Published online Apr 21, 2008. doi: 10.3748/wjg.14.2418
Revised: February 1, 2008
Published online: April 21, 2008
AIM: To examine the relations of alcohol consumption to the prevalence of metabolic syndrome in Shanghai adults.
METHODS: We performed a cross-sectional analysis of data from the randomized multistage stratified cluster sampling of Shanghai adults, who were evaluated for alcohol consumption and each component of metabolic syndrome, using the adapted U.S. National Cholesterol Education Program criteria. Current alcohol consumption was defined as more than once of alcohol drinking per month.
RESULTS: The study population consisted of 3953 participants (1524 men) with a mean age of 54.3 ± 12.1 years. Among them, 448 subjects (11.3%) were current alcohol drinkers, including 405 males and 43 females. After adjustment for age and sex, the prevalence of current alcohol drinking and metabolic syndrome in the general population of Shanghai was 13.0% and 15.3%, respectively. Compared with non drinkers, the prevalence of hypertriglyceridemia and hypertension was higher while the prevalence of abdominal obesity, low serum high-density-lipoprotein cholesterol (HDL-C) and diabetes mellitus was lower in subjects who consumed alcohol twice or more per month, with a trend toward reducing the prevalence of metabolic syndrome. Among the current alcohol drinkers, systolic blood pressure, HDL-C, fasting plasma glucose, and prevalence of hypertriglyceridemia tended to increase with increased alcohol consumption. However, low-density-lipoprotein cholesterol concentration, prevalence of abdominal obesity, low serum HDL-C and metabolic syndrome showed the tendency to decrease. Moreover, these statistically significant differences were independent of gender and age.
CONCLUSION: Current alcohol consumption is associated with a lower prevalence of metabolic syndrome irrespe-ctive of alcohol intake (g/d), and has a favorable influence on HDL-C, waist circumference, and possible diabetes mellitus. However, alcohol intake increases the likelihood of hypertension, hypertriglyceridemia and hyperglycemia. The clinical significance of these findings needs further investigation.
- Citation: Fan JG, Cai XB, Li L, Li XJ, Dai F, Zhu J. Alcohol consumption and metabolic syndrome among Shanghai adults: A randomized multistage stratified cluster sampling investigation. World J Gastroenterol 2008; 14(15): 2418-2424
- URL: https://www.wjgnet.com/1007-9327/full/v14/i15/2418.htm
- DOI: https://dx.doi.org/10.3748/wjg.14.2418
Alcohol consumption is a double-edged sword, and perhaps no other factor in cardiovascular health is capable of cutting so deeply in either direction depending on how it is used. Accumulating scientific evidence indicates that light to moderate alcohol consumption is associated with a lower cardiovascular mortality and a reduced risk of developing type 2 diabetes mellitus[1–6]. Some of the biological mechanisms reported to explain this observation include an improvement in lipid profile, especially high-density-lipoprotein-cholesterol (HDL-C) and increased insulin sensitivity[1–6]. In contrast, heavy or risky drinking is toxic to both the heart and the overall health and is the third leading cause of premature death among Americans[1].
Metabolic syndrome is a clustering of low serum HDL-C, elevated serum triglycerides, hyperglycemia, abdominal obesity, and elevated blood pressure, mediated in part by insulin resistance. Metabolic syndrome is associated with an increased risk of developing diabetes mellitus and cardiovascular disease[7]. Alcohol consumption has a favorable influence on selective components of metabolic syndrome, contributing to the reduction in risk of developing metabolic syndrome in the U.S. population[8–10]. However, the validity of its putative benefits to metabolic disorders has not been well evaluated in Chinese.
The present study was to investigate the prevalence of current alcohol drinking and metabolic syndrome among Shanghai adults, and to explore the relationship between alcohol consumption and components of metabolic syndrome.
We assigned a number to each of the 16 urban districts of Shanghai and selected two districts at random (Yangpu District and Pudong New District). Of the 11 residential districts within Yangpu and Pudong, we randomly selected the Pingliang and Shanggang residential districts, containing 30 and 26 neighborhood communities, respectively. From these, we selected eight neighborhood communities in total. Resident groups were randomly selected from each sample neighborhood community. From October 2002 to April 2003, investigations were conducted in adults aged 20 years or more in the selected resident groups at home. We excluded individuals from the study if they had a history of malignancy and other severe diseases.
