recent research indicates that at least one - third of us adults report regularly getting less than the 79 hours of sleep per night recommended by the national sleep foundation .
insufficient sleep , variably defined , has been associated with health - risk behaviors , such as smoking [ 2 , 3 ] , alcohol use [ 2 , 3 ] , and with adverse health outcomes such as obesity , and frequent mental distress ( fmd ) ( 14 days / past 30 days in which respondents report their mental health was not good ) . noting that the average sleep duration among us adults has decreased during the past 50 years along with a concomitant increase in the prevalence of obesity , wheaton et al
.   found a strong positive relationship between perceived insufficient sleep and body mass index ( bmi ) among community - dwelling adults .
given the linkage between insufficient sleep and increased bmi , the association between insufficient sleep and diabetes   is not surprising .
consistent with these findings , sleep restriction ( defined as 5 hours / night for one week ) was found to be associated with a significant decrease in insulin sensitivity .
notably , the prevalence of several factors associated with insufficient sleep has been reported to vary between different race / ethnicities in large epidemiologic studies .
specifically , an analysis of 20062008 bmi data from the behavioral risk factor surveillance survey ( brfss ) revealed prevalences of obesity of 23.7% among non - hispanic whites ( nhw ) , 35.7% among non - hispanic blacks
although ai / an were not specifically delineated in the latter survey , rates of obesity in ai / an adults have been reported to be 1.5 times greater than among nhw adults .
similarly , aggregated prevalences ( 19992004 ) of diagnosed diabetes reported from the national health and nutrition examination survey ( nhanes ) were 5.9% among nhw , 11.1% among nhb , and 10.9% among mexican americans .
an analysis of data from both the brfss and the indian health service across 19942002 revealed that the age - adjusted prevalence of diabetes among ai / an adults was more than twice that of us adults overall .   despite the relatively high prevalence of factors associated with insufficient sleep in ai / an
, few epidemiologic investigations of insufficient sleep have been conducted in this population . in investigations delineating race / ethnicity disparities , short sleep duration ( average 6 hours/24-hour period ) among workers
was reported significantly more frequently by nhb ( 38.9% ) , nh other ( 35.3% ) , and nh asian ( 33.2% ) than among nhw ( 28.6% ) or hispanic ( 28.8% ) . in
related research using nhanes 20052008 data to assess sleep - related difficulties ( e.g. , concentrating , remembering , driving , and working ) , nhb reported a greater prevalence of sleep - related difficulties in driving or taking public transportation ( 14.8% ) than the other racial / ethnic populations studied ( nhw , mexican americans , and others ) .
similarly , reporting 30 days of insufficient sleep or rest was significantly more prevalent among nhb ( 13.3% ) than nhw ( 11.2% ) 2008 brfss respondents .
it is worthy of note that because of small sample sizes of ai / an in national surveillance systems , ai / an are often categorized as 
others ,  thus rendering it difficult to ascertain the prevalence of sleep sufficiency and risk factors in this population .  
as many risk factors associated with frequent insufficient sleep appear to be of increased prevalence in ai / an , we sought to determine the prevalence of insufficient sleep in a community - based sample of this population . specifically , to examine
if ai / an are more likely to experience insufficient sleep relative to nhw , as has already been reported among nhb , we aggregate data from the 2009 and 2010 brfss . furthermore , we assess the impact of recognized sleep correlates ( i.e. , socioeconomic indicators , lifestyle behaviors , obesity , age , and fmd ) on potential race / ethnicity disparities in insufficient sleep .
data were obtained from the recent brfss , a large , random - digit - dialed telephone survey conducted in all 50 states , the district of columbia , and us territories .
the 2009 - 2010 brfss collected data on health - related behaviors , including sleep , smoking , physical inactivity , binge drinking , obesity , and frequent mental distress among the us civilian population aged 18 years living in households with landline telephones .
as previously noted , we combined 2009 and 2010 brfss data in order to yield an adequate sample size of ai / an . before aggregating these data , we observed no difference between 2009 and 2010 in frequent insufficient sleep , defined as 14 days / past 30 days in which respondents reported that they did not get enough rest or sleep . additionally , the two years shared a similar median response rate to the question assessing frequent insufficient sleep ( 52.5% and 54.6% , respectively ) ( brfss 2009 and 2010 summary quality report , version 1 , revised on 2/18/2011 for 2009 and on 5/2/2011 for 2011 ) .
a detailed description of the brfss survey design , data collection techniques , and the full - text questionnaire can be found at http://www.cdc.gov/brfss .
data were obtained from 810,168 respondents ( 96.9% ) who self - identified as nhw , ( n = 671,448 ) , nhb ( n = 67,685 ) , hispanic ( n = 59,528 ) , or ai / an ( n = 11,507 ) after excluding respondents who had missing data on the insufficient sleep question ( n = 15,322 ) and other variables of interest ( n = 25,636 ) .
all respondents were asked ,  during the past 30 days , for about how many days have you felt you did not get enough rest or sleep ?  we defined frequent insufficient sleep as 14 days , as this cutoff has been shown to have a strong relationship with the prevalence of chronic disease and health risk behaviors .
