Dietary glycemic index, glycemic load and blood lipid levels in middle-aged Japanese men and women

Sex Differences in Low-Density Lipoprotein Cholesterol Treatment Among Young Israeli Patients Following Premature Acute Coronary Syndrome

Introduction: Effective management of dyslipidemias is crucial for reducing morbidity and mortality among patients after acute coronary syndrome (ACS). Sex differences in dyslipidemia management after premature ACS in Israeli patients have not been extensively studied. This study aimed to investigate potential disparities between men and women in managing dyslipidemia, considering current guidelines. Methods: This retrospective cohort study examined patients who were 55 years old or younger and admitted to Meir Medical Center for ACS from January 2018 to February 2019. The study aimed to evaluate the use of lipid-lowering therapy (LLT), measure the achievement of target low-density lipoprotein cholesterol (LDL-C) levels, and analyze the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) in both male and female patients. Results: The study included a total of 687 participants, of which 23.3% were identified as females. Upon discharge, ∼80% of the patients were prescribed high-intensity statins. After 1 year, it was observed that females had higher levels of LDL-C and lower rates of achieving target LDL-C levels (<70 and 55 mg/dL) as compared with males (45% vs. 54.6% and 30% vs. 42.2%, respectively). The use of non-statin LLT at the 1-year mark was minimal in both groups. Finally, it was found that the occurrence of MACCE was similar between males and females. Conclusion: Sex disparities in dyslipidemia management after a premature ACS were apparent, with females having higher LDL-C levels and lower rates of target achievement. Intervention is necessary to address these disparities and encourage greater use of non-statin LLT.

Associations between Dietary Glycemic Index and Glycemic Load Values and Cardiometabolic Risk Factors in Adults: Findings from the China Health and Nutrition Survey

Studies investigating the associations between dietary glycemic index (GI) and glycemic load (GL) values and cardiometabolic risk factors (CMRF) among Chinese populations are strikingly limited. To assess the associations between dietary GI and GL values and CMRF, including dyslipidemia, hyperglycemia, and hyperuricemia in Chinese adults, we extracted data of 7886 apparently healthy adults from the 2009 wave of the China Health and Nutrition Survey. Dietary GI and GL values were calculated using data collected from three consecutive 24 h dietary recalls. Fasting lipid, glucose, and uric acid concentrations were measured and CMRF were defined on the basis of established criteria. There were no significant associations between dietary GI values and CMRF, and analyzing the data by age, sex, body mass index (BMI), and region did not alter these results. Dietary GL values were positively associated with prevalence of hyperuricemia in all participants (Q4 compared with Q1: odds ratio (OR) = 1.46; 95% CI: 1.14, 1.87; p-trend = 0.0030) and prevalence of hypercholesterolemia in participants ≥ 60 years old (Q5 compared with Q1: OR = 1.72; 95% CI: 1.11, 2.68; p-trend < 0.0010). Higher dietary GL but not GI values were associated with increased prevalence of hyperuricemia in apparently healthy Chinese adults and hypercholesterolemia in older Chinese adults. Further studies are required to confirm the public health implication of these findings.

The Effect of High Carbohydrate-to-fat Intake Ratios on Hypo-HDL-cholesterolemia Risk and HDL-cholesterol Levels over a 12-year Follow-up

Considering the strong correlation between carbohydrate and fat intake, we defined and assessed the association of the carbohydrate-to-fat ratio with the high-density lipoprotein cholesterol (HDL-c) level using 12-year follow-up data from the community-based cohort of the Korean Genome Epidemiology Study. We evaluated the long-term changes in HDL-c levels according to quartiles of carbohydrate-to-fat ratio using a mixed model. We also assessed the effect of the carbohydrate-to-fat ratio on the prevalence and incidence of hypo-HDL-cholesterolemia. Of 6,627 subjects, the prevalence of undiagnosed hypo-HDL-cholesterolemia at baseline was 35.3% (n = 2,339). Among the disease-free subjects, 56.8% developed hypo-HDL-cholesterolemia (incidence = 92/1,000 person-years). The prevalence and incidence of hypo-HDL-cholesterolemia were higher in females than in males. The highest carbohydrate-to-fat ratio quartile, which was characterized by high and low intake of carbohydrate and fat, was consistently associated with a lower HDL-c level during the 12-year follow up. Moreover, those in the highest quartile had a 1.14-fold greater risk of incident hypo-HDL-cholesterolemia than those in the lowest quartile, with a significant dose-response relationship. We found that high and low intake of carbohydrate and fat, respectively, was consistently associated with a low HDL-c level over a prolonged period. More research is needed to promote appropriate intake of macronutrients.

