Genetic explanations 2: adaptations in body size, shape, and composition

2019 ◽  
pp. 58-74
Author(s):  
Raj S. Bhopal
Keyword(s):  
South Asians ◽  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Lower Limbs ◽  
Skeletal Structure ◽  
Central Adiposity ◽  
Evolutionary Forces ◽  
Fat Deposits ◽  
Central Fat ◽  
Small Muscle

Central body fat has been shown to be metabolically harmful while peripheral fat is neutral or even beneficial. The adipose tissue (compartment) overflow and the variable disease selection hypotheses aim to explain why South Asians tend to central adiposity. The former proposes it results from a small superficial subcutaneous fat compartment especially in the lower limbs, so excess energy is deposited as fat in central compartments. The evolutionary forces for this are presumed to be climatic. The latter proposes central fat deposits in South Asians are an evolutionary adaptation to combat gastrointestinal infections. South Asians’ also have small muscle mass, and small hips, for which there are no well-defined hypotheses. The small size at birth of South Asians may be relevant to all these observations. These differences in fat distribution, muscle and skeletal structure could explain a tendency to central (apple-shaped) obesity than generalized or peripheral obesity (pear-shaped).

A genome-wide linkage scan for familial partial lipodystrophy susceptibility genes in a German kindreds

2007 ◽  
Vol 30 (4) ◽  
pp. 86
Author(s):  
M. Lanktree ◽  
J. Robinson ◽  
J. Creider ◽  
H. Cao ◽  
D. Carter ◽  
...  
Keyword(s):  
Subcutaneous Fat ◽  
Visceral Obesity ◽  
Fat Distribution ◽  
Dominant Negative ◽  
Molecular Forms ◽  
Partial Lipodystrophy ◽  
Genome Wide ◽  
A Genome ◽  
Familial Partial Lipodystrophy ◽  
Promoter Mutations

Background: In Dunnigan-type familial partial lipodystrophy (FPLD) patients are born with normal fat distribution, but subcutaneous fat from extremities and gluteal regions are lost during puberty. The abnormal fat distribution leads to the development of metabolic syndrome (MetS), a cluster of phenotypes including hyperglycemia, dyslipidemia, hypertension, and visceral obesity. The study of FPLD as a monogenic model of MetS may uncover genetic risk factors of the common MetS which affects ~30% of adult North Americans. Two molecular forms of FPLD have been identified including FPLD2, resulting from heterozygous mutations in the LMNA gene, and FPLD3, resulting from both heterozygous dominant negative and haploinsufficiency mutations in the PPARG gene. However, many patients with clinically diagnosed FPLD have no mutation in either LMNA or PPARG, suggesting the involvement of additional genes in FPLD etiology. Methods: Here, we report the results of an Affymetrix 10K GeneChip microarray genome-wide linkage analysis study of a German kindred displaying the FPLD phenotype and no known lipodystrophy-causing mutations. Results: The investigation identified three chromosomal loci, namely 1q, 3p, and 9q, with non-parametric logarithm of odds (NPL) scores >2.7. While not meeting the criteria for genome-wide significance, it is interesting to note that the 1q and 3p peaks contain the LMNA and PPARG genes respectively. Conclusions: Three possible conclusions can be drawn from these results: 1) the peaks identified are spurious findings, 2) additional genes physically close to LMNA, PPARG, or within 9q, are involved in FPLD etiology, or 3) alternative disease causing mechanisms not identified by standard exon sequencing approaches, such as promoter mutations, alternative splicing, or epigenetics, are also responsible for FPLD.

scholarly journals EFFECTS OF BREED AND SEX ON THE PATTERNS OF FAT DEPOSITION AND DISTRIBUTION IN SWINE

1980 ◽  
Vol 60 (2) ◽  
pp. 223-230 ◽  
Author(s):  
S. D. M. JONES ◽  
R. J. RICHMOND ◽  
M. A. PRICE ◽  
R. B. BERG
Keyword(s):  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Allometric Equation ◽  
Muscle Weight ◽  
Constant Weight ◽  
Independent Variables ◽  
Fat Depots ◽  
Wide Range ◽  
Sex Type ◽  
Breed Differences

