Caffeine consumption, insomnia and sleep duration: Results from a nationally representative sample

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Vol. 32; no. 11-12; pp. 1193 - 1199
• Main Authors: Chaudhary, Ninad S., MBBS, MPH, Grandner, Michael A., PhD, MTR, Jackson, Nicholas, MPH, Chakravorty, Subhajit, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2016; Elsevier Limited
• Subjects: Adult; Anxiety; Caffeine; Caffeine - administration & dosage; Caffeine - adverse effects; Central Nervous System Stimulants - administration & dosage; Central Nervous System Stimulants - adverse effects; Coffee; College students; Consumption; Female; Gastroenterology and Hepatology; Humans; Insomnia; Laboratories; Male; Middle age; Middle Aged; Military personnel; Nutrition Surveys; Population; Prevalence; Regression analysis; Sleep; Sleep - drug effects; Sleep - physiology; Sleep deprivation; Sleep Initiation and Maintenance Disorders - epidemiology; Sleep Initiation and Maintenance Disorders - etiology; Sleep Initiation and Maintenance Disorders - physiopathology; Sleep initiation and maintenance disturbance; Studies; United States - epidemiology; Young Adult; sleep deprivation; and anxiety; sleep initiation and maintenance disturbance; Caffeine; population; Sleep initiation and maintenance disturbance; Population; Anxiety; Sleep deprivation
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2016.04.005

Abstract Objective Insomnia symptoms have been individually associated with both caffeine consumption and sleep duration abnormalities in prior studies. In this investigation, we evaluated whether caffeine consumption was associated with insomnia symptoms, from a population perspective. We also explored if this relationship between insomnia symptoms and caffeine consumption depended on habitual sleep duration. Research Methods & Procedures Data was extracted from the 2007-2008 National Health and Nutritional Examination Survey (NHANES,N=4730). Caffeine consumption was quantified as milligrams/day (mg/d) from two typical days of use, 7-10 days apart. Insomnia symptoms were evaluated using frequencies of difficulty falling asleep (DFA), difficulty staying asleep (DSA), non-restful sleep (NRS), and daytime sleepiness (DS). Habitual sleep duration (SD) was assessed as the hours of sleep obtained on a typical night. Binomial logistic regression analysis evaluated the relationships of individual insomnia and sleepiness symptoms (DFA, DSA, NRS and DS) with caffeine consumption and sleep duration variables, after adjusting for covariates. Results The mean±S.D. caffeine consumption was 176.6±201.0 mg/day, whereas that for habitual sleep duration was 6.8±1.4 hours. Insomnia symptoms were prevalent in 19.1-28.4% of the respondents. Although caffeine consumption was associated with all insomnia symptoms in the unadjusted models, the adjusted models demonstrated a trend towards significance with DSA. SD was inversely associated with the insomnia symptoms in unadjusted and adjusted analysis. Finally, NRS was associated with an interaction of increased caffeine consumption on sleep duration. Conclusion The association between caffeine use and insomnia symptoms depends on the habitual sleep duration at a population level.