Nutrition & Metabolism

  1743-7075

 

 

Cơ quản chủ quản:  BMC , BioMed Central Ltd.

Lĩnh vực:
Medicine (miscellaneous)Nutrition and DieteticsEndocrinology, Diabetes and Metabolism

Các bài báo tiêu biểu

Fructose, insulin resistance, and metabolic dyslipidemia Dịch bởi AI
Tập 2 Số 1 - 2005
Heather Basciano, Lisa Federico, Khosrow Adeli
Tóm tắt

Béo phì và tiểu đường tuýp 2 đang diễn ra với tỷ lệ dịch bệnh ở Hoa Kỳ và nhiều khu vực khác trên thế giới. "Dịch béo phì" dường như đã xuất hiện chủ yếu từ các thay đổi trong chế độ ăn uống của chúng ta và sự giảm hoạt động thể chất. Một thay đổi trong chế độ ăn quan trọng nhưng ít được đánh giá cao đã là sự gia tăng đáng kể lượng tiêu thụ fructose từ việc tiêu thụ sucrose và siro ngô có hàm lượng fructose cao, một chất làm ngọt phổ biến được sử dụng trong ngành công nghiệp thực phẩm. Một dòng fructose cao vào gan, cơ quan chính có khả năng chuyển hóa carbohydrate đơn giản này, gây rối loạn chuyển hóa glucose và các con đường tiếp nhận glucose, và dẫn đến tăng đáng kể tốc độ tổng hợp lipogenesis và triglyceride (de novo) do dòng fructose cao. Sự rối loạn chuyển hóa này dường như là nguyên nhân gây nên tình trạng kháng insulin thường được quan sát thấy với việc ăn fructose cao trong cả người và mô hình động vật. Các trạng thái kháng insulin do fructose gây ra thường được đặc trưng bởi bệnh dyslipidemia chuyển hóa sâu sắc, vốn dường như bắt nguồn từ sản xuất quá mức các hạt lipoprotein gây xơ vữa động mạch từ gan và ruột. Do đó, những bằng chứng mới nổi từ nghiên cứu dịch tễ và sinh hóa gần đây rõ ràng cho thấy rằng việc tiêu thụ fructose trong chế độ ăn uống cao đã nhanh chóng trở thành một yếu tố gây nên tình trạng hội chứng chuyển hóa. Có một nhu cầu cấp thiết để tăng cường sự nhận thức của công chúng về những rủi ro liên quan đến việc tiêu thụ fructose cao và cần có những nỗ lực lớn hơn để hạn chế việc bổ sung thực phẩm đóng gói với các phụ gia fructose cao. Bài báo này sẽ thảo luận về các xu hướng tiêu thụ fructose, hậu quả chuyển hóa của việc tăng cường tiêu thụ fructose, và các cơ chế phân tử dẫn đến việc gây nên lipogenesis, kháng insulin và bệnh dyslipidemia chuyển hóa do fructose.

#Béo phì #tiểu đường tuýp 2 #kháng insulin #dyslipidemia chuyển hóa #fructose #tiêu thụ sucrose #sức khỏe công cộng.
The pivotal role of pyruvate dehydrogenase kinases in metabolic flexibility
Tập 11 Số 1 - 2014
Shuai Zhang, Matthew W. Hulver, Ryan P. McMillan, Mark A. Cline, Elizabeth R. Gilbert
Carbohydrate restriction improves the features of Metabolic Syndrome. Metabolic Syndrome may be defined by the response to carbohydrate restriction
- 2005
Jeff S. Volek, Richard D. Feinman
Abstract

Metabolic Syndrome (MetS) represents a constellation of markers that indicates a predisposition to diabetes, cardiovascular disease and other pathologic states. The definition and treatment are a matter of current debate and there is not general agreement on a precise definition or, to some extent, whether the designation provides more information than the individual components. We consider here five indicators that are central to most definitions and we provide evidence from the literature that these are precisely the symptoms that respond to reduction in dietary carbohydrate (CHO). Carbohydrate restriction is one of several strategies for reducing body mass but even in the absence of weight loss or in comparison with low fat alternatives, CHO restriction is effective at ameliorating high fasting glucose and insulin, high plasma triglycerides (TAG), low HDL and high blood pressure. In addition, low fat, high CHO diets have long been known to raise TAG, lower HDL and, in the absence of weight loss, may worsen glycemic control. Thus, whereas there are numerous strategies for weight loss, a patient with high BMIandhigh TAG is likely to benefit most from a regimen that reduces CHO intake. Reviewing the literature, benefits of CHO restriction are seen in normal or overweight individuals, in normal patients who meet the criteria for MetS or in patients with frank diabetes. Moreover, in low fat studies that ameliorate LDL and total cholesterol, controls may do better on the symptoms of MetS. On this basis, we feel that MetS is a meaningful, useful phenomenon and may, in fact, be operationally defined as the set of markers that responds to CHO restriction. Insofar as this is an accurate characterization it is likely the result of the effect of dietary CHO on insulin metabolism. Glucose is the major insulin secretagogue and insulin resistance has been tied to the hyperinsulinemic state or the effect of such a state on lipid metabolism. The conclusion is probably not surprising but has not been explicitly stated before. The known effects of CHO-induced hypertriglyceridemia, the HDL-lowering effect of low fat, high CHO interventions and the obvious improvement in glucose and insulin from CHO restriction should have made this evident. In addition, recent studies suggest that a subset of MetS, the ratio of TAG/HDL, is a good marker for insulin resistance and risk of CVD, and this indicator is reliably reduced by CHO restriction and exacerbated by high CHO intake. Inability to make this connection in the past has probably been due to the fact that individual responses have been studied in isolation as well as to the emphasis of traditional therapeutic approaches on low fat rather than low CHO.