The growth and distribution of fat from 163 pig carcasses were compared among five breeds (Duroc × Yorkshire (D × Y), Hampshire × Yorkshire (H × Y), Yorkshire (Y × Y), Yorkshire × Lacombe-Yorkshire (Y × L-Y) and Lacombe × Yorkshire (L × Y)) and two sex-types (barrows and gilts) over a wide range in carcass weight. The growth pattern of fat and the fat depots were estimated from the allometric equation (Y = aXb) using side muscle weight and side fat weight separately as independent variables. Growth coefficients (b) for intermuscular and subcutaneous fat depots were similar for the hindquarter but the intermuscular depot coefficient was slightly higher for the forequarter. The coefficient for body cavity fat was highest in all comparisons. No significant differences were detected for coefficients among breeds and between sexes using both total muscle and total side fat as independent variables. Significant breed and sex-type differences were found in the fat depots at a constant weight of side muscle. This would indicate that breed differences in fatness seemed to be more influenced by the initiation of fattening at different muscle weights than by any inherent differences in rate of fattening. Significant breed differences were also found in the fat depots at a constant fat weight, indicating that breed may influence fat distribution. Sex-type had no effect on fat distribution when the evaluation was made at constant fatness.

Evolution of various adipose deposits in growing rabbits and sheep

1975 ◽  
Vol 20 (3) ◽  
pp. 363-370 ◽  
Author(s):  
A. Vezinhet ◽  
M. Prud'hon
Keyword(s):  
Subcutaneous Fat ◽  
Growth Period ◽  
Fatty Tissue ◽  
Relative Importance ◽  
Relative Growth ◽  
Fat Deposits ◽  
Intermuscular Fat ◽  
Total Fat ◽  
Perirenal Fat

SUMMARYThe importance of the different adipose deposits with respect to the total dissectible fatty tissue in growing rabbits and lambs was studied. Development of the subcutaneous fat in the lamb is late and occurs after birth. In contrast, the internal types of fat, such as the perirenal and pelvic fat, represent at birth an important percentage of the total fat. They tend to lose part of their relative importance between 0 and 250 days after birth. In the rabbit the situation concerning the development of subcutaneous and perirenal fat is inverted. For both species the intermuscular fat remains almost constant in relative importance during the whole growth period.After the period required for the establishment of the different fat deposits, we could observe in lambs, and to a smaller degree in rabbits, a relative growth which tends to become isometric with regard to the total fat deposits.

scholarly journals Testosterone therapy decreases subcutaneous fat and adiponectin in aging men

2012 ◽  
Vol 166 (3) ◽  
pp. 469-476 ◽  
Author(s):  
L Frederiksen ◽  
K Højlund ◽  
D M Hougaard ◽  
T H Mosbech ◽  
R Larsen ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fat Mass ◽  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Controlled Study ◽  
Testosterone Therapy ◽  
Testosterone Levels ◽  
Bioavailable Testosterone ◽  
Aging Men ◽  
Total Fat

ObjectiveTestosterone 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.DesignA 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 >94 cm.MethodsCentral 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 placebo-controlled mean effect of intervention.ResultsLEFM was decreased (b=−0.47 kg, P=0.07) while CFM did not change significantly (b=−0.66 kg, P=0.10) during testosterone therapy. SAT (b=−3.0%, P=0.018) and TFA (b=−3.0%, P<0.001) decreased, while VAT (b=1.0%, P=0.54) remained unchanged. Adiponectin levels decreased during testosterone therapy (b=−1.3 mg/l, P=0.001).ConclusionTestosterone therapy decreased subcutaneous fat on the abdomen and lower extremities, but visceral fat was unchanged. Moreover, adiponectin levels were significantly decreased during testosterone therapy.

scholarly journals Dietary and non-dietary determinants of central adiposity among Tehrani women

