Effects of male hypogonadism on regional adipose tissue fatty acid storage and lipogenic proteins

Testosterone has long been known to affect body fat distribution, although the underlying mechanisms remain elusive. We investigated the effects of chronic hypogonadism in men on adipose tissue fatty acid (FA) storage and FA storage factors. Twelve men with chronic hypogonadism and 13 control men matched for age and body composition: 1) underwent measures of body composition with dual energy x-ray absorptiometry and an abdominal CT scan; 2) consumed an experimental meal containing [(3)H]triolein to determine the fate of meal FA (biopsy-measured adipose storage vs. oxidation); 3) received infusions of [U-(13)C]palmitate and [1-(14)C]palmitate to measure rates of direct free (F)FA storage (adipose biopsies). Adipose tissue lipoprotein lipase, acyl-CoA synthetase (ACS), and diacylglycerol acetyl-transferase (DGAT) activities, as well as, CD36 content were measured to understand the mechanism by which alterations in fat storage occur in response to testosterone deficiency. Results of the study showed that hypogonadal men stored a greater proportion of both dietary FA and FFA in lower body subcutaneous fat than did eugonadal men (both p<0.05). Femoral adipose tissue ACS activity was significantly greater in hypogonadal than eugonadal men, whereas CD36 and DGAT were not different between the two groups. The relationships between these proteins and FA storage varied somewhat between the two groups. We conclude that chronic effects of testosterone deficiency has effects on leg adipose tissue ACS activity which may relate to greater lower body FA storage. These results provide further insight into the role of androgens in body fat distribution and adipose tissue metabolism in humans.     

Adipose tissue intracrinology: potential importance of local androgen/estrogen metabolism in the regulation of adiposity.

The present article summarizes some of the studies available on steroid hormone conversion through the specific expression of steroidogenic enzymes in adipose tissue (adipose tissue intracrinology) and discusses the potential impact of local adipose tissue steroid metabolism on the regulation of adipocyte function and other metabolic parameters. Several studies have demonstrated significant steroid hormone uptake and conversion by adipose tissues from various body sites and in various cell fractions. Activities and/or mRNAs of aromatase, 3beta-hydroxysteroid dehydrogenase (HSD), 3alpha-HSD, 11beta-HSD, 17beta-HSD, 7alpha-hydroxylase, 17alpha-hydroxylase, 5alpha-reductase and UDP-glucuronosyltransferase 2B15 have been detected in adipose tissue or adipose cells. These studies have demonstrated potentially important roles for these enzymes in obesity, central fat accumulation, and the metabolic syndrome. Future studies on adipose tissue intracrinology will contribute further to our understanding of steroid action in adipocytes.     

Androgens and body fat distribution

An important sex difference in body fat distribution is generally observed. Men are usually characterized by the android type of obesity, with accumulation of fat in the abdominal region, whereas women often display the gynoid type of obesity, with a greater proportion of their body fat in the gluteal-femoral region. Accordingly, the amount of fat located inside the abdominal cavity (intra-abdominal or visceral adipose tissue) is twice as high in men compared to women. This sex difference has been shown to explain a major portion of the differing metabolic profiles and cardiovascular disease risk in men and women. Association studies have shown that circulating androgens are negatively associated with intra-abdominal fat accumulation in men, which explains an important portion of the link between low androgens and features of the metabolic syndrome. In women, the low circulating sex hormone-binding globulin (SHBG) levels found in abdominal obesity may indirectly indicate that elevated free androgens are related to increased visceral fat accumulation. However, data on non SHBG-bound and total androgens are not unanimous and difficult to interpret for total androgens. These studies focusing on plasma levels of sex hormones indirectly suggest that androgens may alter adipose tissue mass in a depot-specific manner. This could occur through site-specific modulation of preadipocyte proliferation and/or differentiation as well as lipid synthesis and/or lipolysis in mature adipocytes. Recent results on the effects of androgens in cultured adipocytes and adipose tissue have been inconsistent, but may indicate decreased adipogenesis and increased lipolysis upon androgen treatment. Finally, adipose tissue has been shown to express several steroidogenic and steroid-inactivating enzymes. Their mere presence in fat indirectly supports the notion of a highly complex enzymatic system modulating steroid action on a local basis. Recent data obtained in both men and women suggest that enzymes from the aldoketoreductase 1C family are very active and may be important modulators of androgen action in adipose tissue.     

