title: Effects of intermittent fasting on serum lipid levels, coagulation status and plasma homocysteine levels.
abstract: BACKGROUND
  During Ramadan, Muslims fast during the daylight hours for a month. The duration of restricted food and beverage intake is approximately 12 h/day which makes Ramadan a unique model of intermittent fasting. Many physiological and psychological changes are observed during Ramadan that are probably due to the changes in eating and sleeping patterns.
  
  
  METHODS
  Serum total cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), prothrombin time, activated partial thromboplastin time (aPTT), plasma fibrinogen, D-dimer and homocysteine levels were measured in 24 healthy fasting volunteers (12 females, 12 males) aged 21-35 years. Venous blood samples were taken 1 week before Ramadan, on the 21st day of Ramadan and 20 days after Ramadan.
  
  
  RESULTS
  No significant changes were observed on serum total cholesterol, triglycerides and LDL levels. HDL levels were significantly elevated during Ramadan (p < 0.001) and 20 days after Ramadan (p < 0.05). Prothrombin time, aPTT, fibrinogen and D-dimer levels were in the physiologic limits in all samples but D-dimer levels were significantly low at the end of Ramadan in comparison to pre- and post-fasting levels (p < 0.001). Homocysteine levels, being still in reference ranges, were low during Ramadan (p < 0.05) and reached the pre-fasting levels after Ramadan.
  
  
  CONCLUSIONS
  Our results demonstrate that intermittent fasting led to some beneficial changes in serum HDL and plasma homocysteine levels, and the coagulation status. These changes may be due to omitting at least one meal when the body was particularly metabolically active and possibly had a low blood viscosity level at the same time. We conclude that intermittent fasting may have beneficial effects on hemostatic risk markers for cardiovascular diseases.
authors.affiliation: Department of Biochemistry, School of Medicine, Maltepe University, Istanbul, Turkey. fehimebenli@hotmail.com
authors.forename: Fehime Benli
authors.initials: FB
authors.lastname: Aksungar
authors.forename: Aynur
authors.initials: A
authors.lastname: Eren
authors.forename: Sengul
authors.initials: S
authors.lastname: Ure
authors.forename: Onder
authors.initials: O
authors.lastname: Teskin
authors.forename: Gursel
authors.initials: G
authors.lastname: Ates
mesh_terms: D000328:Adult; D001777:Blood Coagulation / Q000502:physiology*; D002784:Cholesterol / Q000097:blood; D005215:Fasting / Q000097:blood*; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005340:Fibrinogen / Q000032:analysis; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007514:Islam; D008055:Lipids / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D010314:Partial Thromboplastin Time / Q000379:methods; D011517:Prothrombin Time / Q000379:methods; D012016:Reference Values; D012890:Sleep / Q000502:physiology; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D008055:Lipids; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; C036309:fibrin fragment D; D006710:Homocysteine; D005340:Fibrinogen; D002784:Cholesterol