Regional fat deposition in the legs is useful as a presumptive marker of antiatherogenesity in Japanese

Different Associations of Trunk and Lower-Body Fat Mass Distribution with Cardiometabolic Risk Factors between Healthy Middle-Aged Men and Women

The aim of this study was to assess whether the gender-specific pattern of fat mass (FM) distribution is related to gender differences in cardiometabolic risk factors. 207 healthy middle-aged Japanese were included in the study. We measured FM in the total body, trunk, and lower-body with dual-energy X-ray absorptiometry (DXA). The percentage of trunk FM (TFM) and lower-body FM (LFM) is noted as %TFM and %LFM, respectively. Other measurements included glucose and insulin during oral glucose tolerance test (OGTT), leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and systemic oxidative stress marker. Arterial properties were indicated by cardio-ankle vascular index (CAVI) and intima-media thickness (IMT) of the common carotid artery. The results showed that %TFM is higher whereas %LFM is lower in men than in women and men have a more atherogenic cardiometabolic profile. In both genders, %TFM (%LFM) is related to an unfavorable (favorable) cardiometabolic profile. In particular, the relation between %LFM and OGTT-derived insulin sensitivity index is stronger in women than in men. These findings suggested that in relatively healthy adults, android and gynoid pattern of FM distribution contributes to gender differences in cardiometabolic risk factors.

Subcutaneous Fat Accumulation Shows a Beneficial Correlation with Serum Cholesterol in Postmenopausal Japanese Women

This study aimed to investigate whether accumulation of subcutaneous abdominal fat has a beneficial correlation with lipid metabolism in premenopausal and/or postmenopausal Japanese women. The study enrolled 146 premenopausal women, ranging in age from 19 to 54 years, and 82 postmeno-pausal women, ranging in age from 47 to 66 years. Fat distribution, including abdominal visceral fat area (VFA) and abdominal subcutaneous fat area (SFA), were measured in an outpatient clinic by magnetic resonance imaging. Homogeneity of the regression slopes for SFA to total cholesterol ( P = 0.030), low-density lipoprotein cholesterol ( P = 0.020), apolipoprotein B (apoB) ( P = 0.001), and the ratio of apoB to apolipoprotein A-I (apoA-I) ( P = 0.003) were not found between premenopausal and postmenopausal women, even after adjustment for both VFA and age. However, the regression slopes for VFA to all measured lipid parameters, as well as apolipoproteins, were homogeneous between the premenopausal and postmeno-pausal groups. Abdominal SFA in postmenopausal women correlated negatively with total cholesterol ( P = 0.007), low-density lipoprotein cholesterol ( P = 0.002), apoB ( P < 0.001), and the ratio of apoB to apoA-I ( P = 0.001), after adjustment for age and VFA, but this was not the case in premenopausal women. The mechanisms involved in the beneficial effects of subcutaneous fat accumulation in postmenopausal women remain obscure, but upregulated aromatase expression, derived from adipose tissue, may possibly improve lipid and apolipoprotein metabolism.

Visceral abdominal and subfascial femoral adipose tissue have opposite associations with liver fat in overweight and obese premenopausal caucasian women

Abdominal obesity has been associated with liver fat storage. However, the relationships between other body composition depots and metabolic syndrome features with hepatic fat are still unclear. We examined abdominal and thigh adipose tissue (AT) compartments associations with liver fat in 140 overweight and obese premenopausal Caucasian women. Blood lipids and, proinflammatory and atherothrombotic markers associations with hepatic fat were also analyzed. A larger visceral AT (VAT) was related with liver fat (P < 0.05). Contrarily, thigh subfascial AT was inversely related to liver fat (P < 0.05). Increased fasting insulin, triglycerides, PAI-1 concentrations, and a higher total-cholesterol/HDL-cholesterol ratio were also associated with hepatic fat, even after adjustment for VAT (P < 0.05). Thigh subfascial adiposity was inversely associated with liver fat, suggesting a potential preventive role against ectopic fat storage in overweight and obese women. These results reinforce the contribution of an abdominal obesity phenotype associated with a diabetogenic and atherothrombotic profile to liver lipotoxicity.

Effect of loss of regional fat assessed by DXA on insulin resistance and dyslipidaemia in obese men

OBJECTIVE

To investigate the impact of reduction in total fat mass (FM) and regional FMs on indices of insulin resistance and dyslipidaemia in obese men (BMI > 30 kg/m²) after a 1-year weight loss (WL), and secondly, to examine the potential predictive effect of baseline insulin resistance on reduction in total and regional FMs.

