Association of dietary intakes of total and subtypes of fat substituted for carbohydrate with metabolic syndrome in Koreans

20-Year Trends in Metabolic Syndrome Among Korean Adults From 2001 to 2020

Background

The number of people with metabolic syndrome (MetS) is increasing worldwide, and many socioeconomic and environmental factors contribute to this.

Objectives

The authors investigated tangible trends in the prevalence of MetS using the 2001 to 2020 versions of the Korea National Health and Nutrition Examination Survey (KNHANES).

Methods

In these surveys, stratified multistage sampling designs were used to approximate the entire population. Blood pressure, waist circumference, and lifestyle variables were examined in a standardized fashion. Metabolic biomarkers were measured in a central laboratory operated by the Korean government.

Results

The age-adjusted prevalence of MetS increased significantly from 27.1% in 2001 to 33.2% in 2020. It was more prevalent in men (25.8%→40.0%) but did not change in women (28.2%→26.2%). Among the 5 MetS components, the proportions of high glucose level and large waist circumference increased substantially by 17.9% and 12.2% over 20 years, while high-density lipoprotein cholesterol levels increased significantly, resulting in a decrease in low high-density lipoprotein cholesterol by 20.4%. Caloric intake derived from carbohydrates decreased from 68.1% to 61.3%, while fat consumption increased from 16.7% to 23.0%. Notably, sugar-sweetened beverage consumption showed an almost 4-fold increase from 2007 to 2020, while physical activity levels decreased by 12.2% from 2014 to 2020.

Conclusions

Glycemic dysregulation and abdominal obesity were key features contributing to the increased prevalence of MetS observed in Korean men during the past 20 years. Rapid economic and socioenvironmental changes in this period may be involved in this phenomenon. Understanding these changes in MetS could be valuable for other countries undergoing such socioeconomic transformation.

Self-initiated changes in physical activity and incidence of Metabolic Syndrome: A longitudinal follow-up study

AIM

The aim of this study was to analyze the association between longitudinal physical activity patterns (persistently inactive, became active, became inactive, and persistently active) and the incidence of Metabolic Syndrome (MS) among adults.

METHODS

Our cohort included 5766 adults (18-59y) undergoing repeated routine health screening examinations, with a mean follow-up period of three years. Only subjects without MS at baseline were included in the study. MS was defined according to the ATP III definition, including assessments of fasting blood samples for the collection of HDL-C, triglycerides and glucose, blood pressure, and waist circumference. Physical activity was estimated using the international physical activity questionnaire and four patterns were created (persistently active, became active, became inactive, and persistently inactive). Information on tobacco smoking and alcohol consumption (through structured validated questionnaires), age, interval between baseline and follow-up, anti-hypertensive drugs, statin, anti-diabetic drugs were used as covariates. Logistic regression was conducted.

RESULTS

The mean age of participants at baseline was 41.6 ± 7.9 years. We identified 1701 subjects who were active at both moments, 1246 who became active, 709 who became inactive, and 2210 who were inactive at both moments. Persistently inactive subjects presented a higher incidence of MS [10.4% (95%CI = 9.2-11.8%)]. In the adjusted logistic regression analyses, subjects that became active [OR = 0.55(95%CI = 0.40-0.74)] and persistently active [OR = 0.35(95%CI = 0.26-0.46)] were less likely to develop MS when compared with persistently inactive subjects.

CONCLUSION

Persistently active subjects demonstrated the lowest likelihood of developing MS, while subjects who became active presented an attenuated risk.

Prevalence of metabolic syndrome among ethnic groups in China

Background

Metabolic syndrome (MetS) is common in China, which has a multi-ethnic population of 1·3 billion. We set out to determine the prevalence of MetS and its components in different ethnic groups.

Methods

This nationwide cross-sectional survey involved 24,796 participants from eight ethnicities in six provinces in China from 2008 to 2011. MetS was defined using the modified National Cholesterol Education Program Adult Treatment Panel III criteria. Results were analysed using SPSS version 22·0 in 2018. Logistic regression was used for deriving odds ratios and 95% confidence intervals of risk factors for the MetS.

