First direct comparison of platelet reactivity and thrombolytic status between Japanese and Western volunteers: Possible relationship to the “Japanese paradox”

Gorog, Diana A.; Yamamoto, Junichiro; Saraf, Smriti; Ishii, Hiromitsu; Ijiri, Yoshinobu; Ikarugi, Hideo; Wellsted, David M.; Mori, Mari; Yamori, Yukio

doi:10.1016/j.ijcard.2010.07.002

« Previous Next »International Journal of Cardiology
Volume 152, Issue 1 , Pages 43-48, 6 October 2011

First direct comparison of platelet reactivity and thrombolytic status between Japanese and Western volunteers: Possible relationship to the “Japanese paradox”

Diana A. Gorog
- Imperial College, London, UK
- Cardiology Department, East and North Hertfordshire NHS Trust, UK
- Corresponding author. Imperial College, London, UK. Tel.: +44 207 034 8934; fax: +44 207 034 8935.
Junichiro Yamamoto
- Laboratory of Physiology, Kobe Gakuin University, Kobe, Japan
Smriti Saraf
- Cardiology Department, East and North Hertfordshire NHS Trust, UK
Hiromitsu Ishii
- Ishii Hospital, Akashi, Japan
Yoshinobu Ijiri
- Department of Nutrition Management, Faculty of Health Science, Hyogo University, Kakogawa, Japan
Hideo Ikarugi
- Laboratory of Health and Sport Sciences, University of Hyogo, Kobe, Japan
David M. Wellsted
- Health Research and Development Support Unit, University of Hertfordshire, UK
Mari Mori
- Mukogawa Women's University Institute for World Health Development, Nishinomiya, Japan
Yukio Yamori
- Mukogawa Women's University Institute for World Health Development, Nishinomiya, Japan

Received 1 September 2009; received in revised form 5 June 2010; accepted 2 July 2010. published online 16 August 2010.

Abstract

Objective

To determine and compare thrombotic and endogenous thrombolytic status in Japanese and Western populations.

Background

Incidence of coronary heart disease (CHD) and AMI in Japan remains lower than in Western countries. Primary genetic effects are unlikely, given the increased CHD in Japanese migrants. For men, cholesterol and blood pressure have been similar in Japan and the U.S. Dietary factors are implicated, but how these effect CHD is unclear. We postulated that differences in thrombotic and/or thrombolytic status may contribute.

Methods

We measured thrombotic and thrombolytic status in 100 healthy Japanese (J) from Japan and 100 healthy Westerners (W) from the U.K. using the Global Thrombosis Test (GTT). The GTT employs non-anticoagulated blood to create platelet-rich thrombi under high shear (occlusion time OT; seconds), and then measures the restart of blood flow, due to spontaneous thrombolysis (lysis time LT; seconds).

Results

OT was longer in (J) compared to (W) (545 vs. 364, p<0.0001). LT was longer in (J) than in (W) (1753 vs. 1052, p<0.0001). Distribution of LT in (J) did not conform to a normal population, with markedly impaired thrombolytic status (LT>3000s) in 18%, compared to none of the Westerners (p<0.0001).

Conclusions

There are marked differences in thrombotic and thrombolytic status, with (J) having less prothrombotic (longer OT) but less favourable endogenous thrombolytic profile (longer LT). This may be important in the aetiology of thrombotic events. Since platelets and thrombolysis were both inhibited in (J) and yet incidence of AMI is lower, OT would seem more important than LT as a determinant of overall thrombotic risk in this population.

Keywords: Thrombosis, Thrombolysis, Cardiovascular, Race