This program was approved by the Research Ethics Committee of the Shanghai Health Bureau and all participants provided their written informed consent prior to their inclusion in the study. General physical examinations and laboratory assessments were performed for each study subject at a mobile examination center following an overnight fast of at least 12 h.
Interview: Selected individuals were interviewed at their homes using a self-designed questionnaire that gathered information on demographic characteristics, medical history, medications and health-related habits. Consumption of alcohol was ascertained from a series of questions including whether the respondent consumed 12 drinks (one drink is considered to contain 10 g alcohol) in the past 12 mo. If so, respondents were asked to quantify the number of days they consumed alcohol over the past 1 year and the number of drinks per day on drinking days. From these data, we calculated an average daily intake of alcohol. The questionnaire was pre-tested in the population prior to the study.
Physical examination: Body weight of the participants was measured in light clothing and without shoes to the nearest half kilogram. Their height was measured to the nearest half centimeter. Body mass index (BMI) was calculated as weight (kg) divided by height squared (m2). Waist circumference (to the nearest half centimeter) was measured at the mid-point between the lower border of the rib cage and the iliac crest, whereas hip circumference was similarly obtained at the widest point between the hip and buttock, enabling calculation of the waist-to-hip ratio. Three blood pressure readings were obtained at intervals of one min. The second and third systolic and diastolic pressure readings were averaged and used in the analyses.
Laboratory assessments: Venous blood samples were collected at 0 and 120 min following a 75 g oral glucose challenge for non-diabetics or 100 g steamed bread for diabetics. Samples were centrifuged at 2000 g for 10 min at 25°C immediately, frozen and shipped to a central laboratory of the Shanghai Center for Disease Control and Prevention, where they were stored initially at -20°C and then at -70°C. Subsequently, serum glucose was determined using a modified hexokinase method. Fasting serum total cholesterol (TC) and triglyceride concentrations were measured enzymatically by color absorptiometry based on a peroxidase-catalysed reaction. HDL-C was measured after precipitation of other lipoproteins with a polyanion/divalent cation mixture. Low-density-lipoprotein-cholesterol (LDL-C) was calculated from the measured values of TC, triglycerides and HDL-C using the following formula: LDL = (TC) - (HDL) - (triglycerides/5). LDL was not calculated if the triglyceride concentration was > 4.52 mmol/L. All these serum biochemistries were performed using a Bayer model 1650 automated bio-analyzer (Bayer Diagnostic, Basingstoke, UK).
Quality control: Field researchers were recruited from Shanghai Center for Disease Control and Prevention, and Shanghai Jiaotong University School of Medicine. Before the investigation, the researchers were given systematic training to ensure standardization of the investigation procedure. For further quality control, 5% of questionnaires and blood samples were re-examined. Kappa analysis of these samples showed a good consistency in the diagnostic test (data not shown).
Definitions: Obesity and abdominal obesity were categorized according to the new BMI criteria for Asians by the regional office for Western Pacific Region of the World Health Organization (WHO)[11]. Hypertension was defined as given in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7)[12]. Diagnoses of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes were based on WHO criteria published in 1999 (WHO/NCD/NCS/99.2)[1314]. Dyslipidemia (including hypertriglyceridemia and low HDL-C) and metabolic syndrome were diagnosed on the basis of the adapted U.S. National Cholesterol Education Program’s Adult Treatment Panel III (NCEP ATP III) criteria with the exception of abdominal obesity (waist circumference 90 cm in men and 80 cm in women)[715]. We regarded participants who reported current use of antihypertensive or anti-diabetic medications or fibrates as participants with a high blood pressure or diabetes or hypertriglyceridemia, respectively.
Current alcohol consumption was defined as more than once of alcohol drink per month. The participants were then divided into current alcohol drinkers and current non drinkers, the former were further classified into light drinkers (1-9.9 g/d), moderate drinkers (10-29.9 g/d) and excessive drinkers (≥ 30 g/d) according to their average daily alcohol intake in the past 12 mo[191016].
All data were analyzed using SPSS 11.0 software (SPSS, Chicago, IL, USA). Unpaired t-test, χ2 contingency test, Fisher’s exact test and trend analysis were performed whenever appropriate. Non-parametric methods were also used for abnormally distributed values. Some analyses were adjusted for age and sex. Kappa analysis was performed for blood biochemical data as a quality control. All P values provided are for two-sided tests. P < 0.05 was considered statistically significant.
