Obesity and lipids

Spatial analysis of overweight prevalence in China: exploring the association with air pollution

BACKGROUND

Overweight is a known risk factor for various chronic diseases and poses a significant threat to middle-aged and elderly adults. Previous studies have reported a strong association between overweight and air pollution. However, the spatial relationship between the two remains unclear due to the confounding effects of spatial heterogeneity.

METHODS

We gathered height and weight data from the 2015 China Health and Retirement Long-term Survey (CHARLS), comprising 16,171 middle-aged and elderly individuals. We also collected regional air pollution data. We then analyzed the spatial pattern of overweight prevalence using Moran's I and Getis-Ord Gi* statistics. To quantify the explanatory power of distinct air pollutants for spatial differences in overweight prevalence across Southern and Northern China, as well as across different age groups, we utilized Geodetector's q-statistic.

RESULTS

The average prevalence of overweight among middle-aged and elderly individuals in each city was 67.27% and 57.39%, respectively. In general, the q-statistic in southern China was higher than that in northern China. In the north, the prevalence was significantly higher at 54.86% compared to the prevalence of 38.75% in the south. SO2 exhibited a relatively higher q-statistic in middle-aged individuals in both the north and south, while for the elderly in the south, NO2 was the most crucial factor (q = 0.24, p < 0.01). Moreover, fine particulate matter (PM2.5 and PM10) also demonstrated an important effect on overweight. Furthermore, we found that the pairwise interaction between various risk factors improved the explanatory power of the prevalence of overweight, with different effects for different age groups and regions. In northern China, the strongest interaction was found between NO2 and SO2 (q = 0.55) for middle-aged individuals and PM2.5 and SO2 (q = 0.27) for the elderly. Conversely, in southern China, middle-aged individuals demonstrated the strongest interaction between SO2 and PM10 (q = 0.60), while the elderly showed the highest interaction between NO2 and O3 (q = 0.42).

CONCLUSION

Significant spatial heterogeneity was observed in the effects of air pollution on overweight. Specifically, air pollution in southern China was found to have a greater impact on overweight than that in northern China. And, the impact of air pollution on middle-aged individuals was more pronounced than on the elderly, with distinct pollutants demonstrating significant variation in their impact. Moreover, we found that SO2 had a greater impact on overweight prevalence among middle-aged individuals, while NO2 had a greater impact on the elderly. Additionally, we identified significant statistically interactions between O3 and other pollutants.

Gene-diet interaction in response to defatted flaxseed flour supplementation on obesity-related traits in Chinese overweight and obese adults: A randomized controlled trial

Effects of dietary fiber on obesity-related traits in previous studies were inconsistent. The aim of the present study was to explore whether variants in genes related to satiety and appetite can modulate the effect of dietary fiber on obesity-related traits. Fifty-one overweight or obese adults were randomly allocated to two groups to consume control biscuits (n = 24) or biscuits containing defatted flaxseed flour (n = 27) at breakfast for 8 wk. Four single-nucleotide polymorphisms related to satiety and appetite were genotyped: rs11076023 on the FTO gene, rs16147 on the NPY gene, rs155971 on the PCSK1 gene, and rs6265 on the BDNF gene. A linear regression model was used to evaluate the gene-diet interaction between obesity-related traits. Compared with control biscuits, defatted flaxseed-flour biscuits significantly reduced body weight (P = 0.001) and body mass index (BMI) (P = 0.001) in A-allele carriers (AA + AT) of rs11076023 on the FTO gene but not in non-carriers (TT) (P for the interaction = 0.005 and 0.006) and decreased fasting serum glucose in participants with CC genotype (P = 0.019) but had less effect in T-allele carriers (TT + TC) (P = 0.021) of rs16147 on the NPY gene (P for the interaction = 0.002). Compared with the control biscuits, defatted flaxseed flour significantly reduced body weight (P < 0.001) in T-allele carriers (TT + TC) of rs155971 on the PCSK1 gene but not in non-carriers (CC) (P for the interaction = 0.041) and reduced body weight (P = 0.001) and BMI (P < 0.001) in A-allele carriers (AA + AG) of rs6265 on the BDNF gene but not non-carriers (GG) (P for the interaction = 0.017 and 0.018). Variants of genes related to satiety and appetite could modulate the effect of defatted flaxseed flour on obesity-related traits.

Association of Mammary Gland Disease With Metabolic Syndrome Factors in Japanese Women—Case-Control Study Based on Health Screening Results

Background:

The association of obesity with breast cancer is clear. Although body mass index (BMI) is used as an indicator of obesity, its accuracy remains questionable. Although, there factors for diagnosing metabolic syndrome are caused by obesity, the association with breast cancer has not been clarified.

Methods:

Women who underwent breast cancer screening with mammography and measurements of metabolic syndrome factors, including waist circumference, blood glucose, triglycerides, HDL (high-density lipoprotein) cholesterol levels, and systolic and diastolic pressure, twice within a 2-year period were enrolled (n = 314), with a final sample size of 256. To determine the presence of mammary gland disease, 2 expert physicians interpreted radiogram findings, with category 3 or higher shown by mammography considered to indicate an abnormality.

