Abdominal obesity, insulin resistance, metabolic syndrome and cholesterol homeostasis

Chromogranin A and its derived peptides: potential regulators of cholesterol homeostasis

Chromogranin A (CHGA), a member of the granin family of proteins, has been an attractive therapeutic target and candidate biomarker for several cardiovascular, neurological, and inflammatory disorders. The prominence of CHGA stems from the pleiotropic roles of several bioactive peptides (e.g., catestatin, pancreastatin, vasostatins) generated by its proteolytic cleavage and by their wide anatomical distribution. These peptides are emerging as novel modulators of cardiometabolic diseases that are often linked to high blood cholesterol levels. However, their impact on cholesterol homeostasis is poorly understood. The dynamic nature of cholesterol and its multitudinous roles in almost every aspect of normal body function makes it an integral component of metabolic physiology. A tightly regulated coordination of cholesterol homeostasis is imperative for proper functioning of cellular and metabolic processes. The deregulation of cholesterol levels can result in several pathophysiological states. Although studies till date suggest regulatory roles for CHGA and its derived peptides on cholesterol levels, the mechanisms by which this is achieved still remain unclear. This review aims to aggregate and consolidate the available evidence linking CHGA with cholesterol homeostasis in health and disease. In addition, we also look at common molecular regulatory factors (viz., transcription factors and microRNAs) which could govern the expression of CHGA and genes involved in cholesterol homeostasis under basal and pathological conditions. In order to gain further insights into the pathways mediating cholesterol regulation by CHGA/its derived peptides, a few prospective signaling pathways are explored, which could act as primers for future studies.

Dietary Micronutrient Status and Relation between Micronutrient Intakes and Overweight and Obesity among Non-Pregnant and Non-Lactating Women Aged 18 to 49 in China

Women between the ages of 18 and 49 are women of reproductive age, for whom physical health and nutritional status are closely related to successful pregnancy, good pregnancy outcomes and the nurturing of the next generation. Overweight and obesity have become important nutrition and health problems of women aged 18−49 years in China. In social life, non-pregnant and non-lactating Chinese women aged 18−49 are the most vulnerable and neglected group. At present, there are no research data on their dietary micronutrient intake, and the relationship between dietary micronutrient intake and overweight and obesity in China. However, non-pregnant and non-lactating women aged 18−49 are the best window of opportunity to implement strategies, correct nutrition and improve physical health. It remains to be explored whether their overweight and obesity are related to inadequate dietary micronutrient intake. The aim of this study was to evaluate dietary micronutrient intake in non-pregnant and non-lactating Chinese women aged 18−49 years, and to analyze the relationship between dietary micronutrient intake and overweight and obesity. Data were obtained from 2015 China Adult Chronic Disease and Nutrition Surveillance (CACDNS 2015). In CACDNS 2015, 12,872 women aged 18 to 49 years (excluding pregnant women and lactating mothers) were surveyed for a three-day 24 h dietary recall and a three-day household weighing of edible oil and condiments. The average daily dietary intake of micronutrients was calculated according to the Chinese food composition table. In 2015, the median intake of vitamin A, vitamin B1, vitamin B2, vitamin C and folate in non-pregnant and non-lactating women aged 18−49 years in China was 267.0 μg RE/day, 0.7 mg/day, 0.6 mg/day, 63.5 mg/day and 121.0 μg/day, respectively. The median mean intake of vitamin A, niacin, calcium and zinc in overweight/obese group was lower than that in non-overweight/obese group, and the difference was statistically significant (p < 0.05). Multivariate Logistic regression analysis showed that vitamin A intake (Q3 vs. Q1: OR = 0.785, 95% CI: 0.702~0.878; Q4 vs. Q1: OR = 0.766, 95% CI: 0.679~0.865), niacin intake (Q2 vs. Q1: OR = 0.801, 95% CI: 0.715−0.898; Q3 vs. Q1: OR = 0.632, 95% CI: 0.554~0.721; Q4 vs. Q1: OR = 0.662, 95% CI: 0.568~0.772), Zinc intake (Q4 vs. Q1: OR = 0.786, 95% CI: 0.662~0.932) were a protective factor for overweight/obesity in women, while vitamin B2 intake (Q2 vs. Q1: OR = 1.256, 95% CI: 1.120~1.408; Q3 vs. Q1: OR = 1.416, 95% CI: 1.240~1.617; Q4 vs. Q1: OR = 1.515, 95% CI: 1.293−1.776), vitamin E intake (Q2 vs. Q1: OR = 1.114, 95% CI: 1.006−0.235; Q3 vs. Q1: OR = 1.162, 95% CI: 1.048~0.288; Q4 vs. Q1: OR = 1.234, 95% CI: 1.112−1.371) was a risk factor for overweight/obesity in females. The intakes of most dietary micronutrients in non-pregnant and non-lactating women aged 18−49 in China were low. The intakes of dietary vitamin A, niacin and zinc were negatively correlated with the risk of overweight/obesity, while the intakes of vitamin B2 and vitamin E were positively correlated with the risk of overweight/obesity.

