Three types of a high-carbohydrate diet are differently associated with cardiometabolic risk factors in Korean adults

Carbohydrate Intake Levels and the Risk of Metabolic Syndrome in Korean Populations: A Prospective Study

In Korea and other Asian countries, traditional high-carbohydrate diets are increasingly associated with metabolic syndrome (MetS) and its complications. As dietary patterns shift, there is a growing need to assess the effect of these changes on health outcomes related to MetS. This study aimed to investigate the prospective relationship between carbohydrate consumption and the risk of MetS and its components. We analyzed data from 7902 participants from the Korean Association Resource, part of the Korean Genome and Epidemiology Study Dietary intakes, including carbohydrates and fiber, were assessed using a validated semi-quantitative food frequency questionnaire, allowing for the calculation of the proportion of total energy from carbohydrates (P_CARB) and the carbohydrate-to-fiber ratio to assess carbohydrate quality. Blood samples were collected after at least eight hours of fasting for laboratory analysis. We employed Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals, focusing on the relationship between the P_CARB and the risk of developing MetS and its individual components, while adjusting for carbohydrate quality. In the fully adjusted model, which accounted for carbohydrate quality as a covariate, individuals in the highest percentile of the P_CARB showed a significantly increased risk of MetS, hypertriglyceridemia, hypo-high density lipoprotein cholesterolemia, dyslipidemia, and high blood pressure, compared to those in the lowest P_CARB group. Spline curve analyses indicated that the risks for MetS and its components consistently escalated with increasing P_CARB, with all p-values for nonlinearity exceeding 0.05. The findings suggest that higher levels of P_CARB are associated with an increased risk of MetS and related conditions, except for high fasting glucose. These results highlight the importance of dietary awareness and potential adjustments for populations consuming high-carbohydrate diets.

Dietary patterns derived by reduced rank regression are associated with lipid disorders among Korean adults: a cross-sectional analysis

BACKGROUND

Lipid disorders are a potent risk factor for cardiovascular diseases. Moreover, the intake of dietary fatty acids has been closely related to blood lipid levels. Therefore, this cross-sectional study examined the associations between dietary patterns related to fatty acid intake and lipid disorders in Korean adults.

METHODS

From the 2013-2019 Korea National Health and Nutrition Examination Surveys data, 8399 men and 11404 women (aged ≥ 19 years) were selected. Reduced rank regression was employed to identify dietary patterns from 26 food groups, aiming to explain the maximum variation in the intake of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), omega-3 fatty acids, and the PUFA/SFA ratio. Associations of quintiles (Q) of dietary pattern scores with lipid disorders were examined using multiple logistic regression stratified by sex.

RESULTS

Three dietary patterns were identified: dietary pattern 1 showed positive factor loadings for vegetable oils, seasonings, legumes, nuts, and fish; dietary pattern 2 was high in consumption of red meat, bread and snacks, and milk and dairy products; and dietary pattern 3 was rich in fish and milk and dairy products. In men, dietary pattern 3 was inversely associated with elevated triglycerides (Q5 vs. Q1: odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.69-0.97, P-trend = 0.008). In women, dietary pattern 2 was positively associated with elevated total cholesterol (OR = 1.31, 95% CI = 1.12-1.52, P-trend < 0.001) but inversely associated with low HDL-cholesterol (OR = 0.70, 95% CI = 0.59-0.83, P-trend < 0.001).

CONCLUSION

In this study, dietary patterns explaining the intake of various types of fatty acids were differentially associated with lipid disorders in Korean adults. Dietary pattern characterized by higher intakes of red meat, bread and snacks and milk and dairy products were positively associated with elevated total cholesterol, whereas dietary pattern rich in fish consumption showed an inverse association with elevated triglycerides. These findings could be instrumental in developing dietary guidelines and strategies for preventing and managing lipid disorders in this population.

Greater Protection of Lower Dietary Carbohydrate to Fiber Ratio (CFR) against Poor Blood Pressure Control in Patients with Essential Hypertension: A Cross-Sectional Study

(1) Background: Carbohydrate combined with dietary fiber (DF) applied as a surrogate marker of overall carbohydrate quality is a more essential determinant of cardiometabolic health. However, to date, no studies have applied this metric to analyze its associations with poor blood pressure control in hypertensive patients. (2) Methods: A cross-sectional design was implemented in one tertiary hospital and one community hospital in China. Using Feihua Nutrition Software to analyze participants' two-day dietary log, the quantity of carbohydrate and fiber was obtained and the carbohydrate to fiber ratio (CFR) was calculated. The participants were divided into Q1, Q2, Q3, and Q4 groups by quartile method, from low to high according to CFR. The poor systolic and diastolic blood pressure (SBP and DBP) controls were defined as ≥140 mmHg and ≥90 mmHg, respectively. (3) Results: A convenience sample of 459 participants was included and the mean CFR was 29.6. Taking Q1 as reference, after adjusting for covariates, the CFR in Q4 was associated with higher poor SBP-controlled rate (OR, 4.374; 95% CI, 2.236-8.559). Taking Q2 as reference, after adjusting for covariates, the CFRs in Q3 and Q4 were associated with higher poor DBP-controlled rates [(OR = 1.964, 95% CI: 1.016-3.795) and (OR = 4.219, 95% CI: 2.132-8.637), respectively]. The CFR was the stronger protective determinant of SBP and DBP than DF or carbohydrate alone. (4) Conclusions: A higher CFR is a stronger risk factor for blood pressure (BP) control, and low CFR foods or a combination of corresponding food components, should be recommended in the dietary management of hypertensive patients.

