Clinical Trials Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. May 15, 2017; 8(5): 202-212
Published online May 15, 2017. doi: 10.4239/wjd.v8.i5.202
Association between dairy intake, lipids and vascular structure and function in diabetes
Kristina S Petersen, Jennifer B Keogh, Natalie Lister, Jacquelyn M Weir, Peter J Meikle, Peter M Clifton
Kristina S Petersen, Jennifer B Keogh, Natalie Lister, Peter M Clifton, School of Pharmacy and Medical Sciences and Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5000, Australia
Jacquelyn M Weir, Peter J Meikle, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
Author contributions: Petersen KS saw the volunteers, measured the physiological and dietary variables, analysed the data and wrote the first draft; Clifton PM and Keogh JB designed the study, analysed the data and drafted the manuscript; Lister N measured the physiological and dietary variables; Weir JM and Meikle PJ performed the lipidomics; all authors read and approved the final manuscript.
Supported by the Heart Foundation and the Government of South Australia, No. CR 12A 6750 to Keogh JB; NHMRC Principal Research Fellowship, No. APP1125691 to Clifton PM; NHMRC Senior Research Fellowship, No. APP1042095 to Meikle PJ; an Australian Postgraduate Award, No. 138093 to Petersen KS; and a University of South Australia Postgraduate Award, No. 128123 to Lister N.
Institutional review board statement: Ethics approval was obtained from the University of South Australian Human Research Ethics Committee.
Clinical trial registration statement: The trial was registered with the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au/) (ACTRN12613000251729) on 4/09/2014.
Informed consent statement: All the participants provided written informed consent prior to study enrolment.
Conflict-of-interest statement: The authors declare that they have no competing interests.
Data sharing statement: Dataset available from the corresponding author at Jennifer.keogh@unisa.edu.au. Consent for data sharing was not obtained but the data is anonymised and risk of identification is very low.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Jennifer B Keogh, School of Pharmacy and Medical Sciences and Sansom Institute for Health Research, University of South Australia, GPO Box 2471 Adelaide, SA 5000, Australia. jennifer.keogh@unisa.edu.au
Telephone: +61-8-83022579 Fax: +61-8-83022389
Received: October 25, 2016
Peer-review started: October 28, 2016
First decision: December 1, 2016
Revised: December 15, 2016
Accepted: March 12, 2017
Article in press: March 13, 2017
Published online: May 15, 2017
Abstract
AIM

To determine lipid species that change in response to a change in dairy consumption. In addition, to investigate whether dairy associated lipid species are correlated with changes in measures of vascular structure and function.

METHODS

A 12-mo randomised controlled trial was conducted to determine the effect of increased consumption of fruit, vegetables and dairy, compared to usual diet, on measures of vascular structure and function in adults with type 1 and type 2 diabetes (n = 108). This paper comprises post-hoc analyses investigating the relationship between dairy intake, serum lipid species and vascular health. Central and peripheral blood pressure, carotid femoral pulse wave velocity, augmentation index, serum lipid species and dietary intake were measured at baseline and 3-mo. Common carotid artery intima media thickness was measured at baseline and 12-mo.

RESULTS

Serum lipid species [lysophosphatidylcholine (LPC) 14:0, LPC 15:0, LPC 16:1, phosphatidylcholine (PC) 29:0 PC 30:0, PC 31:0 and cholesterol ester (CE) 14:0] were associated with the change in full fat dairy consumption (rho 0.19-0.25; P < 0.05). The 3-mo change in some lipids was positively associated with the 3-mo change in central systolic [LPC 14:0 (rho 0.30; P = 0.007), PC 30:0 (rho 0.28; P = 0.010)] and diastolic blood pressure [LPC 14:0 (rho 0.32; P = 0.004), LPC 15:0 (rho 0.23; P = 0.04), LPC 16:1 (rho 0.23; P = 0.035), PC 29:0 (rho 0.28; P = 0.01), PC 30:0 (rho 0.36; P = 0.001), PC 31:0 (rho 0.30; P = 0.007)] and 12-mo change in common carotid artery intimal medial thickness [CE 14:0 (rho 0.22; P = 0.02)]. Pulse wave velocity and augmentation index were unrelated to dairy and lipid species.

CONCLUSION

An increase in dairy associated lipids appears to be associated with an increase in blood pressure and common carotid intimal medial thickness.

Keywords: Lipids, Phospholipids, Atherosclerosis, Dairy, Lysophosphatidylcholine, Lipidomics, Carotid intima media thickness, Pulse wave velocity, Diabetes

Core tip: We have examined the relationship between changes in dairy intake, lipid species and vascular function. Although it was expected that an increase in dairy intake would lower blood pressure and be associated with improvements in vascular structure we found that increases in lipid species associated with dairy (LPC 14:0, LPC 15:0, LPC 16:1, CE 14:0) were associated with adverse changes in these parameters. Dairy does not appear to be beneficial in people with diabetes.