Adipocyte Turnover: Relevance to Human Adipose Tissue Morphology

  1. Erik Arner1,
  2. Pål O. Westermark2,
  3. Kirsty L. Spalding3,
  4. Tom Britton4,
  5. Mikael Rydén1,
  6. Jonas Frisén3,
  7. Samuel Bernard5 and
  8. Peter Arner1
  1. 1Department of Medicine, Karolinska Institutet at Karolinska University Hospital, Stockholm, Sweden;
  2. 2Institute for Theoretical Biology, Humboldt University Berlin and Charité, Berlin, Germany;
  3. 3Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden;
  4. 4Department of Mathematics, Stockholm University, Stockholm, Sweden;
  5. 5Institut Camille Jordan, University of Lyon, Villeurbanne, France.
  1. Corresponding author: Peter Arner, peter.arner{at}ki.se.

Abstract

OBJECTIVE Adipose tissue may contain few large adipocytes (hypertrophy) or many small adipocytes (hyperplasia). We investigated factors of putative importance for adipose tissue morphology.

RESEARCH DESIGN AND METHODS Subcutaneous adipocyte size and total fat mass were compared in 764 subjects with BMI 18–60 kg/m2. A morphology value was defined as the difference between the measured adipocyte volume and the expected volume given by a curved-line fit for a given body fat mass and was related to insulin values. In 35 subjects, in vivo adipocyte turnover was measured by exploiting incorporation of atmospheric 14C into DNA.

RESULTS Occurrence of hyperplasia (negative morphology value) or hypertrophy (positive morphology value) was independent of sex and body weight but correlated with fasting plasma insulin levels and insulin sensitivity, independent of adipocyte volume (β-coefficient = 0.3, P < 0.0001). Total adipocyte number and morphology were negatively related (r = −0.66); i.e., the total adipocyte number was greatest in pronounced hyperplasia and smallest in pronounced hypertrophy. The absolute number of new adipocytes generated each year was 70% lower (P < 0.001) in hypertrophy than in hyperplasia, and individual values for adipocyte generation and morphology were strongly related (r = 0.7, P < 0.001). The relative death rate (∼10% per year) or mean age of adipocytes (∼10 years) was not correlated with morphology.

CONCLUSIONS Adipose tissue morphology correlates with insulin measures and is linked to the total adipocyte number independently of sex and body fat level. Low generation rates of adipocytes associate with adipose tissue hypertrophy, whereas high generation rates associate with adipose hyperplasia.

Footnotes

  • The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

    • Received June 26, 2009.
    • Accepted October 8, 2009.
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  1. Diabetes vol. 59 no. 1 105-109
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