Objective: Testosterone therapy increases lean body mass and decreases total fat mass in aging men with low normal testosterone levels. The major challenge is, however, to determine whether the metabolic consequences of testosterone therapy are overall positive. We have previously reported that 6-month testosterone therapy did not improve insulin sensitivity. We investigated the effect of testosterone therapy on regional body fat distribution and on the levels of the insulin-sensitizing adipokine, adiponectin, in aging men with low normal bioavailable testosterone levels. Design: A randomized, double-blinded, placebo-controlled study on 6-month testosterone treatment (gel) in 38 men, aged 60-78 years, with bioavailable testosterone !7.3 nmol/l, and a waist circumference O94 cm. Methods: Central fat mass (CFM) and lower extremity fat mass (LEFM) were measured by dual X-ray absorptiometry. Subcutaneous abdominal adipose tissue (SAT), visceral adipose tissue (VAT), and thigh subcutaneous fat area (TFA) were measured by magnetic resonance imaging. Adiponectin levels were measured using an in-house immunofluorometric assay. Coefficients (b) represent the placebocontrolled mean effect of intervention. Results: LEFM was decreased (bZK0.47 kg, PZ0.07) while CFM did not change significantly (bZK0.66 kg, PZ0.10) during testosterone therapy. SAT (bZK3.0%, PZ0.018) and TFA (bZK3.0%, P!0.001) decreased, while VAT (bZ1.0%, PZ0.54) remained unchanged. Adiponectin levels decreased during testosterone therapy (bZK1.3 mg/l, PZ0.001). Conclusion: Testosterone therapy decreased subcutaneous fat on the abdomen and lower extremities, but visceral fat was unchanged. Moreover, adiponectin levels were significantly decreased during testosterone therapy.

Physical exercise increases peripheral insulin sensitivity, but regional differences are poorly elucidated in humans. We investigated the effect of aerobic exercise training on insulin-stimulated glucose uptake in five individual femoral muscle groups and four different adipose tissue regions, using dynamic (femoral region) and static (abdominal region) 2-deoxy-2-[ ; mean(SD)], moderately overweight [BMI 28.1(1.8) kg/m 2 ], young [age: 30(6) yr] men were randomized to sedentary living (CON; n ϭ 17 completers) or moderate (MOD; 300 kcal/day, n ϭ 18) or high (HIGH; 600 kcal/day, n ϭ 18) dose physical exercise for 11 wk. At baseline, insulin-stimulated glucose uptake was highest in femoral skeletal muscle followed by intraperitoneal visceral adipose tissue (VAT), retroperitoneal VAT, abdominal (anterior ϩ posterior) subcutaneous adipose tissue (SAT), and femoral SAT (P Ͻ 0.0001 between tissues). Metabolic rate of glucose increased similarly (ϳ30%) in the two exercise groups in femoral skeletal muscle (MOD 24[9,39] , P ϭ 0.003) (mean[95% CI]) and in five individual femoral muscle groups but not in femoral SAT. Standardized uptake value of FDG decreased ϳ24% in anterior abdominal SAT and ϳ20% in posterior abdominal SAT compared with CON but not in either intra-or retroperitoneal VAT. Total adipose tissue mass decreased in both exercise groups, and the decrease was distributed equally among subcutaneous and intra-abdominal depots. In conclusion, aerobic exercise training increases insulin-stimulated glucose uptake in skeletal muscle but not in adipose tissue, which demonstrates some interregional differences. overweight; obesity; metabolism WE HAVE PREVIOUSLY SHOWN that 11 wk of moderate-(ϳ30 min/day) and high-dose (ϳ60 min/day) aerobic physical exercise increases peripheral insulin sensitivity to the same extend in overweight men as measured by the hyperinsulinemicisoglycemic clamp technique (31). However, it was not addressed in which tissues the increase occurred. Skeletal muscle (constituting ϳ40% of body mass) is the major tissue involved in the glucose metabolism and an important site of insulin resistance in obesity and type 2 diabetes (1). Insulin resistance is associated with a reduced percentage of red oxidative skeletal muscle fibers (10), as glucose uptake capacity is larger in red oxidative than in white glycolytic muscle fibers (12,17). Skeletal muscle shows regional heterogeneity metabolically and by distribution of fiber types, with the same tissue at different locations having different metabolic and structural properties (13,23). This metabolic heterogeneity is also found in adipose tissue (8).Physical training is well known to increase insulin-stimulated glucose uptake in the leg as measured by Fick's principle (5, 6). However, this technique does not allow for differentiation between glucose uptake in various tissues of the leg or between individual muscle groups. Uptake of glucose in different tissues can be estimated noninvasively by use of computer tomography (CT) and PET using the glucose anal...

Abdominal adiposity including accumulation of both sc and visceral fat may constitute primary nongenetic factors associated with low birth weight and reduced fetal growth before the third trimester. Reduced fetal growth during vs. before the third trimester may define distinct adult trajectories of metabolic and anthropometric characteristics influencing risk of developing type 2 diabetes.

Abstract. This paper presents a method for automatically segmenting abdominal adipose tissue from 3-dimensional magnetic resonance images. We distinguish between three types of adipose tissue; visceral, deep subcutaneous and superficial subcutaneous. Images are pre-processed to remove the bias field effect of intensity in-homogeneities. This effect is estimated by a thin plate spline extended to fit two classes of automatically sampled intensity points in 3D. Adipose tissue pixels are labelled with fuzzy c-means clustering and locally determined thresholds. The visceral and subcutaneous adipose tissue are separated using deformable models, incorporating information from the clustering. The subcutaneous adipose tissue is subdivided into a deep and superficial part by means of dynamic programming applied to a spatial transformation of the image data. Regression analysis shows good correspondences between our results and total abdominal adipose tissue percentages assessed by dualemission X-ray absorptiometry (R 2 = 0.86).

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