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Subcutaneous fat composition

Subcutaneous fat composition

Article CAS Subcutaneous fat composition Scholar Bucci M, Karmi Subcutanrous, Iozzo P, Commposition BA, Viljanen A, Subcutaneeous RM et al. Subcutaneoks Subcutaneous fat composition two low-level X-ray Pre-exercise nutrition to develop estimates of fat-free mass, fat mass, and bone mineral density. Diabetes Mellitus and Obesity 6th ed. The thrifty gene hypothesis also called the famine hypothesis states that in some populations the body would be more efficient at retaining fat in times of plenty, thereby endowing greater resistance to starvation in times of food scarcity. If you cannot sign in, please contact your librarian.

Subcutaneous fat composition -

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Cardiometabolic diseases are primarily linked to enlarged visceral adipose tissue VAT. However, some data suggest heterogeneity within the subcutaneous adipose tissue SAT depot with potential metabolic differences between the superficial SAT sSAT and deep SAT dSAT compartments.

We aimed to investigate the heterogeneity of these three depots with regard to fatty acid FA composition and gene expression. Adipose tissue biopsies were collected from 75 obese women undergoing laparoscopic gastric bypass surgery. FA composition and gene expression were determined with gas chromatography and quantitative real-time-PCR, respectively.

Stearoyl CoA desaturase-1 SCD-1 activity was estimated by product-to-precursor FA ratios. All polyunsaturated FAs PUFA with 20 carbons were consistently lower in VAT than either SAT depots, whereas essential PUFA linoleic acid, n-6 and α-linolenic acid, n-3 were similar between all three depots.

Lauric and palmitic acid were higher and lower in VAT, respectively. The SCD-1 product palmitoleic acid as well as estimated SCD-1 activity was higher in VAT than SAT. Overall, there was a distinct association pattern between lipid metabolizing genes and individual FAs in VAT.

In conclusion, SAT and VAT are two distinct depots with regard to FA composition and expression of key lipogenic genes. However, the small differences between sSAT and dSAT suggest that FA metabolism of SAT is rather homogenous. Excess adipose tissue and obesity predispose to metabolic disease.

Recently, it was also reported that dSAT harbors more saturated FAs than sSAT as assessed by magnetic resonance imaging spectroscopy 7 or gas chromatography.

In Spanish overweight and obese subjects, there were specific differences in FA composition between omental VAT, perivisceral VAT and SAT. However, the authors did not investigate dSAT and sSAT. FA composition and gene expression have previously been compared between different adipose depots 6 , whereas knowledge about the associations between FAs and gene expressions within each depot is lacking.

The aim of the present study was to determine if FA composition, desaturase activity, and the association between FAs and expression of key lipogenic genes differ between the three different abdominal adipose tissue depots in a large sample of obese subjects undergoing laparoscopic gastric bypass surgery.

Exclusion criteria for bariatric surgery were several, and included severe psychiatric disease and uncontrolled binge eating. The mean age of the study population was 39±10 years and body mass index was The subjects approved participation through written informed consent.

All biopsies were collected during the Roux-en-Y gastric bypass surgery. The biopsies from sSAT and dSAT were obtained from the upper left side of the abdomen, through the opening used for accessing the abdominal cavity with surgical instruments.

The VAT biopsies were taken from the greater omentum in conjunction with its division. No complications occurred. Aliquots of the biopsies were used to measure FA composition. Percentages of individual FAs were measured in total adipose tissue triglycerides using gas chromatography as previously described.

The real-time reverse transcription-PCR and pre-PCR procedures were performed on a representative subgroup consisting of the 47 patients 38±10 years and TaqMan probes from Applied Biosystems, CA, USA were used.

The expression was normalized against LRP10 expression. Data are presented as mean±s. Non-parametric tests were used since many of the variables were not normally distributed even after log transformation.

All statistical tests were analyzed using IBM SPSS Statistics Table 1 presents FA composition in the three examined depots. Notably, FA profiles differed mainly between VAT and SAT.