MATERIAL AND METHODS

In nine men with WL > 4 kg, body composition by DXA (dual X-ray absorptiometry) and indices of insulin resistance were assessed: fasting insulin, C-Peptide and HOMA-IR. Insulin sensitivity (QUICKI) and serum lipids were also assessed.

RESULTS

Mean WL was 10.8%; Δ trunk and Δ leg FM were reduced by 30.1% and 21.3%, respectively, increasing leg/trunk FM ratio by 13.2%. Improvement in HOMA-IR was 63.1%, insulin 59.1%, and in QUICKI 17.4%. Loss of total FM, trunk FM, and increase in leg/trunk FM ratio were correlated with improvement in HOMA-IR (p < 0.001-0.05). Linear regression analysis of ln-transformed improvements in HOMA-IR was non-significantly related with losses of trunk FM and increases in leg/trunk FM ratio (p = 0.06). Multivariate analysis suggested improvements in fasting insulin and C-Peptide could be explained by leg/trunk FM ratio (R² = 0.60, p = 0.013, R² = 0.37, p = 0.012, respectively) and in HOMA-IR by trunk FM (R² = 0.42, p = 0.06). The loss of FM and change in FM distribution had no effect on serum lipids.

CONCLUSION

Both loss of trunk FM and increase in leg/trunk FM ratio assessed by DXA contribute to the improvement in insulin resistance.

Regional adiposity and risk for coronary artery disease in type 1 diabetes: does having greater amounts of gluteal-femoral adiposity lower the risk?

AIMS

Evidence suggests that the degree of gluteal-femoral adiposity may be inversely associated with coronary artery disease (CAD) risk; however, this association has not been evaluated in type 1 diabetes (T1D).

METHODS

The relationship between regional adiposity, cardiovascular risk factors, and presence of CAD was examined in participants from the Pittsburgh Epidemiology of Diabetes Complications (EDC) study using data collected from the 18-year exam (n=163). Total and regional adiposity was assessed by dual X-ray absorptiometry (DEXA).

RESULTS

Participants with CAD exhibited lower % leg fat mass (FM) (33.42 vs. 36.96, p=0.006) and higher % trunk FM (48.33 vs. 45.18, p=0.02), respectively, after adjusting for age, sex, height, and total adiposity compared to those without CAD. Multivariate logistic regression analyses revealed that in females, every 1 SD increase in % leg FM was associated with an approximate 60% reduction in CAD risk (OR=0.40, 95% CI 0.16-0.99). Higher % trunk FM was also associated with greater risk of CAD prevalence in females (OR=2.79, 95% CI 1.08-7.20 per SD change). These associations were not observed in males.

CONCLUSIONS

This is novel evidence that DEXA-assessed lower body adiposity is inversely associated with CAD in T1D, however, this association seems to only exist in females.

Effect of regional fat loss assessed by DXA on insulin resistance and dyslipidaemia in obese women

OBJECTIVE

To investigate the impact of reduction in total fat mass (FM) and regional FMs on indices of insulin resistance and dyslipidaemia in obese women (BMI > 30 kg/m(2)) after a 1-year weight loss (WL) program; and, secondly, to investigate the potential predictive effect of baseline insulin resistance on reduction in total and regional FMs.

MATERIAL AND METHODS

In 35 women with > 4 kg weight loss, body composition by DXA (dual X-ray absorptiometry), fasting insulin, C-Peptide, insulin resistance (HOMA-IR), insulin sensitivity (QUICKI), metabolic clearance rate (MCRestOGTT) and serum lipids were assessed.

RESULTS

Mean WL was 9.6%; trunk and leg FM were reduced proportionally (14.9-14.7%). Improvement in HOMA-IR was 34.7%, insulin 30.7%, QUICKI 8.6% and MCRest OGTT 74%. The reduction in total, trunk and leg FM were similarly correlated with improvement in indices of insulin resistance (p < 0.001-0.05) and also with initial HOMA-IR (p = 0.000-0.02). In linear regressions improvement in HOMA-IR was similarly related with these FMs (p = 0.008), and initial HOMA predicted loss of trunk FM (p = 0.01). In multivariate analysis improvement in HOMA-IR was explained by loss of total FM (R(2) = 0.20, p = 0.004); improvement of QUICKI by loss of leg FM (R(2) = 0.33, p < 0.001).