Results and Conclusions:

Waist circumference at the initial measurement was marginally significant as a risk factor for onset of mammary gland disease (odds ratio [OR] = 1.036, P = .045) and thus was concluded to be a risk factor for disease onset. Although not significant, a 2-year increase in systolic and diastolic blood pressure has been presumed to be risk factors (systolic: OR = 1.020, P = .085, diastolic: OR = 1.040, P = .065), while high levels of HDL cholesterol have been presumed to protect against the disease (OR = 0.982, P = .064). Based on these results, waist circumference and blood pressure are speculated to be related to development of mammary gland disease.

Associations between low HDL, sex and cardiovascular risk markers are substantially different in sub-Saharan Africa and the UK: analysis of four population studies

INTRODUCTION

Low high-density lipoprotein (HDL) is widely used as a marker of cardiovascular disease risk, although this relationship is not causal and is likely mediated through associations with other risk factors. Low HDL is extremely common in sub-Saharan African populations, and this has often been interpreted to indicate that these populations will have increased cardiovascular risk. We aimed to determine whether the association between HDL and other cardiovascular risk factors differed between populations in sub-Saharan Africa and the UK.

METHODS

We compared data from adults living in Uganda and Malawi (n=26 216) and in the UK (n=8747). We examined unadjusted and adjusted levels of HDL and applied the WHO recommended cut-offs for prevalence estimates. We used spline and linear regression to assess the relationship between HDL and other cardiovascular risk factors.

RESULTS

HDL was substantially lower in the African than in the European studies (geometric mean 0.9-1.2 mmol/L vs 1.3-1.8 mmol/L), with African prevalence of low HDL as high as 77%. Total cholesterol was also substantially lower (geometric mean 3.3-3.9 mmol/L vs 4.6-5.4 mmol/L). In comparison with European studies the relationship between HDL and adiposity (body mass index, waist to hip ratio) was greatly attenuated in African studies and the relationship with non-HDL cholesterol reversed: in African studies low HDL was associated with lower non-HDL cholesterol. The association between sex and HDL was also different; using the WHO sex-specific definitions, low HDL was substantially more common among women (69%-77%) than men (41%-59%) in Uganda/Malawi.

CONCLUSION

The relationship between HDL and sex, adiposity and non-HDL cholesterol in sub-Saharan Africa is different from European populations. In sub-Saharan Africans low HDL is a marker of low overall cholesterol and sex differences are markedly attenuated. Therefore low HDL in isolation is unlikely to indicate raised cardiovascular risk and the WHO sex-based cut-offs are inappropriate.

Excess Body Weight and Cancer-Related Fatigue, Systemic Inflammation, and Serum Lipids in Breast Cancer Survivors

BACKGROUND

Cancer-related fatigue (CRF) is a common side effect impacting breast cancer survivors. Research points to a relationship between obesity and CRF in breast cancer survivors related to elevated systemic inflammation and metabolic alterations.

METHODS

This cross-sectional study examined the relationship of obesity to CRF, inflammatory markers and serum lipids through a secondary analysis of a nationwide randomized controlled trial. Breast cancer survivors with CRF were categorized based on BMI category. Symptoms of CRF, inflammatory markers and serum fatty acids were assessed among groups.

RESULTS

There were 105 breast cancer survivors in the analysis. BMI was positively associated with CRF based on MFSI General (p = 0.020; 95% C.I. 0.024, 0.273) and MFSI Physical (p = 0.013; 95% C.I. 0.035, 0.298) subscales. TNF-α (p = 0.007; 95% C.I. 0.007, 0.044), and IL-6 (p = 0.020; 95% C.I. 0.006, 0.073) were elevated in the obese. Monounsaturated fatty acid levels (p = 0.047; 95% C.I. 0.000, 0.053) and the omega-6 to omega-3 fatty acid ratio were associated with obesity (p = 0.047; 95% C.I. 0.002, 0.322).

CONCLUSIONS

Obese breast cancer survivors had greater levels of CRF, inflammatory markers and certain fatty acids. Inflammatory markers and fatty acids were not found to have any mediating or positive association with CRF variables in this analysis. NCT02352779.

