The metabolic syndrome in relation with the glycemic index and the glycemic load

Dietary carbohydrate quality index (CQI), cardio-metabolic risk factors and insulin resistance among adults with obesity

BACKGROUND

Metabolic syndrome (MetS), as a cluster of cardiometabolic risk factors, is a global public health concern due to its increasing prevalence. Considering the previous evidence of the association between carbohydrate quality and cardiometabolic risk factors, our study was aimed to evaluate any possible association between carbohydrate quality index (CQI) and cardiometabolic risk factors among obese adults.

METHODS

In this cross-sectional study, 336 apparently healthy individuals with obesity were participated. Dietary intake was assessed by a semi-quantitative Food Frequency Questionnaire (FFQ), including 168 food items validated for the Iranian population. CQI was calculated with three components of solid carbohydrates to total carbohydrates ratio, dietary fiber intake, and dietary glycemic index (GI). Body composition was determined by bioelectrical impedance analysis (BIA). Blood pressure was measured by sphygmomanometer and enzymatic methods were used to evaluate serum lipid, glucose, and insulin concentrations.

RESULTS

Subjects in the third quartile of CQI had significantly lower systolic blood pressure (SBP) (P = 0.03) and diastolic blood pressure (DBP) (P = 0.01). Participants in the higher quartiles of CQI had more intake of energy, carbohydrates, fat, saturated fatty acid (SFA), and mono-saturated fatty acid (MUFA) (P < 0.05). Moreover, the homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in the second quartile of CQI [odds ratio (OR) = 0.146, P = 0.01) after adjustment for age, body mass index (BMI), sex, physical activity, socioeconomic status (SES) and energy intake.

CONCLUSION

According to our findings, a higher quality of dietary carbohydrates, determined by CQI, could be associated with a lower risk of hypertension.

The association of dietary glycemic index and glycemic load with the risk of insomnia in the adult population

BACKGROUND

A dietary pattern with a high glycemic index (GI) and glycemic load (GL) can be a precursor to sleep disorders that link to many chronic diseases. We aimed to assess the association of dietary GI and GL with the risk of insomnia in Iranian adults.

METHODS

A total of 111 newly diagnosed insomnia cases and 333 controls aged 18-60 years were included in this case-control study. The participants' dietary intakes were collected using a valid and reliable food frequency questionnaire. The diagnosis of insomnia in subjects was performed by a neurologist using the Insomnia Severity Index (ISI) questionnaire. Multivariable logistic regression models, adjusted for the potential confounders, were used to determine the risk of insomnia according to tertiles of dietary glycemic indices.

RESULTS

The mean (SD) age and BMI of the study population (78.6% female) were 31.8 (10.0) years and 24.70 (3.62) kg/m², respectively. The median (IQR) of dietary GI and GL in subjects was 62.7 (57.0-68.6) and 213.5(167.4-268.5), respectively. Based on the multivariable-adjusted model, after controlling for age, sex, physical activity, obesity, smoking, socioeconomic score, general health questionnaire (GHQ) score, and dietary energy intake, the odds of insomnia were increased across tertiles of dietary GL[(OR:2.72,95%CI:1.10-6.70),(P_trend = 0.017)], however, no significant association was observed between high GI diet and insomnia risk [(OR:1.38,95%CI:0.77-2.47),(P_trend = 0.298)].

CONCLUSIONS

Our results revealed that greater adherence to dietary pattern with high GL could be increased the odds of insomnia in Iranian adults.

The Role of Dietary Glycemic Index and Glycemic Load in Mediating Genetic Susceptibility via MC4R s17782313 Genotypes to Affect Cardiometabolic Risk Factors among Apparently Healthy Obese Individuals

Background

The association of genetic and dietary factors with occurrence and progression of chronic diseases such as metabolic syndrome (MetS) has long been addressed but there is a lack of evidence for complex interrelationships, including direct and indirect effects of these variables. Hence, this study is aimed at evaluating the mediating role of glycemic indices in the association of melanocortin-4 receptor (MC4R) rs17782313 polymorphism, sociodemographic, and psychological factors with the risk of MetS in obese adults using structural equation modeling.

Methods

We performed a cross-sectional analysis of data from 287 apparently healthy adults. Dietary glycemic index (GI) and glycemic load (GL) were calculated from a validated 147-item food frequency questionnaire (FFQ). MC4R s17782313 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Structural equation modeling was used to explore direct and indirect effects of genetic and nongenetic factors on MetS.