Results

The prevalence of MetS increased with age from 3·60% to 21·68%. After age standardization, the prevalence of MetS, in descending order, was 35·42% (Korean), 22·82% (Hui), 19·80% (Han), 13·72% (Miao), 12·90% (Tujia), 12·04% (Li), 11·61% (Mongolian), 6·17% (Tibetan). Korean ethnicity was associated with a higher prevalence in five components of MetS, while Tibetan ethnicity was associated with lower prevalence except decreased HDL cholesterol. Logistic regression analyses showed that age, drinking and being non-Tibetan were associated with a higher risk of MetS.

Conclusions

Within one country, albeit a large one, the prevalence of MetS can vary greatly. Chinese of Korean ethnicity had a much higher prevalence than Tibetan ethnicity. Measures to tackle MetS should be tailored to the ethnic groups within a population.

Dietary fat intake and metabolic syndrome in adults: A systematic review

BACKGROUND AND AIMS

The metabolic syndrome (MetS) is a cluster of coexisting cardiovascular risk factors. The role of specific dietary fats was reemphasized by dietary recommendations. This systematic review aims to assess evidence for the effect of dietary fat intake on MetS occurrence and reversion in adults.

METHODS AND RESULTS

The MEDLINE database was used to search the existing literature. We included observational studies that analyzed dietary fat intake in adults with MetS and clinical trials that compared the effects of different dietary fat diets on MetS and/or its components. Thirty articles were selected (14 observational and 16 clinical trials), and we included information of dietary fat and fatty acids as well as MetS, body mass index, cholesterol, hypertension, and diabetes in adults. SFA intake was found to be positively associated with MetS components. Most of the observational reviewed studies found beneficial associations between MUFA and PUFA (including n-3 and n-6 subtypes) intake and MetS components. Clinical trials also supported the benefits of MUFA- or PUFA-enriched diets (including low-fat diets) in reducing MetS.

CONCLUSIONS

The effects of dietary SFAs on MetS will be influenced by other specific nutrients. Replacement of SFA by MUFA and PUFA has been associated with a decrease in MetS. Dietary recommendations should emphasize on different qualities of fat intake, not only to reduce total fat intake, to obtain health benefits in adults.

Inadequate fat or carbohydrate intake was associated with an increased incidence of type 2 diabetes mellitus in Korean adults: A 12-year community-based prospective cohort study

AIMS

Few studies have focused on the relationship between long-term fat intake and type 2 diabetes mellitus (T2D) risk in Asia where fat intake is relatively lower than the Western countries. We examined association of dietary fat and carbohydrate intake with incidence of T2D among Korean adults.

METHODS

Based on the data from the Korean Genome and Epidemiology Study, a total of 5595 adults aged 40-69 years without diabetes, cardiovascular diseases or any cancer at baseline were included. Dietary intake was measured by the validated semi-quantitative food frequency questionnaire. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 138-months, 1010 cases of T2D were newly determined. The proportion of participants with fat intake less than 15% of total energy and with carbohydrate intake more than 65% of total energy was 59.0% and 88.9%, respectively. After adjusting for confounders, a very-low-fat intake was associated with an increased risk of T2D (RR of Quartile 1 vs Quartile 4, 1.74; 95% CI, 1.18-2.57; p for trend = 0.0058) in women. A very-high-carbohydrate intake was associated with an increased risk of T2D in men (RR of Quartile 4 vs Quartile 1, 1.54; 95% CI, 1.03-2.30; p for trend = 0.0124) and women (RR of Quartile 4 vs Quartile 1, 1.69; 95% CI, 1.08-2.67; p for trend = 0.0376).

CONCLUSIONS

A very-low-fat or very-high-carbohydrate intake may increase the T2D risk and might be associated with lower intake of various nutrients and unbalanced macronutrient composition.