School-based soccer practice is an effective strategy to improve cardiovascular and metabolic risk factors in overweight children

We examined the effects of a 6-month school-based soccer programme on cardiovascular (CV) and metabolic risk factors in overweight children. Methods: 40 boys [8-12 years; body mass index (BMI) >2 standard deviations of WHO reference values] participated in complementary school-based physical education classes (two sessions per week, 45-90 min each). The participants were divided into a soccer group (SG; n = 20) and a control group (CG; n = 20). The SG intervention involved 3 extra-curricular school-based soccer sessions per week, 60-90 min each. The intervention lasted for 6-months. All measurements were taken at baseline and after 6-months. From baseline to 6-months, the SG significantly improved (p < .05) BMI z-score, waist circumference, waist-to-height ratio, percentage of fat mass, percentage of fat-free mass, diastolic blood pressure, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol, but no such improvements were observed for the CG. After the intervention, the prevalence of soccer participants with normal waist-to-height ratio (30 vs. 5%; p = .037), systolic blood pressure (90 vs. 55%; p = .039), total cholesterol (80 vs. 65%; p = .035) and LDL-C (90 vs. 75%; p = .012) were significantly higher than at baseline. The findings suggest that a 6-month school-based soccer intervention program represents an effective strategy to reduce CV and metabolic risk factors in overweight children prepared to take part in a soccer program.

Obesity and severe asthma

Obesity is an important global health issue for both children and adults. Obesity increases the prevalence and incidence of asthma and also increases the risk for severe asthma. Here we describe the features of severe asthma phenotypes for which obesity is a defining characteristic, including steroid resistance, airway inflammation, and co-morbidities. We also review current concepts regarding the mechanistic basis for the impact of obesity in severe asthma, including possible roles for vitamin D deficiency, systemic inflammation, and the microbiome. Finally, we describe data indicating a role for diet, weight loss, and exercise in the treatment of severe asthma with obesity. Better understanding of the mechanistic basis for the role of obesity in severe asthma could lead to new therapeutic options for this population.

Trans-ethnic analysis of metabochip data identifies two new loci associated with BMI

OBJECTIVE

Body mass index (BMI) is commonly used to assess obesity, which is associated with numerous diseases and negative health outcomes. BMI has been shown to be a heritable, polygenic trait, with close to 100 loci previously identified and replicated in multiple populations. We aim to replicate known BMI loci and identify novel associations in a trans-ethnic study population.

SUBJECTS

Using eligible participants from the Population Architecture using Genomics and Epidemiology consortium, we conducted a trans-ethnic meta-analysis of 102 514 African Americans, Hispanics, Asian/Native Hawaiian, Native Americans and European Americans. Participants were genotyped on over 200 000 SNPs on the Illumina Metabochip custom array, or imputed into the 1000 Genomes Project (Phase I). Linear regression of the natural log of BMI, adjusting for age, sex, study site (if applicable), and ancestry principal components, was conducted for each race/ethnicity within each study cohort. Race/ethnicity-specific, and combined meta-analyses used fixed-effects models.

RESULTS

We replicated 15 of 21 BMI loci included on the Metabochip, and identified two novel BMI loci at 1q41 (rs2820436) and 2q31.1 (rs10930502) at the Metabochip-wide significance threshold (P<2.5 × 10-7). Bioinformatic functional investigation of SNPs at these loci suggests a possible impact on pathways that regulate metabolism and adipose tissue.

CONCLUSION

Conducting studies in genetically diverse populations continues to be a valuable strategy for replicating known loci and uncovering novel BMI associations.

A Lipidomics Approach to Identifying Key Lipid Species Involved in VEGF-Inhibitor Mediated Attenuation of Bleomycin-Induced Pulmonary Fibrosis

PURPOSE

Poor molecular characterization of idiopathic pulmonary fibrosis (IPF) has led to insufficient understanding of the pathogenesis of the disease, resulting in lack of effective therapies and poor prognosis. Particularly, the role of lipid imbalance due to impaired lipid metabolism in the pathogenesis of IPF has been poorly studied.

EXPERIMENTAL DESIGN

The authors have used shotgun lipidomics in a bleomycin (BLM) mouse model of pulmonary fibrosis with vascular endothelial growth factor (VEGF)-inhibitor CBO-P11 as a therapeutic measure, to identify a comprehensive set of lipids that contribute to the pathogenesis of pulmonary fibrosis.

RESULTS

The authors report that attenuation of BLM-induced fibrotic response with CBO-P11 cotreatment is accompanied by a decrease in total lipid content and specific downregulation of lipids, which are upregulated in response to BLM treatment.

CONCLUSION AND CLINICAL RELEVANCE

Dysregulated lipids identified in this study hold the potential of being future biomarkers for IPF.

Lipid profile in relation to anthropometric indices and insulin resistance in overweight women with polycystic ovary syndrome

BACKGROUND

The present study was aimed to investigate lipid profile in relation to anthropometric indices and insulin resistance in overweight or obese women with polycystic ovary syndrome (PCOS).

METHODS

In this cross-sectional study, lipid profile and anthropometric indices including body mass index (BMI), waist and hip circumference, waist to hip ratio (WHR), and waist to height ratio (WHtR) were evaluated in 63 overweight or obese PCOS patients subdivided into insulin-resistant (IR) and non insulin-resistant (NIR) groups. IR was defined as homeostasis model of insulin resistance (HOMA-IR) ≥3.8.

