title: Simultaneous coffee caffeine intake and sleep deprivation alter glucose homeostasis in Iranian men: a randomized crossover trial.
abstract: OBJECTIVE
  Sleep deprivation and coffee caffeine consumption have been shown to affect glucose homeostasis separately, but the combined effects of these two variables are unknown.
  
  
  METHODS
  Forty-two healthy Iranian men, aged 20-40 years old, were assigned to three groups in a randomised crossover trial involving three treatments with two-week washout periods. Subjects were moderate coffee consumers (<=3 cups/day), and had a Pittsburgh Sleep Quality Index <=5. Each treatment involved three nights of deprived sleep (4 hrs. in bed) plus 3×150 cc/cup of boiled water (BW treatment), decaffeinated coffee (DC treatment, without sugar, 99.9% caffeine-free), and caffeinated coffee (CC treatment, without sugar, 65 mg caffeine/ cup). DC and CC treatments were blinded. At the end of each treatment, fasting serum glucose (using enzyme assays) and insulin (using electrochemiluminescence immunoassay) were measured and, again, two hours after an oral glucose tolerance test (OGTT). Insulin resistance was quantified with the homeostasis model.
  
  
  RESULTS
  Repeated measures ANOVA indicated no significant difference between the treatments in fasting serum glucose (p=0.248) or insulin resistance (p=0.079). However, ANOVA demonstrated differences between treatments in fasting serum insulin (p=0.004) and glucose, as well as insulin after OGTT (p<0.001). Pairwise comparisons test (within subjects) showed that the CC treatment yielded higher serum glucose and insulin after OGTT (p<0.001), higher fasting serum insulin (p=0.001), and increased insulin resistance (p=0.039) as compared to the DC treatment.
  
  
  CONCLUSIONS
  Thus caffeinated coffee was more adverse for glucose homeostasis compared to decaffeinated coffee in individuals who were simultaneously sleep deprived.
authors.affiliation: Nutritional Sciences Programme, School of Healthcare Sciences, Faculty of Health Sciences, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
authors.forename: Behrouz
authors.initials: B
authors.lastname: Rasaei
authors.affiliation: Nutritional Sciences Programme, School of Healthcare Sciences, Faculty of Health Sciences, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
authors.forename: Ruzita Abd
authors.initials: RA
authors.lastname: Talib
authors.affiliation: School of Hospitality, Tourism and Culinary Arts, Taylors University, Selangor, Malaysia.
authors.forename: Mohd Ismail
authors.initials: MI
authors.lastname: Noor
authors.affiliation: Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishpur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Karandish
authors.affiliation: Nutritional Sciences Programme, School of Healthcare Sciences, Faculty of Health Sciences, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia. Email: norimahkarim@ukm.edu.my; nak@fsk.ukm.my.
authors.forename: Norimah A
authors.initials: NA
authors.lastname: Karim
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects*; D003069:Coffee; D018592:Cross-Over Studies; D005215:Fasting; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007492:Iran; D008297:Male; D012892:Sleep Deprivation / Q000150:complications*
chemical_list: D001786:Blood Glucose; D003069:Coffee; D007328:Insulin; D002110:Caffeine