We used a stratified, multistage probability cluster sampling method to obtain a representative sample from the Shanghai non-institutionalized population. The neighborhoods investigated contained 3953 residents aged 20 years or more as subjects in the present study, corresponding to approximately 2.99/10 000 of the Shanghai population according to the data collected in the Fifth China National Census in 2002 (http://www.china-un.ch/eng/ljzg/shjjtj/t85845.htm).
The study population included 1524 males and 2379 females (excluding pregnant women), giving a male to female ratio of 1:1.56. Their age ranged 20-88 years and no significant difference was noted between the ages of male and female subjects. In comparison with the sex and age obtained from the Fifth National Census of Shanghai, the study population contained a higher percentage of elderly subjects and women (P < 0.01). Therefore, some of the results were adjusted for age and sex in order to better represent the real situation in Shanghai.
Of the 3953 enrolled subjects, 448 (11.3%) had a history of current alcohol consumption, men accounted for 26.6% and women 1.8% (P < 0.001). As shown in Table 1, the prevalence of current alcohol drinking both in overall subjects and in males increased with age and reached its peak at the age of 40-49 years. However, no significant changes were found in females. After adjusted for age and sex, the prevalence of current alcoholic drinking among Shanghai adults was found to be 13.0%, which was significantly higher in males than in females (24.5% vs 1.5%, P < 0.001).
| Age (yr) | Total | Current drinking | Male | Current drinking | Female | Current drinking |
| 20-29 | 139 | 8 (5.8) | 61 | 7 (11.5) | 78 | 1 (1.3) |
| 30-39 | 157 | 16 (10.2) | 65 | 15 (23.1) | 92 | 1 (1.1) |
| 40-49 | 895 | 118 (13.2) | 306 | 108 (35.3) | 589 | 10 (1.7) |
| 50-59 | 1305 | 167 (12.8) | 477 | 153 (32.1) | 828 | 14 (1.7) |
| 60-69 | 794 | 77 (9.7) | 327 | 67 (19.1) | 467 | 10 (2.1) |
| ≥ 70 | 663 | 62 (9.4) | 288 | 55 (19.1) | 375 | 7 (1.9) |
| Total | 3953 | 448 (11.3) | 1524 | 405 (26.6) | 2379 | 43 (1.8) |
Among the 448 participants with a history of current alcohol drinking, over two-thirds (72.1%) of them were light to moderate drinkers, light to moderate female drinkers accounted for 95%. There was no difference in age among different drinking groups (Table 2). Since only 125 (27.9%) subjects were found to be excessive drinkers in the study, their average daily alcohol consumption was 58 g, and few of them were heavy or risky drinkers (alcohol consumption > 40 g/d), so we did not further distinguish heavy drinkers from excessive drinkers.
| Light drinking | Moderate drinking | Excessive drinking | |
| Total (n = 448) | 180 (40.2) | 143 (31.9) | 125 (27.9) |
| Male (n = 405) | 149 (36.8) | 133 (32.8) | 123 (30.4) |
| Female (n = 43) | 31 (72.1) | 10 (23.3) | 2 (4.7) |
| Age (yr) | 54.47 ± 10.80 | 55.35 ± 11.62 | 55.05 ± 9.84 |
| Alcohol intake (g/d) | 2.60 ± 2.84 | 17.95 ± 5.07 | 58.30 ± 80.13 |
The prevalence of obesity, abdominal obesity, hypertension, hypertriglyceridemia, low serum HDL-C, diabetes mellitus and metabolic syndrome in the 3953 study subjects was 43.3%, 35.4%, 49.3%, 25.7%, 21.3%, 14.8% and 23.9%, respectively. After adjusted for age and sex, the prevalence of metabolic syndrome among adults in Shanghai was 15.3% according to the adapted NCEP-ATP III criteria[17].
The effects of current alcohol drinking on metabolic syndrome features in 3953 Shanghai adults are shown in Table 3. The blood pressure, serum concentration of triglyceride, HDL-C and FPG, prevalence of hypertension and hypertriglyceridemia were higher while the prevalence of abdominal obesity, low serum HDL-C and diabetes mellitus were lower in alcoholic drinkers than in non-alcoholic drinkers. However, the prevalence of metabolic syndrome in alcoholic drinkers only decreased mildly compared with the non-alcoholic drinkers. When adjusted for sex and age, the differences in metabolic syndrome features still existed between the two groups.