Low-carbohydrate diet and the risk of metabolic syndrome in Korean adults

BACKGROUND & AIMS

The association of low-carbohydrate diet with weight loss and the risk of cardiovascular diseases has recently been the focus of increasing research attention. However, studies on low-carbohydrate diet in the Asian population are limited. The present study was aimed to examine the association between low-carbohydrate diet and metabolic syndrome among Korean adults.

METHODS AND RESULTS

A total of 16,349 participants aged 30 years or older who participated in a 24-h dietary recall survey of the fifth and sixth Korea National Health and Nutrition Examination Survey were included in this study. Low-carbohydrate diet was evaluated using the low-carbohydrate-diet score, which was calculated based on the percentage of energy from carbohydrate, protein, and fat by sex. The association between the low-carbohydrate-diet score and metabolic syndrome was analyzed using multiple logistic regression analysis. A low-carbohydrate diet was not associated with metabolic syndrome and its components such as waist circumference, blood pressure, and triglyceride levels. However, women in the highest decile of the animal- or plant-based low-carbohydrate-diet score showed a decreased risk of reduced high-density lipoprotein (HDL)-cholesterol levels, and men in the highest decile of the animal-based low-carbohydrate-diet score showed a decreased risk of reduced HDL-cholesterol levels than those in the lowest decile of the low-carbohydrate-diet score.

CONCLUSION

These findings indicate that, in Korea, a low-carbohydrate diet did not increase the risk of metabolic syndrome among adults who typically consume a high-carbohydrate low-fat diet. However, it may moderately decrease the risk of reduced HDL-cholesterol levels.

Differential association of dietary carbohydrate intake with metabolic syndrome in the US and Korean adults: data from the 2007-2012 NHANES and KNHANES

BACKGROUND/OBJECTIVES

The risk factors for metabolic syndrome may differ between Western and Asian countries due to their distinct dietary cultures. However, few studies have directly compared macronutrient intake and its association with the risk of metabolic syndrome in the US and Korean adults using national survey data.

SUBJECT/METHODS

Based on the data from the US and Korean versions of the 2007-2012 National Health and Nutrition Examination Survey (NHANES, KNHANES), a total of 3,324 American and 20,515 Korean adults were included. In both countries, dietary intake was measured using a 24-h dietary recall method and metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

The percentages of energy intake from carbohydrate, protein, and fat were 50:16:33 in the US adults and 66:15:19 in the Korean adults. Regarding metabolic abnormalities, Korean adults in the highest quintile of carbohydrate intake showed an increased risk of metabolic syndrome in men and women, with abnormalities of reduced HDL cholesterol and elevated triglyceride levels. In contrast, the US men showed no significant association with metabolic syndrome and its abnormalities, while the US women showed an increased risk of reduced HDL cholesterol and elevated triglycerides.

CONCLUSIONS

A high carbohydrate intake is associated with metabolic abnormalities. As Korean adults consume more carbohydrate than American adults, stronger associations of dietary carbohydrate with metabolic syndrome were observed. Thus, further studies are necessary to elucidate the underlying mechanisms of different contributors to developing metabolic disease in Western and Asian populations.

Dietary carbohydrate and fat intakes are differentially associated with lipid abnormalities in Korean adults

BACKGROUND

A high prevalence of metabolic syndrome along with increasing rates of low high-density lipoprotein cholesterol (HDL-C) and elevated triglycerides (TGs) is shown in Korean adults. Little is known about the associations between macronutrient intake and lipid abnormalities in the Asian population, whose major energy source is carbohydrates.

OBJECTIVE

We examined the associations of dietary carbohydrate and fat intakes with lipid abnormalities in Korean adults.

