title: Reduction of specific circulating lymphocyte populations with metabolic risk factors in patients at risk to develop type 2 diabetes.
abstract: Low-grade inflammation, characterized by increased pro-inflammatory cytokine levels, is present in patients with obesity-linked insulin resistance, hyperglycemia and hyperlipidemia and considered to play a leading role to progression into type 2 diabetes (T2D). In adipose tissue in obese patients and in pancreatic islets in T2D patients cellular inflammation is present. However, the systemic leukocyte compartment and the circulating endothelial/precursor compartment in patients at risk to develop T2D has so far not been analyzed in detail. To address this, peripheral blood cells from a cohort of 20 subjects at risk to develop diabetes with normal to impaired glucose tolerance were analyzed by flow cytometry using a wide range of cellular markers and correlated to known metabolic risk factors for T2D i.e. fasting plasma glucose (FPG), 2 h plasma glucose (2 h PG), HbA1c, body mass index (BMI), homeostasis model assessment of β-cell function (HOMA-B), homeostasis model assessment of insulin sensitivity (HOMA-IS) and fasting insulin (FI). The four highest ranked cell markers for each risk factor were identified by random forest analysis. In the cohort, a significant negative correlation between the number of TLR4(+) CD4 T cells and increased FPG was demonstrated. Similarly, with increased BMI the frequency of TLR4(+) B cells was significantly decreased, as was the frequency of IL-21R(+) CD4 T cells. Unlinked to metabolic risk factors, the frequency of regulatory T cells was reduced and TLR4(+) CD4 T cells were increased with age. Taken together, in this small cohort of subjects at risk to develop T2D, a modulation of the circulating immune cell pool was demonstrated to correlate with risk factors like FPG and BMI. This may provide novel insights into the inflammatory mechanisms involved in the progression to diabetes in subjects at risk.
authors.affiliation: Hagedorn Research Institute. Department of Diabetic Complications Biology Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Helena
authors.initials: H
authors.lastname: Cucak
authors.affiliation: Department of Clinical Epidemiology, Steno Diabetes Center, Gentofte, Denmark.
authors.forename: Dorte
authors.initials: D
authors.lastname: Vistisen
authors.affiliation: Department of Clinical Epidemiology, Steno Diabetes Center, Gentofte, Denmark.
authors.forename: Daniel
authors.initials: D
authors.lastname: Witte
authors.affiliation: Department of Clinical Epidemiology, Steno Diabetes Center, Gentofte, Denmark.
authors.forename: Annelotte
authors.initials: A
authors.lastname: Philipsen
authors.affiliation: Hagedorn Research Institute. Department of Diabetic Complications Biology Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rosendahl
mesh_terms: D000375:Aging / Q000276:immunology; D001786:Blood Glucose / Q000378:metabolism; D002452:Cell Count; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000276:immunology*; D004435:Eating; D066026:Endothelial Progenitor Cells / Q000166:cytology; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology; D012307:Risk Factors; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism
chemical_list: D001786:Blood Glucose; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4