RESULTS

Fasting insulin concentration and HOMA-IR were higher (P<0.001) and high-density lipoprotein cholesterol (P=0.012) was lower in IR group. All of the anthropometric measures other than WHR and BMI showed significant correlations with several lipid parameters. Amongst, WHtR showed the strongest correlation with total cholesterol (TC) (r=0.37; P=0.004) and low density lipoprotein cholesterol (LDL-C) (r=0.33; P=0.011) in the whole PCOS patients.

CONCLUSION

Anthropometric characteristics (especially BMI and hip circum-ference) are more important parameters correlated to lipid profile than IR in overweight or obesePCOS patients, confirming the importance of early treat-ment of obesity to prevent dyslipidemia in the future.

Fine Mapping and Identification of BMI Loci in African Americans

Genome-wide association studies (GWASs) primarily performed in European-ancestry (EA) populations have identified numerous loci associated with body mass index (BMI). However, it is still unclear whether these GWAS loci can be generalized to other ethnic groups, such as African Americans (AAs). Furthermore, the putative functional variant or variants in these loci mostly remain under investigation. The overall lower linkage disequilibrium in AA compared to EA populations provides the opportunity to narrow in or fine-map these BMI-related loci. Therefore, we used the Metabochip to densely genotype and evaluate 21 BMI GWAS loci identified in EA studies in 29,151 AAs from the Population Architecture using Genomics and Epidemiology (PAGE) study. Eight of the 21 loci (SEC16B, TMEM18, ETV5, GNPDA2, TFAP2B, BDNF, FTO, and MC4R) were found to be associated with BMI in AAs at 5.8 × 10(-5). Within seven out of these eight loci, we found that, on average, a substantially smaller number of variants was correlated (r(2) > 0.5) with the most significant SNP in AA than in EA populations (16 versus 55). Conditional analyses revealed GNPDA2 harboring a potential additional independent signal. Moreover, Metabochip-wide discovery analyses revealed two BMI-related loci, BRE (rs116612809, p = 3.6 × 10(-8)) and DHX34 (rs4802349, p = 1.2 × 10(-7)), which were significant when adjustment was made for the total number of SNPs tested across the chip. These results demonstrate that fine mapping in AAs is a powerful approach for both narrowing in on the underlying causal variants in known loci and discovering BMI-related loci.

Hormonal, metabolic, and inflammatory profiles and endometrial cancer risk within the EPIC cohort--a factor analysis

A "Western" lifestyle characterized by physical inactivity and excess weight is associated with a number of metabolic and hormonal dysregulations, including increased circulating estrogen levels, hyperinsulinemia, hyperglycemia, and chronic inflammation. The same hormonal and metabolic axes might mediate the association between this lifestyle and the development of endometrial cancer. Using data collected within the European Prospective Investigation into Cancer and Nutrition (EPIC), a prospective cohort study carried out in 10 European countries during 1992-2000, we conducted a factor analysis to delineate important components that summarize the variation explained by a set of biomarkers and to examine their association with endometrial cancer risk. Prediagnostic levels of testosterone, androstenedione, dehydroepiandrosterone sulfate, sex hormone-binding globulin, estrone, estradiol, C-peptide, insulin-like growth factor-binding proteins 1 and 2, adiponectin, high- and low-density lipoprotein cholesterol, glucose, triglycerides, tumor necrosis factor (TNF) α, soluble TNF receptors 1 and 2, C-reactive protein, interleukin-6, and interleukin-1 receptor antagonist were measured in 233 incident endometrial cancer cases and 446 matched controls. Factor analysis identified 3 components associated with postmenopausal endometrial cancer risk that could be labeled "insulin resistance/metabolic syndrome," "steroids," and "inflammation" factors. A fourth component, "lipids," was not significantly associated with endometrial cancer. In conclusion, besides the well-known associations of risk with sex hormones and insulin-regulated physiological axes, our data further support the hypothesis that inflammation factors play a role in endometrial carcinogenesis.

Gene-centric meta-analyses of 108 912 individuals confirm known body mass index loci and reveal three novel signals