Aromatase activity in the breast and other peripheral tissues and its therapeutic regulation

Studies using [³H]androstenedione (A) demonstrated that this substrate can be aromatized to estrone (E₁) in homogenates of breast carcinoma tissue and breast adipose tissue, in breast carcinoma and breast adipose stromal cells in culture, and in cultured adipose stromal cells from sites remote from the tumor. Using cultured breast carcinoma cells, it was shown that estrogen formation was stimulated by Cortisol (10⁻⁶ M) and inhibited by endogenous 5-reduced androgens: 5-androstene-dione>androsterone>dihydrotestosterone>epiandrosterone>3- and 3β-androstanediol. It was also shown that 19-nortestosterone and 19-norandrostenedione (10⁻⁶ M) inhibited E₁ formation by 80%. Progesterone (10⁻⁶ M) had no effect on aromatase activity, while the progestational agent R5020 (10⁻⁶ M) caused a 70% inhibition. These studies emphasize that a variety of compounds can influence aromatase activity and that drugs which are used as aromatase inhibitors in patients with breast carcinoma may have multiple sites of action.     

Androgen conversion in osteoarthritis and rheumatoid arthritis synoviocytes--androstenedione and testosterone inhibit estrogen formation and favor production of more potent 5alpha-reduced androgens

In synovial cells of patients with osteoarthritis (OA) and rheumatoid arthritis (RA), conversion products of major anti-inflammatory androgens are as yet unknown but may be proinflammatory. Therefore, therapy with androgens in RA could be a problem. This study was carried out in order to compare conversion products of androgens in RA and OA synoviocytes. In 26 OA and 24 RA patients, androgen conversion in synovial cells was investigated using radiolabeled substrates and analysis by thin-layer chromatography and HPLC. Aromatase expression was studied by immunohistochemistry. Dehydroepiandrosterone (DHEA) was converted into androstenediol, androstenedione (ASD), 16alphaOH-DHEA, 7alphaOH-DHEA, testosterone, estrone (E1), estradiol (E2), estriol (E3), and 16alphaOH-testosterone (similar in OA and RA). Surprisingly, levels of E2, E3, and 16alpha-hydroxylated steroids were as high as levels of testosterone. In RA and OA, 5alpha-dihydrotestosterone increased conversion of DHEA into testosterone but not into estrogens. The second androgen, ASD, was converted into 5alpha-dihydro-ASD, testosterone, and negligible amounts of E1, E2, E3, or 16alphaOH-testosterone. 5alpha-dihydro-ASD levels were higher in RA than OA. The third androgen, testosterone, was converted into ASD, 5alpha-dihydro-ASD, 5alpha-dihydrotestosterone, and negligible quantities of E1 and E2. 5alpha-dihydrotestosterone was higher in RA than OA. ASD and testosterone nearly completely blocked aromatization of androgens. In addition, density of aromatase-positive cells and concentration of released E2, E3, and free testosterone from superfused synovial tissue was similar in RA and OA but estrogens were markedly higher than free testosterone. In conclusion, ASD and testosterone might be favorable anti-inflammatory compounds because they decrease aromatization and increase anti-inflammatory 5alpha-reduced androgens. In contrast, DHEA did not block aromatization but yielded high levels of estrogens and proproliferative 16alpha-hydroxylated steroids. Androgens were differentially converted to pro- and anti-inflammatory steroid hormones via diverse pathways.     