CONCLUSION

Loss of leg FM and trunk FM had similar importance for the improvement in insulin resistance. Baseline HOMA-IR predicted the potential for reduction in trunk FM.

Racial differences in body fat distribution among reproductive-aged women

We examined the influence of race/ethnicity on body fat distribution for a given body mass index (BMI) among reproductive-aged women. Body weight, height, and body fat distribution were measured with a digital scale, wall-mounted stadiometer, and dual-energy x-ray absorptiometry, respectively, on 708 healthy black, white, and Hispanic women 16 to 33 years of age. Multiple linear regression was used to model the relationship between race/ethnicity and different body fat distribution variables after adjusting for BMI, age at menarche, and demographic and lifestyle variables. For a given BMI, white women had the highest total fat mass (FM(total)), trunk fat mass (FM(trunk)), and leg fat mass (FM(leg)), whereas Hispanic women had the highest percentage of FM(trunk) (%FM(trunk)) and trunk-to-limb fat mass ratio (FMR(trunk-to-limb)). Conversely, black women had the lowest FM(total), FM(trunk), percentage body fat mass (%FM), %FM(trunk), and FMR(trunk-to-limb), and the highest percentage of FM(leg). The %FM was similar in whites and Hispanics and lower in blacks. The race x BMI interactions were significant for almost all of the body fat distribution variables. Increasing in differences with increasing BMI were apparent between blacks and whites in FM(trunk), %FM(trunk), FMR(trunk-to-limb), %FM(leg), and %FM, and between blacks and Hispanics in FM(trunk), %FM(trunk), FMR(trunk-to-limb), and FM(leg). In summary, the distribution of body fat for a given BMI differs by race among reproductive-aged women. These findings raise questions regarding universally applied BMI-based guidelines for obesity and have implications for patient education regarding individual risk factors for cardiovascular disease and metabolic complications.

Leg fat mass as measured by dual X-ray absorptiometry (DXA) impacts insulin resistance differently in obese women versus men

OBJECTIVE

To investigate the association between regional fat mass (FM) and insulin resistance and dyslipidaemia in obese women and men.

MATERIAL AND METHODS

Body composition was measured by dual-energy X-ray absorptiometry (DXA) in 109 obese women and 113 obese men. Insulin resistance was measured by (HOMA-IR); insulin sensitivity was estimated by metabolic clearance rate (MCRestOGTT) and insulin secretion by HOMAsecr. Serum lipids were assessed.

RESULTS

In women, leg FM was negatively (favourably) associated with HOMA-IR and cholesterol/HDL-cholesterol ratio (p<0.05). Trunk FM was positively (unfavourably) associated with HOMA-IR. Leg/trunk FM ratio was negatively associated with HOMA-IR (p<0.001), cholesterol/HDL-cholesterol ratio (p<0.001) and triglycerides (p<0.01); positively (favourably) with MCRestOGTT (p<0.01) and HDL-cholesterol (p<0.05). No associations were found in men. In women, multiple regression analysis demonstrated that leg/trunk FM ratio was the only explanatory FM for HOMA-IR and MCRestOGTT (R(2) = 0.23 and R(2) = 0.13, respectively; p<0.001), but postmenopausal status was also of importance (R(2) = 0.23, p = 0.019 and R(2) = 0.29, p = 0.015, respectively).

CONCLUSIONS

Leg FM has a favourable influence on insulin resistance and dyslipidaemia in obese women, but not demonstrated in this cohort of obese men.

Independent and opposite associations of hip and waist circumference with metabolic syndrome components and with inflammatory and atherothrombotic risk factors in overweight and obese women