| Non-drinking (n = 3505) | Current drinking (n = 448) | P value | |
| Age (yr) | 54.2 ± 12.4 | 54.9 ± 10.8 | > 0.05 |
| BMI (kg/m2) | 24.6 ± 4.39 | 24.8 ± 3.84 | > 0.05 |
| Waist-to-hip ratio | 0.84 ± 0.14 | 0.85 ± 0.15 | 0.12 |
| SBP (mmHg) | 129.0 ± 18.8 | 132.8 ± 17.2 | < 0.001 |
| DBP (mmHg) | 81.8 ± 11.9 | 85.8 ± 10.4 | < 0.001 |
| Triglyceride (mmol/L) | 1.36 ± 1.04 | 1.62 ± 1.38 | < 0.001 |
| Total cholesterol (mmol/L) | 4.98 ± 0.97 | 4.91 ± 0.93 | 0.15 |
| HDL-C (mmol/L) | 1.49 ± 0.40 | 1.57 ± 0.41 | < 0.001 |
| LDL-C (mmol/L) | 2.90 ± 0.82 | 2.73 ± 0.83 | < 0.001 |
| FPG (mmol/L) | 5.77 ± 1.60 | 5.98 ± 1.70 | < 0.01 |
| Obesity, n (%) | 1512 (43.1) | 199 (44.2) | 0.67 |
| Abdominal obesity, n (%) | 1270 (36.2) | 129 (28.8) | < 0.01 |
| Hypertension, n (%) | 1525 (43.5) | 246 (45.9) | < 0.001 |
| Hypertriglyceridemia, n (%) | 874 (24.9) | 140 (31.3) | < 0.001 |
| Low HDL-C, n (%) | 770 (22.0) | 72 (16.1) | < 0.05 |
| IFG/IGT, n (%) | 950 (27.1) | 118 (26.3) | 0.24 |
| Diabetes mellitus, n (%) | 540 (15.4) | 45 (10.0) | < 0.01 |
| Metabolic syndrome, n (%) | 841 (24.0) | 103 (23.0) | 0.09 |
Among the 448 subjects with current alcohol consumption, the trend analysis showed that systolic blood pressure (SBP), serum HDL-C and FPG, and prevalence of hypertriglyceridemia increased progressively, while serum LDL-C, prevalence of abdominal obesity, low serum HDL-C and metabolic syndrome declined progressively with increased alcohol consumption among the three drinker groups (Table 4). When adjusted for sex and age, alcohol consumption still showed its effects on metabolic disorders among alcoholic drinkers.
| Light drinking (n = 180) | Moderate drinking (n = 143) | Excessive drinking(n = 125) | P value | |
| BMI (kg/m2) | 24.9 ± 3.25 | 24.7 ± 4.59 | 24.9 ± 3.72 | > 0.05 |
| Waist-to-hip ratio | 0.85 ± 0.12 | 0.86 ± 0.14 | 0.84 ± 0.18 | > 0.05 |
| SBP (mmHg) | 132.3 ± 16.6 | 132.6 ± 17.1 | 133.7 ± 18.3 | < 0.05 |
| DBP (mmHg) | 85.7 ± 10.1 | 85.4 ± 9.4 | 86.5 ± 12.0 | > 0.05 |
| Triglyceride (mmol/L) | 1.47 ± 1.12 | 1.77 ± 1.61 | 1.66 ± 1.41 | > 0.05 |
| TC (mmol/L) | 4.92 ± 0.92 | 4.86 ± 0.92 | 4.96 ± 0.94 | > 0.05 |
| HDL-C (mmol/L) | 1.56 ± 0.39 | 1.57 ± 0.39 | 1.60 ± 0.44 | < 0.05 |
| LDL-C (mmol/L) | 2.74 ± 0.79 | 2.72 ± 0.77 | 2.71 ± 0.92 | < 0.05 |
| FPG (mmol/L) | 5.92 ± 1.46 | 5.96 ± 1.60 | 6.09 ± 2.10 | < 0.01 |
| Obesity, n (%) | 84 (46.7) | 60 (42.0) | 55 (44.0) | > 0.05 |
| Abdominal obesity, n (%) | 66 (36.7) | 34 (23.8) | 29 (23.2) | < 0.05 |
| Hypertension, n (%) | 100 (55.6) | 73 (51.1) | 73 (58.4) | > 0.05 |
| Hypertriglyceridemia, n (%) | 53 (29.4) | 46 (32.2) | 41 (32.8) | < 0.05 |
| Low HDL-C, n (%) | 36 (20.0) | 24 (16.8) | 12 (9.6) | < 0.01 |
| IFG/IGT, n (%) | 43 (23.9) | 43 (30.1) | 32 (25.6) | > 0.05 |
| Diabetes mellitus, n (%) | 21 (11.7) | 1 (0.70) | 10 (8.0) | > 0.05 |
| Metabolic syndrome, n (%) | 46 (25.6) | 32 (22.4) | 25 (20.0) | < 0.05 |
In the present study, the sex- and age-adjusted prevalence of current alcohol drinking and metabolic syndrome among Shanghai adults was 13.0% and 15.3%, respectively; serum LDL-C concentration, risk of abdominal obesity, low serum HDL-C and metabolic syndrome tended to decrease in parallel to the history of alcohol consumption; arterial blood pressure, FPG and serum triglyceride concentration tended to increase in parallel to the amount of alcohol consumption; the effects of current alcohol drinking on metabolic syndrome features were independent of gender and age.