The only FAs displaying differential levels between sSAT and dSAT were n-6 and n-6, which were slightly lower in dSAT. The proportions of the essential diet-derived PUFA n-6 and n-3, which are also precursors for longer PUFA, were similar between all adipose tissue depots.

In addition to this, VAT showed lower , and higher n The gene expression differed between the depots but could not explain the regional differences in FA composition. For instance, although SCD-1 expression was lower in VAT, levels were higher data not shown.

Therefore, the FA levels within each depot were compared with the expression of a few key lipogenic genes selected from hypothesis-based interactions with FA composition, that is, genes involved in FA uptake, signaling and metabolism Figure 1. The correlation pattern differed between the depots with a distinct pattern for VAT.

SCD-1 expression was consistently associated with estimated SCD activity including n-7 in sSAT and dSAT, but not significantly in VAT. Only the correlations with and with SCD-1 expression in the SAT depots remained significant after a Bonferroni correction of P -values.

The saturation of SAT was predominantly associated with SCD-1 expression whereas the saturation of VAT was associated with MLXIPL expression.

Expression of TLR4 and FFAR4 were more pronouncedly correlated with FA levels in dSAT in comparison to sSAT and VAT. This is the first study that has compared FA composition and its relationship with the expression of genes involved in desaturation and lipogenesis in all three abdominal adipose tissue depots.

We observed differences in FA composition between SAT and VAT but, in contrast to what has been previously suggested, 6 , 7 sSAT and dSAT displayed similar FA profiles. However, the relationships between FAs and gene expression differed among all depots suggesting some heterogeneity within SAT.

The consistently lower proportions of non-essential PUFA in VAT versus the SAT depots have not been reported previously. The fact that essential FAs—n-6 and n-3—were similar between the depots indicates that the variations in the non-essential PUFA are due to differences in endogenous FA turnover rather than dietary intake.

The FA composition of SAT and omental VAT has previously been investigated in a Mediterranean population. These discrepancies might be explained by important differences in the study design, for instance that the subjects in the current study underwent an LCD intervention prior to biopsy.

Speculatively, a hypocaloric state may decrease the more easily oxidized PUFA in VAT, a depot which has an elevated lipolytic activity compared with SAT. In fact, n-3 has been shown to be the most readily oxidized PUFA and would therefore have been expected to be lower in VAT.

Noteworthy is that the present study compared the sub-depots of SAT in 75 participants compared with 30—43 subjects in previous reports. Other differences between the studies include the methodology used for assessment of FA composition, and phenotype, that is, gas chromatography versus magnetic resonance imaging and obese versus non-obese, respectively.

We investigated if FA composition associates with gene expression of lipogenic genes, but we could not observe any consistent associations across the depots. Studies have previously shown that gene expression levels vary between the depots studied herein.

In fact, the transcriptional response to stimuli, such as glucocorticoids, differs between VAT and SAT. This should be taken into consideration when comparing the regulation of FA composition in different depots since the responsible factors may differ.

Furthermore, expression levels of TLR4 , which SFA bind and induce inflammation through 20 , were negatively associated with SFA and positively associated with MUFA levels in dSAT but not in the other depots. Speculatively, this may be explained by a protective feature of dSAT against FA induced inflammation.

An interesting observation was the correlation pattern across the depots. Although not entirely consistent, SFA exhibited a negative association with lipogenic genes in dSAT and a positive association in VAT with reversed observations for MUFAs.

Similar patterns were observed for n-6 PUFA. Further, although inconclusive, VAT seemed to be more similar to sSAT than dSAT with regard to associations between FAs and gene expressions. Secondly, FA species are ligands to nuclear receptors and modulate cellular processes directly through transcriptional regulation.

These larger fat cells become resistant to insulin, which increases the risk of type 2 diabetes and cardiovascular disease. Weight loss can reduce the size of fat cells but not the number.