Recent genetic association studies have made progress in uncovering components of the genetic architecture of the body mass index (BMI). We used the ITMAT-Broad-Candidate Gene Association Resource (CARe) (IBC) array comprising up to 49 320 single nucleotide polymorphisms (SNPs) across ~2100 metabolic and cardiovascular-related loci to genotype up to 108 912 individuals of European ancestry (EA), African-Americans, Hispanics and East Asians, from 46 studies, to provide additional insight into SNPs underpinning BMI. We used a five-phase study design: Phase I focused on meta-analysis of EA studies providing individual level genotype data; Phase II performed a replication of cohorts providing summary level EA data; Phase III meta-analyzed results from the first two phases; associated SNPs from Phase III were used for replication in Phase IV; finally in Phase V, a multi-ethnic meta-analysis of all samples from four ethnicities was performed. At an array-wide significance (P < 2.40E-06), we identify novel BMI associations in loci translocase of outer mitochondrial membrane 40 homolog (yeast) - apolipoprotein E - apolipoprotein C-I (TOMM40-APOE-APOC1) (rs2075650, P = 2.95E-10), sterol regulatory element binding transcription factor 2 (SREBF2, rs5996074, P = 9.43E-07) and neurotrophic tyrosine kinase, receptor, type 2 [NTRK2, a brain-derived neurotrophic factor (BDNF) receptor gene, rs1211166, P = 1.04E-06] in the Phase IV meta-analysis. Of 10 loci with previous evidence for BMI association represented on the IBC array, eight were replicated, with the remaining two showing nominal significance. Conditional analyses revealed two independent BMI-associated signals in BDNF and melanocortin 4 receptor (MC4R) regions. Of the 11 array-wide significant SNPs, three are associated with gene expression levels in both primary B-cells and monocytes; with rs4788099 in SH2B adaptor protein 1 (SH2B1) notably being associated with the expression of multiple genes in cis. These multi-ethnic meta-analyses expand our knowledge of BMI genetics.

The association between obesity, cardiometabolic disease biomarkers, and innate immunity-related inflammation in Canadian adults

INTRODUCTION

Obesity is associated with a state of chronic inflammation, and increased cardiometabolic disease risk. The present study examined the relationship between body mass index (BMI) and cardiometabolic and inflammatory biomarkers among normal weight, overweight, and obese Canadian adults.

METHODS

Subjects (n = 1805, aged 18 to 79 years) from the Canadian Health Measures Survey (CHMS) were examined for associations between BMI, cardiometabolic markers (apolipoprotein [Apo] A1, ApoB, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], total cholesterol, total cholesterol/HDL ratio [total:HDL-C ratio], triglycerides, and glycosylated hemoglobin [HbA(1c)]), inflammatory factors (C-reactive protein [CRP], fibrinogen, and homocysteine), and 25-hydroxyvitamin D [25(OH)D]. Bootstrap weights for variance and sampling weights for point estimates were applied to account for the complex survey design. Linear regression models adjusted for age, sex, physical activity, smoking status, and ethnicity (in addition to season of clinic visit, for vitamin D analyses only) were used to examine the association between cardiometabolic markers, inflammatory factors, and BMI in Canadian adults.

RESULTS

All biomarkers were significantly associated with BMI (P ≤ 0.001). ApoA1 (β = -0.31, P < 0.0001), HDL-C (β = -0.61, P < 0.0001), and 25(OH)D (β = -0.25, P < 0.0001) were inversely associated with BMI, while all other biomarkers showed positive linear associations. Distinct patterns of association were noted among normal weight, overweight, and obese groups, excluding CRP which showed a significant positive association with BMI in the overall population (β = 2.80, P < 0.0001) and in the normal weight (β = 3.20, P = 0.02), overweight (β = 3.53, P = 0.002), and obese (β = 2.22, P = 0.0002) groups.

CONCLUSIONS

There is an apparent profile of cardiometabolic and inflammatory biomarkers that emerges as BMI increases from normal weight to obesity. Understanding these profiles may permit developing an effective approach for early risk prediction for cardiometabolic disease.

Association of hypertension with small, dense low-density lipoprotein in patients without metabolic syndrome

A higher proportion of small, dense low-density lipoprotein (sdLDL) is known to be associated with a high prevalence of cardiovascular disease in association with metabolic syndrome (MS). Hypertension (HTN) is one of the known risk factors for MS. However, whether HTN is associated with sdLDL in patients without MS is not yet clear. The lipid profiles, including low-density-lipoprotein (LDL) subfractions, of 383 consecutive subjects were evaluated. The patients without MS consisted of 198 hypertensive patients (non-MS/HTN group) and 108 normotensive subjects (non-MS/non-HTN group). The peak and mean particle diameter of LDL were measured by gradient gel electrophoresis. Plasma total cholesterol, LDL cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride (TG), HDL cholesterol/Apo A1, LDL-C/ApoB and Apo(A1, B, CII and E) levels did not differ between the non-MS/non-HTN and non-MS/HTN groups. When analyzing LDL subfraction, the absolute amount of patterns A and B was not different between the non-MS/non-HTN and non-MS/HTN groups. Compared with the non-MS/non-HTN groups, the proportion of sdLDL was higher in the non-MS/HTN group (37.7% versus 39.9%, P=0.046), but not significant after adjustment of waist circumference, serum TG, age and statin usage. The proportion of sdLDL to total LDL was higher in hypertensive subjects, even those without MS, than in normotensive subjects. However, this difference of LDL subfraction in hypertensive patients is associated with higher waist circumference, higher serum TG, older age and more statin usage. This result suggests that HTN may contribute to atherosclerosis and endothelial dysfunction with associated risk factors that influence LDL size.

Smaller Mean LDL Particle Size and Higher Proportion of Small Dense LDL in Korean Type 2 Diabetic Patients

BACKGROUND

Small dense low density lipoprotein (sdLDL) has recently emerged as an important risk factor of coronary heart disease.

