title: Intermuscular adipose tissue and thigh muscle area dynamics during an 18-month randomized weight loss trial.
abstract: It remains unclear whether intermuscular adipose tissue (IMAT) has any metabolic influence or whether it is merely a marker of abnormalities, as well as what are the effects of specific lifestyle strategies for weight loss on the dynamics of both IMAT and thigh muscle area (TMA). We followed the trajectory of IMAT and TMA during 18-mo lifestyle intervention among 278 sedentary participants with abdominal obesity, using magnetic resonance imaging. We measured the resting metabolic rate (RMR) by an indirect calorimeter. Among 273 eligible participants (47.8 ± 9.3 yr of age), the mean IMAT was 9.6 ± 4.6 cm(2) Baseline IMAT levels were directly correlated with waist circumference, abdominal subdepots, C-reactive protein, and leptin and inversely correlated with baseline TMA and creatinine (P < 0.05 for all). After 18 mo (86.3% adherence), both IMAT (-1.6%) and TMA (-3.3%) significantly decreased (P < 0.01 vs. baseline). The changes in both IMAT and TMA were similar across the lifestyle intervention groups and directly corresponded with moderate weight loss (P < 0.001). IMAT change did not remain independently associated with decreased abdominal subdepots or improved cardiometabolic parameters after adjustments for age, sex, and 18-mo weight loss. In similar models, 18-mo TMA loss remained associated with decreased RMR, decreased activity, and with increased fasting glucose levels and IMAT (P < 0.05 for all). Unlike other fat depots, IMAT may not represent a unique or specific adipose tissue, instead largely reflecting body weight change per se. Moderate weight loss induced a significant decrease in thigh muscle area, suggesting the importance of resistance training to accompany weight loss programs.
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Anat
authors.initials: A
authors.lastname: Yaskolka Meir
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel;
authors.forename: Ilan
authors.initials: I
authors.lastname: Shelef
authors.affiliation: Nuclear Research Center Negev, Israel;
authors.forename: Dan
authors.initials: D
authors.lastname: Schwarzfuchs
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Yftach
authors.initials: Y
authors.lastname: Gepner
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Lilac
authors.initials: L
authors.lastname: Tene
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Hila
authors.initials: H
authors.lastname: Zelicha
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Gal
authors.initials: G
authors.lastname: Tsaban
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Avital
authors.initials: A
authors.lastname: Bilitzky
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Oded
authors.initials: O
authors.lastname: Komy
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Noa
authors.initials: N
authors.lastname: Cohen
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Nitzan
authors.initials: N
authors.lastname: Bril
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Michal
authors.initials: M
authors.lastname: Rein
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Dana
authors.initials: D
authors.lastname: Serfaty
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Shira
authors.initials: S
authors.lastname: Kenigsbuch
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel;
authors.forename: Yoash
authors.initials: Y
authors.lastname: Chassidim
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel;
authors.forename: Lior
authors.initials: L
authors.lastname: Zeller
authors.affiliation: Department of Medicine, University of Leipzig, Leipzig, Germany;
authors.forename: Uta
authors.initials: U
authors.lastname: Ceglarek
authors.affiliation: Department of Medicine, University of Leipzig, Leipzig, Germany;
authors.forename: Michael
authors.initials: M
authors.lastname: Stumvoll
authors.affiliation: Department of Medicine, University of Leipzig, Leipzig, Germany;
authors.forename: Matthias
authors.initials: M
authors.lastname: Blüher
authors.affiliation: Department of Medicine, University of Leipzig, Leipzig, Germany;
authors.forename: Joachim
authors.initials: J
authors.lastname: Thiery
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel;
authors.forename: Assaf
authors.initials: A
authors.lastname: Rudich
authors.affiliation: Ben-Gurion University of the Negev, Beer-Sheva, Israel; irish@bgu.ac.il.
authors.forename: Iris
authors.initials: I
authors.lastname: Shai
mesh_terms: D050153:Abdominal Fat / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D009765:Obesity / Q000503:physiopathology* / Q000628:therapy*; D056128:Obesity, Abdominal / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D009929:Organ Size; D013848:Thigh / Q000473:pathology / Q000503:physiopathology; D015431:Weight Loss
keywords: intermuscular adipose tissue; magnetic resonance imaging; muscle area; obesity; physical activity