2007 ◽  
Vol 11 (5) ◽  
pp. 528-534 ◽  
Author(s):  
Leila Azadbakht ◽  
Ahmad Esmaillzadeh
Keyword(s):  
Physical Activity ◽  
Vitamin C ◽  
Pearson Correlation ◽  
Demographic Data ◽  
Analysis Of Covariance ◽  
Dietary Intakes ◽  
Central Adiposity ◽  
Fat Accumulation ◽  
Dairy Consumption ◽  
Central Fat

AbstractObjectiveTo determine the correlates of central adiposity.DesignPopulation-based cross-sectional study.SubjectsA total of 926 women (aged 40–60 years) from all districts of Tehran.MethodsDemographic data were collected and anthropometric indices were measured according to standard protocols. Dietary intakes were assessed by means of a semi-quantitative food-frequency questionnaire. The suggested cut-off point for waist-to-hip ratio (WHR≥0.84) for Tehrani people, adjusted for their age group, was used to determine central adiposity. Logistic regression analysis was used to determine the correlates of WHR, which were adjusted for age, taking medications and body mass index (BMI). The components of dietary intake were determined by factor analysis. Pearson correlation was used to determine the association between the dietary components and WHR. Analysis of covariance was employed to compare the mean values of WHR in different lifestyle groups, with adjustment for BMI and age.ResultsMean WHR was 0.82 ± 0.06. The possibility of being centrally obese was higher in women with light physical activity (odds ratio: 2.11; 95% confidence interval: 1.40–2.53), depressed women (1.36; 1.02–1.93), smokers (1.21; 1.02–1.56) and unemployed women (1.41; 1.13–1.72). Marriage (1.31; 1.10–1.82), menopause (1.22; 1.02–1.61), low vitamin C intake (2.31; 1.25–4.25) and low calcium intake (1.30; 1.07–3.78) were associated with central fat accumulation. Dairy consumption was inversely correlated with central fat accumulation (r = −0.2, P < 0.05).ConclusionCentral adiposity is associated with poor lifestyle factors including low physical activity, depression, smoking, low intake of vitamin C, low intake of calcium and dairy products and high fat consumption. Thus lifestyle modifications should be encouraged to achieve a healthier body shape.

scholarly journals Body fat distribution and metabolic consequences — Examination opportunities in dogs

2014 ◽  
Vol 62 (2) ◽  
pp. 169-179 ◽  
Author(s):  
Linda Müller ◽  
Eszter Kollár ◽  
Lajos Balogh ◽  
Zita Pöstényi ◽  
Teréz Márián ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Fat ◽  
Regional Distribution ◽  
Subcutaneous Fat ◽  
Metabolic Status ◽  
Metabolic Effects ◽  
Body Regions ◽  
Fat Deposits ◽  
The Relationship ◽  
Fat Volume

The relationship between metabolic disorders and the distribution of fat in different body regions is not clearly understood in humans. The aim of this study was to develop a suitable method for assessing the regional distribution of fat deposits and their metabolic effects in dogs. Twenty-five dogs were subjected to computed tomographic (CT) imaging and blood sampling in order to characterise their metabolic status. The different fat areas were measured on a cross-sectional scan, and the animals’ metabolic status was evaluated by measuring fasting glucose, insulin and leptin levels. The volume of visceral adipose tissue is the main determinant of leptin levels. The correlation of visceral fat volume and leptin concentration was found to be independent of insulin levels or the degree of insulin resistance. There was a positive correlation between the visceral to subcutaneous fat volume ratio and serum insulin concentration, and a similar trend was observed in the relationship of fat ratio and insulin resistance. The distribution of body fat essentially influences the metabolic parameters in dogs, but the effects of adiposity differ between humans and dogs. The findings can facilitate a possible extrapolation of results from animal studies to humans with regard to the metabolic consequences of different obesity types.

scholarly journals Independent Genetic Factors Determine the Amount and Distribution of Fat in Women after the Menopause1