METHODS

A total of 14,301 adults (5715 men and 8586 women) aged ≥30 years with no diagnosis and treatment for diabetes, hypertension, or dyslipidemia were selected from the 2008 to 2012 Korea National Health and Nutrition Examination Survey data. From the 24-hour recall data, dietary carbohydrate and fat intakes were estimated. Multivariate logistic regression was used to estimate odds ratios for lipid abnormalities, that is, elevated total cholesterol (TC), low HDL-C, high TC to HDL-C ratio, elevated non-HDL-C, elevated LDL cholesterol (LDL-C), and elevated TG across quintiles of dietary carbohydrate and fat intakes.

RESULTS

Percentage of energy from carbohydrate was positively associated with elevated TG and low HDL-C but inversely associated with elevated TC and elevated LDL-C in both men and women. Energy-adjusted carbohydrate intake also showed a positive association with low HDL-C. Dietary fat intakes had the opposite associations with lipid abnormalities than results for carbohydrate.

CONCLUSION

High carbohydrate diet is undesirable with regard to increased TG and reduced HDL-C despite the benefit for LDL-C. Dietary strategies emphasizing appropriate macronutrient intakes by the type of lipid abnormalities are recommended for the prevention of cardiovascular disease in Korean adults.

Blood Triglycerides Levels and Dietary Carbohydrate Indices in Healthy Koreans

Objectives:

Previous studies have obtained conflicting findings regarding possible associations between indices measuring carbohydrate intake and dyslipidemia, which is an established risk factor of coronary heart disease. In the present study, we examined cross-sectional associations between carbohydrate indices, including the dietary glycemic index (GI), glycemic load (GL), total amount of carbohydrates, and the percentage of energy from carbohydrates, and a range of blood lipid parameters.

Methods:

This study included 1530 participants (554 men and 976 women) from 246 families within the Healthy Twin Study. We analyzed the associations using a generalized linear mixed model to control for familial relationships.

Results:

Levels of the Apo B were inversely associated with dietary GI, GL, and the amount of carbohydrate intake for men, but these relationships were not significant when fat-adjusted values of the carbohydrate indices were used. Triglyceride levels were positively associated with dietary GI and GL in women, and this pattern was more notable in overweight participants (body mass index [BMI] ≥25 kg/m²). However, total, low-density lipoprotein and high-density lipoprotein cholesterol levels were not significantly related with carbohydrate intake overall.

Conclusions:

Of the blood lipid parameters we investigated, only triglyceride levels were positively related with dietary carbohydrate indices among women participants in the Healthy Twin Study, with an interactive role observed for BMI. However, these associations were not observed in men, suggesting that the association between blood lipid levels and carbohydrate intake depends on the type of lipid, specific carbohydrate indices, gender, and BMI.

Dietary glycemic index and glycemic load and their relationship to cardiovascular risk factors in Chinese children

The purpose of this study was to examine the cross-sectional associations between dietary glycemic index (GI) and glycemic load (GL) and cardiovascular disease (CVD) risk factors in Chinese children. A total of 234 Chinese schoolchildren aged 8-11 years in Guangdong participated in the study. Dietary intake was assessed via a 3-day dietary record. Seven established cardiovascular indicators were analyzed in this study: fasting plasma glucose (FPG), fasting triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), systolic blood pressure, and diastolic blood pressure. Higher dietary GI was significantly associated with higher TG levels (P = 0.037) and lower HDL-C levels (P = 0.005) after adjusting for age, sex, nutritional intake, physical activity, and body mass index z score. LDL-C was found to differ across tertiles of dietary GL. The middle tertile tended to show the highest level of LDL-C. TC, FPG, and blood pressure were independent of both dietary GI and GL. Our findings suggest that higher dietary GI is differentially associated with some CVD risk factors, including lower HDL-C and higher TG, in school-aged children from south China.

[Effects of a long-term intervention in a work cafeteria on employee vegetable intake]

OBJECTIVES

We examined the effects on employee vegetable intake of a long-term intervention in an employee work cafeteria.

METHODS

The subjects were approximately 1,200 employees (aged 19-61 years) of an industrial company in Fukui prefecture. We promoted the intake of typical Japanese style meals that combined three elements (staple foods, main dishes and vegetable dishes) to increase vegetables intake. We displayed all items on the menus of the employee cafeteria using three colors (yellow, red and green to denote three elements) to indicate healthy food choices for the maintenance of a healthy food environment. We advised employees to choose meals containing the three elements at the time of payment, for nutritional education (appropriate portion choice: APC). We evaluated the ratio of APC at the same time. To calculate the mean daily intake per person, we carried out a questionnaire survey similar to the "semi-quantitative food frequency questionnaire" and asked about the frequency and approximate intake of vegetables.

