title: Consumption of vitamin D-fortified yogurt drink increased leptin and ghrelin levels but reduced leptin to ghrelin ratio in type 2 diabetes patients: a single blind randomized controlled trial.
abstract: OBJECTIVE
  This study aimed to evaluate the effect of daily consumption of vitamin D-fortified yogurt drink (doogh) in comparison with plain doogh on appetite-regulating hormones including leptin and ghrelin in type 2 diabetes (T2D) patients.
  
  
  METHODS
  In a single blind randomized clinical trial, subjects with T2D were randomly allocated to one of the two groups and received either vitamin D3-fortified doogh (FD; containing 170 mg calcium and 500 IU/250 mL, n2= 50) or plain doogh (PD; containing 170 mg calcium and no vitamin D/250 mL, n1= 50) twice a day for 12 weeks. Leptin and ghrelin were evaluated at the beginning and after 12 weeks of intervention.
  
  
  RESULTS
  The intervention resulted in a significant improvement of circulating 25(OH)D, fasting glucose, Quantitative Insulin Check Index (QUICKI), hs-CRP, in FD compared with PD group. A significant rise in both serum leptin (+1.3 ± 7.2 mg/L; p = 0.013) and ghrelin (10.1 ± 26.1 ng/L; p = 0.012) was observed in FD group. A between-group difference for ghrelin changes (p = 0.029) remained significant after adjusting for changes QUICKI (p = 0.039), body mass index (p = 0.034) and hs-CRP (p = 0.022). Despite an increase in both leptin and ghrelin, leptin to ghrelin (L/G) ratio actually decreased in FD. Changes of L/G ratio showed a significant between-group difference (p = 0.036), which remained significant even after adjusting for changes of hs-CRP (p = 0.028) and fat mass (p = 0.047) but disappeared after adjusting for changes of QUICKI (p = 0.42).
  
  
  CONCLUSIONS
  Daily intake of vitamin D-fortified doogh may increase circulating leptin and ghrelin but L/G ratio may actually decrease. Our results suggest that improving vitamin D may result in an improvement in insulin sensitivity which may finally regulate beneficially appetite hormones. Further studies with adequate power are needed to confirm the results.
authors.affiliation: Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, 19395-4763, Iran.
authors.forename: Mina
authors.initials: M
authors.lastname: Hajimohammadi
authors.affiliation: Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, 19395-4763, Iran. s_shabbidar@tums.ac.ir.
authors.forename: Sakineh
authors.initials: S
authors.lastname: Shab-Bidar
authors.affiliation: Laboratory of Nutrition Research, National Research Institute and Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. t.neyestani@nnftri.ac.ir.
authors.forename: Tirang R
authors.initials: TR
authors.lastname: Neyestani
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002136:Calcium, Dietary / Q000008:administration & dosage; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004032:Diet; D005260:Female; D005527:Food, Fortified; D054439:Ghrelin / Q000097:blood; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D016037:Single-Blind Method; D014807:Vitamin D / Q000008:administration & dosage*; D015014:Yogurt
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D002097:C-Reactive Protein; D002136:Calcium, Dietary; D054439:Ghrelin; D006442:Glycated Hemoglobin; D020738:Leptin; D014807:Vitamin D
keywords: Ghrelin; Leptin; Type 2 diabetes; Vitamin D