Clinical use of a carbohydrate-restricted diet to treat the dyslipidemia of the metabolic syndrome

Dietary patterns in association with the risk of elevated blood pressure, lipid profile and fasting plasma glucose among adults in Jiangsu Province of China

BACKGROUND AND AIMS

This study aimed to identify unique dietary patterns, and to examine the correlation of dietary patterns with elevated blood pressure, lipid profile and fasting plasma glucose (FPG) among adults in Jiangsu Province of China.

METHODS AND RESULTS

4951 individuals were selected in this cross-sectional study from nutrition and health survey in Jiangsu Province in 2014. Factor analysis was used to identify the dietary patterns. Higher quartile of the cereals-seafood-dairy dietary pattern was inversely associated with high low-density lipoprotein cholesterol (LDL) (composed to Q1, OR = 0.834, 95% CI: 0.700∼0.993, P < 0.05) and FPG (composed to Q1, OR = 0.725, 95% CI: 0.609-0.862, P < 0.05), while higher quartile of the traditional Jiangsu dietary pattern was positively associated with low high-density lipoprotein cholesterol (HDL) (composed to Q1, OR = 1.395, 95% CI: 1.067∼1.825, P < 0.05) and high systolic blood pressure (SBP) (composed to Q1, OR = 1.238, 95% CI: 1.020∼1.503, P < 0.05). Higher scores of the refined food-oriented dietary pattern was inversely related to high triglycerides (TG) (composed to Q1, OR = 0.665, 95% CI: 0.551∼0.802, P < 0.05), but was positively related to high TC (composed to Q1, OR = 2.179, 95% CI: 1.817∼2.614), high LDL (composed to Q1, OR = 2.431, 95% CI: 2.037∼2.902, P < 0.05) and elevated FPG (composed to Q1, OR = 1.734, 95% CI: 1.458∼2.061, P < 0.05).

CONCLUSION

Different structure of dietary patterns do affect the blood pressure, lipid profile and fasting plasma glucose among adults in Jiangsu Province, China.

Using a low-carbohydrate diet to treat obesity and type 2 diabetes mellitus

PURPOSE OF REVIEW

This study will provide a narrative review of the history of the clinical use of low-carbohydrate diets and give a practical example of how to implement a low-carbohydrate diet, with an emphasis on deprescribing medications.

RECENT FINDINGS

Low-carbohydrate diets have been used since the late 19th century to treat obesity and type 2 diabetes mellitus (T2DM). Recently, clinical research has validated the use of low-carbohydrate diets for individuals affected by obesity and T2DM, and these diets are included in several national clinical guidelines. Because medications are commonly used to treat hypertension and T2DM, special consideration must be made to monitor and reduce these medications to avoid overmedication. Clinic visits and home monitoring of blood pressure and glucose levels are important tools to alert clinicians that a reduction in medication levels may be indicated.

SUMMARY

Low-carbohydrate diets have been utilized clinically for many years to treat obesity and T2DM and can be used alongside effective monitoring to safely deprescribe dispensable medications for these diseases.

Starch synthase IIIa and starch branching enzyme IIb-deficient mutant rice line ameliorates pancreatic insulin secretion in rats: screening and evaluating mutant rice lines with antidiabetic functionalities

Diabetes mellitus is a metabolic disease spreading worldwide that has been reported to worsen the development and progression of other diseases (cancer, vascular diseases and dementia). To establish functional rice lines with anti-postprandial hyperglycaemic effects, we developed mutant rice lines, which lack one or two gene(s) related to starch synthesis, and evaluated their effects. Powder of mutant rice lines or other grains was loaded to rats fasted overnight (oral grain powder loading test). Incremental area under time-concentration curves (iAUC) were calculated with monitored blood glucose levels. Rice lines with anti-postprandial hyperglycaemic effects were separated by cluster analysis with calculated iAUC. A double mutant rice #4019 (starch synthase IIIa (ss3a)/branching enzyme IIb (be2b)), one of the screened mutant rice lines, was fed to Goto-Kakizaki (GK) rats, an animal model for type 2 diabetes, for 5 weeks. Plasma levels of C-peptide, a marker of pancreatic insulin secretion, were measured with ELISA. Forin vitrostudy, a rat pancreatic cell line was cultured with a medium containing rat serum which was sampled from rats fed #4019 diet for 2 d. After 24-h of incubation, an insulin secretion test was performed. Through the oral rice powder loading test, seven rice lines were identified as antidiabetic rice lines. The intake of #4019 diet increased plasma C-peptide levels of GK rats. This result was also observedin vitro.In rat serum added to cell medium, ornithine was significantly increased by the intake of #4019. In conclusion, the mutant rice #4019 promoted pancreatic insulin secretion via elevation of serum ornithine levels.