We emphasize that MetS is not a disease but a collection of markers. Individual physicians must decide whether high LDL, or other risk factors are more important than the features of MetS in any individual case but if MetS is to be considered it should be recognized that reducing CHO will bring improvement. Response of symptoms to CHO restriction might thus provide a new experimental criterion for MetS in the face of on-going controversy about a useful definition. As a guide to future research, the idea that control of insulin metabolism by CHO intake is, to a first approximation, the underlying mechanism in MetS is a testable hypothesis.

Anti-inflammatory and anti-coagulatory activities of caffeic acid and ellagic acid in cardiac tissue of diabetic mice
- 2009
Pei-Chun Chao, Cheng‐Chin Hsu, Mei‐chin Yin
Abstract Background

Caffeic acid (CA) and ellagic acid (EA) are phenolic acids naturally occurring in many plant foods. Cardiac protective effects of these compounds against dyslipidemia, hypercoagulability, oxidative stress and inflammation in diabetic mice were examined.

Methods

Diabetic mice were divided into three groups (15 mice per group): diabetic mice with normal diet, 2% CA treatment, or 2% EA treatment. One group of non-diabetic mice with normal diet was used for comparison. After 12 weeks supplement, mice were sacrificed, and the variation of biomarkers for hypercoagulability, oxidative stress and inflammation in cardiac tissue of diabetic mice were measured.

Results

The intake of CA or EA significantly increased cardiac content of these compounds, alleviated body weight loss, elevated plasma insulin and decreased plasma glucose levels in diabetic mice (p < 0.05). These treatments also significantly enhanced plasma antithrombin-III and protein C activities (p < 0.05); and decreased triglyceride content in cardiac tissue and plasma (p < 0.05), in which the hypolipidemic effects of EA were significantly greater than that of CA (p < 0.05). CA or EA significantly lowered cardiac levels of malondialdehyde, reactive oxygen species, interleukin (IL)-beta, IL-6, tumor necrosis factor (TNF)-alpha and monocyte chemoattractant protein (MCP)-1 (p < 0.05); and retained cardiac activity of glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (p < 0.05). These compounds also significantly up-regulated cardiac mRNA expression of GPX1, SOD and catalase; and down-regulated IL-1beta, IL-6, TNF-alpha and MCP-1 mRNA expression in diabetic mice (p < 0.05).

Conclusion

These results support that CA and EA could provide triglyceride-lowering, anti-coagulatory, anti-oxidative, and anti-inflammatory protection in cardiac tissue of diabetic mice. Thus, the supplement of these agents might be helpful for the prevention or attenuation of diabetic cardiomyopathy.

Circulating omentin concentration increases after weight loss
- 2010
José María Moreno-Navarrete, Victoria Catalán, Francisco Ortega, Javier Gómez-Ambrosi, Wifredo Ricart, Gema Frühbeck, José Manuel Fernández‐Real
Abstract Background

Omentin-1 is a novel adipokine expressed in visceral adipose tissue and negatively associated with insulin resistance and obesity. We aimed to study the effects of weight loss-induced improved insulin sensitivity on circulating omentin concentrations.

Methods

Circulating omentin-1 (ELISA) concentration in association with metabolic variables was measured in 35 obese subjects (18 men, 17 women) before and after hypocaloric weight loss.

Results

Baseline circulating omentin-1 concentrations correlated negatively with BMI (r = -0.58, p < 0.001), body weight (r = -0.35, p = 0.045), fat mass (r = -0.67, p < 0.001), circulating leptin (r = -0.7, p < 0.001) and fasting insulin (r = -0.37, p = 0.03). Circulating omentin-1 concentration increased significantly after weight loss (from 44.9 ± 9.02 to 53.41 ± 8.8 ng/ml, p < 0.001). This increase in circulating omentin after weight loss was associated with improved insulin sensitivity (negatively associated with HOMA value and fasting insulin, r = -0.42, p = 0.02 and r = -0.45, p = 0.01, respectively) and decreased BMI (r = -0.54, p = 0.001).