Sex steroids and leptin regulate 11beta-hydroxysteroid dehydrogenase I and P450 aromatase expressions in human preadipocytes: Sex specificities

Adipose tissue is an important site of steroid hormone biosynthesis, as type I 11β-hydroxysteroid dehydrogenase (HSD1), the enzyme responsible for the conversion of cortisone into cortisol and the P450 aromatase, the enzyme catalysing androgens aromatization into estrogens, are both expressed in human adipose tissue. In the present report, we have investigated the possibility that sex steroids and leptin could regulate these two enzymes in cultured preadipocytes from men and women intra-abdominal fat depots.

In women preadipocytes, human recombinant leptin down-regulates HSD1 mRNA expression (−58%) and P450 aromatase activity (−26%). Conversely, leptin up-regulates the HSD1 (2.4-fold) and the P450 aromatase (1.6-fold) mRNA expression in men preadipocytes. In women preadipocytes, 17β-estradiol strongly stimulates HSD1 mRNA expression (10-fold) and, in contrast, decreases by half the P450 aromatase expression. In men, 17β-estradiol has no influence on HSD1 expression but up-regulates P450 aromatase mRNA expression (2.4-fold). Finally, androgens increase by a factor of 2.5–5 the mRNA expression of both enzymes in men.

These findings suggest that sex steroids and leptin either increase or decrease local cortisol and estrogens productions in men or in women preadipocytes, respectively. They also indicate that steroid metabolism in adipose tissue is controlled by a coordinated regulation of P450 aromatase and HSD1 expressions. Finally, the important sex-specific differences described herein may also contribute to explain the sexual dimorphism of body fat distribution in humans.     

5alpha-reductase isoenzymes 1 and 2 in the rat testis during postnatal development

The pubertal initiation of spermatogenesis is reliant on androgens, and during this time, 5alpha-reduced androgens such as dihydrotestosterone (DHT) are the predominant androgens in the testis. Two 5alpha-reductase (5alphaR) isoenzymes (5alphaR1 and 5alphaR2) have been identified, which catalyze the conversion of testosterone to the more potent androgen DHT. The present study aimed to investigate the developmental pattern of 5alphaR isoenzymes and their relationship to the production of 5alpha-reduced androgens in the postnatal rat testis. Both 5alphaR1 and 5alphaR2 isoenzyme mRNAs were measured by real-time polymerase chain reaction, isoenzyme activity levels by specific assays, and testicular androgens by radioimmunoassay after high-performance liquid chromatographic separation. Both 5alphaR1 and 5alphaR2 mRNAs and activity levels were low in the 10-day-old (prepubertal) testis, peaked between Days 20 and 40 during puberty, and then declined to low levels at 60-160 days of age. The developmental pattern of both 5alphaR isoenzyme activity levels was mirrored by the testicular production of 5alpha-reduced metabolites. Although 5alphaR1 was greater than 5alphaR2 at all ages, it is likely, given the substrate preferences of the two, that both isoenzymes contribute to the pubertal peak of 5alpha-reduced androgen biosynthesis. The peak in 5alphaR isoenzymes and 5alpha-reduced metabolite production coincided with the first wave of spermatogenesis in the rat, suggesting a role for 5alpha-reduced metabolites in the initiation of spermatogenesis. This was explored by acute administration of a 5alphaR inhibitor (L685,273) to immature rats. The L685,273 markedly suppressed testicular 5alphaR activity during puberty by 75%-86%. However, a marked increase was observed in testicular testosterone levels (in the absence of changes in LH), and no decrease was observed in the absolute levels of 5alpha-reduced metabolites. Therefore, whether the formation of DHT in the presence of low testosterone levels in the pubertal testis is required for the initiation of spermatogenesis cannot be tested using 5alphaR inhibitors. We conclude that both 5alphaR1 and 5alphaR2 isoenzymes are involved in the peak of 5alpha-reduced androgen biosynthesis in the testis during the pubertal initiation of spermatogenesis.     