Results

MC4R gene variant was directly associated with the risk of MetS (B = 0.010; P = 0.023). On the other hand, this variant was found to be indirectly and positively associated with LDL-C (B = 6.589; P = 0.042) through mediatory effects of GI and GL. Moreover, GI and GL also mediated indirect positive effects of sex and age on LDL-C (B = 3.970; P ≤ 0.01; B = 0.878; P ≤ 0.01, respectively) and HDL (B = 2.203; P ≤ 0.01; B = 0.129; P ≤ 0.01, respectively). MC4R rs17782313 polymorphism had positive effects on GI (B = 1.577; P ≤ 0.01) and GL (B = 1.235; P ≤ 0.01).

Conclusion

Our data may state a hypothesis of the mediating effect of quantity and quality of carbohydrates consumed in relationship between genetic susceptibility to obesity and cardiometabolic risk factors. Further analyses should be carried out in high-quality cohort studies in order to confirm the findings.

Glycemic index, but not glycemic load, is associated with an increased risk of metabolic syndrome: Meta-analysis of observational studies

BACKGROUND

Diets with high glycemic index (GI) or high glycemic load (GL) have been linked to important risk factors associated with the development of metabolic syndrome (MetS), such as dyslipidemia, higher blood glucose, and insulin concentrations. However, the role of GI and GL in relation to Mets is still understudied and controversial. This review, therefore, assessed whether high GI or GL contribute to development of Mets.

METHODS

A systematic search of four bibliographic databases was conducted (MEDLINE/PubMed, EMBASE, Web of Sciences, and Scopus) from inception to January 2020 for observational studies assessing GI/GL in relation to MetS. Risk estimates were pooled using random-effect models for the highest versus lowest intake categories, and assessed for heterogeneity using subgroup analysis. The dose-response nature of the relationship was also investigated. Sensitivity analysis and Egger test were used to check the robustness of findings and the possibility of publication bias, respectively.

RESULTS

Data from 12 publications (one cohort study and eleven cross-sectional studies) with a total sample size of 36,295 subjects are included. The pooled effect sizes from the nine studies indicated high versus low dietary GI was associated with increased risk of MetS (OR = 1.05, 95% CI: 1.01 to 1.09) (I²  = 58.1, P = .004). This finding was supported by all subgroup analyses except where studies used 24-h recalls for dietary assessment. Additionally, a linear dose-response investigation revealed that each 5-point increment in GI was associated with 2% increase in the risk of MetS (OR = 1.02, 95% CI: 1.01 to 1.02); non-linear pattern was insignificant, however (p-nonlinearity = 0.63). Moreover, pooled effect sizes from ten studies suggested that no association was found between the GL and MetS with results remaining consistent in all subgroup analyses.

CONCLUSION

A diet with lower GI may protect against MetS. Nutrition policy and clinical practices should encourage a diet with low GI. Future studies should include both GI and GL and different criteria of MetS to provide a better comparison.

Mens Sana in Corpore Sano: Does the Glycemic Index Have a Role to Play?

Although diet interventions are mostly related to metabolic disorders, nowadays they are used in a wide variety of pathologies. From diabetes and obesity to cardiovascular diseases, to cancer or neurological disorders and stroke, nutritional recommendations are applied to almost all diseases. Among such disorders, metabolic disturbances and brain function and/or diseases have recently been shown to be linked. Indeed, numerous neurological functions are often associated with perturbations of whole-body energy homeostasis. In this regard, specific diets are used in various neurological conditions, such as epilepsy, stroke, or seizure recovery. In addition, Alzheimer’s disease and Autism Spectrum Disorders are also considered to be putatively improved by diet interventions. Glycemic index diets are a novel developed indicator expected to anticipate the changes in blood glucose induced by specific foods and how they can affect various physiological functions. Several results have provided indications of the efficiency of low-glycemic index diets in weight management and insulin sensitivity, but also cognitive function, epilepsy treatment, stroke, and neurodegenerative diseases. Overall, studies involving the glycemic index can provide new insights into the relationship between energy homeostasis regulation and brain function or related disorders. Therefore, in this review, we will summarize the main evidence on glycemic index involvement in brain mechanisms of energy homeostasis regulation.