Obesity, defined as an excessive amount of body fat, is a common and expensive medical condition in the U. Obesity, or body fatness, is calculated with various methods that range in accuracy and have limitations. Combining two or more methods, if possible, may better predict if someone has increased health risks related to weight.

One of the most widely used tools for estimating excess fat is the body mass index BMI. In comparison with these methods that require expensive equipment, BMI is noninvasive, easy to calculate, and can be used anywhere. Because of its simplicity and widespread use, BMI is often used when studying populations.

Researchers can compare the BMI of groups of people over time in different areas, to screen for obesity and its related health risks. BMI does have several limitations. For these reasons, BMI might be used as a screening tool for potential weight-related problems rather than to diagnose certain conditions.

The accuracy of BMI in predicting health risk may vary across different individuals and racial and ethnic groups. Some populations have higher rates of obesity but that do not have corresponding rates of metabolic diseases like diabetes, and vice versa.

BMI might be supplemented with other measures such as waist circumference or waist-hip ratio that better assess fat distribution. When examining the relationship between BMI and mortality, failure to adjust for these variables can lead to reverse causation where a low body weight is the result of underlying illness, rather than the cause or confounding by smoking because smokers tend to weigh less than non-smokers and have much higher mortality rates.

Experts say these methodological flaws have led to paradoxical, misleading results that suggest a survival advantage to being overweight. Some researchers consider waist circumference to be a better measure of unhealthy body fat than BMI as it addresses visceral abdominal fat, which is associated with metabolic problems, inflammation, and insulin resistance.

In people who do not have overweight, increasing waist size over time may be an even more telling warning sign of increased health risks than BMI alone. Wear thin clothing or no clothing. Stand up straight and wrap a flexible measuring tape around your midsection, laying the tape flat so it crosses your navel belly button.

The tape should be snug but not pinched too tightly around the waist. You can repeat the measurement times to ensure a consistent reading.

According to an expert panel convened by the National Institutes of Health, a waist size larger than 40 inches for men and 35 inches for women increases the chances of developing heart disease, cancer, or other chronic diseases.

Like the waist circumference, the waist-to-hip ratio WHR is used to measure abdominal obesity. It is inexpensive and simple to use, and a good predictor of disease risk and early mortality. Some believe that WHR may be a better indicator of risk than waist circumference alone, as waist size can vary based on body frame size, but a large study found that waist circumference and WHR were equally effective at predicting risk of death from heart disease, cancer, or any cause.

The World Health Organization has also found that cut-off points that define health risks may vary by ethnicity. For example, Asians appear to show higher metabolic risk when carrying higher body fat at a lower BMI; therefore the cut-off value for a healthy WHR in Asian women is 0.

Stand up straight and follow the directions for measuring waist circumference. Then wrap the tape measure around the widest part of the buttocks.

Divide the waist size by the hip size. The WHO defines abdominal obesity in men as a WHR more than 0. Waist-to-height ratio WHtR is a simple, inexpensive screening tool that measures visceral abdominal fat. It has been supported by research to predict cardiometabolic risk factors such as hypertension, and early death, even when BMI falls within a healthy range.

To determine WHtR, divide waist circumference in inches by height in inches. A measurement of 0. Equations are used to predict body fat percentage based on these measurements.

It is inexpensive and convenient, but accuracy depends on the skill and training of the measurer. At least three measurements are needed from different body parts.

The calipers have a limited range and therefore may not accurately measure persons with obesity or those whose skinfold thickness exceeds the width of the caliper. BIA equipment sends a small, imperceptible, safe electric current through the body, measuring the resistance.

The current faces more resistance passing through body fat than it does passing through lean body mass and water. Equations are used to estimate body fat percentage and fat-free mass.

Readings may also not be as accurate in individuals with a BMI of 35 or higher. Individuals are weighed on dry land and then again while submerged in a water tank. This method is accurate but costly and typically only used in a research setting.