Metabolic syndrome is highly prevalent in industrialized Shanghai with a high Western life style[15–17]. However, the prevalence of current alcohol drinking among Shanghai adults is relative lower (only accounting for 13.0% of the total population and 24.5% of men), than that in other cities of China (accounting for 27.0% in Hangzhou, Zhejiang Province and 35.1% in Xi’an, Shaanxi Province)[1819]. According to the Third National Health and Nutrition Examination Survey conducted in the USA, 57.9% of the participants were current alcohol drinkers with a higher percentage of men (66.0%) than of women (50.0%)[9], and the prevalence of current alcohol drinking in 27 030 healthy Korean men was even up to 83.3%[20]. The majority of subjects were light to moderate alcohol drinkers, and the average daily alcohol consumption even in the excessive drinkers was less than 60 g/d in the present study. This might be related to the different alcohol drinking culture backgrounds worldwide and the universal concern about the overall health among Shanghai adults[161821]. The low prevalence of current alcohol drinking is consequently consistent with the uncommon alcoholic fatty liver (0.79%). Alcoholism only accounts for 5% of the etiology of fatty liver among Shanghai adults[16].
Although alcohol consumption has a negative effect on the morbidity and mortality of liver disease, the correlation between alcohol consumption and metabolic syndrome gives rise to much controversy[12562022–27]. A cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey conducted in the USA showed that mild to moderate alcohol consumption is associated with a lower prevalence of metabolic syndrome, showing a favorable influence on lipids, waist circumference, and fasting insulin[89]. Yoon et al[24] reported that 1-15 g of alcohol per day is associated with decreased prevalence of metabolic syndrome. Park et al[25] reported that the prevalence of metabolic syndrome decreases only in women, and Santos et al[26] have not found any association between alcohol consumption and metabolic syndrome in both genders. However, Yokoyama et al[22] reported that alcohol consumption (> 20 g/d) is associated with an increased prevalence of metabolic syndrome in male Japanese. In the present study, alcohol consumption was associated with reduced prevalence of metabolic syndrome and excessive alcohol drinkers had the lowest prevalence of metabolic syndrome. However, no statistically significant difference was found between alcohol and non-alcohol drinkers. Inconsistent results were also found between alcohol consumption and obesity. Some studies demonstrated that light to moderate alcohol drinking can reduce weight whereas non-alcohol and heavy alcohol drinking cannot reduce weight[122325]. In the present study, neither positive nor negative association was found between alcohol consumption and BMI and risk of obesity. However, a consistent association was observed between alcohol consumption and decreased prevalence of abdominal obesity. Most excessive alcohol drinkers consumed only a little higher than 30 g/d in our study, and might be moderate alcohol drinkers in some other studies[1218202428–30]. Therefore, it is not entirely clear how different levels of alcohol consumption affect the risk of obesity and metabolic syndrome.
Epidemiologic investigations showed that moderate alcohol consumption is associated with increased blood pressure[12930]. It was reported that SBP and diastolic blood pressure (DBP) are increased to 2.7 mmHg and 1.4 mmHg, respectively, after a period of sustained alcohol consumption[129]. In the present study, SBP and DBP had an average increase of 3.78 mmHg and 4.06 mmHg, respectively, in current alcoholic drinkers. Furthermore, SBP increased gradually in alcohol drinkers. A meta-analysis of data showed that excessive alcohol consumption was associated with a higher blood pressure while a fall in blood pressure of 2-4 mmHg is associated with reduced alcohol consumption[30].
It is well known that increased concentration of triglycerides and HDL-C is associated with increased alcohol consumption[12]. Interestingly, alcohol consumption was negatively associated with serum LDL-C concentration and was the lowest in excessive alcohol drinkers in this study, which is consisted with the findings in Korean men[20].