METHODS

The mean LDL particle size was measured in 203 patients with type 2 diabetes mellitus (T2DM) and 212 matched subjects without diabetes using polyacrylamide tube gel electrophoresis. Major vascular complications were defined as stroke, angiographically-documented coronary artery disease or a myocardial infarction. Peripheral vascular stenosis, carotid artery stenosis (≥50% in diameter) or carotid artery plaque were considered minor vascular complications. Overall vascular complications included both major and minor vascular complications.

RESULTS

Diabetic patients had significantly smaller mean-LDL particle size (26.32 nm vs. 26.49 nm) and a higher percentage of sdLDL to total LDL compared to those of subjects without diabetes (21.39% vs. 6.34%). The independent predictors of sdLDL in this study were serum triglyceride level and body mass index (odds ratio [OR], 1.020 with P<0.001 and OR 1.152 with P<0.027, respectively). However, no significant correlations were found between sdLDL and major vascular complications (P=0.342), minor vascular complications (P=0.573) or overall vascular complications (P=0.262) in diabetic subjects.

CONCLUSION

Diabetic patients had a smaller mean-LDL particle size and higher proportion of sdLDL compared to those of subjects without diabetes. Obese diabetic patients with hypertriglyceridemia have an increased risk for atherogenic small dense LDL. However, we could not verify an association between LDL particle size and vascular complications in this study.

Plasma and liver lipidomics response to an intervention of rimonabant in ApoE*3Leiden.CETP transgenic mice

Background

Lipids are known to play crucial roles in the development of life-style related risk factors such as obesity, dyslipoproteinemia, hypertension and diabetes. The first selective cannabinoid-1 receptor blocker rimonabant, an anorectic anti-obesity drug, was frequently used in conjunction with diet and exercise for patients with a body mass index greater than 30 kg/m² with associated risk factors such as type II diabetes and dyslipidaemia in the past. Less is known about the impact of this drug on the regulation of lipid metabolism in plasma and liver in the early stage of obesity.

Methodology/Principal Findings

We designed a four-week parallel controlled intervention on apolipoprotein E3 Leiden cholesteryl ester transfer protein (ApoE*3Leiden.CETP) transgenic mice with mild overweight and hypercholesterolemia. A liquid chromatography–linear ion trap-Fourier transform ion cyclotron resonance-mass spectrometric approach was employed to investigate plasma and liver lipid responses to the rimonabant intervention. Rimonabant was found to induce a significant body weight loss (9.4%, p<0.05) and a significant plasma total cholesterol reduction (24%, p<0.05). Six plasma and three liver lipids in ApoE*3Leiden.CETP transgenic mice were detected to most significantly respond to rimonabant treatment. Distinct lipid patterns between the mice were observed for both plasma and liver samples in rimonabant treatment vs. non-treated controls. This study successfully applied, for the first time, systems biology based lipidomics approaches to evaluate treatment effects of rimonabant in the early stage of obesity.

Conclusion

The effects of rimonabant on lipid metabolism and body weight reduction in the early stage obesity were shown to be moderate in ApoE*3Leiden.CETP mice on high-fat diet.

Apolipoprotein B/A-I ratio related to visceral but not to subcutaneous adipose tissue in elderly Swedes

OBJECTIVE

To investigate whether the amount of visceral (VAT) or subcutaneous adipose tissue (SAT) independently of the other can determine the apolipoprotein (apo)B/A-I ratio.

METHODS

VAT and SAT areas were assessed using magnetic resonance imaging in 247 randomly selected 70-year-old men and women who did not use lipid-lowering drugs. Their adipose tissue areas were compared to their apoB and apo A-I levels and to their apoB/A-I ratios.

RESULTS

The VAT area and the gender were significantly related to the apoB/A-I ratio whereas the SAT area was not. There was a positive relationship between the VAT area and the apoB/A-I ratio.

CONCLUSION

A positive relationship was established between the amount of VAT and the apoB/A-I ratio, whereas there was no relationship between the amount of SAT and the apoB/A-I ratio. This observation supports the notion that VAT is metabolically active.

Herring (Clupea harengus) intake influences lipoproteins but not inflammatory and oxidation markers in overweight men

