Short and long sleep are positively associated with obesity, diabetes, hypertension, and cardiovascular disease among adults in the United States.

Research associates short (and to a lesser extent long) sleep duration with obesity, diabetes, and cardiovascular disease; and although 7-8 h of sleep seems to confer the least health risk, these findings are often based on non-representative data. We hypothesize that short sleep (<7 h) and long sleep (>8 h) are positively associated with the risk of obesity, diabetes, hypertension, and cardiovascular disease; and analyze 2004-2005 US National Health Interview Survey data (n=56,507 observations, adults 18-85) to test this. We employ multilevel logistic regression, simultaneously controlling for individual characteristics (e.g., ethnoracial group, gender, age, education), other health behaviors (e.g., exercise, smoking), family environment (e.g., income, size, education) and geographic context (e.g., census region). Our model correctly classified at least 76% of adults on each of the outcomes studied, and sleep duration was frequently more strongly associated with these health risks than other covariates. These findings suggest a 7-8 h sleep duration directly and indirectly reduces chronic disease risk. Copyright (c) 2010 Elsevier Ltd. All rights reserved.