The relationship between alcohol consumption and glucose regulation is rather complex[12]. A meta-analysis based largely on the prospective studies suggested that there is a U-shaped relationship between alcohol consumption and type 2 diabetes, and moderate alcohol drinkers have the lowest risk of developing type 2 diabetes[31]. However, several cross-sectional evaluations of healthier population have reported higher fasting glucose concentrations and greater risk of diabetes associated with alcohol consumption[31–34]. Paradoxically, alcohol consumption has also been found to be associated with lower insulin concentrations[820]. In our study, alcohol consumption was positively associated with FPG but negatively with the risk of diabetes. However, no change was observed in IFG and IGT, suggesting that regular alcohol consumption might benefit to insulin sensitivity and improve insulin resistance. However, it is not entirely clear how different levels of alcohol consummation affect glucose homeostasis.
The strengths of our investigation include the use of a large sample from Shanghai adults with good quality control (thereby enhancing our generalization) and the evaluation of both serum lipids and oral glucose tolerance. However, there are several limitations that merit comment. First, given the cross-sectional design, we could not draw any causal inferences regarding the association of alcohol consumption with metabolic syndrome. Second, the data on alcohol consumption were based on self-report with the possibility of misclassification of exposure (e.g., under reporting). However, such bias, if non-differential, would be expected only to increase the amount of alcohol consumption associated with reduced prevalence of metabolic syndrome. Third, other factors such as smoking, physical activity, and type of beverages were not excluded by multivariable linear regression analysis, thus limiting our ability to give comment on the relation of alcohol consumption to the prevalence of metabolic syndrome[1235]. Prospective studies are therefore needed to confirm these findings and to assess the influence of alcohol drinking patterns and other possible factors on the association between alcohol consumption and metabolic syndrome.
In summary, current alcohol drinking is associated with a lower prevalence of metabolic syndrome and a favorable influence on serum lipids, waist circumference, and possibly type 2 diabetes mellitus. The clinical significance of these findings needs further investigation. It must be noted that alcohol consumption also causes hypertension, hypertriglyceridemia and hyperglyceridemia, constituting alcohol-related metabolic syndrome. The latest American Heart Association guidelines advise that people should not start alcohol drinking if they have not drunk it, because it is not possible to predict who will have a problem due to alcohol abuse[35].
Alcohol consumption is a double-edged sword to health. Light to moderate alcohol consumption is usually associated with a lower cardiovascular mortality and a reduced risk of developing type 2 diabetes mellitus. However, heavy or risky alcohol drinking is toxic to the heart and overall health, and is the third leading cause for premature death among Americans. Metabolic syndrome is associated with an increased risk of developing diabetes and cardiovascular disease, the favorable influence of alcohol consumption on selective components of metabolic syndrome has contributed to the possibility that alcohol consumption reduces the risk of metabolic syndrome in the adults of USA, Japan and South Korean. However, its putative effect on metabolic disorders has not been well evaluated in mainland China or oversea Chinese.
It was recently reported that moderate alcohol drinking is associated with a lower prevalence of metabolic syndrome. Although studies showed statistically significant interactions between alcohol consumption and metabolic syndrome, integration of variables and homogeneity in definitions is required. Since alcohol-associated health problem is also influenced by ethnicity, it is thus needed to investigate the interactions in Chinese.
One of the major findings in the present study is the relative lower prevalence of current alcohol drinking (13%) in Shanghai than in other regions of China and most foreign countries. This might be due to the different alcohol drinking culture backgrounds and the general concern about the dangers of alcohol consumption to the overall health among Shanghai people. However, metabolic syndrome is common in Shanghai as compared to Japan and South Koran, and the prevalence of metabolic syndrome among Shanghai adults is only slightly lower than that in USA, suggesting that alcohol drinking is not a major risk factor for metabolic syndrome in humans, even though current alcohol consumption is associated with a lower prevalence of metabolic syndrome irrespective of the average daily alcohol consumption in the present study. On the one hand, alcohol drinking reduces serum LDL-C concentration, risk of abdominal obesity and low HDL-C. On the other hand, alcohol consumption might increase the prevalence of hypertension, hypertriglyceridemia and hyperglycemia. These effects of alcohol consumption on metabolic disorders are consistent with the most other related or similar findings from other countries. The results of this study provide the epidemiological data on the correlation between alcohol consumption and metabolic syndrome in Chinese.