Can vitamin E supplementation affect obesity indices? A systematic review and meta-analysis of twenty-four randomized controlled trials

BACKGROUND

Several mechanisms have been proposed for the effect of vitamin E on weight loss. Yet various interventional studies with wide ranges of doses and durations have reported contradictory results.

METHODS

Cochrane Library, PubMed, Scopus, and Embase databases were searched up to December 2020. Meta-analysis was performed using random-effect method. Effect size was presented as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was evaluated using the I² index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta regression analyses was conducted.

RESULTS

A total of 24 studies with 33 data sets were included. There was no significant effect of vitamin E on weight (WMD: 0.15, 95% CI: -1.35 to 1.65, P = 0.847), body mass index (BMI) (WMD = 0.04, 95% CI: -0.29 to 0.37, P = 0.815), and waist circumference (WC) (WMD = -0.19 kg, 95% CI: -2.06 to 1.68, P = 0.842), respectively. However, subgroup analysis revealed that vitamin E supplementation in studies conducted on participants with normal BMI (18.5-24.9) had increasing impact on BMI (P = 0.047).

CONCLUSION

There was no significant effect of vitamin E supplementation on weight, BMI and WC. However, vitamin E supplementation might be associated with increasing BMI in people with normal BMI (18.5-24.9).

Choline supplementation improves the lipid metabolism of intrauterine-growth-restricted pigs

Objective

The objective of this study was to investigate the effects of dietary choline supplementation on hepatic lipid metabolism and gene expression in finishing pigs with intrauterine growth retardation (IUGR).

Methods

Using a 2×2 factorial design, eight normal birth weight (NBW) and eight IUGR weaned pigs were fed either a basal diet (NBW pigs fed a basal diet, NC; IUGR pigs fed a basal diet, IC) or a diet supplemented with two times more choline than the basal diet (NBW pigs fed a high-choline diet, NH; IUGR pigs fed a high-choline diet, IH) until 200 d of age.

Results

The results showed that the IUGR pigs had reduced body weight compared with the NBW pigs (p<0.05 from birth to d 120; p = 0.07 from d 120 to 200). Increased (p<0.05) free fatty acid (FFA) and triglyceride levels were observed in the IUGR pigs compared with the NBW pigs. Choline supplementation decreased (p<0.05) the levels of FFAs and triglycerides in the serum of the pigs. The activities of malate dehydrogenase and glucose 6-phosphate dehydrogenase were both increased (p<0.05) in the livers of the IUGR pigs. Choline supplementation decreased (p<0.05) malate dehydrogenase activity in the liver of the pigs. Gene expression of fatty acid synthase (FAS) was higher (p<0.05) in the IC group than in the other groups, and choline supplementation decreased (p<0.05) FAS and acetyl-CoA carboxylase α expression in the livers of the IUGR pigs. The expression of carnitine palmitoyl transferase 1A (CPT1A) was lower (p<0.05) in the IC group than in the other groups, and choline supplementation increased (p<0.05) the expression of CPT1A in the liver of the IUGR pigs and decreased (p<0.01) the expression of hormone-sensitive lipase in both types of pigs. The gene expression of phosphatidylethanolamine N-methyltransferase (PEMT) was higher (p<0.05) in the IC group than in the other groups, and choline supplementation significantly reduced (p<0.05) PEMT expression in the liver of the IUGR pigs.