Regional uptake of meal fatty acids in humans

Two protocols were performed to study meal fatty acid metabolism. In protocol 1, 14 patients scheduled for elective intra-abdominal surgery (11 undergoing bariatric surgery for severe obesity) consumed a meal containing [3H]triolein in the evening before surgery. This allowed us to measure adipose tissue lipid specific activity (SA) in mesenteric and omental, deep and superficial abdominal subcutaneous adipose tissue. Intra-abdominal adipose tissue lipid SA was greater than subcutaneous lipid SA. There were no significant differences between mesenteric and omental or between deep and superficial abdominal subcutaneous adipose tissue. In protocol 2, meal fatty acid oxidation and uptake into subcutaneous and omental adipose tissue ([3H]triolein) were measured in six normal, healthy volunteers. Meal fatty acid oxidation (3H2O generation) plus that remaining in plasma ( approximately 1%) plus uptake into upper body subcutaneous, lower body subcutaneous, and visceral fat allowed us to account for 98 +/- 6% of meal fatty acids 24 h after meal ingestion. We conclude that omental fat is a good surrogate for visceral fat and that abdominal subcutaneous fat depots are comparable with regard to meal fatty acid metabolic studies. Using [3H]triolein, we were able to account for virtually 100% of meal fatty acids 24 h after meal ingestion. These results support the meal fatty acid tracer model as a way to study the metabolic fate of dietary fat.     

Upper and Lower Body Adipose Tissue Function: A Direct Comparison of Fat Mobilization in Humans

Objectives: Fat in the lower body is not associated with the same risk of cardiovascular disease as fat in the upper body. Is this explained by differences in the physiological functioning of the two depots? This study had two objectives: 1) to determine whether fat mobilization and blood flow differ between gluteal and abdominal adipose tissues in humans, and 2) to develop a new technique to assess gluteal adipose tissue function directly. Research Methods and Procedures: We performed detailed in vivo studies of adipose tissue function involving the assessment of fat mobilization by measurement of adipose tissue blood flows, arterio‐venous differences of metabolites across each depot, and gene expression in tissue biopsies in a small‐scale physiological study. Results: Gluteal adipose tissue has a lower blood flow (67% lower, p < 0.05) and lower hormone‐sensitive lipase rate of action (87% lower, p < 0.05) than abdominal adipose tissue. Lipoprotein lipase rate of action and mRNA expression are not different between the depots. This is the first demonstration of a novel technique to directly investigate gluteal adipose tissue metabolism. Discussion: Direct assessment of fasting adipose tissue metabolism in defined depots show that the buttock is metabolically “silent” in terms of fatty acid release compared with the abdomen.     

Orthogonal factor coefficient development of subcutaneous adipose tissue topography (SAT-Top) in girls and boys

The new optical device Lipometer allows noninvasive, quick, and safe determination of the thickness of subcutaneous adipose tissue (SAT) layers (in mm) at any site of the human body. The specification of 15 evenly distributed body sites enables the precise measurement of subcutaneous body fat distribution, so-called subcutaneous adipose tissue topography (SAT-Top). SAT-Top was measured in 980 children aged 7-19 years. In this paper we describe the degree to which SAT-Top body sites are intercorrelated. We consider whether a meaningful reduction of data is possible using factor analysis, which factors can be extracted, and how SAT-Top data of children can be added to a factor value plot, depicting the essential results of age-dependent subcutaneous fat development. SAT layers situated on the same body area provide correlation coefficients up to +r = 0.91. Two factors are extracted: factor 1, containing all upper body sites (from neck to hip); and factor 2, consisting of all leg body sites. When all 980 children are divided into three age groups in a factor value plot, the first age group (7-11 years) shows almost equal SAT-Top development in boys and girls. Afterwards, for the consecutive age groups 2 (11-15 years) and 3 (15-19 years), the age-dependent subcutaneous fat development of boys and girls progresses into nearly orthogonal directions.     