1997 ◽  
Vol 82 (3) ◽  
pp. 781-785
Author(s):  
K. Samaras ◽  
T. D. Spector ◽  
T. V. Nguyen ◽  
K. Baan ◽  
L. V. Campbell ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Body Fat ◽  
Genetic Factors ◽  
Central Body ◽  
Strong Predictor ◽  
Model Fitting ◽  
Genetic Influence ◽  
Central Adiposity ◽  
Central Fat ◽  
Total Fat

Abstract Central adiposity is a strong predictor of cardiovascular disease in women. We studied postmenopausal twins to explore the strength and the relationship between genetic influences on body fat and its distribution in a group where cardiovascular disease is the major cause of mortality. Healthy twin women were recruited from a national media campaign. One hundred nineteen monozygotic (MZ) and 97 dizygotic twin pairs were studied (mean ± se age 60 ± 0.3 yr, 10 ± 0.4 yr post menopausal). Total and central body fat were measured by dual-energy x-ray absorptiometry. Intrapair resemblance was significantly greater in MZ pairs for total fat (MZ vs. dizygotic, r = 0.70 ± 0.05 vs. r = 0.46 ± 0.08, P = 0.005) and central fat (r = 0.62 ± 0.06 vs. r = 0.35 ± 0.09, P = 0.005), suggesting a strong genetic influence on these traits. Model-fitting analysis indicated that genetic factors contribute up to 60% of total population variance in both total and central body fat. The heritability of central fat remained, after adjustment for the heritability of total fat, suggesting an independent genetic influence on fat distribution. These results were unchanged after adjusting for the effects of estrogen replacement and smoking. In conclusion, total adiposity and central abdominal fat mass in normal postmenopausal women are under strong genetic influence. The data suggest that some of the genes responsible for central adiposity and its metabolic sequelae will be different from those responsible for total adiposity.

Abstract 13062: Epicardial Fat Associates With Endothelial Dysfunction, but Not With Coronary Calcium Score: From the Elsa-brasil Cohort Study

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Karina P Martins ◽  
Sandhi Barreto ◽  
Daniel Bos ◽  
JESIANA PEDROSA ◽  
Douglas Mesquita ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiovascular Risk ◽  
Coronary Artery ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Cardiovascular Risk Factors ◽  
Subcutaneous Fat ◽  
Epicardial Fat ◽  
Fat Deposits ◽  
Multivariable Analyses

Introduction: Epicardial fat has been related to coronary artery disease (CAD) independent of visceral or subcutaneous fat. The mechanism responsible for this association has not yet been elucidated. Our objective was to evaluate the association between automatically measured epicardial fat volume (EFV), cardiovascular risk factors, coronary artery calcium (CAC) and endothelial function in participants of ELSA-Brasil. Methods and Results: The sample comprised 470 (mean age 55± 8y, 52.3% men) participants from ELSA-MG, one of the Investigation Centers of the cohort, who had valid computed tomography scans and endothelial function evaluated by peripheral arterial tonometry (PAT). The mean EFV was 111 (IQ 86-144) mL. CAC=0 was detected in 55% of participants. In the multivariable analyses between cardiovascular risk factors and EFV, the following associations were observed with higher EFV: female sex; and increased age, waist circumference and triglycerides (p <0.001 for all). In multivariable analyses, higher EFV remained associated with worse endothelial function - basal pulse amplitude (q2=1.22, CI95% 1.07-1.40, p=0.004; q3=1.50, CI95% 1.30-1.74, p<0.001; q4=1.50, CI95% 1.28-1.79, p<0.001) and PAT ratio (q2=0.87, CI95% 0.81-0.95, p<0.001; q3=0.86, CI95% 0.79-0.94, p<0.001; q4=0.80, CI95% 0.73-0.89, p<0.001), but not with CAC. Conclusions: Higher EFV was associated with impaired endothelial function, but not with higher CAC. Our results suggest that the mechanism by which epicardial fat deposits relates to CAD may be different from the pathway of CAC, which relates to calcified plaques. A possible mechanism may be through the enhancement of endothelial dysfunction, microvascular disease and predominantly lipidic non-calcified plaques.

Sign in / Sign up

Export Citation Format

Share Document