There is sufficient evidence that light to moderate alcohol consumption is associated with decreased risk of cardiovascular disease. Nevertheless, the effects of alcohol consumption on health are dependent on the consumed amount of alcohol, the pattern of drinking, and the potential for problem drinking, suggesting that alcohol should not be advised for health enhancement of individuals.
Metabolic syndrome refers to a cluster of metabolic derangements that increased the risk of developing type 2 diabetes and cardiovascular diseases associated with insulin resistance. Current alcohol drinker refers to alcohol drinking habituation regardless of the amount of alcohol consumption, and is usually defined as more than once of alcohol drinking per month over the past 12 mo. The classification of current alcohol consumption is far from consensual at present. In the present study, light alcohol drinking is defined as average alcohol consumption of less than 10 g/d, moderate alcohol drinking as average daily alcohol consumption of 10-30 g/d, and excessive alcohol drinking as average alcohol consumption of equal to or more than 30 g per day in the past 12 mo.
The authors conducted a population-based study on 3953 adults in Shanghai to evaluate the association between alcohol consumption and metabolic syndrome, and found that current alcohol consumption was associated with a lower prevalence of metabolic syndrome. Overall, the study was well designed with good quality control, and detailed data were collected from participants with a randomized multistage stratified cluster sampling method. The manuscript provides important data and is relatively well written.
| 1. | O’Keefe JH, Bybee KA, Lavie CJ. Alcohol and cardiovascular health: the razor-sharp double-edged sword. J Am Coll Cardiol. 2007;50:1009-1014. [Cited in This Article: ] |
| 2. | Corella D. Gene-alcohol interactions in the metabolic syndrome. Nutr Metab Cardiovasc Dis. 2007;17:140-147. [Cited in This Article: ] |
| 3. | Naimi TS, Brown DW, Brewer RD, Giles WH, Mensah G, Serdula MK, Mokdad AH, Hungerford DW, Lando J, Naimi S. Cardiovascular risk factors and confounders among nondrinking and moderate-drinking U.S. adults. Am J Prev Med. 2005;28:369-373. [Cited in This Article: ] |
| 4. | Fueki Y, Miida T, Wardaningsih E, Ito M, Nakamura A, Takahashi A, Hanyu O, Tsuda A, Saito H, Hama H. Regular alcohol consumption improves insulin resistance in healthy Japanese men independent of obesity. Clin Chim Acta. 2007;382:71-76. [Cited in This Article: ] |
| 5. | Gigleux I, Gagnon J, St-Pierre A, Cantin B, Dagenais GR, Meyer F, Despres JP, Lamarche B. Moderate alcohol consumption is more cardioprotective in men with the metabolic syndrome. J Nutr. 2006;136:3027-3032. [Cited in This Article: ] |
| 6. | Riserus U, Ingelsson E. Alcohol intake, insulin resistance, and abdominal obesity in elderly men. Obesity (Silver Spring). 2007;15:1766-1773. [Cited in This Article: ] |
| 7. | Fan JG, Peng YD. Metabolic syndrome and non-alcoholic fatty liver disease: Asian definitions and Asian studies. Hepatobiliary Pancreat Dis Int. 2007;6:572-578. [Cited in This Article: ] |
| 8. | Freiberg MS, Cabral HJ, Heeren TC, Vasan RS, Curtis Ellison R. Alcohol consumption and the prevalence of the Metabolic Syndrome in the US: a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey. Diabetes Care. 2004;27:2954-2959. [Cited in This Article: ] |
| 9. | Ford ES, Giles WH, Dietz WH. Prevalence of the metabolic syndrome among US adults: findings from the third National Health and Nutrition Examination Survey. JAMA. 2002;287:356-359. [Cited in This Article: ] |
| 10. | Davies MJ, Baer DJ, Judd JT, Brown ED, Campbell WS, Taylor PR. Effects of moderate alcohol intake on fasting insulin and glucose concentrations and insulin sensitivity in postmenopausal women: a randomized controlled trial. JAMA. 2002;287:2559-2562. [Cited in This Article: ] |