Replacing dietary carbohydrates and refined grains with different alternatives and risk of cardiovascular diseases in a multi-ethnic Asian population

BACKGROUND

Cardiovascular diseases (CVDs) are a major cause of deaths worldwide, but prospective data on dietary risk factors for CVD in South and Southeast Asian populations are sparse.

OBJECTIVE

We aimed to evaluate the relation between macronutrient and food intakes and incidence of major adverse cardiovascular events (MACEs) in a multi-ethnic Asian population.

METHODS

We used data from the Singapore Multi-Ethnic Cohort (n = 12,408), a prospective cohort of ethnic Chinese, Malay, and Indian adults aged 21‒65 y recruited between 2004 and 2010. Dietary intakes were assessed using a validated food-frequency questionnaire, and the incidence of MACEs was ascertained through data linkage with national registries. A Cox proportional hazards model was used to evaluate the associations between dietary intakes and MACE risk.

RESULTS

Over a mean (SD) follow-up of 10.1 (2.3) y, 746 incident cases of MACEs were documented. We observed a direct association between carbohydrate intake and MACE risk (highest vs. lowest quartile, HR: 1.35; 95% CI: 1.07, 1.71; P-trend = 0.001). Replacing 5% of energy from carbohydrate with polyunsaturated fat (HR: 0.79; 95% CI: 0.69, 0.91) but not saturated fat (HR: 0.95; 95% CI: 0.84, 1.09) was significantly associated with a lower MACE risk. In terms of food groups, replacing 1 serving/d of refined grains with fruit (HR: 0.93; 95% CI: 0.87, 0.99), vegetables (HR: 0.92; 95% CI: 0.85, 1.00), and dairy (HR: 0.90; 95% CI: 0.82, 0.98) was associated with lower MACE risk. Cholesterol intake was associated with a higher MACE risk in ethnic Indians (highest vs. lowest quartile, HR: 2.40; 95% CI: 1.53, 3.75; P-trend < 0.001) but not in ethnic Malay or Chinese (P-interaction = 0.015).

CONCLUSIONS

Moderating carbohydrate intakes by increasing polyunsaturated fat intake and replacing refined grains with fruits, vegetables, and dairy was associated with lower MACE risk in Asian populations.

Regional disparities in the associations of cardiometabolic risk factors and healthy dietary factors in Korean adults

BACKGROUND/OBJECTIVES

Regional disparities in dietary factors might be related to regional disparities in cardiometabolic health. Therefore, this study investigated the associations of cardiometabolic risk factors and dietary factors with regional types in Korean adults.

SUBJECTS/METHODS

Based on data from the 2007–2017 Korea National Health and Nutrition Examination Survey, the study included 39,781 adults aged ≥ 19 years who completed the dietary survey and a health examination. Healthy and unhealthy dietary factors (fat, sodium, fruit, and vegetable intakes) were evaluated using 1-day 24-h dietary recall method, as well as the use of nutrition labels with a questionnaire.

RESULTS

Of the participants, 48.7%, 36.0%, and 15.2% lived in metropolitan, urban, and rural areas, respectively. Adults living in urban and rural had higher odds ratios (ORs) for obesity (OR for urban, 1.07; 95% confidence interval (CI), 1.01–1.14; OR for rural, 1.14; 95% CI, 1.05–1.24) than adults living in metropolitan areas; these associations were significantly observed in middle-aged adults. Compared to metropolitan residents, rural residents had lower ORs for hypertension in middle-aged (OR, 0.86; 95% CI, 0.76–0.96) and metabolic syndrome in older adults (OR, 0.78; 95% CI, 0.67–0.91). Regarding urban residents, a lower OR for diabetes in middle-aged adults (OR, 0.85; 95% CI, 0.74–0.97) and a higher OR for hypertension in older adults (OR, 1.19; 95% CI, 1.02–1.39) were observed. Overall rural residents had higher ORs of excessive carbohydrate, low fruit, and high salted-vegetable intakes than metropolitan residents. Low fruit intake was positively associated with obesity, metabolic syndrome, and hypertension, after adjustment for regional type and other confounders in total participants.

CONCLUSIONS

These findings indicate that cardiometabolic risk and unhealthy dietary factors differ among regional types and age groups within Korea. Nutritional policy and interventions should consider regional types for prevention and management of cardiometabolic risk factors.

Quantity, Quality, and Timing of Carbohydrate Intake and Blood Pressure

PURPOSE OF REVIEW

This review discusses recent evidence on the association of dietary carbohydrates (quantity, quality, and timing of intake) with hypertension (HTN) risk and out-of-clinic blood pressure (BP) measures.

RECENT FINDINGS

Studies on carbohydrate quantity are inconclusive, but low carbohydrate diets may be associated with lower BP. Plant-based carbohydrate-containing foods such as fruits, vegetables, and whole grains may lower HTN risk and 24-h BP. Excessive sugar intakes from sugar-sweetened beverages are associated with higher BP levels and HTN risk, with evidence of a dose-response relationship. Preliminary data suggest that timing of carbohydrate intake may influence HTN risk and 24-h BP. The role of carbohydrate nutrition in HTN's etiology warrants further investigation. Additional studies are needed to investigate the influence of dietary carbohydrates on HTN risk and the circadian pattern of BP, evaluate potential sex and racial/ethnic differences in these associations, and elucidate underlying mechanisms.