Higher liver fat content among Japanese in Japan compared with non-Hispanic whites in the United States.
Among Asians, including Japanese, obesity is related to dyslipidemia and insulin resistance at a lower level of body mass index (BMI) compared with non-Hispanic whites (NHW). We hypothesize that this ethnic difference in the relationship between BMI and metabolic risks is partly associated with the ethnic difference in fat distribution, namely, liver fat as well as visceral adipose tissue. To compare liver fat content among Japanese vs NHW men, regional computed tomographic images were taken to measure liver computed tomographic density in population-based samples of 313 Japanese and 288 NHW men aged 40 to 49 years, along with the assessment of metabolic parameters. Liver fat content was higher in Japanese than NHW men (liver to spleen attenuation ratio [lower value means higher liver fat content]: 1.01 +/- 0.16 vs 1.07 +/- 0.15, respectively; P < .01), despite a lower mean BMI in Japanese men (BMI: 23.6 +/- 2.9 vs 27.8 +/- 4.2 kg/m(2), P < .01). Moreover, Japanese men had a greater disposition for fatty liver with a small increase in BMI than NHW (P < .01), whereas both groups had a similar relationship between visceral adipose tissue and BMI. In both groups, liver fat content correlated with triglycerides, homeostasis model assessment of insulin resistance, and C-reactive protein. Liver fat content is higher among Japanese than NHW; and this ethnic difference becomes more robust with a small increase in BMI, suggesting that fatty liver is a sensitive marker for the failure of the adipose tissue to expand to accommodate an increased energy influx, and is associated with similar metabolic risk in Japanese despite lower BMI compared with NHW men.
Azuma
Koichiro
K
Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Kadowaki
Takashi
T
Cetinel
Cemal
C
Kadota
Aya
A
El-Saed
Aiman
A
Kadowaki
Sayaka
S
Edmundowicz
Daniel
D
Nishio
Yoshihiko
Y
Sutton-Tyrrell
Kim
K
Okamura
Tomonori
T
Evans
Rhobert W
RW
Takamiya
Tomoko
T
Ueshima
Hirotsugu
H
Curb
J David
JD
Abbott
Robert D
RD
Kuller
Lewis H
LH
Kelley
David E
DE
Sekikawa
Akira
A
D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data*; D015415:Biomarkers / Q000097:blood; D001823:Body Composition; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D005234:Fatty Liver / Q000453:epidemiology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014280:Triglycerides / Q000097:blood; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data*
D015415:Biomarkers; D014280:Triglycerides; D002097:C-Reactive Protein