Conclusion

As previously described with adiponectin, circulating omentin-1 concentrations increase after weight loss-induced improvement of insulin sensitivity.

Green tea powder and Lactobacillus plantarum affect gut microbiota, lipid metabolism and inflammation in high-fat fed C57BL/6J mice
Tập 9 Số 1 - 2012
Ulrika Axling, Cecilia Olsson, Jie Xu, Céline Fernandez, Sara Larsson, Kristoffer Ström, Siv Ahrné, Cecilia Holm, Göran Molin, Karin Berger
Abstract Background

Type 2 diabetes is associated with obesity, ectopic lipid accumulation and low-grade inflammation. A dysfunctional gut microbiota has been suggested to participate in the pathogenesis of the disease. Green tea is rich in polyphenols and has previously been shown to exert beneficial metabolic effects. Lactobacillus plantarum has the ability to metabolize phenolic acids. The health promoting effect of whole green tea powder as a prebiotic compound has not been thoroughly investigated previously.

Methods

C57BL/6J mice were fed a high-fat diet with or without a supplement of 4% green tea powder (GT), and offered drinking water supplemented with Lactobacillus plantarum DSM 15313 (Lp) or the combination of both (Lp + GT) for 22 weeks. Parameters related to obesity, glucose tolerance, lipid metabolism, hepatic steatosis and inflammation were examined. Small intestinal tissue and caecal content were collected for bacterial analysis.

Results

Mice in the Lp + GT group had significantly more Lactobacillus and higher diversity of bacteria in the intestine compared to both mice in the control and the GT group. Green tea strongly reduced the body fat content and hepatic triacylglycerol and cholesterol accumulation. The reduction was negatively correlated to the amount of Akkermansia and/or the total amount of bacteria in the small intestine. Markers of inflammation were reduced in the Lp + GT group compared to control. PLS analysis of correlations between the microbiota and the metabolic variables of the individual mice showed that relatively few components of the microbiota had high impact on the correlation model.

Conclusions

Green tea powder in combination with a single strain of Lactobacillus plantarum was able to promote growth of Lactobacillus in the intestine and to attenuate high fat diet-induced inflammation. In addition, a component of the microbiota, Akkermansia, correlated negatively with several metabolic parameters known to be risk factors for the development of type 2 diabetes.

Antioxidant rich grape pomace extract suppresses postprandial hyperglycemia in diabetic mice by specifically inhibiting alpha-glucosidase
- 2010
Shelly Hogan, Lei Zhang, Jiànróng Lǐ, Shuwen Sun, Corene Canning, Kequan Zhou
Abstract Background

Postprandial hyperglycemia is an early defect of type 2 diabetes and one of primary anti-diabetic targets. Treatment of postprandial hyperglycemia can be achieved by inhibiting intestinal α-glucosidase, the key enzyme for oligosaccharide digestion and further glucose absorption. Grape pomace is winemaking byproduct rich in bioactive food compounds such as phenolic antioxidants. This study evaluated the anti-diabetic potential of two specific grape pomace extracts by determining their antioxidant and anti-postprandial hyperglycemic activities in vitro and in vivo.

Methods

The extracts of red wine grape pomace (Cabernet Franc) and white wine grape pomace (Chardonnay) were prepared in 80% ethanol. An extract of red apple pomace was included as a comparison. The radical scavenging activities and phenolic profiles of the pomace extracts were determined through the measurement of oxygen radical absorbance capacity, DPPH radical scavenging activity, total phenolic content and flavonoids. The inhibitory effects of the pomace extracts on yeast and rat intestinal α-glucosidases were determined. Male 6-week old C57BLKS/6NCr mice were treated with streptozocin to induce diabetes. The diabetic mice were then treated with vehicle or the grape pomace extract to determine whether the oral intake of the extract can suppress postprandial hyperglycemia through the inhibition of intestinal α-glucosidases.

Results

The red grape pomace extract contained significantly higher amounts of flavonoids and phenolic compounds and exerted stronger oxygen radical absorbance capacity than the red apple pomace extract. Both the grape pomace extracts but not the apple pomace extract exerted significant inhibition on intestinal α-glucosidases and the inhibition appears to be specific. In the animal study, the oral intake of the grape pomace extract (400 mg/kg body weight) significantly suppressed the postprandial hyperglycemia by 35% in streptozocin-induced diabetic mice following starch challenge.

Conclusion

This is the first report that the grape pomace extracts selectively and significantly inhibits intestinal α-glucosidase and suppresses postprandial hyperglycemia in diabetic mice. The antioxidant and anti-postprandial hyperglycemic activities demonstrated on the tested grape pomace extract therefore suggest a potential for utilizing grape pomace-derived bioactive compounds in management of diabetes.