César FERNÁNDEZ-DE-LAS-PEÑAS 4 1 Department of Physical Therapy, 2 Department of Morphological Sciences, Universidad de Granada, 3 Laboratory of Sleep Medicine, Hospital Clínico San Cecilio, Granada, 4 Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation of Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain, and 5 Department of Physical Therapy, School of Allied Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA Abstract Our aim was to estimate the frequency of sleep apnea, non-restorative sleep, and insomnia and their association with demographic factors, lifestyle behaviors and co-morbid conditions in an at-risk population in Spain. A total of 1009 individuals with suspected Obstructive Sleep Apnea Syndrome (OSAS) completed a questionnaire and personal interview including demographic data, lifestyle behaviors, sleep-wake schedule, diurnal and nocturnal symptoms and also co-morbid conditions. Laboratory tests included lung function test, echocardiography, arterial blood analysis, total blood counts, and standard polysomnography for diagnosing sleep apnea. The frequency of OSAS, insom- nia and non-restorative sleep was 88.5%, 16.76%, 59.72%, respectively. The frequency of OSAS was lower in females than in males (OR 0.33, 95% CI 0.20–0.56) whereas the frequency of insomnia was higher (1.95, 1.29–2.95). People in the 61–70 year group exhibited higher frequency of OSAS (3.81, 1.51–9.58) and also insomnia (1.85, 1.08–4.32), whereas the obese exhibited higher probability of OSAS (1.80, 1.15–2.81). OSAS was associated with snoring (7.95, 1.57–24.58), nocturia (1.80, 1.12–2.89), daily fatigue (1.89, 1.12–3.17), apathy (0.53, 0.30–0.89), memory loss (0.44, 0.26– 0.73), and hypertension (2.60, 1.41–4.78). Insomnia was associated with esophageal reflux (1.78, 1.21–2.61), awakening (3.39, 2.19–5.22), apathy (1.68, 1.11–2.55), and memory loss (1.58, 1.06– 2.35). Non-restorative sleep was associated with nocturia (1.43, 1.01–2.05), gastro-esophageal reflux (2.08, 1.31–3.31), diaphoresis (3.31, 1.88–5.83), awakening (1.41, 1.01–2.02), daily fatigue (2.09, 1.47–2.97), memory loss (2.23, 1.40–3.54), irritability (2.26, 1.59–4.03) and headache (2.57, 1.65–4.00). The frequency of sleep-related breathing disorders was high in our sample. Different factors seem to be associated with OSAS, insomnia or non-restorative sleep. Key words: insomnia, non-restorative sleep, Obstructive Sleep Apnea Syndrome. Correspondence: Professor César Fernández-de-las-Peñas, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Avenida de Atenas s/n, 28922 Alcorcón, Madrid, Spain. Email: cesar.fernandez@urjc.es Financial support: No fund were received for this study. Conflict of interest: None declared by any author. Accepted 5 April 2012. Sleep and Biological Rhythms 2012; 10: 222–230 doi:10.1111/j.1479-8425.2012.00565.x 222 © 2012 The Authors Sleep and Biological Rhythms © 2012 Japanese Society of Sleep Research