Influence of 5 alpha-reduced androgens on oestradiol secretion by granulosa cells of pregnant mare serum gonadotrophin treated immature rats

The effect of aromatizable androgens (testosterone and androstenedione) and naturally occurring 5 alpha-androstane, 3 alpha 17 beta-diol and 5 alpha-androstane, -3 beta, 17 beta-diol on oestradiol secretion by granulosa cells isolated from preovulatory follicles of PMSG-primed immature rats was investigated. The amount of oestradiol secreted by granulosa cells in the absence of exogenous aromatizable androgen in a 4h incubation was negligible. However, the addition of testosterone or androstenedione resulted in concentration dependent increases in oestradiol secretion. The 5 alpha-reduced androgens inhibit oestradiol and oFSH-stimulated oestradiol secretion by the granulosa cells in the presence of exogenous testosterone. The least potent of the androgens tested in causing this effect being the 5 alpha-androstane-3 alpha, 17 beta-diol. This result suggests that the naturally occurring 5 alpha-reduced androgens have a direct effect on androgen-aromatizing enzymes. The effect of these androgens may have an important connotation with respect to the control of the onset of puberty and regulation of ovarian oestradiol secretion within the microenvironment of an ovarian follicle.     

Body composition determines direct FFA storage pattern in overweight women

Direct FFA storage in adipose tissue is a recently appreciated pathway for postabsorptive lipid storage. We evaluated the effect of body fat distribution on direct FFA storage in women with different obesity phenotypes. Twenty-eight women [10 upper body overweight/obese (UBO; WHR >0.85, BMI >28 kg/m(2)), 11 lower body overweight/obese (LBO; WHR <0.80, BMI >28 kg/m(2)), and 7 lean (BMI <25 kg/m(2))] received an intravenous bolus dose of [9,10-(3)H]palmitate- and [1-(14)C]triolein-labeled VLDL tracer followed by upper body subcutaneous (UBSQ) and lower body subcutaneous (LBSQ) fat biopsies. Regional fat mass was assessed by combining DEXA and CT scanning. We report greater fractional storage of FFA in UBSQ fat in UBO women compared with lean women (P < 0.01). The LBO women had greater storage per 10(6) fat cells in LBSQ adipocytes compared with UBSQ adipocytes (P = 0.04), whereas the other groups had comparable storage in UBSQ and LBSQ adipocytes. Fractional FFA storage was significantly associated with fractional VLDL-TG storage in both UBSQ (P < 0.01) and LBSQ (P = 0.03) adipose tissue. In conclusion, UBO women store a greater proportion of FFA in the UBSQ depot compared with lean women. In addition, LBO women store FFA more efficiently in LBSQ fat cells compared with UBSQ fat cells, which may play a role in development of their LBO phenotype. Finally, direct FFA storage and VLDL-TG fatty acid storage are correlated, indicating they may share a common rate-limiting pathway for fatty acid storage in adipose tissue.     

Anti-glucocorticoid effects of progesterone in vivo on rat adipose tissue metabolism

Steroid hormones seem to be important for adipose tissue metabolism and accumulation. As progesterone has been suggested to modulate the glucocorticoid effects, the interactions between glucocortioid and progesterone on adipose tissue metabolism were investigated.Forty-eight male Wistar rats were adrenectomized and divided into four groups; controls (treated with vehicle only), dexamethasone treated (10 micro g per rat), progesterone treated (5mg per rat) and the last group received both dexamethasone and progesterone.The dexamethasone-treated group had a significant loss of body weight and smaller intra-abdominal fat depots compared to the control group in addition, dexamethasone increased LPL-activity and increased catecholamine stimulated lipolysis. When progesterone was given concomitantly the dexamethasone effects on adipose tissue mass, LPL-activity and lipolysis were blocked. When given alone progesterone had no influence on body weight, amount of adipose tissue, lipolysis or LPL-activity.These data indicate that progesterone acts as an anti-glucocorticoid in adipose tissue in vivo, thus attenuating the glucocorticoid effect on adipose tissue metabolism.     