Recent studies have shown independent and opposite associations of hip circumference (HC) and waist circumference (WC) with glucose intolerance, insulin resistance, and type 2 diabetes mellitus. However, no studies have simultaneously considered the independent contributions of both markers to metabolic proinflammatory and atherosclerotic risk factors. In this study, we examine the independent associations of WC and HC with metabolic syndrome and with proinflammatory and atherothrombotic features. Independent associations of thigh muscle and adipose tissue (AT) compartments with metabolic features were also studied. Abdominal and thigh muscle and AT distributions were assessed by computed tomography in 140 overweight and obese women (mean +/- SD: age, 38.3 +/- 0.5 years; body mass index, 30.4 +/- 0.3 kg/m(2)). Blood lipids and inflammatory and atherothrombotic markers were measured. For a given WC, a larger HC was inversely associated with fasting insulin (beta = -0.288, P = .008), hemoglobin A(1c) (beta = -0.246, P = .041), and plasminogen activator inhibitor-1 concentrations (beta = -0.241, P = .023). Contrarily, WC was related with an unfavorable metabolic profile. For a given WC, higher total thigh AT and total thigh subcutaneous AT masses were associated with lower hemoglobin A(1c) (beta = -0.244, P = .049; beta = -0.233, P = .049) and low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (beta = -0.252, P = .040; beta = -0.245, P = .037). In addition, total thigh AT was related with leptin (beta = 0.310, P = .012), whereas total thigh subcutaneous AT revealed opposite associations with fasting insulin concentrations (beta = -0.239, P = .034). Total thigh muscular tissue mass was related with lower plasminogen activator inhibitor-1 (beta = -0.164, P = .049) and fibrinogen concentrations (beta = -0.222, P = .018). In conclusion, HC revealed independent and opposite associations with insulin resistance and atherothrombotic disturbances. Contrarily, a larger WC predicted an increased metabolic risk. These contrasting effects in diabetogenic and atherothrombotic disturbances were, respectively, mediated by gluteofemoral AT and thigh muscle tissue. Besides body mass index and WC screening relevance, HC can contribute to additionally predict health risk in overweight and obese women.

Regional fat mass by DXA: high leg fat mass attenuates the relative risk of insulin resistance and dyslipidaemia in obese but not in overweight postmenopausal women

OBJECTIVE

To investigate the influence of regional fat mass (FM) on insulin resistance and dyslipidaemia in obese postmenopausal women (BMI >30 kg/m(2)) compared to overweight women (BMI <30 kg/m(2)). Leg FM may attenuate the increased risk of cardiovascular disease and diabetes imposed by increased trunk FM in normal and overweight postmenopausal women.

MATERIAL AND METHODS

Cross-sectional and consecutively referred patients comprising 63 obese and 36 overweight postmenopausal women. Body composition and regional FM by dual X-ray absorptiometry (DXA), fasting glucose, fasting insulin and C-peptide, insulin resistance by homeostasis model assessment (HOMA-IR), insulin sensitivity by quantitative insulin sensitivity check index (QUICKI) and metabolic clearance rate (MCRestOGTT), insulin secretion (HOMAsecr) and serum lipids were assessed.

RESULTS

In obese subjects, leg FM was favourably associated with HOMA-IR (p<0.05), QUICKI (p<0.05), fasting glucose (p<0.05), fasting insulin (p<0.05), HOMAsecr (p<0.05) and total cholesterol/HDL ratio (p<0.05). Trunk FM was unfavourably associated with MCRestOGTT (p<0.01), QUICKI (p<0.05) and fasting insulin (p<0.05). Compared to leg FM, leg/trunk FM ratio was more strongly associated with fasting insulin (p<0.001), fasting C-peptide (p<0.001), HOMA-IR (p<0.001), MCRestOGTT (p<0.001), QUICKI (p<0.001), HOMAsecr (p<0.001), fasting glucose (p<0.01) and triglycerides (p<0.01). Stepwise multiple regression demonstrated that leg/trunk FM ratio was the most important variable with partial R (2) = 0.26 (p<0.001) for HOMA and R (2) = 0.37 (p<0.001) when QUICKI was used as the dependent variable. In overweight women, no associations between fat mass and parameters of insulin resistance or dyslipidaemia were found.

CONCLUSIONS

A high leg/trunk FM ratio as measured by DXA may give relative protection against diabetes and cardiovascular disease in obese postmenopausal women, but not in overweight women.

