Several studies show that short self-reported sleep duration is associated with elevated body mass index (BMI). Short sleep duration may change appetite hormones, but whether this also influences metabolic measures like cholesterol and triglycerides is less clear. Furthermore, obesity is linked to increases in blood pressure, and recently, short sleep duration has been shown to be an independent risk factor for hypertension. This is a population-based cross-sectional study (The Hordaland Health Study). A subgroup of 8860 subjects, aged 40-45 years, answered a sleep questionnaire. Body weight, height and blood pressure were measured, and non-fasting blood samples were collected and analyzed for total cholesterol, HDL-cholesterol and triglycerides. Sleep duration was divided into the following subgroups: < 5, 5-5.99, 6-6.99, 7-7.99, 8-8.99 and > or = 9 h. The results show that short sleep duration was associated with elevated BMI and increased prevalence of obesity. Similar to BMI, levels of cholesterol, triglycerides, systolic and diastolic blood pressure were higher in subjects with short sleep duration. This co-variation seemed to be attributed to variables like gender, smoking and BMI. In conclusion, our study confirms a clear association between short sleep duration and elevated BMI and obesity. Furthermore, levels of total cholesterol, HDL-cholesterol, triglycerides and blood pressure were associated with sleep duration.