title: Health impact of fasting in Saudi Arabia during Ramadan: association with disturbed circadian rhythm and metabolic and sleeping patterns.
abstract: BACKGROUND
  Muslims go through strict Ramadan fasting from dawn till sunset for one month yearly. These practices are associated with disturbed feeding and sleep patterns. We recently demonstrated that, during Ramadan, circadian cortisol rhythm of Saudis is abolished, exposing these subjects to continuously increased cortisol levels.
  
  
  OBJECTIVE
  Secretory patterns of other hormones and metabolic parameters associated with cortisol, and insulin resistance, might be affected during Ramadan.
  
  
  METHODS
  Ramadan practitioners (18 males, 5 females; mean age ±SEM = 23.16±1.2 years) were evaluated before and two weeks into Ramadan. Blood was collected for measurements of endocrine and metabolic parameters at 9 am (±1 hour) and again twelve hours later.
  
  
  RESULTS
  In Ramadan, glucose concentration was kept within normal range, with a significant increase in the morning. Mean morning concentration of leptin was significantly higher than pre-Ramadan values (p = 0.001), in contrast to that of adiponectin, which was significantly lower (p<0.001). These changes were associated with increased insulin resistance in morning and evening. Concentrations of hsCRP were lower during Ramadan than those during regular living conditions, however, normal circadian fluctuation was abolished (p = 0.49). Even though means of liver enzymes, total bilirubin, total protein and albumin were all decreased during Ramadan, statistically lower means were only noted for GGT, total protein, and albumin (p = 0.018, 0.002 and 0.001 respectively).
  
  
  CONCLUSIONS
  Saudi Ramadan practitioners have altered adipokine patterns, typical of insulin resistance. The noted decreases of hsCRP, liver enzymes, total protein, and albumin, are most likely a result of fasting, while loss of circadian rhythmicity of hsCRP is probably due to loss of circadian cortisol rhythm.
  
  
  CONCLUSIONS
  Modern Ramadan practices in Saudi Arabia, which are associated with evening hypercortisolism, are also characterized by altered adipokines patterns, and an abolished hsCRP circadian rhythm, all likely to increase cardiometabolic risk.
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Ghada M
authors.initials: GM
authors.lastname: Ajabnoor
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Suhad
authors.initials: S
authors.lastname: Bahijri
authors.affiliation: Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; King Abdullah International Medical Research Center (KAIMRC), College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Jeddah, Saudi Arabia.
authors.forename: Anwar
authors.initials: A
authors.lastname: Borai
authors.affiliation: Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Clinical Biochemistry, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia.
authors.forename: Altaf A
authors.initials: AA
authors.lastname: Abdulkhaliq
authors.affiliation: Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; Princess Al-Jawhara Al Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Jumana Y
authors.initials: JY
authors.lastname: Al-Aama
authors.affiliation: Saudi Diabetes Study Research Group, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; First Department of Pediatrics, University of Athens Medical School, "Aghia Sophia" Children's Hospital, Athens, Greece.
authors.forename: George P
authors.initials: GP
authors.lastname: Chrousos
mesh_terms: D001786:Blood Glucose; D002940:Circadian Rhythm / Q000502:physiology*; D005215:Fasting / Q000097:blood*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007514:Islam; D008297:Male; D012529:Saudi Arabia; D012890:Sleep / Q000502:physiology*; D020178:Sleep Disorders, Circadian Rhythm / Q000097:blood / Q000503:physiopathology; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006854:Hydrocortisone