sociodemographic characteristics included sex , age in years ( 1824 , 2534 , 3544 , 4554 , 5564 or 65 ) , years of education ( < 12 , 12 , or > 12 ) , and employment status ( employed for wage / self - employed , unemployed , retired , unable to work , or homemaker / student ) .
health - related lifestyle behaviors included smoking status ( current smoker , former smoker , or never smoked ) , binge drinking ( for men , 5 alcoholic beverages on one occasion in the previous 30 days ; for women , 4 alcoholic beverages on one occasion in the previous 30 days ) , and physical inactivity ( respondent indicated  no  to the question ,  during the past month , other than your regular job , did you participate in any physical activities or exercising such as running , calisthenics , golf , gardening , or walking for exercise ?  ) .
frequent mental distress ( fmd ) was defined as a response of 14 days to the question ,  now thinking about your mental health , which includes stress , depression , and problems with emotions , for how many days during the past 30 days was your mental health not good ?  .
assessment of obesity was based on the body mass index ( bmi , kg / m ) , calculated from respondents ' self - reported height in inches and weight in pounds ( obese : bmi 30  kg / m versus not obese : bmi < 30.0  kg / m ) .
first , the racial / ethnic - specific distributions of the selected characteristics and frequent insufficient sleep were obtained in order to examine unadjusted race / ethnicity disparities .
next , the prevalence of frequent insufficient sleep by race / ethnicity and groups defined by obesity , smoking , binge drinking , physical activity , and fmd status was calculated to demonstrate race / ethnicity - specific associations between these covariates and frequent insufficient sleep .
we used multivariate logistic regression modeling to assess the race / ethnicity disparity in frequent insufficient sleep in separate models controlling first for age , then in a second model with the addition of sex , education , and employment , to which obesity was added to create a third model . a fourth model added smoking status , physical inactivity , and binge drinking to the third model , with a fifth model adding fmd .
all analyses were conducted using sas - callable sudaan to account for the complex sampling design .
ai / an had a higher proportion of male respondents than other racial / ethnicity groups .
relative to nhw , we found that nhb , hispanics , and ai / an tended to be younger , to report < 12 years of education and were more likely to be unemployed or to report being unable to work ( p  0.01 ) .
in addition , nhb , ai / an , and hispanics were more likely to be obese relative to nhw ( p  0.01 ) and , concomitantly , to report they were physically inactive ( p  0.001 ) .
ai / an were more likely to report being current ( 33.2% ) or former ( 25.7% ) smokers than any of the other race / ethnicity groups examined .
binge drinking was similar in all race / ethnicity groups except among nhb who were less likely to report binge drinking .
table 1 also indicates that the unadjusted prevalence of fmd was significantly greater ( p  0.001 ) among ai / an than any other race / ethnicity group .
most notably , we found significantly higher unadjusted prevalences ( 95% confidence interval [ 95% ci ] ) of frequent insufficient sleep among ai / an ( 34.2% [ 32.136.4 ] ) and nhb ( 29.4% [ 28.630.1 ] ) and a significantly lower prevalence among hispanics ( 25.4% [ 24.726.1 ] ) compared to nhw ( 27.4% [ 27.127.6 ] ) .  
 table 2 lists the race / ethnicity - specific prevalences of frequent insufficient sleep by selected characteristics .
obese respondents had a statistically higher prevalence of frequent insufficient sleep than nonobese respondents among all race / ethnicities , excepting ai / an .
regardless of race / ethnicity , current smokers were more likely to report frequent insufficient sleep than former smokers or never smokers ( p  0.01 ) . a higher prevalence of frequent insufficient sleep among binge drinkers compared to nonbinge drinkers reached statistical significance only among nhw and nhb ( p  0.01 ) .
a positive relationship between physical inactivity and frequent insufficient sleep was observed regardless of race / ethnicity ( p  0.01 ) .
persons reporting fmd were significantly more likely to report frequent insufficient sleep than those without fmd in all race / ethnicity groups ( p  0.001 ) .  
results from our adjusted multivariate logistic regression models comparing the likelihood of frequent insufficient sleep among nhb , hispanics , and ai / an relative to frequent insufficient sleep in nhw are shown in table 3 .
after age adjustment ( model 1 ) the disparity in frequent insufficient sleep between nhw and nhb ( pr = 1.02 ; 95% ci : 0.991.04 ) was no longer statistically significant . however , both nhb ( pr = 0.95 ; 95% ci : 0.920.98 ) and hispanics ( pr = 0.84 ; 95% ci : 0.810.86 ) remained significantly less likely ( p  0.001 ) to report frequent insufficient sleep than nhw , even after controlling for all the covariates in the model ( model 5 )
.  
 table 3 also reveals a significant age - adjusted excess prevalence of frequent insufficient sleep in ai / an relative to nhw in model 1 , ( pr = 1.20 ; 95% ci : 1.121.27 ) .
this was modestly weakened by the addition of sex , education , and employment ( pr = 1.12 ; 95% ci : 1.041.19 ) as indicated by model 2 .
