Low HDL cholesterol is associated with increased atherogenic lipoproteins and insulin resistance in women classified with metabolic syndrome

The Impact of Acute Nutritional Interventions on the Plasma Proteome

CONTEXT

Humans respond profoundly to changes in diet, while nutrition and environment have a great impact on population health. It is therefore important to deeply characterize the human nutritional responses.

OBJECTIVE

Endocrine parameters and the metabolome of human plasma are rapidly responding to acute nutritional interventions such as caloric restriction or a glucose challenge. It is less well understood whether the plasma proteome would be equally dynamic, and whether it could be a source of corresponding biomarkers.

METHODS

We used high-throughput mass spectrometry to determine changes in the plasma proteome of i) 10 healthy, young, male individuals in response to 2 days of acute caloric restriction followed by refeeding; ii) 200 individuals of the Ely epidemiological study before and after a glucose tolerance test at 4 time points (0, 30, 60, 120 minutes); and iii) 200 random individuals from the Generation Scotland study. We compared the proteomic changes detected with metabolome data and endocrine parameters.

RESULTS

Both caloric restriction and the glucose challenge substantially impacted the plasma proteome. Proteins responded across individuals or in an individual-specific manner. We identified nutrient-responsive plasma proteins that correlate with changes in the metabolome, as well as with endocrine parameters. In particular, our study highlights the role of apolipoprotein C1 (APOC1), a small, understudied apolipoprotein that was affected by caloric restriction and dominated the response to glucose consumption and differed in abundance between individuals with and without type 2 diabetes.

CONCLUSION

Our study identifies APOC1 as a dominant nutritional responder in humans and highlights the interdependency of acute nutritional response proteins and the endocrine system.

Lipid efflux mechanisms, relation to disease and potential therapeutic aspects

Lipids are hydrophobic and amphiphilic molecules involved in diverse functions such as membrane structure, energy metabolism, immunity, and signaling. However, altered intra-cellular lipid levels or composition can lead to metabolic and inflammatory dysfunction, as well as lipotoxicity. Thus, intra-cellular lipid homeostasis is tightly regulated by multiple mechanisms. Since most peripheral cells do not catabolize cholesterol, efflux (extra-cellular transport) of cholesterol is vital for lipid homeostasis. Defective efflux contributes to atherosclerotic plaque development, impaired β-cell insulin secretion, and neuropathology. Of these, defective lipid efflux in macrophages in the arterial walls leading to foam cell and atherosclerotic plaque formation has been the most well studied, likely because a leading global cause of death is cardiovascular disease. Circulating high density lipoprotein particles play critical roles as acceptors of effluxed cellular lipids, suggesting their importance in disease etiology. We review here mechanisms and pathways that modulate lipid efflux, the role of lipid efflux in disease etiology, and therapeutic options aimed at modulating this critical process.

The Complete Health Improvement Program (CHIP): History, Evaluation, and Outcomes

The Complete Health Improvement Program (CHIP) is a premier lifestyle intervention targeting chronic disease that has been offered for more than 25 years. The intervention has been used in clinical, corporate, and community settings, and the short-term and long-term clinical benefits of the intervention, as well as its cost-effectiveness, have been documented in more than 25 peer-reviewed publications. Being an easily administered intervention, CHIP has been presented not only by health professionals but also by non-health-trained volunteers. The benefits of the program have been extensively studied under these 2 delivery channels, consistently demonstrating positive outcomes. This article provides a brief history of CHIP and describes the content and structure of the intervention. The published evaluations and outcomes of the intervention are presented and discussed and future directions are highlighted.

Implication of low HDL-c levels in patients with average LDL-c levels: a focus on oxidized LDL, large HDL subpopulation, and adiponectin

To evaluate the impact of low levels of high density lipoprotein cholesterol (HDL-c) on patients with LDL-c average levels, focusing on oxidative, lipidic, and inflammatory profiles. Patients with cardiovascular risk factors (n = 169) and control subjects (n = 73) were divided into 2 subgroups, one of normal HDL-c and the other of low HDL-c levels. The following data was analyzed: BP, BMI, waist circumference and serum glucose Total-c, TGs, LDL-c, oxidized LDL, total HDL-c and subpopulations (small, intermediate, and large), paraoxonase-1 (PON1) activity, hsCRP, uric acid, TNF-α, adiponectin, VEGF, and iCAM1. In the control subgroup with low HDL-c levels, significantly higher values of BP and TGs and lower values of PON1 activity and adiponectin were found, versus control normal HDL-c subgroup. However, differences in patients' subgroups were clearly more pronounced. Indeed, low HDL-c subgroup presented increased HbA1c, TGs, non-HDL-c, Ox-LDL, hsCRP, VEGF, and small HDL-c and reduced adiponectin and large HDL. In addition, Ox-LDL, large-HDL-c, and adiponectin presented interesting correlations with classical and nonclassical markers, mainly in the normal HDL-c patients' subgroup. In conclusion, despite LDL-c average levels, low HDL-c concentrations seem to be associated with a poor cardiometabolic profile in a population with cardiovascular risk factors, which is better evidenced by traditional and nontraditional CV biomarkers, including Ox-LDL, large HDL-c, and adiponectin.

Insulin resistance and acne: a new risk factor for men?