RESULTS

The APC was 63.5% after one year of intervention, significantly increased to 82.1% after two years (p < 0.001), and was 80.0% after three years of intervention (p < 0.001). Vegetable intake at breakfast (p < 0.001), lunch (p < 0.001) and dinner (p = 0.011), and from vegetable juice (p = 0.030) significantly increased after three years of intervention. The consumption of pickles significantly decreased after three years of intervention (p = 0.009). It was estimated that the vegetable intake of men increased from 167.3 to 184.6 g, and that of women from 157.9 to 187.7 g.

CONCLUSIONS

Employee estimated vegetable intake was significantly increased and that of pickles was significantly decreased by a long-term intervention (three years) in the employee work cafeteria.

Metabolic syndrome risk factors are associated with white rice intake in Korean adolescent girls and boys

In the present study, we examined the associations of total carbohydrate intake, dietary glycaemic load (DGL) and white rice intake with metabolic syndrome risk factors by sex in Korean adolescents. For the present cross-sectional study, data from the Fourth Korea National Health and Nutrition Examination Survey (2007–9) were used. A total of 2209 adolescents (n 1164 boys and n 1045 girls) aged 10–18 years with complete anthropometric, biochemical and dietary intake data were included in the study. Dietary intake data were obtained using the 24 h recall method, and total carbohydrate intake, DGL and white rice intake were divided into quartiles by sex. The metabolic syndrome and its risk factors were defined using the International Diabetes Federation criteria for children and adolescents. Fasting insulin levels and insulin resistance were included as the metabolic syndrome risk factors. All statistical analyses considered the complex sampling design effect and appropriate sampling weights. Multivariate linear regression analysis was used to estimate means with their standard errors of the mean for the metabolic syndrome risk factors across the quartiles of total carbohydrate intake, DGL and white rice intake. While high DGL was significantly associated with increased fasting glucose levels in boys, high total carbohydrate intake, DGL and white rice intake were consistently associated with reduced HDL-cholesterol levels in girls. High white rice intake was significantly associated with an increased risk of insulin resistance and the metabolic syndrome in girls but not in boys. Optimising dietary carbohydrate intake with respect to the source or amount is fundamental to preventing and managing metabolic diseases in Asian adolescents.

Associations between rice, noodle, and bread intake and sleep quality in Japanese men and women

Background

Previous studies have shown that a diet with a high-glycemic index is associated with good sleep quality. Therefore, we investigated the association of sleep quality with the intake of 3 common starchy foods with different glycemic indexes–rice, bread, and noodles–as well as the dietary glycemic index in a Japanese population.

Methods

The participants were 1,848 men and women between 20 and 60 years of age. Rice, bread, and noodle consumption was evaluated using a self-administered diet history questionnaire. Sleep quality was evaluated by using the Japanese version of the Pittsburgh Sleep Quality Index, and a global score >5.5 was considered to indicate poor sleep.

Results

Multivariate-adjusted odds ratios (95% confidence intervals) for poor sleep across the quintiles of rice consumption were 1.00 (reference), 0.68 (0.49–0.93), 0.61 (0.43–0.85), 0.59 (0.42–0.85), and 0.54 (0.37–0.81) (p for trend = 0.015); those for the quintiles of noodle consumption were 1.00 (reference), 1.25 (0.90–1.74), 1.05 (0.75–1.47), 1.31 (0.94–1.82), and 1.82 (1.31–2.51) (p for trend = 0.002). Bread intake was not associated with sleep quality. A higher dietary glycemic index was significantly associated with a lower risk of poor sleep (p for trend = 0.020).

Conclusion

A high dietary glycemic index and high rice consumption are significantly associated with good sleep in Japanese men and women, whereas bread intake is not associated with sleep quality and noodle consumption is associated with poor sleep. The different associations of these starchy foods with sleep quality might be attributable to the different glycemic index of each food.