this relationship was further attenuated in ai / an by the separate addition of obesity in model 3 ( pr = 1.10 ; 95% ci : 1.031.18 ) , and then by the addition of smoking , physical inactivity , and binge drinking ( pr = 1.08 ; 95% ci : 1.011.16 ) in model 4 .
finally , the disparity in frequent insufficient sleep was no longer significant after adding fmd in model 5 ( pr = 1.05 ; 95% ci : 0.991.13 ) .
this is the first investigation to document the excess prevalence of frequent insufficient sleep among ai / an relative to other race / ethnicity groups . over 34% of ai / an reported frequent insufficient sleep 14 days in the past month in contrast to 29% of nhb , 27% of nhw , and 25% of hispanics .
the disparity in frequent insufficient sleep prevalence between ai / an and nhw remained even after we adjusted for recognized sleep correlates that included sociodemographic characteristics , lifestyle behaviors , and obesity .
however , we also found that this disparity was attributable , in part , to the relatively high rate of fmd in the ai / an population .
notably , previous sleep research in this population has largely been limited to the identification of factors associated with the increased prevalence of sudden infant death syndrome [ 1618 ] and has documented the prevalence of sleep disturbance among ai / an veterans .   other research on sleep health in ai / an suggests possible implications of the results of the present investigation .
specifically , noting that cardiovascular disease ( cvd ) is the leading cause of death among ai / an , sabanayagam et al .  
assessed both symptoms of insomnia  including short sleep duration  and self - reported cvd among 449 ai / an aged 55 years of age in the native elder care study .
notably , these investigators found that relative to participants reporting a 7-hour sleep duration , the multivariable odds ratio for cvd of those with a sleep duration 5 hours was 2.89 ( 95% ci : 1.177.16 ) , after adjusting for demographic , lifestyle , and clinical factors .
these results suggest that the excess insufficient sleep documented in the present investigation could manifest itself in the increased risk for cvd - related morbidity and mortality in the ai / an population . in a review of the literature
metabolic cost ,  and triggers a cascade of metabolic , neuroendocrine , and behavioral changes designed to increase food consumption and decrease energy expenditure , thereby giving rise to obesity .
the excess insufficient sleep observed in this study may thus underlie findings indicating that ai / an are at increased risk of obesity relative to other race / ethnicity groups [ 2325 ] .
furthermore , as diabetes is associated with obesity [ 2629 ] , our findings may describe a heretofore unrecognized risk factor underlying the increased rate of diabetes among ai / an [ 3032 ] .  
first , our measure of frequent insufficient sleep was based on subjective self - report and is not corroborated by actigraphy or polysomnography .
second , the wording of the insufficient sleep question includes both the terms  rest  and  sleep ,  thereby being potentially subject to varying interpretations among respondents .
third , our sample is limited to only households with landline telephones and to respondents residing in noninstitutionalized settings ; thus , our findings may not be generalizable to the overall us population .
our finding of excess insufficient sleep among ai / an thus appears to confirm the importance of sleep health to chronic disease prevention and health promotion in this population .
specifically , assessment of sleep sufficiency appears particularly germane to healthcare providers serving this population , as well as to public health messaging targeting sleep health ( including sleep correlates ) in ai / an communities .
available interventions designed to promote awareness of the importance of sufficient sleep include a  summary for patients  describing the influence of both diet and sufficient sleep on efforts to lose weight , as well as cognitive behavioral therapy for insomnia [ 34 , 35 ] , with the latter improving both subjective and objective sleep quality , as measured by polysomnography .
finally , as fmd appears associated with frequent insufficient sleep among ai / an , mental health assessment and intervention emerge as important components in the evaluation of insufficient sleep in this population .
 
 objective . frequent insufficient sleep , defined as 14 days / past 30 days in which an adult did not get enough rest or sleep , is associated with adverse mental and physical health outcomes . 
 little is known about the prevalence of frequent insufficient sleep among american indians / alaska natives ( ai / an ) . 
 methods . 
 we assessed racial / ethnic differences in the prevalence of frequent insufficient sleep from the combined 2009 - 2010 behavioral risk factor surveillance survey among 810,168 respondents who self - identified as non - hispanic white ( nhw , n = 671,448 ) , non - hispanic black ( nhb , n = 67,685 ) , hispanic ( 
 n = 59,528 ) , or ai / an ( n = 11,507 ) . results . 
 we found significantly higher unadjusted prevalences ( 95% ci ) of frequent insufficient sleep among ai / an ( 34.2% [ 32.136.4 ] ) compared to nhw ( 27.4% [ 27.127.6 ] ) . 
 however , the age - adjusted excess prevalence of frequent insufficient sleep in ai / an compared to nhw was decreased but remained significant with the addition of sex , education , and employment status ; this latter relationship was further attenuated by the separate additions of obesity and lifestyle indicators , but was no longer significant with the addition of frequent mental distress to the model ( pr  =  1.05 ; 95% ci  :  0.991.13 ) . 
 this is the first report of a high prevalence of frequent insufficient sleep among ai / an . 
 these results further suggest that investigation of sleep health interventions addressing frequent mental distress may benefit ai / an populations . 