A fish-based diet intervention improves endothelial function in postmenopausal women with type 2 diabetes mellitus: a randomized crossover trial.
OBJECTIVE
The beneficial effects of fish and n-3 polyunsaturated fatty acids (PUFAs) consumption on atherosclerosis have been reported in numerous epidemiological studies. However, to the best of our knowledge, the effects of a fish-based diet intervention on endothelial function have not been investigated. Therefore, we studied these effects in postmenopausal women with type 2 diabetes mellitus (T2DM).


METHODS
Twenty-three postmenopausal women with T2DM were assigned to two four-week periods of either a fish-based diet (n-3 PUFAs ≧ 3.0 g/day) or a control diet in a randomized crossover design. Endothelial function was measured with reactive hyperemia using strain-gauge plethysmography and compared with the serum levels of fatty acids and their metabolites. Endothelial function was determined with peak forearm blood flow (Peak), duration of reactive hyperemia (Duration) and flow debt repayment (FDR).


RESULTS
A fish-based dietary intervention improved Peak by 63.7%, Duration by 27.9% and FDR by 70.7%, compared to the control diet. Serum n-3 PUFA levels increased after the fish-based diet period and decreased after the control diet, compared with the baseline (1.49 vs. 0.97 vs. 1.19 mmol/l, p < 0.0001). There was no correlation between serum n-3 PUFA levels and endothelial function. An increased ratio of epoxyeicosatrienoic acid/dihydroxyeicosatrienoic acid was observed after a fish-based diet intervention, possibly due to the inhibition of the activity of soluble epoxide hydrolase.


CONCLUSIONS
A fish-based dietary intervention improves endothelial function in postmenopausal women with T2DM. Dissociation between the serum n-3 PUFA concentration and endothelial function suggests that the other factors may contribute to this phenomenon.
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Keiko
K
Kondo
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan. Electronic address: morino@belle.shiga-med.ac.jp.
Katsutaro
K
Morino
Department of Diabetes and Endocrine Medicine, Division of Human and Environmental Sciences, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
Yoshihiko
Y
Nishio
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Motoyuki
M
Kondo
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Keiko
K
Nakao
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan; Osaka Laboratory, JCL Bioassay Corporation, Osaka, Japan.
Fumiyuki
F
Nakagawa
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan; R&D Department, Sunstar Inc, Osaka, Japan.
Atsushi
A
Ishikado
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Osamu
O
Sekine
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Takeshi
T
Yoshizaki
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Atsunori
A
Kashiwagi
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Satoshi
S
Ugi
Department of Medicine, Division of Endocrinology and Metabolism, Shiga University of Medical Science, Shiga, Japan.
Hiroshi
H
Maegawa
D000368:Aged; D000375:Aging; D000818:Animals; D050197:Atherosclerosis / Q000150:complications / Q000517:prevention & control*; D015331:Cohort Studies; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism / Q000503:physiopathology; D003925:Diabetic Angiopathies / Q000517:prevention & control*; D015930:Diet Records; D004041:Dietary Fats / Q000032:analysis / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use; D015777:Eicosanoids / Q000097:blood / Q000378:metabolism; D004730:Endothelium, Vascular / Q000503:physiopathology*; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use; D005260:Female; D005399:Fishes; D006801:Humans; D007564:Japan; D008875:Middle Aged; D017698:Postmenopause; D017747:Seafood / Q000032:analysis
D004041:Dietary Fats; D015777:Eicosanoids; D015525:Fatty Acids, Omega-3
Diabetes mellitus; Diet; Endothelial function; Intervention studies; n-3 PUFA