白藜芦醇对成年期追赶生长大鼠体成分的影响及机制

目的:观察白藜芦醇对成年期追赶生长大鼠体成分的影响及可能机制。方法:8周龄雄性 SD 大鼠分为6组(共2个时间点),即4周时间点3组:正常饮食4周 (NC4)组、热卡限制4周(R4)组,热卡限制同时白藜芦醇治疗(R4E)组;12周时间点3组:正常饮食12周(NC12)组,追赶生长(CUG)组,追赶生长白藜芦醇治疗(CUGE)组。每组含6只大鼠,白藜芦醇用生理盐水配制成一定浓度悬浊液,按100 mg/(kg·d)剂量予实验动物灌胃治疗。实验第4周、12周检测体重、躯干和全身的肌肉及脂肪含量、躯干与全身脂肪比例,实验第12周检测骨骼肌与附睾脂肪组织SIRT1的表达,附睾脂肪组织PPARγ的表达。结果:与NC12组相比,CUG组躯干及全身的脂肪含量、躯干与全身脂肪比例、附睾脂肪组织PPARγ的表达均明显升高(P＜0.05),肌肉含量、骨骼肌与附睾脂肪组织SIRT1的表达显著降低(P＜0.05或P＜0.01);与CUG组相比,经白藜芦醇干预后的CUGE组全身的脂肪含量、躯干与全身脂肪比例、附睾脂肪组织PPARγ的表达均明显降低(P＜0.05),肌肉含量、骨骼肌与附睾脂肪组织SIRT1的表达较CUG组显著提高(P＜0.05)。结论:白藜芦醇降低成年期追赶生长大鼠体脂含量,增加肌肉含量,改善腹部脂肪堆积,其机制可能与增加骨骼肌及内脏脂肪组织SIRT1表达,抑制内脏脂肪PPARγ的表达有关。     

Heredity and changes in body composition and adipose tissue metabolism after short-term exercise-training

The purpose of the experiment was to investigate the genotype dependency of body composition and adipose tissue metabolism following short-term exercise-training. Six pairs of male, sedentary monozygotic twins took part in a 22 day ergocycle training program at 58% VO2max, with a mean exercise duration of 116 min x day-1. Body weight, fat mass, percent body fat and VO2max, were evaluated before and after the training program. From a suprailiac region fat biopsy, the following adipose tissue metabolic variables were evaluated: fat cell diameter, basal and epinephrine stimulated lipolysis, basal and insulin stimulated lipogenesis from glucose and heparin releasable lipoprotein lipase activity. The exercise-training program increased (p less than 0.01) VO2max and decreased (p less than 0.01) body weight, fat mass and percent body fat. Variation in response within twin pairs was not significantly different than response between pairs in the aforementioned variables. However, a significant within pair resemblance (p less than 0.01) for changes in fat free mass was observed. Adipose tissue metabolic indicators exhibited a large interindividual variation in response to exercise-training. Significant within twin pair resemblance was observed only for basal lipogenesis. Moreover, the non significant within twin pair resemblance for changes in body fat and adipose tissue metabolic indicators suggests that heredity is not a major factor influencing changes in body fat and adipose tissue indicators to short-term training resulting in negative energy balance. Changes in fat free mass were, however, closely coupled to the genotype.     

Androgen binding to ammonium sulfate precipitates of human adipose tissue cytosols