Regional body fat distribution and metabolic profile in postmenopausal women

The aim of the study was to examine how body fat distribution variables were associated with metabolic parameters in a sample of 113 postmenopausal women not receiving hormone therapy (56.9 +/- 4.4 years, 28.4 +/- 5.1 kg/m(2)). Body fat distribution variables (visceral adipose tissue [AT], subcutaneous AT, and total midthigh AT) were measured using computed tomography; body fat mass was assessed by hydrostatic weighing; insulin sensitivity was determined with the euglycemic-hyperinsulinemic clamp; fasting plasma glucose (FPG) and 2-hour plasma glucose (2hPG) concentrations were measured by a 75-g oral glucose load; and (high-sensitivity) C-reactive protein (hs-CRP) was measured using a highly sensitive assay. After controlling for fat mass, visceral AT was positively associated with plasma triglyceride, hs-CRP, FPG, and 2hPG, and negatively associated with high-density lipoprotein cholesterol (HDL-C) and insulin sensitivity. Total midthigh AT was negatively associated with apolipoprotein B, FPG, and 2hPG, and positively associated with insulin sensitivity. Stepwise multiple regression analyses including abdominal visceral AT, subcutaneous AT and total midthigh AT as independent variables showed that abdominal visceral AT best predicted the variance in plasma triglyceride, HDL-C, low-density lipoprotein peak particle size, hs-CRP, FPG, 2hPG, and insulin sensitivity. Abdominal subcutaneous AT was a significant predictor of only insulin sensitivity, whereas total midthigh AT predicted HDL-C, low-density lipoprotein peak particle size, and apolipoprotein B. These multivariate analyses also indicated that total midthigh AT was favorably related to these outcomes, whereas abdominal visceral AT and subcutaneous AT were unfavorably related. These results confirmed that abdominal visceral fat is a critical correlate of metabolic parameters in postmenopausal women. In addition, a higher proportion of AT located in the total midthigh depot is associated with a favorable metabolic profile.

Is the reduction of lower-body subcutaneous adipose tissue associated with elevations in risk factors for diabetes and cardiovascular disease?

AIMS/HYPOTHESIS

Since the accumulation of lower-body subcutaneous adipose tissue (LBSAT) is associated with decreased cardiometabolic risk, we evaluated whether reductions in LBSAT independent of changes in visceral AT (VAT) and abdominal SAT are associated with elevations in diabetes and cardiovascular disease risk factors.

METHODS

Overweight and obese men (n = 58) and premenopausal women (n = 49) with elevated cardiometabolic risk underwent 3 months of diet and/or exercise induced weight-loss treatment; regional body composition assessment by magnetic resonance imaging (MRI); and cardiometabolic risk assessment, including an OGTT.

RESULTS

After control for potential confounders, reductions in VAT, abdominal SAT and LBSAT were all associated with improvements in selective cardiometabolic risk factors, including fasting glucose levels, lipid status and OGTT glucose and insulin. Independent of changes in the other AT depots, reductions in VAT and abdominal SAT, but not LBSAT, remained associated with improvement in fasting glucose levels, glucose tolerance and lipid status.

CONCLUSIONS/INTERPRETATION

Among overweight and obese adults with increased cardiometabolic risk, the selective reduction of LBSAT is not associated with elevations in risk factors for diabetes and cardiovascular disease. Thus, the reduction of excess AT conveys health benefit regardless of origin.

Adipose tissue, insulin resistance and low-grade inflammation: implications for atherogenesis and the cardiovascular harm of estrogen plus progestogen therapy

OBJECTIVE

To summarize recent findings providing mechanistic insight into why the relative presence of central to peripheral fat mass is a critical determinant of atherogenesis and why postmenopausal women with android obesity represent a risk population with increased susceptibility to the cardiovascular harm of estrogen plus progestin therapy (EPT).

METHODS

Review of own research and related literature in PubMed.

RESULTS

In postmenopausal women, android obesity characterized by excessive upper-body combined with relatively poorly developed lower-body fat mass is frequently associated with insulin resistance, low-grade inflammation, and early atherosclerosis. Underlying mechanisms involve disequilibrium between proinflammatory cytokines (high interleukin-6/C-reactive protein) and the anti-inflammatory adipokine (low adiponectin). Recent findings point out that women with abnormal glucose tolerance, a metabolic alteration closely linked to android adiposity, respond with increases in low-grade inflammation and accelerated atherogenesis to EPT that collectively may promote acute complications. We recently pointed out that a progestin could exert a dose-dependent inhibitory effect on circulating adiponectin. Thus, when EPT is prescribed to women with android obesity, further decreases in the protective adiponectin pool may become critical and act as a promoter of thromboembolic complications via its effects on plaque formation and stability. Since android obesity is associated with the highest levels of free estradiol, women with this phenotype might not be trivial candidates for EPT.