Dietary glycemic index, glycemic load and incidence of type 2 diabetes in Japanese men and women: the Japan Public Health Center-based Prospective Study

Background

Japanese diets contain a relatively high amount of carbohydrates, and its high dietary glycemic index and glycemic load may raise the risk of diabetes in the Japanese population. The current study evaluated the associations between the dietary glycemic index, glycemic load, and the risk of type 2 diabetes in a population based cohort in Japan.

Methods

We observed 27,769 men and 36,864 women (45–75 y) who participated in the second survey of the Japan Public Health Center-based Prospective Study. The dietary glycemic index and glycemic load were estimated using a food-frequency questionnaire. The development of diabetes was reported in a questionnaire administered five years later, and the associations were analyzed using logistic regression after controlling for age, area, total energy intake, smoking status, family history of diabetes, physical activity, hypertension, BMI, alcohol intake, magnesium, calcium, dietary fiber and coffee intake, and occupation.

Results

The dietary glycemic load was positively associated with the risk of diabetes among women: the multivariable-adjusted odds ratio comparing the highest vs. the lowest quartile was 1.52 (95% CI, 1.13-2.04; P-trend = 0.01). The association was implied to be stronger among women with BMI < 25 than the women with BMI ≥ 25. The dietary glycemic index was positively associated with the risk of diabetes among men with a high intake of total fat: the multivariable-adjusted odds ratio comparing the highest vs. the lowest quartile was 1.46 (95% CI, 0.94-2.28; P-trend = 0.04). Among women with a high total fat intake, those in the first and second quartiles of the dietary glycemic index had a significant reduced risk of diabetes, compared with those in the first quartile who had a lower total fat level (multivariable-adjusted odds ratio = 0.59 with 95% CI, 0.37-0.94, and odds ratio = 0.63 with 95% CI, 0.40-0.998 respectively).

Conclusions

The population-based cohort study in Japan indicated that diets with a high dietary glycemic load increase the risk of type 2 diabetes among women. Total fat intake may modify the association between the dietary glycemic index and the risk of type 2 diabetes among men and women.

Sugar-sweetened beverage and diet soda consumption and the 7-year risk for type 2 diabetes mellitus in middle-aged Japanese men

PURPOSE

This cohort study investigated the association between sugar-sweetened beverage (SSB) and diet soda consumption and the incidence of type 2 diabetes in Japanese men.

METHODS

The participants were 2,037 employees of a factory in Japan. We measured consumption of SSB and diet soda using a self-administered diet history questionnaire. The incidence of diabetes was determined in annual medical examinations over a 7-year period. Hazard ratios (HRs) with 95 % confidence intervals (CIs) for diabetes were estimated after adjusting for age, body mass index, family history, and dietary and other lifestyle factors.

RESULTS

During the study, 170 participants developed diabetes. The crude incidence rates (/1,000 person-years) across participants who were rare/never SSB consumers, <1 serving/week, ≥ 1 serving/week and <1 serving/day, and ≥ 1 serving/day were 15.5, 12.7, 14.9, and 17.4, respectively. The multivariate-adjusted HR compared to rare/never SSB consumers was 1.35 (95 % CI 0.80-2.27) for participants who consumed ≥ 1 serving/day SSB. Diet soda consumption was significantly associated with the incident risk of diabetes (P for trend = 0.013), and multivariate-adjusted HRs compared to rare/never diet soda consumers were 1.05 (0.62-1.78) and 1.70 (1.13-2.55), respectively, for participants who consumed <1 serving/week and ≥ 1 serving/week.

CONCLUSIONS

Consumption of diet soda was significantly associated with an increased risk for diabetes in Japanese men. Diet soda is not always effective at preventing type 2 diabetes even though it is a zero-calorie drink.

Family history of diabetes, lifestyle factors, and the 7-year incident risk of type 2 diabetes mellitus in middle-aged Japanese men and women

Aims/Introduction

This cohort study of middle‐aged Japanese participants investigated the relationship between family history of diabetes, the incident risk of type 2 diabetes and the interaction of these variables with other factors.