Although androgens are believed to influence the distribution of human adipose tissue and have been detected in human fat, receptors for these sex hormones have yet to be identified. These studies demonstrate that a high-affinity, limited-capacity binding component for the synthetic androgen methyltrienolone (R1881) exists in ammonium sulfate precipitates of human adipose tissue cytosols. The equilibrium dissociation constant (Kd = 0.1 to 0.4 nmol/L, n = 6) and the number of binding sites (2 to 26 fmol/mg protein, n = 22) are consistent with those reported for androgen receptors in rat prostate, human prostatic carcinoma, MCF-7 cells, and baboon myocardium. The relative steroid-binding specificities of the human adipose tissue androphile (R1881 approximately 5 alpha-dihydrotestosterone greater than testosterone greater than estradiol approximately progesterone much greater than dexamethasone) are similar, but not identical, to those reported for androgen receptors in rat prostate (R1881 greater than 5 alpha-dihydrotestosterone approximately testosterone greater than estradiol greater than progesterone much greater than cortisol) and baboon myocardium (R1881 greater than 5 alpha-dihydrotestosterone greater than testosterone greater than progesterone greater than estradiol much greater than cortisol). The function of the androgen-binding component in human adipose tissue is not known.     

Evaluation of risk profiles by subcutaneous adipose tissue topography in obese juveniles

Objective: To compare subcutaneous adipose tissue topography (SAT‐top) in obese juveniles with age‐matched normal‐weight controls. Research Methods and Procedures: The optical device LIPOMETER (European Patent EP 0516251) enables the non‐invasive, rapid, safe, and precise measurement of the thickness of subcutaneous adipose tissue. Fifteen defined body sites (1 = neck to 15 = calf) characterize the individual SAT‐top like an individual fingerprint. SAT‐top of 1351 juveniles (obese: 42 boys, 59 girls, normal weight: 680 boys, 570 girls) from 7 to 19 years of age were measured. For visual comparison, the 15‐dimensional SAT‐top information was condensed by factor analysis into a two‐dimensional factor plot. Results: Both female and male obese juveniles had markedly increased adipose tissue layers at 7 = upper abdomen, 8 = lower abdomen, 5 = front chest, and 6 = lateral chest. The pubertal changes of body shape and fat distribution of the normal‐weight boys and girls (boys show thinner adipose tissue layers on their legs, whereas girls had thicker adipose tissue layers at the extremities) were not seen in the obese group. Independently of age and sex, all of the obese juveniles showed a similar, more android body fat distribution with increased trunk fat. Discussion: SAT‐top of the obese juveniles is similar to that of patients with type 2 diabetes, polycystic ovary syndrome, and coronary heart disease. Patients with these metabolic disorders and obese juveniles are located in the factor plot in the same area. This body shape may indicate a risk profile for developing polycystic ovary syndrome (women), type 2 diabetes, and early atherosclerosis (both sexes).     

Detecting Body Fat–A Weighty Problem BMI versus Subcutaneous Fat Patterns in Athletes and Non-Athletes

We aimed to describe the relationship between BMI and the subcutaneous adipose tissue topography within young athletes and non-athletic controls, to comparatively evaluate the diagnostic powers of subcutaneous adipose tissue thicknesses at different body sites, furthermore to explore appropriate cut-offs to discriminate between athletes and controls. Measurements were determined in 64 males and 42 females, who were subsequently separated into two even groups (athletes and non-athletes). The optical device LIPOMETER was applied at standardised body sites to measure the thickness of subcutaneous adipose tissue layers. To calculate the power of the different body sites and the BMI to discriminate between athletes and non-athletes, receiver operating characteristic curve analysis was performed. In men, the neck (optimal cut-off value 2.3 mm) and trunk (optimal cut-off value 15.5 mm) provided the strongest discrimination power: with 90.6% (58 of 64) of the subjects being correctly classified into athletes or non-athletes. Discrimination power of the BMI values was 64.1% (41 of 64 were correctly classified). In women, the upper back (optimal cut-off value 3.3 mm) and arms (optimal cut-off value 15.9 mm) provided the strongest discrimination power with 88.1% (37 of 42 being correctly classified). When using BMI to discriminate between athletes and non-athletes only 52.4% (22 of 42) were correctly classified. These results suggest that compared to BMI levels, subcutaneous fat patterns are a more accurate way of discriminating between athletes and non-athletes. In particular the neck and the trunk compartment in men and the upper back and arms compartment in women, were the best sites to discriminate between young athletes and non-athletes on the basis of their fat patterns.