CONCLUSIONS

The herein summarized findings shed light on important interactions between sex steroids and body fat mass, with functional implications for cardiovascular risk. Since previous trials have not optimized the dose of the progestin for its effect on circulating adiponectin, utmost caution should be exercised in the prescription of available estrogen plus progestin therapies to women with android obesity and/or symptoms of the insulin resistance syndrome.

ACDC/adiponectin and PPAR-gamma gene polymorphisms: implications for features of obesity

OBJECTIVE

The main purpose of this study was to investigate associations of single-nucleotide polymorphisms (SNPs) in the adipocyte C1q and collagen domain-containing (ACDC) gene and its regulator, the nuclear peroxisome proliferator-activated receptor (PPAR)-gamma gene, with body fat mass and its topographical distribution in postmenopausal women.

RESEARCH METHODS AND PROCEDURES

Participants were 1501 healthy women, 60 to 85 years old, who were genotyped for four SNPs in the ACDC gene (-11391G/A, -11377C/G, +45T/G, +276G/T) and the Pro12Ala SNP in the PPAR-gamma gene. Total body fat mass and the central to peripheral fat mass ratio (CFM/PFM ratio) were measured using DXA. Adiponectin and homeostasis model assessment of insulin resistance were measured in 287 subjects.

RESULTS

The -11377C/G SNP was associated with adiponectin (p < 0.001) and the CFM/PFM ratio (p = 0.005); the G allele being associated with low adiponectin and high CFM/PFM ratio. Similar associations of adiponectin (p = 0.0001) and the CFM/PFM ratio (p = 0.002) characterized the 1_2 (G_G) promoter haplotype (11391G/A_-11377C/G). Genotype variation of SNP Pro12Ala was associated with total body fat mass (p = 0.04); women with GG being the most obese (p = 0.01). The Ala/Ala (GG) genotype of Pro12Ala SNP interacted with the CC genotype of SNP-11377C/G in the determination of BMI (p = 0.001), when analyzed using a codominant model.

DISCUSSION

Polymorphisms in the ACDC gene are associated with body fat distribution, whereas the Pro12Ala polymorphism in PPAR-gamma is associated with overall adiposity, apparently in interaction with an ACDC promoter SNP.

Waist circumference correlates with metabolic syndrome indicators better than percentage fat

OBJECTIVE

Percent fat is often considered the reference for establishing the magnitude of adipose tissue accumulation and the risk of excess adiposity. However, the increasing recognition of a strong link between central adiposity and metabolic disturbances led us to test whether waist circumference (WC) is more highly correlated with metabolic syndrome components than percent fat and other related anthropometric measures such as BMI.

RESEARCH METHODS AND PROCEDURES

BMI, WC, and percent fat, measured by DXA, were evaluated in 1010 healthy white and African-American men and women [age, 48.3 +/- 17.2 (standard deviation) years; BMI, 27.0 +/- 5.3 kg/m(2)]. The associations of BMI, WC, and percent fat with age and laboratory-adjusted health risk indicators (i.e., serum glucose, insulin, triglycerides, high-density lipoprotein cholesterol, blood pressure) in each sex and ethnicity group were examined.

RESULTS

For 18 of 24 comparisons, the age- and laboratory-adjusted correlations were lowest for percent fat and in 16 of 24 comparisons were highest for WC. Fifteen of the between-method differences reached statistical significance. With health risk indicator as the dependent variable and anthropometric measures as the independent variable, the contribution of percent fat to the WC regression model was not statistically significant; in contrast, adding WC to the percent fat regression model did make a significant independent contribution for most health risk indicators.

DISCUSSION

WC had the strongest associations with health risk indicators, followed by BMI. Although percent fat is a useful measure of overall adiposity, health risks are best represented by the simply measured WC.

Leg fat percentage correlates negatively with coronary atherosclerosis

BACKGROUND

Visceral fat is related to coronary atherosclerosis, but little is known about the relation between coronary atherosclerosis and percent body fat accumulated in different parts of the body.

METHODS AND RESULTS

The subjects were 100 consecutive patients with demonstrated electrocardiographic ischemic changes. Coronary atherosclerosis was assessed using Gensini's coronary score (CS), and for body fat distribution dual energy X-ray absorptiometry was used. The parameters measured were serum lipid concentrations, body weight, body mass index, percent total fat, trunk fat percent, arm fat percent and leg fat percent. Trunk fat percent correlated significantly with CS (p<0.01), and concentrations of low-density lipoprotein cholesterol (LDL-C) (p<0.01) and very low-density lipoprotein cholesterol (VLDL-C) (p<0.05) in men and women. Leg fat percent correlated negatively with CS in both men and women (p<0.01 for each). Concentrations of both LDL-C and VLDL-C correlated positively with CS in both men and women (p<0.01).

