The effect of a vegetarian versus conventional hypocaloric diet on serum concentrations of persistent organic pollutants in patients with type 2 diabetes.
The aim of this study was to explore the effect of a vegetarian versus conventional diet on the serum levels of persistent organic pollutants (POPs) in patients with T2D after 12 weeks of dietary intervention and to assess their relationships with metabolic parameters.



Men and women with T2D were randomly assigned to follow either a vegetarian diet without fish or meat (n = 37) or an isocaloric conventional antidiabetic diet (n = 37). Both diets were energy restricted (minus 500 kcal/day). All foods were provided to the participants. At randomization (week 0) and 12 weeks, the meal test was performed to assess the β-cell function and serum levels of 24 POPs. Dioxins and dioxin-like POPs were analyzed by isotope dilution high-resolution gas chromatography (HRGC) and mass spectrometry after cleanup of the silica and carbon columns. Non-dioxin-like POPs were analyzed by gas chromatography with an electron capture detector (GC-ECD). Statistical analyses used were repeated-measures analysis of variance (ANOVA), a multivariate regression model, and Pearson's correlations. We observed a statistically nonsignificant trend toward increases in the serum levels of most POPs in response to both hypocaloric diets with no differences between groups. In the groups combined, the change in serum concentrations of total POPs was correlated to changes in HbA1c (r = +0.34; p < 0.01), fasting plasma glucose (r = +0.41; p < 0.01) levels, and β-cell function measured as insulin secretion at a reference glucose level (r = -0.37; p < 0.01), independent of the changes in body weight and volume of visceral fat.



Short-term hypocaloric vegetarian and conventional diets did not reduce the POP levels, possibly due to mobilization of fat stores. Our findings support the relationship between POPs and diabetes, especially β-cell function.



ClinicalTrials.gov number, NCT00883038, completed.
Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech Republic. Electronic address: hana.kahleova@gmail.com.
H
H
Kahleova
Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway.
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S
Tonstad
State Veterinary Institute Prague, Sidlistni 24, 165 03 Prague, Czech Republic.
J
J
Rosmus
State Veterinary Institute Prague, Sidlistni 24, 165 03 Prague, Czech Republic.
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P
Fisar
C.N.R. (National Research Council) Institute of Systems Science and Biomedical Engineering, Padua, Italy.
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A
Mari
Institute of Endocrinology, Narodni 8, 11394 Prague, Czech Republic.
M
M
Hill
Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech Republic.
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T
Pelikanova
D050154:Adiposity; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D031204:Caloric Restriction; D018153:Czech Republic; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000178:diet therapy* / Q000503:physiopathology; D004038:Diet, Reducing; D014676:Diet, Vegetarian; D004147:Dioxins / Q000009:adverse effects / Q000097:blood*; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000009:adverse effects / Q000097:blood*; D005260:Female; D005506:Food Contamination; D008401:Gas Chromatography-Mass Spectrometry; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D050417:Insulin-Secreting Cells / Q000378:metabolism; D050152:Intra-Abdominal Fat / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss
D015415:Biomarkers; D001786:Blood Glucose; D004147:Dioxins; D004785:Environmental Pollutants; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human
Persistent organic pollutants; Type 2 diabetes; Vegetarian diet