Drinking is a leading factor in the global burden of ailments, causing more than 200 diseases and damage [1]. As of 2018, it has been reported that 5.3% of the global mortalities are connected to drinking [2]. Drinking is one of the health-impacting behaviors, affecting various factors such as smoking, physical activity and diet. Despite the widespread perception to avoid excessive drinking, this vice has seen a steady rise in Korea [3]. The Korea National Health and Nutrition Examination Survey (KNHANES) defines binge drinking as the consumption of more than 7 cups alcohol for men and 5 cups alcohol for women [4]. Such drinking at a level that is harmful to health, such as heavy drinking or binge drinking, is called high-risk drinking, especially when binge drinking is more than twice a week [1].

Compared to 2018, the 2019 National Health Statistics declared that the monthly drinking rate for men was 73.4% and the monthly binge drinking rate was 52.6% (up by 1.8%) [45]. Recent reports also indicate increased drinking rates among women. From 2008 to 2017, the monthly drinking rate of men and women decreased by 5.7%, while the monthly drinking rate of women increased by 4.5% [6]. According to a survey conducted by the Ministry of Food and Drug Safety in 2020, 66.9% individuals in their 20s and 70.0% in their 30s have experienced high risk drinking. It further reported that 49.0–50.9% in the 20–30 years age group have experienced bomb shots [7].

Metabolic syndrome (MetS) is a condition in which high blood pressure (BP), high blood glucose, dyslipidemia, and abdominal circumference excesses exist simultaneously in one person [8]. According to a study analyzing the prevalence and changes in MetS in Korean adults, MetS in men was observed to have increased from 24.5% in 2008 to 28.1% in 2017 [9], with increased levels of waist circumference (WC) and fasting blood glucose (FBG) and decreased high density lipoprotein cholesterol (HDL-C). However, although MetS was determined to be stable in women, at 18.7% in 2017, the FBG was determined to have increased from 22.2% in 2008 to 26.7% in 2017 [9]. In terms of age-related MetS prevalence, individuals in their 20s and 30s showed an average 5.7% and 14.7%, respectively, with a sharp increase determined in the 40s [10]. Social beginners have high job stress and innumerable worries about employment and housing shortages. The generation with high job stress were afflicted with abdominal obesity, low-HDL cholesterol, high triglyceride (TG), and MetS [10]. Therefore, people in their 20s and 30s may be vulnerable to MetS [11]. Particularly, previous studies had revealed the relation between drinking and MetS, and established that excessive drinking habits result in increased abdominal obesity and high BP, dyslipidemia and diabetes [1213141516]. The prevalence of MetS among young people is on the rise, reaching up to 25.2% in the 20–30s age group [17]. Thus, preventive efforts related to drinking are required to control MetS in the 20–30-year adults.

Numerous studies have reported the relationship between drinking behaviors and MetS for adults, but very few studies have covered the 20–30 age group. Since adults between 20–30 have a longer life, it is important to strategize healthy living habits, which requires the management of risk factors associated with MetS. The present study was therefore conducted to analyze the association between drinking behavior and components of MetS among drinking adults in their 20s and 30s.

Our study was undertaken to determine the association between components of MetS and drinking behaviors in subjects in their 20s and 30s, for preventive management of MetS in Korea. The age-selected group had different gender-specific risk factors for MetS associated with drinking behaviors. In men, frequent drinking resulted in increased risk of high TG, whereas frequent drinking and binge drinking increased the risk of high TG, low HDL-C, high BP, and prevalence of MetS. In women, frequent drinking without binge drinking increased the risk of low HDL-C and MetS, whereas frequent drinking and binge drinking increased the risk of abdominal obesity, high TG, and low HDL-C.

Although the pathological cause of MetS remains unclear, it is known to be associated with the relation between genetic and lifestyle-related environmental risk factors [24]. Previous studies have shown that various socio-demographics, such as gender, age, marital status, education level, income level, and occupation, are related to factors that affect drinking [325]. Traditionally, Korean drinking problems have been limited to adult men. Recently, however, drinking problems among women have intensified due to the increase in socioeconomic activities and factors such as stress relief and human relationships [3]. In this study, married men and women were often reported to drink alcohol, but not indulge in frequent binge drinking. Among the different occupations examined, administrative women did not drink often, but frequently indulged in binge drinking, whereas men drank frequently but not binge drinking. Women who graduated high school disclosed frequent drinking and binge drinking. Considering the income levels, no difference was obtained for men and their drinking behaviors, but women of lower income level often indulged in binge drinking, regardless of the frequency of drinking.