Fish consumption is associated with a lower incidence of CVD and decreases in risk factors for atherosclerosis. Although fish contains other interesting components than fish oil, few studies focus on total fish composition and the influence food preparation might have on health-beneficial components. In the present cross-over intervention study the effect of a 6-week herring diet compared with a reference diet on CVD risk factors was investigated. Thirty-five healthy, but overweight, men (mean BMI 28·3 kg/m2) were randomised to a 6-week herring diet (150 g baked herring fillets/d, 5 d/week) or a reference diet (150 g baked lean pork and chicken fillets/d, 5 d/week). Diets were switched after a 12-week washout period. Plasma total cholesterol, TAG, HDL, HDL2, HDL3, LDL, C-reactive protein, IL-6, IL-18, intercellular adhesion molecule-1, oxidised LDL, oxygen radical absorbance capacity using perchloric acid (ORACPCA), whole-blood fatty acids, bleeding time and blood pressure were measured at the beginning and end of each dietary period. HDL was significantly higher after the herring diet period compared with after the reference diet period: 1·04v.0·99 mmol/l. TAG decreased after both diets, with no significant difference between the two diets. ORACPCAvalues did not indicate lower concentrations of non-protein plasma antioxidants, and oxidised LDL was not higher after the herring diet than after the reference diet. To conclude, a 6-week herring-rich diet significantly raised HDL compared with a diet of matched lean pork and chicken dishes. No adverse effects onin vivooxidation or serum antioxidants were found after herring intake.

In vitro release of propofol and binding capacity with regard to plasma constituents

PURPOSE

New evidence suggests that the anesthetic effect of parenteral propofol emulsions varies between commercial preparations. We examined and compared different propofol preparations to determine propofol release and binding capacity with regard to plasma lipoproteins and albumin.

METHODS

We created a novel assay consisting of microtiter plates coated with either low-density lipoprotein (LDL) or albumin to analyze propofol binding kinetics. Using high performance liquid chromatography (HPLC), we measured propofol release from the oily phase and the corresponding amount of propofol bound to the plates in a time-dependent manner and at equilibrium conditions attained after 30 min of incubation at 37 degrees C. The concentrations of free propofol in the aqueous phase of different propofol preparations - Diprivan, and the generic formulations Propofol "Fresenius" (1% and 2% propofol) and Propofol-Lipuro - were analyzed using ultracentrifugation or dialysis for phase separation. Finally, we investigated the effect of isolated lipoprotein fractions on propofol release.

RESULTS

Propofol bound to LDL-coated plates with approximately twofold higher affinity than to albumin-coated plates. No significant differences in total propofol release were observed between preparations. Moreover, similar amounts of free propofol were observed in the aqueous phase of all products tested (1% propofol preparations: 18 microg/ml; 2% propofol preparations: 35 microg/ml), except for the medium-chain and long-chain triglyceride (MCT/LCT) preparation studied, in which the concentration of free propofol was lower. Lipoproteins had no effect on propofol release, except for high-density lipoprotein (HDL), which triggered almost 100% release from the oily phase at HDL concentrations above 1000 microg/ml.

CONCLUSIONS

No differences were observed between the binding/release capacity and lipoprotein interactions of any of the propofol preparations tested. We propose that clinical observations of inconsistent propofol activity are related to variations in the lipoprotein profile, enzyme activity or genetic disorders of individual patients, rather than to the propofol preparation itself.

Non-pharmacological control of plasma cholesterol levels

The importance of non-pharmacological control of plasma cholesterol levels in the population is increasing, along with the number of subjects whose plasma lipid levels are non-optimal, or frankly elevated, according to international guidelines. In this context, a panel of experts, organized and coordinated by the Nutrition Foundation of Italy, has evaluated the nutritional and lifestyle interventions to be adopted in the control of plasma cholesterol levels (and specifically of LDL cholesterol levels). This Consensus document summarizes the view of the panel on this topic, with the aim to provide an updated support to clinicians and other health professionals involved in cardiovascular prevention.

Visceral adiposity is associated with serum retinol binding protein-4 levels in healthy women

OBJECTIVE

Retinol binding protein-4 (RBP4) has been reported to impair insulin sensitivity throughout the body. We investigated the relationship between serum RBP4 levels and adiposity indices as well as metabolic risk variables.

RESEARCH METHODS AND PROCEDURE

We recruited a total of 102 healthy women 21 to 67 years old. We assessed body composition by computed tomography and divided the study population into four groups based on body weight and visceral fat area (non-obese without visceral adiposity, non-obese with visceral adiposity, obese without visceral adiposity, and obese with visceral adiposity). Serum RBP4 levels were measured by radioimmunoassay.

RESULTS

Despite similar levels of total body fat, non-obese women had lower systolic blood pressure, total cholesterol, triglyceride (TG), low-density lipoprotein (LDL)-cholesterol levels, insulin resistance indices, and RBP4 levels than non-obese women with visceral adiposity and had higher high-density lipoprotein-cholesterol levels. Similarly, obese women without visceral adiposity had lower blood pressure, total cholesterol, TG levels, insulin resistance indices, and RBP4 levels than obese women with visceral adiposity. In addition, despite having increased body fat, obese women without visceral adiposity had lower TGs, insulin resistance indices, and serum RBP4 levels than non-obese women with visceral adiposity. By step-wise multiple regression analysis, visceral fat areas and LDL-cholesterol levels independently affected RBP4 levels.

DISCUSSION

We determined that serum RBP4 levels are independently associated with visceral fat and LDL-cholesterol levels. These results suggest that, irrespective of body weight, visceral obesity is an independent predictor of serum RBP4 levels, and RBP4 may represent a link between visceral obesity and cardiovascular disease.