CONCLUSION

There is a difference between the effect of body fat in the legs and the trunk that suggests leg fat has an anti-atherosclerotic effect and a negative correlation with CS, and conversely, that trunk fat has a pro-atherosclerotic effect and correlates positively with CS.

Central fat mass versus peripheral fat and lean mass: opposite (adverse versus favorable) associations with arterial stiffness? The Amsterdam Growth and Health Longitudinal Study

Central and peripheral fatness seem to confer opposite (i.e. adverse vs. protective) effects on cardiovascular risk, but how this occurs is not clear. In addition, the role of peripheral lean mass needs to be elucidated. We therefore investigated, in 336 (175 women) 36-yr-old and apparently healthy adults, the relationship between trunk fat, peripheral fat, and peripheral lean mass on the one hand, and estimates of stiffness of three large arteries on the other. Body composition was assessed by dual-energy x-ray absorptiometry. Arterial properties were assessed by ultrasound imaging. We found that 1) trunk fat was positively (i.e. adversely) associated with stiffness of the carotid and femoral arteries, whereas peripheral fat was inversely (i.e. favorably) associated with stiffness of the brachial and the carotido-femoral segment; 2) peripheral lean mass was positively associated with arterial diameter and carotid compliance and inversely associated with stiffness of the carotido-femoral segment; and 3) after adjustment for the other body composition variables, the above-mentioned associations remained, but peripheral fat in addition became, if anything, favorably associated with stiffness of the femoral artery. We conclude that trunk fat is adversely associated with large artery stiffness, whereas some degree of protection is conferred by peripheral fat and lean mass.

Increased expression of TNF-alpha, IL-6, and IL-8 in HALS: implications for reduced adiponectin expression and plasma levels

Human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is a side effect of highly active antiretroviral therapy of HIV-infected patients; however, the mechanism of the lipodystrophy and insulin resistance seen in this syndrome remains elusive. Adiponectin, an adipocyte-specific protein, is thought to play an important role in regulating insulin sensitivity. We investigated circulating levels and gene expression of adiponectin in subcutaneous abdominal adipose tissue (AT) from 18 HIV-infected patients with HALS compared with 18 HIV-infected patients without HALS. Implications of cytokines for adiponectin levels were investigated by determining circulating levels of TNF-alpha, IL-6, and IL-8 as well as gene expression of these cytokines in AT. HALS patients exhibited 40% reduced plasma adiponectin levels (P < 0.05) compared with non-HALS subjects. Correspondingly, adiponectin mRNA levels in AT were reduced by >50% (P = 0.06). HALS patients were insulin resistant, and a positive correlation was found between plasma adiponectin and insulin sensitivity (r = 0.55, P < 0.01) and percent limb fat (r = 0.61, P < 0.01). AT mRNA of TNF-alpha, IL-6, and IL-8 was increased in AT of HALS subjects (P < 0.05), and both AT TNF-alpha mRNA and plasma TNF-alpha were negatively correlated to plasma adiponectin (P < 0.05). Finally, TNF-alpha was found in vitro to inhibit human AT adiponectin mRNA by 80% (P < 0.05). In conclusion, HALS patients have reduced levels of plasma adiponectin and adiponectin mRNA in AT. Increased cytokine mRNA in AT is hypothesized to exert an inhibitory effect on adiponectin gene expression and, consequently, to play a role in the reduced plasma adiponectin levels found in HALS patients.

Peripheral adiposity exhibits an independent dominant antiatherogenic effect in elderly women

BACKGROUND

Although several lines of evidence point to an atherogenic role of central fat mass (CFM), few data are available to address the specific role played by peripheral fat mass (PFM).