Materials and Methods

Study participants were 3,517 employees (2,037 men and 1,480 women) of a metal products factory in Japan. Baseline health examinations included questions about medical history, physical examination, anthropometric measurements, questions about lifestyle factors, such as smoking, alcohol consumption and habitual exercise, and a self‐administered diet history questionnaire. Family history of diabetes was defined as having at least one‐first‐degree relative with diabetes. The incidence of diabetes was determined in annual medical examinations over a 7‐year period. Hazard ratios (HRs) for type 2 diabetes were estimated by Cox proportional hazards analysis.

Results

Of the 3,517 participants, 630 (18%) had a family history of diabetes mellitus. During the study, 228 participants developed diabetes. The age and sex‐adjusted HR for type 2 diabetes in participants with a family history of diabetes was 1.82 (95% confidence interval 1.36–2.43) as compared with those without a family history of diabetes. HRs did not change after adjustment for body mass index and lifestyle factors. We found no interactions with body mass index, insulin resistance, pancreatic β‐cell function or lifestyle factors.

Conclusions

Family history of diabetes was associated with the incident risk of diabetes, and these associations were independent of other risk factors, such as obesity, insulin resistance, and lifestyle factors in Japanese men and women.

Carbohydrate nutrition differs by diabetes status and is associated with dyslipidemia in Boston Puerto Rican adults without diabetes

Puerto Rican adults have a greater prevalence of type 2 diabetes (T2D) and lower HDL-cholesterol (HDL-C) than the general U.S. population. Carbohydrate nutrition may play a role in this disparity. Cross-sectional analyses included data from 1219 Puerto Ricans aged 45-75 y enrolled in the Boston Puerto Rican Health Study. Using the Pearson chi-square test and ANCOVA, lifestyle characteristics and dietary intake, as assessed by semiquantitative FFQ, were compared by T2D status based on fasting plasma glucose concentration and medication use. Food source rankings for carbohydrate, dietary glycemic load (GL), and fiber were obtained using the SAS procedure PROC RANK. Geometric mean plasma HDL-C and TG concentrations were compared across quintiles of dietary carbohydrate, glycemic index (GI), GL, and fiber by using ANCOVA and tests for linear trend. In multivariable analyses, individuals with T2D (39.5%) had lower dietary carbohydrate, GL, and total sugar intake from lower intake of sugar, fruit drinks, and soda compared with those without T2D. In individuals without T2D, dietary carbohydrate and GL were inversely associated with HDL-C (P < 0.0001). Associations between dietary fiber and HDL-C were confounded by carbohydrate intake, apparently from concurrent consumption of legumes with white rice, a refined carbohydrate food. No associations were observed between carbohydrate, dietary GI, GL, or fiber and TG. In conclusion, individuals with T2D showed evidence of dietary modification. Among those without diabetes, a high intake of refined carbohydrates was associated with decreased HDL-C. Longitudinal research on carbohydrate nutrition in relation to diabetes risk factors and blood lipids in Puerto Ricans is warranted.

Self-reported speed of eating and 7-year risk of type 2 diabetes mellitus in middle-aged Japanese men

OBJECTIVE

This cohort study investigated the association between eating speed and the incidence of type 2 diabetes in middle-aged Japanese men.

MATERIALS/METHODS

Participants were 2,050 male employees of a metal products factory in Japan. We measured self-reported categorical eating speed. The incidence of diabetes was determined in annual medical examinations over a 7-year period. The association between eating speed and the incidence of diabetes adjusted for multiple variables (age, family history of diabetes, smoking, alcohol drinking, habitual exercise, and presence of hypertension and hyperlipidemia) was evaluated using Cox proportional hazards models.

RESULTS

The prevalence of obesity (BMI≥25 kg/m(2)) across the categories of eating speed (slow, medium, and fast) was 14.6, 23.3, and 34.8%, respectively, and a faster eating speed was associated with a higher prevalence of obesity. During the study, 177 participants developed diabetes. Crude incidence rates (/1,000 person-years) across the three categories of eating speed were 9.9, 15.6, and 17.3, respectively. Multivariate-adjusted hazard ratios (95% CI) across the categories were 1.00 (reference), 1.68 (0.93-3.02), and 1.97 (1.10-3.55), respectively, and eating speed was associated with the risk of diabetes (p for trend=0.030). After further adjustment for BMI, a significant association was not observed.

CONCLUSIONS

Eating speed was associated with the incidence of diabetes. Since these associations were not significant after adjusting for BMI, eating speed may act via its effect on body weight. Eating speed is a controllable risk factor, and eating slowly could be an acceptable lifestyle intervention for the prevention of diabetes mellitus.