Conclusion

In conclusion, the lipid metabolism was abnormal in IUGR pigs, but the IUGR pigs consuming twice the normal level of choline had improved circulating lipid parameters, which could be related to the decreased activity of nicotinamide adenine dinucleotide phosphate-generating enzymes or the altered expressions of lipid metabolism-related genes.

CCL2 Serum Levels and Adiposity Are Associated with the Polymorphic Phenotypes -2518A on CCL2 and 64ILE on CCR2 in a Mexican Population with Insulin Resistance

Genetic susceptibility has been described in insulin resistance (IR). Chemokine (C-C motif) ligand-2 (CCL2) is overexpressed in white adipose tissue and is the ligand of C-C motif receptor-2 (CCR2). The CCL2 G-2518A polymorphism is known to regulate gene expression, whereas the physiological effects of the CCR2Val64Ile polymorphism are unknown. The aim of the study is to investigate the relationship between these polymorphisms with soluble CCL2 levels (sCCL2), metabolic markers, and adiposity. In a cross-sectional study we included 380 Mexican-Mestizo individuals, classified with IR according to Stern criteria. Polymorphism was identified using PCR-RFLP/sequence-specific primers. Anthropometrics and metabolic markers were measured by routine methods and adipokines and sCCL2 by ELISA. The CCL2 polymorphism was associated with IR (polymorphic A+ phenotype frequencies were 70.9%, 82.6%, in individuals with and without IR, resp.). Phenotype carriers CCL2 (A+) displayed lower body mass and fat indexes, insulin and HOMA-IR, and higher adiponectin levels. Individuals with IR presented higher sCCL2 compared to individuals without IR and was associated with CCR2 (Ile+) phenotype. The double-polymorphic phenotype carriers (A+/Ile+) exhibited higher sCCL2 than double-wild-type phenotype carriers (A-/Ile-). The present findings suggest that sCCL2 production possibly will be associated with the adiposity and polymorphic phenotypes of CCL2 and CCR2, in Mexican-Mestizos with IR.

A moderate-fat diet containing pistachios improves emerging markers of cardiometabolic syndrome in healthy adults with elevated LDL levels

A randomised, cross-over, controlled-feeding study was conducted to evaluate the cholesterol-lowering effects of diets containing pistachios as a strategy for increasing total fat (TF) levels v. a control (step I) lower-fat diet. Ex vivo techniques were used to evaluate the effects of pistachio consumption on lipoprotein subclasses and functionality in individuals (n 28) with elevated LDL levels ( ≥ 2·86 mmol/l). The following test diets (SFA approximately 8 % and cholesterol < 300 mg/d) were used: a control diet (25 % TF); a diet comprising one serving of pistachios per d (1PD; 30 % TF); a diet comprising two servings of pistachios per d (2PD; 34 % TF). A significant decrease in small and dense LDL (sdLDL) levels was observed following the 2PD dietary treatment v. the 1PD dietary treatment (P= 0·03) and following the 2PD dietary treatment v. the control treatment (P= 0·001). Furthermore, reductions in sdLDL levels were correlated with reductions in TAG levels (r 0·424, P= 0·025) following the 2PD dietary treatment v. the control treatment. In addition, inclusion of pistachios increased the levels of functional α-1 (P= 0·073) and α-2 (P= 0·056) HDL particles. However, ATP-binding cassette transporter A1-mediated serum cholesterol efflux capacity (P= 0·016) and global serum cholesterol efflux capacity (P= 0·076) were only improved following the 2PD dietary treatment v. the 1PD dietary treatment when baseline C-reactive protein status was low ( < 103μg/l). Moreover, a significant decrease in the TAG:HDL ratio was observed following the 2PD dietary treatment v. the control treatment (P= 0·036). There was a significant increase in β-sitosterol levels (P< 0·0001) with the inclusion of pistachios, confirming adherence to the study protocol. In conclusion, the inclusion of pistachios in a moderate-fat diet favourably affects the cardiometabolic profile in individuals with an increased risk of CVD.