Cardiovascular and Metabolic Functioning in Habitual Short Sleepers (CHARTS Study)

There is growing evidence from epidemiological and experimental studies that individuals who report short sleep are at risk for a number of adverse cardiovascular and metabolic outcomes. The proposed study is the first step in a larger program of research that will bridge the existing epidemiologic and experimental literatures and develop behavioral interventions for insufficient sleep. Forty (40) subjects will be recruited and assessed (about 26 short and 14 normal duration sleepers), following an on-line survey, in two phases. Phase 1 will include a 2-week, home-based study, and Phase 2 will include a 3-night, in-lab study. Phase 1 will assess subjective and objective sleep at home to prospectively corroborate survey responses and screen for sleep disordered breathing. Also, Phase 1 will include a 24-hour recording of ambulatory measures of blood pressure. Phase 2 will gather lab-based measures of sleep (polysomnography, 1 night each habitual and unlimited sleep opportunity; and actigraphy monitoring), sleepiness (sleep propensity), psychomotor performance (Psychomotor Vigilance Task), aortic pulse wave velocity (arterial tonometry), cognitive functioning (a battery of neurocognitive testing), glucose homeostasis (an Oral Glucose Challenge Test) and several cardiometabolic biomarkers including atherogenic lipoproteins (i.e., HDL and LDL), IL-6, CRP, leptin and ghrelin. These lab-based data will be used to (1) determine whether short and normal duration sleepers differ on objective measures of sleep and sleepiness/performance and cardiometabolic function, as well as (2) explore whether subgroups within the short sleeper cohort account for the association between sleep duration and health. This will lead to future studies with the purpose of developing behavioral interventions

Study phase: N/A

Basic eligibility criteria:
Please contact the study coordinator for additional eligibility information.

All subjects may participate in the screening survey. The validity of study inferences depend on the selection of the sample from survey respondents. We debated several strategies for minimizing various types of selection bias in this observational study and have chosen to adopt a principled strategy designed to produce groups in which the expected distribution of the observed covariates are identical for subjects chosen to be in the short sleep or normal sleep groups admitted to the study. Though we will choose methods based on the nature of the survey data, one approach is the Nearest Available Mahalanobis metric, matching within calipers defined by the propensity score320.
Subjects invited into the study must also be willing to participate in a protocol that requires a 1-night home sleep screening, 24-hour blood pressure, 2 weeks of home monitoring, 3 overnights in the Sleep Research Laboratory, 1 day in the Sleep Research Laboratory (administration of the MSLT and PVT), and one visit to CATS for the OGTT (which requires blood work). This inclusive approach is to allow for a proper exploration of the factors that may contribute to, account for, (without any presupposition) the short sleep phenomenon.
Forty (40) subjects will be enrolled into this study. All subjects will be adults between the ages of 25-60 years of age who are identified as “short sleepers” or “7-8 hour sleepers” in response to a survey during screening. Please note that this study was originally opened at UPenn where 54 subjects were enrolled. This data will be transferred to the UA which will be the single study site going forward.

Key exclusion criteria
All adults age 25-60+ are admitted to Phase-1 study. Exclusion criteria for Phase-2 include:
1. Failure to commit to the study. The subjects willingness to commit to the protocol which includes 3 nights and one day in the Sleep Center in BUMCT Pulmonary and one morning at the Clinical and Translational Research Center (CATS). This will be assessed during the informed consent process. This will help ensure compliance and (ideally) reduce dropout.
2. Signs or Symptoms of Insomnia or Phase Advance/Delay Syndrome will be assessed with the STQ and ISI. This will be to assure that the subjects recruited for Phase-2 of the study are not short sleepers owing to these factors.
3. Unstable medical or psychiatric illness will be assessed with SAFTEE, PHQ-9. GAD7 and MINI. This will be to assure that these factors do not confound the in-lab assessments.
4. Evidence of active illicit substance use or fitting criteria for alcohol abuse or dependence will be assessed with a structured psychiatric interview schedule (the MINI), written versions of clinical interview queries regarding alcohol abuse and dependence (the AUDIT and CAGE), and a toxicology screen which is part of the clinical chemistries obtained at CATS. This will be to assure that these factors do not confound the in-lab assessments.
5. Inadequate language comprehension will be assessed informally by the Clinical Research Coordinator during Intake Interview, to assure the quality of self-report data as all of the measures are in English.
6. Pregnancy will be assessed by self-report and from the clinical chemistries data obtained during the CATS visit, to assure that 1) the fetus is not exposed to the procedures involved with the study and 2) the biopsychosocial changes that occur with pregnancy do not confound the in-lab assessments.
7. Failure to exhibit a reliable sleep pattern over the two week prospective assessment will be assessed using the sleep diaries during the home monitoring period. Subjects that do not complete 12 of 14 dairies or subjects that exhibit sleep profiles that do not corroborate their retrospective report (based on the internet survey) will not be invited to continue in the study (PSG, MSLT, OGTT data will not be collected on this individuals). Actigraphy will be used to screen out individuals that are unreliable historians or people that enroll as professional subjects (disqualifying those with 1hrdiscordance between sleep diary and actigraphic total sleep time).
8. Sleep apnea will be assessed initially using a predictive equation using the MAP and demographic data234, and by home screening with an Embletta235 monitor. This monitor is the clinical standard of care for use in assessing sleep apnea. This will ensure that the subjects recruited for Phase-2 of the study are not short sleepers owing to sleep apnea, and impairments do not reflect the effects of this condition. All subjects with an AHI 5 will be informed of these results and referred for further evaluation and treatment for sleep apnea at the Sleep Center at BUMCT.

No vulnerable populations will be included in this research

Primary disease category: Sleep Disorders

This study is enrolling healthy volunteers.

Sponsor: NIH

Projected enrollment dates: November 2015 to December 2019

Official study title: Cardiovascular and Metabolic Functioning in Habitual Short Sleepers (CHARTS Study)