Glycine treatment decreases proinflammatory cytokines and increases interferon-gamma in patients with type 2 diabetes.
BACKGROUND
Amino acids have been shown to stimulate insulin secretion and decrease glycated hemoglobin (A1C) in patients with Type 2 diabetes. In vitro, glycine reduces tumor necrosis factor (TNF)-alpha secretion and increases interleukin-10 secretion in human monocytes stimulated with lipopolysaccharide. The aim of this study was to determine whether glycine modifies the proinflammatory profiles of patients with Type 2 diabetes.


METHODS
Seventy-four patients, with Type 2 diabetes were enrolled in the study. The mean age was 58.5 yr, average age of diagnosis was 5 yr, the mean body mass index was 28.5 kg/m2, the mean fasting glucose level was 175.5 mg/dl and the mean A1C level was 8%. They were allocated to one of two treatments, 5 g/d glycine or 5 g/d placebo, po tid, for 3 months.


RESULTS
A1C levels of patients given glycine were significantly lower after 3 months of treatment than those of the placebo group. A significant reduction in TNF-receptor I levels was observed in patients given glycine compared with placebo. There was a decrease of 38% in the interferon (IFN)-gamma level of the group treated with placebo, whereas that of the group treated with glycine increased up to 43%. These data showed that patients treated with glycine had a significant decrease in A1C and in proinflammatory cytokines and also an important increase of IFN-gamma.


CONCLUSIONS
Treatment with glycine is likely to have a beneficial effect on innate and adaptive immune responses and may help prevent tissue damage caused by chronic inflammation in patients with Type 2 diabetes.
Cruz
M
M
Biochemistry Medical Research Unit, Hospital de Especialidades, Centro Medico Nacional Siglo XXI. IMSS, Col. Doctores. México DF, Mexico City, México. mcruzl@yahoo.com
Maldonado-Bernal
C
C
Mondragón-Gonzalez
R
R
Sanchez-Barrera
R
R
Wacher
N H
NH
Carvajal-Sandoval
G
G
Kumate
J
J
D000368:Aged; D016207:Cytokines / Q000097:blood* / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005998:Glycine / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D018836:Inflammation Mediators / Q000097:blood / Q000378:metabolism; D007371:Interferon-gamma / Q000097:blood* / Q000378:metabolism; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D010919:Placebos; D052243:Resistin / Q000097:blood
D016207:Cytokines; D007004:Hypoglycemic Agents; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D010919:Placebos; D052243:Resistin; D007371:Interferon-gamma; D005998:Glycine