The purpose of this study is to investigate the relationship between acne and insulin resistance as well as other metabolic impairment in young males. Acne is a skin disease that can be influenced by endocrine abnormalities. In females, it is associated with polycystic ovary syndrome, with peripheral insulin resistance and hyperinsulinemia, whereas few data are available in males. For investigating this, 22 young males with acne have been compared to 22 controls of comparable age and gender. Acne was scored using the global acne grading system score. Clinical as well as biochemical parameters of glucose and lipid metabolism, circulating levels of androgens, and IGF-1 were evaluated. Oral glucose tolerance test was performed and homeostasis model assessment of insulin resistance was calculated. The results thus obtained are as follows, patients had higher BMI (p = 0.003), WC (p = 0.002), WHR (p = 0.02), SBP (p = 0.0001), DBP (p = 0.001), basal (p = 0.01) and 120 min. oGTT serum insulin concentrations (p = 0.002), basal glucose concentrations (p = 0.03), HOMA-IR (p = 0.016), and lower HDL-cholesterol than controls (p = 0.001). Among the subgroup of subjects with BMI <24.9, HDL-cholesterol (p = 0.05) and 120 min. oGTT serum insulin concentrations (p = 0.009) resulted to be independent predictors of acne at multivariate analysis. In conclusion, these findings highlight a metabolic imbalance in young males affected with acne. Insulin resistance seems to play the main role for the development of acne in these subjects. Insulin resistance could represent an effective target for therapy in male acne.

Role of Endogenous Estrogen on the Incidence of Coronary Heart Disease in Men

Estrogens protect the vascular system in women, but its effect in men is unclear. We evaluated the impact of estrogen on the male cardiovascular system. Of 140 Chinese males, 55 (aged 61.2 ± 3.5) were cases and 60 (aged 59.5 ± 4.6) were controls. Compared with the control group, only serum estradiol ([E2]; P < .01) levels but not testosterone ([T]; P = .21) were significantly lower in the cases. Linear and multiple regression analysis showed that serum T was positively associated with triglycerides ([TG]; r = .439, P < .01) and d-dimer ( r = .258, P < .05) but negatively associated with high-density lipoprotein cholesterol (HDL-C) levels ( r = −.267, P < .05) and C-reactive protein (CRP; r = −.214, P < .05). Estradiol was highly associated with TG ( r = .783, P < .01) and HDL-C ( r = .515, P < .01) but was negatively related with low-density lipoprotein cholesterol (LDL-C; P < .05), total cholesterol/HDL-C ( P < .05), CRP ( P < .01), and d-dimer ( P < .01). In conclusion, serum E2 and T levels affect coronary heart disease risk factors in males.

Unfavourable plasma and erythrocyte phospholipid fatty acid profile in elite amateur boxers

Research on possible physiological changes as a consequence of a specific lifestyle and long-term strenuous exercise in boxing has been sparse. We determined plasma and erythrocyte phospholipid (PL) fatty acids (FA) profile of 16 elite amateur male boxers (22.4±3.3 years of age), and compared them with a control group composed of 19 sedentary (24.4±3.4) year-old men. The percentages of total saturated fatty acids (SFA) and monosaturated FA in plasma phospholipids were significantly higher (P <0.001) in boxers compared to the control group. On the other hand, all studied polyunsaturated fatty acids (PUFA) in plasma PL with the exception of eicosapentaenoic acid (EPA, 20:5, n-3) and docosatetraenoic acid (DTA, 22:4, n-6) were significantly lower in boxers than in sedentary men. Total PUFA, n-6 PUFA and n-3 PUFA were also significantly lower in boxers (P <0.001), whereas the n-6/n-3 ratio was higher in boxers than in control group (P <0.01). Boxers had significantly higher proportion of all SFA in erythrocyte PL compared to the control group (P <0.05). In addition, the percentage of linoleic acid was lower in boxers' erythrocyte PL than in the control group (P <0.05). The results show two potentially unfavourable main features of the FA profile of boxers, that is, a higher n-6/n-3 ratio in plasma PL and a higher percentage of SFA in both plasma and erythrocyte phospholipids compared to controls. As SFA correlates directly with the incidence of cardiovascular disease and high n-6/n-3 ratio has been shown to stimulate carcinogenesis and modulate inflammation and autoimmunity, this profile could be detrimental to the health of boxers. The mechanism underlying these differences requires further investigation; however the results suggest benefits of nutritional intervention.

Lipoprint adequately estimates LDL size distribution, but not absolute size, versus polyacrylamide gradient gel electrophoresis

Recently, a new cost-effective and less labor-intensive technique termed the "lipoprint LDL system" was developed to measure LDL particle size. However, the agreement between lipoprint and previously validated techniques, such as polyacrylamide gradient gel electrophoresis (PGGE), has never been tested. Therefore, we measured LDL size by lipoprint and PGGE in 16 obese subjects at 4 different time points. Lipoprint significantly overestimated (P = 0.003) integrated LDL particle size by 1.1 ± 3.0 Å when compared to PGGE. As for distribution, there was good agreement between methods for the estimation of large, medium, and small particles (mean difference between the methods was <3% for each parameter). Correlational analysis also revealed good relationships between methods for the proportion of large (r = 0.81, P < 0.0001), medium (r = 0.67, P < 0.0001), and small (r = 0.73, P < 0.0001) particles. In sum, although there is good agreement between lipoprint and PGGE for the determination of LDL size distribution, absolute LDL size values may differ between the two methods.