Macrophage Infiltration into Omental Versus Subcutaneous Fat across Different Populations: Effect of Regional Adiposity and the Comorbidities of Obesity

• Published in: The journal of clinical endocrinology and metabolism Vol. 92; no. 6; pp. 2240 - 2247
• Main Authors: Harman-Boehm, Ilana, Blüher, Matthias, Redel, Henry, Sion-Vardy, Netta, Ovadia, Shira, Avinoach, Eliezer, Shai, Iris, Klöting, Nora, Stumvoll, Michael, Bashan, Nava, Rudich, Assaf
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Oxford University Press 01.06.2007; Endocrine Society
• Subjects: Adipose tissue; Adult; Aged; Biological and medical sciences; Biopsy; Body Mass Index; Cardiovascular disease; Cell Movement - immunology; Chemokine CCL2 - genetics; Cohort Studies; Colony-stimulating factor; Comorbidity; Coronary artery disease; Diabetes mellitus; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Heart diseases; Homeostasis; Humans; Infiltration; Macrophage colony-stimulating factor; Macrophage Colony-Stimulating Factor - genetics; Macrophages; Macrophages - cytology; Macrophages - immunology; Male; Metabolic syndrome; Middle Aged; Monocyte chemoattractant protein; Monocyte chemoattractant protein 1; Monocytes; mRNA; Obesity; Obesity - immunology; Obesity - mortality; Obesity - pathology; Omentum - cytology; Omentum - immunology; RNA, Messenger - metabolism; Subcutaneous Fat, Abdominal - cytology; Subcutaneous Fat, Abdominal - immunology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Human; Obesity; Adipose tissue; Nutrition; Subcutaneous; Nutrition disorder; Metabolic diseases; Omentum; Regional; Concomitant disease; Multiple comorbid diseases; Adiposity; Population; Infiltration; Endocrinology; Nutritional status; Comparative study; Macrophage
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2006-1811

Context: Macrophage infiltration into adipose tissue has been demonstrated to accompany obesity, with a potential preferential infiltration into intraabdominal vs. sc fat. Objective: Our objective was to determine whether this occurs across different populations with a range of body mass indexes and to assess the relationship with regional adiposity and comorbidity of obesity. Setting and Patients: In two independent cohorts, we used paired omental (OM) and sc fat biopsies from lean controls or predominantly sc or intraabdominally obese persons with minimal comorbidity (n = 60, cohort 1), or from severely obese women with a significant rate of comorbidity (n = 29, cohort 2). Results: Elevated macrophage infiltration into OM vs. sc fat was observable in lean subjects and exaggerated by obesity, particularly if predominantly intraabdominal. This was paralleled by increased monocyte chemoattractant protein-1 (MCP1) and colony-stimulating factor-1 (CSF1) mRNA levels. Level of CSF1 and MCP1 mRNA correlated with the number of OM macrophages (r = 0.521, P < 0.0001 and r = 0.258, P < 0.051, respectively). In severely obese women (mean body mass index = 43.0 ± 1.1 kg/m2), higher protein expression of both MCP1 and CSF1 was detected in OM vs. sc fat. Number of OM macrophages, but not of sc macrophages, correlated with waist circumference (r = 0.636, P = 0.001 vs. r = 0.170, P = 0.427) and with the number of metabolic syndrome parameters (r = 0.385, P = 0.065 vs. r = −0.158, P = 0.472, respectively). Preferential macrophage infiltration into OM fat was mainly observed in a subgroup in whom obesity was associated with impaired glucose homeostasis. Conclusions: Preferential macrophage infiltration into OM fat is a general phenomenon exaggerated by central obesity, potentially linking central adiposity with increased risk of diabetes and coronary heart disease.