Dietary Glycemic Index and Glycemic Load Are Not Associated with the Metabolic Syndrome in Lebanese Healthy Adults: A Cross-Sectional Study

High dietary glycemic index (GI) and glycemic load (GL) were suggested to increase the risk of metabolic syndrome (MetS). This study aims to estimate dietary GI and GL in a sample of healthy Lebanese adults and examine their association with MetS and its individual abnormalities. The study uses data from a community-based survey of 501 Lebanese urban adults. Dietary intake was assessed using a food frequency questionnaire. Biochemical, anthropometric, and blood pressure measurements were obtained. Subjects with previous diagnosis of chronic disease, metabolic abnormalities, or with incomplete data or implausible energy intakes were excluded, yielding a sample of 283. Participants were grouped into quartiles of GI and GL. Multivariate logistic regression analyses were performed. Average dietary GI and GL were estimated at 59.9 ± 8 and 209.7 ± 100.3. Participants belonging to the highest GI quartile were at increased risk of having MetS (odds ratio (OR) = 2.251, 95% CI:1.120–4.525) but this association lost significance with further adjustments. Those belonging to the second quartile of GI had significantly lower odds of having hyperglycemia (OR: 0.380, 95% CI:0.174–0.833). No associations were detected between GL and MetS. The study contributes to the body of evidence discussing the relationship between GI, GL, and MetS, in a nutrition transition context.

Changes in glucose levels and fecal excretion of lipids due to consumption of yacon flour

Purpose

As studies investigating the effects of fructan sources, such as yacon, on glucose and lipid metabolism showed different results, additional research is required to establish a clear relationship between them. Thus, this paper aims to evaluate possible effects of the consumption of the yacon pulp flour (YPF) on biological and metabolic parameters such as food consumption, weight gain, serum glucose levels and fecal lipid excretion of rats, as well as determine the role of glycemic index (GI) of the diets added of this ingredient on those parameters.

Design/methodology/approach

For this purpose, 24 male albino Wistar rats were divided into four groups, which received the following treatments for 17 days: Group 1 (G1) (Control) – American Institute of Nutrition (AIN)-M; Group 2 (G2) – AIN-M added 5 per cent YPF; Group 3 (G3) – AIN-M added 10 per cent YPF and Group 4 (G4) – AIN-M added 15 per cent YPF. Analysis of fasting and postprandial glycemia was conducted for elaboration of the glycemic curve and calculation of the GI of the diets. Lipids loss was measured by quantification of crude fat in feces after consumption of the diet.

Findings

YPF, regarding the concentration in the diets, did not elevate the fasting glucose among the groups. The postprandial glucose of the animals declined in different postprandial glucose peaks of the groups ingesting YPF in relation to the control one, especially in group treated with 15 per cent YPF, between 30 and 60 min (p <0,05), confirming the influence of the dietary fiber on the absorption of the glucose. The ingestion of YPF increased dragging of lipids to the animal feces, proportional to the amounts of YPF added to the diets. According to the regression analysis, followed by regression testing to 5 per cent, there was a significant difference between the experimental groups, being that the elevation of the percentage of YPF added to the diet caused a proportional increase in the lipid levels in the animal feces.

Originality/value

YPF could be an alimentary source of interest, mainly when the focus is on disease risk prevention such as diabetes, obesity and dyslipidemias.

Associação entre índice glicêmico e carga glicêmica dietéticos e síndrome metabólica em idosos

OBJETIVO: Investigar a associação entre índice glicêmico (IG) e/ou carga glicêmica (CG) da dieta e síndrome metabólica (SM). MÉTODOS: Trata-se de estudo documental e do tipo caso-controle, com uma amostra de 229 idosos. Calcularam-se o IG e a CG, classificando-os em adequado (baixo) e inadequado (moderado e alto). Calculou-se ainda a prevalência de consumo dos alimentos, consumidos por pelo menos metade dos avaliados. A análise estatística dos dados foi efetuada por meio do teste c² e teste t de Student. Adotou-se p < 0,05 como nível de significância. RESULTADOS: Dos indivíduos estudados (n = 229), 74,2% pertenciam ao sexo feminino. A média de idade do grupo foi de 70,1 (6,4) anos. A média diária de IG do grupo caso foi de 62,3 (6,5), e do grupo controle de 62,1 (6,1), com p = 0,864. As médias diárias de CG não foram estatisticamente diferentes (p = 0,212), sendo a do grupo caso de 99,8 (33,8) e do grupo controle de 108,9 (45,7). Os alimentos consumidos tanto pelos casos como pelos controles, com maior contribuição ao IG, foram: pão, arroz, banana e açúcar refinado. CONCLUSÃO: No grupo avaliado, não houve associação entre índice glicêmico e carga glicêmica dietéticos e síndrome metabólica. O padrão identificado, no entanto, coloca portadores e não portadores em situação de risco à saúde, merecendo ações educativas.

Detection of glucose abnormalities in patients with acute coronary heart disease: study of reliable tools in clinical practice

AIM

To investigate the prevalence of glucose abnormalities in patients with acute coronary syndrome and to assess the reliability of certain clinical or analytical variables to predict a pathologic result of oral glucose tolerance test (OGTT) at 3 months from discharge.

