title: Endocrine and metabolic diurnal rhythms in young adult men born small vs appropriate for gestational age.
abstract: OBJECTIVE
  Sleep disturbances and alterations of diurnal endocrine rhythms are associated with increased risk of type 2 diabetes (T2D). We previously showed that young men born small for gestational age (SGA) and with increased risk of T2D have elevated fat and decreased glucose oxidation rates during nighttime. In this study, we investigated whether SGA men have an altered diurnal profile of hormones, substrates and inflammatory markers implicated in T2D pathophysiology compared with matched individuals born appropriate for gestational age (AGA).
  
  
  METHODS
  We collected hourly blood samples for 24 h, to measure levels of glucose, free fatty acids (FFA), triglycerides (TG), insulin, C-peptide, leptin, resistin, ghrelin, plasminogen activator inhibitor-1 (PAI-1), incretins (GLP-1 and GIP), and inflammatory markers (TNF-α and IL-6) in 13 young men born SGA and 11 young men born AGA.
  
  
  RESULTS
  Repeated measurements analyses were used to analyze the diurnal variations and differences between groups. The SGA subjects had increased 24-h glucose (P=0.03), glucagon (P=0.03) and resistin (P=0.003) levels with no difference in diurnal rhythms compared with AGA controls. We found significant diurnal variations in levels of blood glucose, plasma TG, FFA, insulin, C-peptide, GLP-1, GIP, leptin, visfatin, TNF-α, IL-6 and PAI-1. The variation in FFA levels differed between the groups during the evening. Plasma ghrelin and glucagon levels did not display diurnal variations.
  
  
  CONCLUSIONS
  Young men born SGA exhibit elevated 24-h blood glucose, and plasma glucagon and resistin levels with no major differences in diurnal rhythms of these or other key metabolic hormones, substrates or inflammatory markers implicated in the origin of adiposity and T2D.
authors.affiliation: Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark Steno Diabetes CenterGentofte, Denmark charlotte.broens@regionh.dk.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Brøns
authors.affiliation: Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark.
authors.forename: Pernille N
authors.initials: PN
authors.lastname: Saltbæk
authors.affiliation: Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark Steno Diabetes CenterGentofte, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Friedrichsen
authors.affiliation: Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark Steno Diabetes CenterGentofte, Denmark.
authors.forename: Allan
authors.initials: A
authors.lastname: Vaag
mesh_terms: D001786:Blood Glucose; D002096:C-Peptide / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005865:Gestational Age; D054439:Ghrelin / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007328:Insulin / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D020738:Leptin / Q000097:blood; D008297:Male; D052243:Resistin / Q000097:blood; D014280:Triglycerides / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D005230:Fatty Acids, Nonesterified; D054439:Ghrelin; D007328:Insulin; D015850:Interleukin-6; D020738:Leptin; C499624:RETN protein, human; D052243:Resistin; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; D052216:Glucagon-Like Peptide 1