Elevated C-Reactive Protein Is a Risk Factor for the Development of Type 2 Diabetes in Japanese Americans

  1. Shuhei Nakanishi, MD,
  2. Kiminori Yamane, MD,
  3. Nozomu Kamei, MD,
  4. Masamichi Okubo, MD and
  5. Nobuoki Kohno, MD
  1. From the Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
  1. Address correspondence and reprint requests to Dr. Shuhei Nakanishi, Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan. E-mail: nshuhei{at}rerf.or.jp

Abstract

OBJECTIVE—Increasing evidence from a cohort of Caucasians recently suggests that an elevated level of C-reactive protein (CRP) is associated with an increased risk of developing type 2 diabetes. However, Japanese subjects are skewed to lower CRP concentrations than westerners. Therefore, the effect of CRP on the development of type 2 diabetes among Japanese is unclear.

RESEARCH DESIGN AND METHODS—We examined 396 male and 551 female nondiabetic Japanese Americans who underwent a 75-g oral glucose tolerance test (GTT) and were then followed for an average of 6.5 years. We investigated whether elevated serum CRP level is a risk factor in the development of type 2 diabetes among these subjects.

RESULTS—Subjects with a high CRP level showed a significantly higher incidence of type 2 diabetes compared with subjects with a low level among both men (P = 0.028) and women (P = 0.004) in a log-rank test. In a Cox proportional hazards model dividing quartiles of CRP, the hazard ratios for diabetes development in the highest versus lowest quartile of CRP levels were 2.84 (95% CI 1.09–7.39) among men and 3.11 (1.25–7.75) among women after adjustment for age, smoking, family history of diabetes, classification of a 75-g GTT, hormone replacement therapy (among women), BMI, and homeostasis model assessment.

CONCLUSIONS—Among Japanese Americans, CRP may be a risk factor for development of type 2 diabetes independent of either obesity or insulin resistance. Our results suggest that inflammation may be closely related to the mechanism of type 2 diabetes among Japanese Americans.

Footnotes

  • A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    • Accepted July 9, 2003.
    • Received April 22, 2003.
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