SUBJECTS AND METHODS

Prospective study of 102 patients admitted to the coronary care units. Patients were classified according to the American Diabetes Association criteria. Three months after discharge, an OGTT was performed to non-diabetic patients.

RESULTS

Forty-six (45.1%) patients were identified as diabetic (5 previously undiagnosed) and 56 (54.9%) as non-diabetic. OGTT identified 22% of diabetes, 33% of impaired glucose tolerance, and 45% of normal glucose tolerance. Fasting glucose (r=0.55, p<0.001), glycated hemoglobin (HbA1c) (r=0.46, p<0.001), low HDL cholesterol (HDLc) levels (r=-0.34, p<0.02), waist-hip ratio (r=0.45, p<0.01), high systolic blood pressure (r=0.5, p<0.01), and presence of acute myocardial infarction (r=0.46, p<0.001) at admission resulted significant to predict a pathologic result of OGTT.

CONCLUSIONS

Glucose abnormalities are frequent in acute coronary syndrome patients. Certain clinical and analytical markers at admission such as fasting glucose, HbA1c, HDL-c<40 mg/dl, waist-hip ratio, and systolic blood pressure, are useful to recognize patients with a higher predisposition to present a pathologic result in OGTT at 3 months from discharge.

Glycemic index differences of high-fat diets modulate primarily lipid metabolism in murine adipose tissue

A low vs. high glycemic index of a high-fat (HF) diet (LGI and HGI, respectively) significantly retarded adverse health effects in adult male C57BL/6J mice, as shown recently (Van Schothorst EM, Bunschoten A, Schrauwen P, Mensink RP, Keijer J. FASEB J 23: 1092–1101, 2009). The LGI diet enhanced whole body insulin sensitivity and repressed HF diet-induced body and white adipose tissue (WAT) weight gain, resulting in significantly reduced serum leptin and resistin levels and increased adiponectin levels. We questioned how WAT is modulated and characterized the molecular mechanisms underlying the glycemic index-mediated effects using whole genome microarrays. This showed that the LGI diet mainly exerts its beneficial effects via substrate metabolism, especially fatty acid metabolism. In addition, cell adhesion and cytoskeleton remodeling showed reduced expression, in line with lower WAT mass. An important transcription factor showing enhanced expression is PPAR-γ. Furthermore, serum levels of triglycerides, total cholesterol, and HDL- and LDL-cholesterol were all significantly reduced by LGI diet, and simultaneously muscle insulin sensitivity was significantly increased as analyzed by protein kinase B/Akt phosphorylation. Cumulatively, even though these mice were fed an HF diet, the LGI diet induced significantly favorable changes in metabolism in WAT. These effects suggest a partial overlap with pharmacological approaches by thiazolidinediones to treat insulin resistance and statins for hypercholesterolemia. It is therefore tempting to speculate that such a dietary approach might beneficially support pharmacological treatment of insulin resistance or hypercholesterolemia in humans.

Metabolic responses to prolonged consumption of glucose- and fructose-sweetened beverages are not associated with postprandial or 24-h glucose and insulin excursions

BACKGROUND

Consumption of sugar-sweetened beverages has been shown to be associated with dyslipidemia, insulin resistance, fatty liver, diabetes, and cardiovascular disease. It has been proposed that adverse metabolic effects of chronic consumption of sugar-sweetened beverages are a consequence of increased circulating glucose and insulin excursions, ie, dietary glycemic index (GI).

OBJECTIVE

We determined whether the greater adverse effects of fructose than of glucose consumption were associated with glucose and insulin exposures.

DESIGN

The subjects were studied in a metabolic facility and consumed energy-balanced diets containing 55% of energy as complex carbohydrate for 2 wk (GI = 64). The subjects then consumed 25% of energy requirements as fructose- or glucose-sweetened beverages along with their usual ad libitum diets for 8 wk at home and then as part of energy-balanced diets for 2 wk at the metabolic facility (fructose GI = 38, glucose GI = 83). The 24-h glucose and insulin profiles and fasting plasma glycated albumin and fructosamine concentrations were measured 0, 2, 8, and 10 wk after beverage consumption.

RESULTS

Consumption of fructose-sweetened beverages lowered glucose and insulin postmeal peaks and the 23-h area under the curve compared with the baseline diet and with the consumption of glucose-sweetened beverages (all P < 0.001, effect of sugar). Plasma glycated albumin concentrations were lower 10 wk after fructose than after glucose consumption (P < 0.01, effect of sugar), whereas fructosamine concentrations did not differ between groups.