Differential effects of oral hypoglycemic agents on glucose control and cardiovascular risk

Cardiovascular disease (CVD) burden remains the predominant cause of mortality and morbidity in the United States and in most of the developed world. The ongoing twin epidemics of obesity and type 2 diabetes mellitus provide a groundswell source for sustaining this trend for the foreseeable future (increasing the prevalence of CVD by 2-4 times), unless radical changes are made in public health policy. Oral hypoglycemic agents (OHAs) remain a mainstay for management of type 2 diabetes in most practice settings. Although these agents are primarily prescribed to achieve better glycemic control, it is important to evaluate what effects they have on cardiovascular risk and whether there are significant differences in effects among the different OHAs. This review presents the available data on the effects of the various OHAs on cardiovascular risk surrogates and actual events in retrospective and prospective study design settings.

Deficiency of adiponectin receptor 2 reduces diet-induced insulin resistance but promotes type 2 diabetes

Adiponectin/adiponectin receptors (AdipoR) are involved in energy homeostasis and inflammatory pathways. To investigate the role of AdipoR2 in metabolic control, we studied the lipid and glucose metabolic phenotypes in AdipoR2-deficient mice. AdipoR2 deletion diminished high-fat diet-induced dyslipidemia and insulin resistance yet deteriorated glucose homeostasis as high-fat feeding continued, which resulted from the failure of pancreatic beta-cells to adequately compensate for the moderate insulin resistance. A defect in the AdipoR2 gene may represent a mechanism underlying the etiology of certain subgroups of type 2 diabetic patients who eventually develop overt diabetes, whereas other obese patients do not.

Clinical importance and therapeutic modulation of small dense low-density lipoprotein particles

The National Cholesterol Education Programme Adult Treatment Panel III accepted the predominance of small dense low-density lipoprotein (sdLDL) as an emerging cardiovascular disease (CVD) risk factor. Most studies suggest that measuring low-density lipoprotein (LDL) particle size, sdLDL cholesterol content and LDL particle number provides additional assessment of CVD risk. Therapeutic modulation of small LDL size, number and distribution may decrease CVD risk; however, no definitive causal relationship is established, probably due to the close association between sdLDL and triglycerides and other risk factors (e.g., high-density lipoprotein, insulin resistance and diabetes). This review addresses the formation and measurement of sdLDL, as well as the relationship between sdLDL particles and CVD. The effect of hypolipidaemic (statins, fibrates and ezetimibe) and hypoglycaemic (glitazones) agents on LDL size and distribution is also discussed.

Epidemiologic perspectives of risk for developing diabetes and diabetes complications

The incidence and prevalence of diabetes is increasing worldwide. National recommendations for screening and diagnosis of diabetes, hypertension, and dyslipidemia provide a basis for early detection, treatment, and intervention that may potentially decrease related complications, and personal and economic costs of the disease. Most important is that knowledge exists about who is at risk for diabetes by weight, family history of diabetes, ethnicity, and history of gestational diabetes that allows for the development and implementation of diabetes primary prevention programs. Multiple national health care providers, systems of care, and communities that can be used to guide such prevention, early screening, and disease detection and intervention programs aimed at decreasing the burden of diabetes.

The Changing Roles of Dietary Carbohydrates

The dietary recommendations made for carbohydrate intake by many organizations/agencies have changed over time. Early recommendations were based on the need to ensure dietary sufficiency and focused on meeting micronutrient intake requirements. Because carbohydrate-containing foods are a rich source of micronutrients, starches, grains, fruits, and vegetables became the foundation of dietary guidance, including the base of the US Department of Agriculture’s Food Guide Pyramid. Dietary sufficiency recommendations were followed by recommendations to reduce cholesterol levels and the risk for cardiovascular disease; reduction in total fat (and hence saturated fat) predominated. Beginning in the 1970s, carbohydrates were recommended as the preferred substitute for fat by the American Heart Association and others to achieve the recommended successive reductions in total fat and low-density lipoprotein cholesterol (LDL-C). Additional research on fats and fatty acids found that monounsaturated fatty acids could serve as an alternative substitution for saturated fats, providing equivalent lowering of LDL-C without concomitant reductions in high-density lipoprotein cholesterol and increases in triglycerides witnessed when carbohydrates replace saturated fat. This research led to a sharper focus in the guidelines in the 1990s toward restricting saturated fat and liberalizing a range of intake of total fat. Higher-fat diets, still low in saturated fatty acids, became alternative strategies to lower-fat diets. As the population has become increasingly overweight and obese, the emergence of the metabolic syndrome and its associated disruptions in glucose and lipid metabolism has led to reconsiderations of the role of carbohydrate-containing foods in the American diet. Consequently, a review of the evidence for and against high-carbohydrate diets is important to put this controversy into perspective. The current dietary recommendations for carbohydrate intake are supported by the evidence.