Pleiotropic effects of TCF7L2 gene variants and its modulation in the metabolic syndrome: from the LIPGENE study

AIMS/HYPOTHESIS

Variants of the TCF7L2 gene predict the development of type 2 diabetes mellitus (T2DM). We investigated the associations between gene variants of TCF7L2 and clinical features of the metabolic syndrome (MetS) (an entity often preceding T2DM), and their interaction with non-genetic factors, including plasma saturated fatty acids (SFA) concentration and insulin resistance (IR).

METHODS

Fasting lipid profiles, insulin sensitivity, insulin secretion, anthropometrics, blood pressure and 10 gene variations of the TCF7L2 gene were determined in 450 subjects with MetS.

RESULTS

Several single nucleotide polymorphisms (SNP) showed phenotypic associations independent of SFA or IR. Carriers of the rare T allele of rs7903146, and of three other SNPs in linkage disequilibrium with rs7903146, had lower blood pressure and insulin secretion. High IR and the presence of the T-allele of rs7903146 acted synergistically to define those with reduced insulin secretion. Carriers of the minor allele of rs290481 exhibited an altered lipid profile, with increased plasma levels of apolipoprotein B, non-esterified fatty acids, cholesterol and apolipoprotein B in triglyceride rich lipoproteins, and LDL cholesterol. Carriers of the minor allele of rs11196224 that had higher plasma SFA levels showed elevated procoagulant/proinflammatory biomarkers, impaired insulin secretion and increased IR, whereas carriers of the minor allele of rs17685538 with high plasma SFA levels exhibited higher blood pressure.

CONCLUSIONS/INTERPRETATION

SNP in the TCF7L2 gene are associated with differences in insulin secretion, blood pressure, blood lipids and coagulation in MetS patients, and may be modulated by SFA in plasma or IR.

Management of the metabolic syndrome and type 2 diabetes through lifestyle modification

Sustainable lifestyle modifications in diet and physical activity are the initial, and often the primary, component in the management of diabetes and the metabolic syndrome. An energy-prudent diet, coupled with moderate levels of physical activity, favorably affects several parameters of the metabolic syndrome and delays the onset of diabetic complications. Weight loss, albeit not an absolute prerequisite for improvement, is a major determinant and maximizes effectiveness. Adopting a healthy lifestyle pattern requires a series of long-term behavioral changes, but evidence to date indicates low long-term adherence to diet and physical activity recommendations. This calls for greater research and public health efforts focusing on strategies to facilitate behavior modification.

Has carbohydrate-restriction been forgotten as a treatment for diabetes mellitus? A perspective on the ACCORD study design

Prior to the discovery of medical treatment for diabetes, carbohydrate-restriction was the predominant treatment recommendation to treat diabetes mellitus. In this commentary we argue that carbohydrate-restriction should be reincorporated into contemporary treatment studies for diabetes mellitus.

Low-carbohydrate nutrition and metabolism

The persistence of an epidemic of obesity and type 2 diabetes suggests that new nutritional strategies are needed if the epidemic is to be overcome. A promising nutritional approach suggested by this thematic review is carbohydrate restriction. Recent studies show that, under conditions of carbohydrate restriction, fuel sources shift from glucose and fatty acids to fatty acids and ketones, and that ad libitum-fed carbohydrate-restricted diets lead to appetite reduction, weight loss, and improvement in surrogate markers of cardiovascular disease.

The case for low carbohydrate diets in diabetes management

A low fat, high carbohydrate diet in combination with regular exercise is the traditional recommendation for treating diabetes. Compliance with these lifestyle modifications is less than satisfactory, however, and a high carbohydrate diet raises postprandial plasma glucose and insulin secretion, thereby increasing risk of CVD, hypertension, dyslipidemia, obesity and diabetes. Moreover, the current epidemic of diabetes and obesity has been, over the past three decades, accompanied by a significant decrease in fat consumption and an increase in carbohydrate consumption. This apparent failure of the traditional diet, from a public health point of view, indicates that alternative dietary approaches are needed. Because carbohydrate is the major secretagogue of insulin, some form of carbohydrate restriction is a prima facie candidate for dietary control of diabetes. Evidence from various randomized controlled trials in recent years has convinced us that such diets are safe and effective, at least in short-term. These data show low carbohydrate diets to be comparable or better than traditional low fat high carbohydrate diets for weight reduction, improvement in the dyslipidemia of diabetes and metabolic syndrome as well as control of blood pressure, postprandial glycemia and insulin secretion. Furthermore, the ability of low carbohydrate diets to reduce triglycerides and to increase HDL is of particular importance. Resistance to such strategies has been due, in part, to equating it with the popular Atkins diet. However, there are many variations and room for individual physician planning. Some form of low carbohydrate diet, in combination with exercise, is a viable option for patients with diabetes. However, the extreme reduction of carbohydrate of popular diets (<30 g/day) cannot be recommended for a diabetic population at this time without further study. On the other hand, the dire objections continually raised in the literature appear to have very little scientific basis. Whereas it is traditional to say that more work needs to be done, the same is true of the assumed standard low fat diets which have an ambiguous record at best. We see current trends in the national dietary recommendations as a positive sign and an appropriate move in the right direction.