The drinking behavior of men exerted no difference on the BMI or obesity status; conversely, regardless of the frequency of drinking, women who partook frequent binge drinking particularly had a high BMI status. Moreover, the rate of men and women smoking every day was high in groups who often consumed drinks and binge drinking. Considering a previous study which reported that factors affecting MetS in the age group 20-30 years include obesity and smoking [11], frequent binge drinking groups along with high-rate BMI and excessive daily smoking is dangerous. Considering the increased prevalence of MetS with increasing age [11], it is imperative that a negative lifestyle of people in their 20s and 30s needs to be improved.

A previous study reported that increased alcohol intake increases the number of calories, protein, and lipids, which increases the possibility of developing diseases, such as abdominal obesity [26]. It was demonstrated that limited intake of energy and saturated fat induces a positive change in the components of MetS [827]. In this study, we analyzed the rate of energy and macronutrients intake by subjects according to various drinking behaviors. Men who did not drink frequently but frequently indulged in binge drinking had higher intakes of carbohydrate and protein (% energy) than other groups. Men who drank frequently but not frequent binge drinking consumed lower intakes of energy. Men with frequent drinking and binge drinking had lower intakes of carbohydrate and carbohydrate (% energy), and higher intakes of protein (% energy), as compared to other groups. Among women, not drinking frequently but frequently binge drinking had lower intakes of energy, protein, and protein (% energy) than other groups, whereas frequent drinking but not binge drinking had higher intakes of protein and carbohydrate (% energy). Women who frequently indulged in drinking and binge drinking had higher intakes of energy, protein, and protein (% energy), but lower intakes of carbohydrate (% energy), as compared to other groups.

MetS is a cluster of risk factors including cardiovascular disease and diabetes, and is characterized by abdominal obesity, high FBG, high TG, low HDL-C, and high BP [2428]. Each MetS component is a known risk factor for increased blood vessel occlusion, and incidence and mortality due to diabetes, cardiovascular disease, and stroke [28]. Risk factors for MetS are known to contribute to socioeconomic factors, lack of physical activity, and excessive energy intake, alcohol drinking status, etc. Kim and Cho [29] reported that higher the drinking level (AUDIT scores > 20), greater is the WC, indicating abdominal obesity. Generally, alcohol is known that it makes to increase the risk of abdominal obesity [14]. This is because alcohol itself adds to the accumulation of fat in the body in various ways, rather than being converted into fat [14]. A study for adults over the age of 30 compared to this study, it showed that abdominal obesity increased when both men and women have excessive drinking [29]. In this study, women who indulged in frequent drinking and binge drinking had a 2.959-fold higher prevalence risk of abdominal obesity. However, the prevalence risk of abdominal obesity showed no association with the drinking behaviors for men.

In another study, drinkers regardless drink amount was associated with low HDL-C in both men and women [28]. In this study, it showed similar results for HDL-C, when compared to the previous study. And both men and women who drank frequently and indulged in frequent binge drinking had an increased prevalence risk for low HDL-C (0.668- and 0.424-fold, respectively). Amongst women who drank frequently but did not binge drink, the risk prevalence of low HDL-C increased to 0.353-fold. However, the risk prevalence of raised FBG showed no significant association with the prevalence of MetS.

According to the association analysis between the drinking volume of men with TG and BP, the risk prevalence of high TG and BP increased with increasing drinking volume [28]. Contrarily, in the current study, the risk prevalence of high TG increased by 2.051- and 1.965-fold in men who drank frequently but did not binge drinking, and those who indulged in frequent drinking and binge drinking, respectively. The risk prevalence of high BP increased 2.147-fold in men who partook frequent drinking and binge drinking. The risk prevalence of high BP showed no association with the drinking behaviors of women. However, the risk prevalence of high TG increased 1.824-fold in women who were frequent drinkers and did binge drinking.

This study is a secondary analysis study by using the KNHANES data, which includes a large representative sample of the general adults in the age group 20-30 years in Korea. However, this is a cross-sectional study, where the cause and effect could not be identified. This can be a limitation related to the study. Previous studies were focused on the effects of binge drinking or high-risk drinking on MetS [1313], but this study analyzed MetS and the association with various drinking behaviors.

In conclusion, our data indicate that in men, frequent drinking increases the risk of high TG, whereas frequent drinking and binge drinking increase the risk of high TG, low HDL-C, high BP, and the prevalence of MetS. In women, frequent drinking without binge drinking increases the risk of low HDL-C and MetS, whereas frequent drinking and binge drinking also increase the risk of abdominal obesity, high TG, and low HDL-C. Based on the results of this study, it is possible to manage the components of MetS in the 20s and 30s; moreover, this study provides basic data to change drinking behaviors among the young adults. Improvements in drinking behaviors can therefore help reduce the prevalence of MetS. Further studies examining the association between various factors and MetS are required in the future.