High carbohydrate intake was inversely associated with high-density lipoprotein cholesterol among Korean adults

The traditional Asian diet, which is characterized as being high in carbohydrate with an abundance of vegetables, may be beneficial for preventing metabolic syndrome abnormalities within the Asian population. However, the prevalence of metabolic syndrome is increasing in Asian countries. This study explored the association between dietary carbohydrates and low high-density lipoprotein cholesterol (HDL-C) prevalence, one of the abnormalities of metabolic syndrome in Korean adults. We used the data from the Fourth Korea National Health and Nutrition Examination Survey and evaluated a total of 9947 Korean adults older 20 years. To measure carbohydrate quality and quantity, total carbohydrate intake (g/d), percentage of energy from carbohydrate, glycemic index, and glycemic load were divided into quintiles. Mean levels of HDL-C significantly decreased across the quintiles for all types of dietary carbohydrate intake except glycemic index after adjusting for potential variables in both men and women. Odds ratios for having low HDL-C in the highest quintile were 1.66 (95% confidence interval, 1.24-2.22) for total carbohydrate, 1.34 (1.02-1.75) for percentage of energy from carbohydrate, and 1.54 (1.17-2.03) for glycemic load in men as compared with the second quintile as a reference. Odds ratio for low HDL-C was 1.38 (1.12-1.71) for percentage of energy from carbohydrate in women. In conclusion, our study indicates that low HDL-C is associated with high carbohydrate intake without regard to energy or fat intake. Further studies would be necessary to optimize carbohydrate intake quantitatively on dyslipidemia for Asian population.

The glycemic index issue

PURPOSE OF REVIEW

In recent years, many of the concerns surrounding the glycemic index have been addressed by methodological studies and clinical trials comparing diets carefully matched for other nutrients. These findings are reviewed together with new observational evidence for the role of the dietary glycemic index in the etiology of cardiovascular disease.

RECENT FINDINGS

The determination and classification of the glycemic index of a food product is now standardized by the International Standards Organization. Systematic studies using isoenergetic single and mixed meals have shown that glycemic index and/or glycemic load are stronger predictors of postprandial glycemia and insulinemia than carbohydrate content alone. In overweight individuals, a diet that combined modestly higher protein and lower glycemic index carbohydrates was the most effective diet for prevention of weight regain. New observational studies have reported increased risks of coronary heart disease associated with higher intakes of carbohydrates from high glycemic index foods. Epidemiological evidence has emerged linking dietary glycemic index to visceral fat and inflammatory disease mortality.

SUMMARY

There is growing recognition that replacing saturated fat with refined, high glycemic index carbohydrates increases postprandial glycemia and may be detrimental for weight control and predisposition to cardiovascular and inflammatory disease. In contrast, low glycemic index carbohydrates reduce risk.

Dietary glycemic index and risk of type 2 diabetes mellitus in middle-aged Japanese men

This cohort study investigated the association between dietary glycemic index (GI), glycemic load (GL), and the incidence of type 2 diabetes mellitus in middle-aged Japanese men, and the effect of insulin resistance and pancreatic B-cell function on the association. Participants were 1995 male employees of a metal products factory in Japan. Dietary GI and GL were assessed using a self-administered diet history questionnaire. The incidence of diabetes was detected in annual medical examinations over a 6-year period. The association between GI, GL, and the incidence of diabetes was evaluated using Cox proportional hazards models. During the study, 133 participants developed diabetes. Age- and body mass index-adjusted hazard ratios across the GI quintiles were 1.00 (reference), 1.62, 1.50, 1.68, and 1.80; and those of GL were 1.00 (reference), 1.07, 1.48, 0.95, and 0.98. The hazard ratio for the highest GI quintile was significantly greater than that for the lowest quintile. The influence of GI was more pronounced in the lowest insulin resistance subgroups. GI and pancreatic B-cell function were independently associated with the incidence of type 2 diabetes mellitus; participants with low B-cell function and the highest tertile of GI had the highest risk of diabetes. Dietary GI is associated with the incidence of diabetes in middle-aged Japanese men. GI and B-cell function were independently associated with incidence of diabetes.