METHODS AND RESULTS

This study was a cross-sectional analysis of 1356 women aged 60 to 85 years. Study variables were physical measures, CFM and PFM measured by DEXA, aortic calcification (AC) graded on lateral radiographs, lipid and glucose metabolites, blood pressure, and information on lifestyle factors and coronary disease. Peripheral fat mass showed independent negative correlation with both atherogenic metabolic risk factors and AC (P<0.001). The most severe insulin resistance-dyslipidemic syndrome and AC (score 5.10+/-0.76) was found in women with high central fat percentage (CF%, 21.7+/-0.2%) and low peripheral fat percentage (PF%, 18.3+/-0.2%, n=48). The least severe AC (score 2.45+/-0.31) was found in obese women with high CF% (21.6+/-0.1%) and high PF% (27.3+/-0.14%, n=112). The insulin resistance-dyslipidemic syndrome was also less severe compared with those with the same CF% but low PF%. The most favorable metabolic profile characterized women with low CF% (11.56+/-0.16%) and high PF% (26.86+/-0.33%, n=44). In women with a history of myocardial infarct (18.41+/-0.55%, n=45), CF% was significantly higher compared with women with no manifest coronary disease (16.48+/-0.12%, n=1210) without differences in PF%.

CONCLUSIONS

In elderly women, localization of fat mass is apparently more important for atherosclerosis than obesity per se; although CFM is associated with atherogenic tendencies, PFM seems to exhibit an independent dominant antiatherogenic effect.

Detection of cardiovascular risk factors by indices of obesity obtained from anthropometry and dual-energy X-ray absorptiometry in Japanese individuals

OBJECTIVE

To determine the cut-off points of indices of obesity for detecting hypertension, dyslipidemia and diabetes mellitus in Japanese individuals.

DESIGN

Cross-sectional study.

SUBJECTS

A total of 2728 Japanese individuals (768 males and 1960 females, aged 20-79 y) who attended the Fukuoka Health Promotion Center, Japan for health check-up.

MEASUREMENTS

Body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR) were measured. Percentage fat mass (%FM), trunk fat mass (FM(trunk)) and trunk fat mass-leg fat mass ratio (FM(trunk)/FM(legs)) were obtained by dual-energy X-ray absorptiometry (DXA). Cardiovascular risk factors were determined by blood pressure, serum lipids, fasting blood glucose and hemoglobin A(1C).

RESULTS

The cut-off points of BMI, WC and WHR were around 23.5 kg/m(2), 84 cm and 0.9 for males, and 22.5 kg/m(2), 72 cm and 0.8 for females. The cut-off points of %FM, FM(trunk) and FM(trunk)/FM(legs) were around 24%, 8 kg and 1.6 for males, and 35%, 9 kg and 1.4 for females. WHR and FM(trunk)/FM(legs) most accurately detected the risk factors.

CONCLUSIONS

For Japanese individuals, the cut-off points for detecting cardiovascular risk factors are lower than the criteria by the World Health Organization. Indices of fat distribution detected the cardiovascular risk factors more accurately than those of overall adiposity. The accuracy of detecting the risk factors was comparable between the anthropometric indices and indices obtained by DXA.

Gender differences in regional body composition and somatotrophic influences of IGF-I and leptin

This study evaluated the arm, trunk, and leg for fat mass, lean soft tissue mass, and bone mineral content (BMC) assessed via dual-energy X-ray absorptiometry in a group of age-matched (approximately 29 yr) men (n = 57) and women (n = 63) and determined their relationship to insulin-like growth factor I (IGF-I) and leptin. After analysis of covariance adjustment to control for differences in body mass between genders, the differences that persisted (P < or = 0.05) were for lean soft tissue mass of the arm (men: 7.1 kg vs. women: 6.4 kg) and fat mass of the leg (men: 5.3 kg vs. women: 6.8 kg). Men and women had similar (P > or = 0.05) values for fat mass of the arms and trunk and lean soft tissue mass of the legs and trunk. Serum IGF-I and insulin-like growth factor binding protein-3 correlated (P < or = 0.05) with all measures of BMC (r values ranged from 0.31 to 0.39) and some measures of lean soft tissue mass for women (r = 0.30) but not men. Leptin correlated (P < or = 0.05) similarly for measures of fat mass for both genders (r values ranging from 0.74 to 0.85) and for lean soft tissue mass of the trunk (r = 0.40) and total body (r = 0.32) for men and for the arms in women (r = 0.56). These data demonstrate that 1) the main phenotypic gender differences in body composition are that men have more of their muscle mass in their arms and women have more of their fat mass in their legs and 2) gender differences exist in the relationship between somatotrophic hormones and lean soft tissue mass.