SAN ANTONIO — Body mass index is strongly correlated with self-reported days of insufficient sleep per month among U.S. adults, according to a large national study.
The study included 384,020 U.S. adults who participated in the Centers for Disease Control and Prevention’s 2008 Behavioral Risk Factor Surveillance System survey, the world’s largest telephone health survey. The 2008 version included this question: "During the past 30 days, for about how many days have you felt you did not get enough rest or sleep?"
Days of insufficient sleep followed a linear trend across body mass index (BMI) categories. Among the 36.8% of respondents who were normal weight or underweight, the mean number of days of insufficient sleep in the past month was 7.9. The 36.4% of the population who were overweight averaged 8.4 days. For the 17.1% who were obese class I with a BMI of at least 30 and less than 35 kg/m2, it was 9.4 days. And the 3.5% of adults were obese class III with a BMI of 40 kg/m2 or more averaged 11.1 days of insufficient sleep per month, Anne G. Wheaton reported at the meeting.
Twenty-five percent of normal-weight respondents indicated they had 14 or more days of insufficient sleep in the past 30 days. This proportion rose steadily through the BMI categories, reaching 37.1% among individuals who were obese class III, added Ms. Wheaton of the CDC.
In a multivariate regression analysis adjusted for demographic variables, physical activity, and smoking, respondents who were obese class I, II, or III were, respectively, 1.4-fold, 1.6-fold, and 1.8-fold more likely than were normal-weight individuals to have had at least 14 days of insufficient sleep in the past 30 days.
The implication of this study, she said, is that insufficient sleep should be addressed in weight reduction programs, and excess weight ought to be considered in developing programs to address sleep disorders.
This study was supported by a grant from the Association for Prevention Teaching and Research, and the CDC.
Ms. Wheaton reported no financial conflicts.