CONCLUSION

The results suggest that the specific effects of fructose, but not of glucose and insulin excursions, contribute to the adverse effects of consuming sugar-sweetened beverages on lipids and insulin sensitivity. This study is registered at clinicaltrials.gov as NCT01165853.

Effects of glycemic load on metabolic risk markers in subjects at increased risk of developing metabolic syndrome

BACKGROUND

Epidemiologic studies suggest that diets with a low glycemic index (GI) or glycemic load (GL) are associated with a decreased risk of developing metabolic syndrome. Intervention studies are inconsistent, however, possibly due to differences in macronutrient and fiber compositions of the experimental diets.

OBJECTIVE

We tested side-by-side test foods with similar macronutrient and fiber compositions but with different sucrose-flour ratios or carbohydrate source to determine the effects of different GIs and GLs on metabolic risk markers in overweight subjects.

DESIGN

Overweight men (n = 9) and women (n = 6) received in random order for 11 wk 4 test foods with an increased GI or a decreased GI (69 compared with 40, 86 compared with 48, 63 compared with 37, and 51 compared with 20, respectively). There was a GL difference of 32 units between the 2 interventions.

RESULTS

At the end of the 11-wk intervention periods, the decreased GL test foods did not change fasting plasma glucose (mean +/- SD: 5.83 +/- 0.6 compared with 5.94 +/- 0.6 mmol/L) or insulin (8.3 +/- 2.8 compared with 9.8 +/- 5.1 mU/L) concentrations compared with increased GL test foods. Serum total cholesterol (5.56 +/- 0.90 compared with 5.76 +/- 1.04 mmol/L), LDL-cholesterol (3.57 +/- 0.72 compared with 3.68 +/- 0.80 mmol/L), HDL-cholesterol (1.21 +/- 0.38 compared with 1.24 +/- 0.37 mmol/L), and triacylglycerol (1.61 +/- 0.77 compared with 1.78 +/- 1.04 mmol/L) concentrations were also not significantly different for decreased and increased GL test foods, respectively. Finally, proinflammatory (high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-alpha, monocyte chemoattractant protein 1) and prothrombotic (plasminogen activator inhibitor 1) markers were not affected. Glucose and lipids were also analyzed after 1 and 5 wk of intervention and were not affected by the intervention.

CONCLUSION

When incorporated into a habitual diet, consumption of test foods with a decreased GL does not ameliorate metabolic risk markers in overweight subjects.

Relationship between major dietary patterns and metabolic syndrome among individuals with impaired glucose tolerance

OBJECTIVE

Dietary habits have been associated with the prevalence of the metabolic syndrome and limited data are available in this field for individuals with impaired glucose tolerance. This study focused on the association between major dietary patterns and prevalence of the metabolic syndrome in individuals with impaired glucose tolerance.

METHODS

This cross-sectional study was done in 425 subjects 35 to 55 y of age. Dietary data were collected using a food-frequency questionnaire. Blood pressure, waist circumference, glucose, triacylglycerols, and high-density lipoprotein cholesterol were measured and metabolic syndrome was defined based on Adult Treatment Panel III guidelines.

RESULTS

Five major dietary patterns were found: a western pattern (high in sweets, butter, soda, mayonnaise, sugar, cookies, tail of a lamb, hydrogenated fat, and eggs), a prudent pattern (high in fish, peas, honey, nuts, juice, dry fruits, vegetable oil, liver and organic meat, and coconuts and low in hydrogenated fat and non-leafy vegetables), a vegetarian pattern (high in potatoes, legumes, fruits rich in vitamin C, rice, green leafy vegetables, and fruits rich in vitamin A), a high-fat dairy pattern (high in high-fat yogurt and high-fat milk and low in low-fat yogurt, peas, and bread), and a chicken and plant pattern (high in chicken, fruits rich in vitamin A, green leafy vegetables, and mayonnaise and low in beef, liver, and organic meat). After adjusting for confounding variables, the western pattern was associated with greater odds of having increased triacylglycerol (odds ratio 1.76, 95% confidence interval 1.01-3.07) and blood pressure (odds ratio 2.62, 95% confidence interval 1.32-5.23). The prudent pattern was positively associated with a prevalence of low high-density lipoprotein cholesterol levels (odds ratio 0.55, 95% confidence interval 0.31-0.96). The vegetarian dietary pattern was inversely associated with a risk of an abnormal fasting blood glucose level (odds ratio 2.26, 95% confidence interval 1.25-4.06).

CONCLUSION

Major dietary patterns were significantly associated with the risk of metabolic syndrome.