It can cause discomfort as individuals must completely submerge under water including the head, and then exhale completely before obtaining the reading. This method uses a similar principle to underwater weighing but can be done in the air instead of in water.

It is expensive but accurate, quick, and comfortable for those who prefer not to be submerged in water. Individuals drink isotope-labeled water and give body fluid samples.

Researchers analyze these samples for isotope levels, which are then used to calculate total body water, fat-free body mass, and in turn, body fat mass.

X-ray beams pass through different body tissues at different rates. DEXA uses two low-level X-ray beams to develop estimates of fat-free mass, fat mass, and bone mineral density. It cannot distinguish between subcutaneous and visceral fat, cannot be used in persons sensitive to radiation e.

These two imaging techniques are now considered to be the most accurate methods for measuring tissue, organ, and whole-body fat mass as well as lean muscle mass and bone mass. However, CT and MRI scans are typically used only in research settings because the equipment is extremely expensive and cannot be moved.

While some white fat is necessary for good health, too much white fat is very harmful. Healthy body fat percentages range depending on your level of fitness or physical activity. According to the American Council on Exercise , men who are non-athletes should have a total body fat percentage in the 14 to 24 percent range, while women who are non-athletes should be in the 21 to 31 percent range.

A body fat percentage higher than recommended can put you at risk for the following health issues:. Brown fat is a type of fat primarily found in babies, although adults do still retain a very small amount of brown fat, typically in the neck and shoulders. This type of fat burns fatty acids to keep you warm.

Researchers are interested in finding ways to stimulate the activity of brown fat to help prevent obesity. Beige or brite fat is a relatively new area of research.

These fat cells function somewhere between brown and white fat cells. Similarly to brown fat, beige cells can help burn fat rather than store it. This is an exciting area of research to possibly help prevent obesity and maximize healthy body fat levels.

Essential fat is exactly that — essential for your life and a healthy body. This fat is found in your:. Essential fat plays a major role in hormone regulation, including the hormones that control fertility, vitamin absorption, and temperature regulation.

According to the American Council on Exercise , women need at least 10 to 13 percent of their body composition to come from essential fat to be in good health, while men require at least 2 to 5 percent. Subcutaneous fat refers to the fat stored under the skin.

The majority of our body fat is subcutaneous. Fitness professionals use calipers to measure subcutaneous fat as a way of estimating total body fat percentage. A certain amount of subcutaneous fat is normal and healthy, but too much can lead to imbalanced hormone levels and sensitivity.

High visceral fat levels can increase your risk for diabetes, heart disease, stroke, artery disease, and some cancers. Body composition is very important.

Your body will function best with an appropriate overall fat percentage. Having a healthy body fat percentage provides many benefits, such as:.

Having too much white fat, particularly visceral fat, can be harmful to your health. Visceral fat can increase your risk for the following health conditions:.

Body composition can be measured using several methods. One common method of estimating body fat percentage is skinfold measurements. A trained technician can use calipers, a tong-like instrument, to pinch and measure folds of skin on your arms, waist, and thighs to estimate total body fat percentage.

Another method is using a device called the Bod Pod. During a body composition assessment, the devise uses body weight and volume ratios to determine total fat percentage. This method theoretically measures all types of fat present in your body. Bioelectrical impedance analysis is another method of determining body fat percentage.

This test involves standing on a device that uses electrical current to measure the amount of lean versus fatty mass in your body. Body mass index BMI and waist circumference tests may also be helpful.

BMI is calculated as a ratio of weight to height, while waist circumference is a measurement of the smallest part of the waist. According to the National Institutes of Health NIH , a BMI greater than 25 is considered overweight, while a BMI over 30 is considered obese.

Thank you Beta-carotene and digestive health visiting nature. Shbcutaneous are using a browser version with fxt support for CSS. Subcutaneeous obtain the best experience, Beta-carotene and digestive health recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Cardiometabolic diseases are primarily linked to enlarged visceral adipose tissue VAT. Subcutaneous fat composition

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