| 11. | Anuurad E, Shiwaku K, Nogi A, Kitajima K, Enkhmaa B, Shimono K, Yamane Y. The new BMI criteria for asians by the regional office for the western pacific region of WHO are suitable for screening of overweight to prevent metabolic syndrome in elder Japanese workers. J Occup Health. 2003;45:335-343. [Cited in This Article: ] |
| 12. | Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003;289:2560-2572. [Cited in This Article: ] |
| 13. | Marchesini G, Forlani G, Cerrelli F, Manini R, Natale S, Baraldi L, Ermini G, Savorani G, Zocchi D, Melchionda N. WHO and ATPIII proposals for the definition of the metabolic syndrome in patients with Type 2 diabetes. Diabet Med. 2004;21:383-387. [Cited in This Article: ] |
| 14. | Shaw JE, de Courten M, Boyko EJ, Zimmet PZ. Impact of new diagnostic criteria for diabetes on different populations. Diabetes Care. 1999;22:762-766. [Cited in This Article: ] |
| 15. | Fan JG, Saibara T, Chitturi S, Kim BI, Sung JJ, Chutaputti A. What are the risk factors and settings for non-alcoholic fatty liver disease in Asia-Pacific? J Gastroenterol Hepatol. 2007;22:794-800. [Cited in This Article: ] |
| 16. | Fan JG, Zhu J, Li XJ, Chen L, Li L, Dai F, Li F, Chen SY. Prevalence of and risk factors for fatty liver in a general population of Shanghai, China. J Hepatol. 2005;43:508-514. [Cited in This Article: ] |
| 17. | Fan JG, Zhu J, Li XJ, Chen L, Lu YS, Li L, Dai F, Li F, Chen SY. Fatty liver and the metabolic syndrome among Shanghai adults. J Gastroenterol Hepatol. 2005;20:1825-1832. [Cited in This Article: ] |
| 18. | Li YM. Alcoholism and alcoholic liver disease: focusing on epidemiological investigation in Asia. Hepatobiliary Pancreat Dis Int. 2005;4:170-172. [Cited in This Article: ] |
| 19. | Lu XL, Luo JY, Tao M, Gen Y, Zhao P, Zhao HL, Zhang XD, Dong N. Risk factors for alcoholic liver disease in China. World J Gastroenterol. 2004;10:2423-2426. [Cited in This Article: ] |
| 20. | Sung KC, Kim SH, Reaven GM. Relationship among alcohol, body weight, and cardiovascular risk factors in 27,030 Korean men. Diabetes Care. 2007;30:2690-2694. [Cited in This Article: ] |
| 21. | Fan JG, Li F, Cai XB, Peng YD, Ao QH, Gao Y. The importance of metabolic factors for the increasing prevalence of fatty liver in Shanghai factory workers. J Gastroenterol Hepatol. 2007;22:663-668. [Cited in This Article: ] |
| 22. | Yokoyama H, Hiroshi H, Ohgo H, Hibi T, Saito I. Effects of excessive ethanol consumption on the diagnosis of the metabolic syndrome using its clinical diagnostic criteria. Intern Med. 2007;46:1345-1352. [Cited in This Article: ] |
| 23. | Dixon JB, Dixon ME, O'Brien PE. Alcohol consumption in the severely obese: relationship with the metabolic syndrome. Obes Res. 2002;10:245-252. [Cited in This Article: ] |
| 24. | Yoon YS, Oh SW, Baik HW, Park HS, Kim WY. Alcohol consumption and the metabolic syndrome in Korean adults: the 1998 Korean National Health and Nutrition Examination Survey. Am J Clin Nutr. 2004;80:217-224. [Cited in This Article: ] |
| 25. | Park YW, Zhu S, Palaniappan L, Heshka S, Carnethon MR, Heymsfield SB. The metabolic syndrome: prevalence and associated risk factor findings in the US population from the Third National Health and Nutrition Examination Survey, 1988-1994. Arch Intern Med. 2003;163:427-436. [Cited in This Article: ] |
| 26. | Santos AC, Ebrahim S, Barros H. Alcohol intake, smoking, sleeping hours, physical activity and the metabolic syndrome. Prev Med. 2007;44:328-334. [Cited in This Article: ] |
| 27. | Djousse L, Arnett DK, Eckfeldt JH, Province MA, Singer MR, Ellison RC. Alcohol consumption and metabolic syndrome: does the type of beverage matter? Obes Res. 2004;12:1375-1385. [Cited in This Article: ] |
| 28. | Arif AA, Rohrer JE. Patterns of alcohol drinking and its association with obesity: data from the Third National Health and Nutrition Examination Survey, 1988-1994. BMC Public Health. 2005;5:126. [Cited in This Article: ] |
| 29. | McFadden CB, Brensinger CM, Berlin JA, Townsend RR. Systematic review of the effect of daily alcohol intake on blood pressure. Am J Hypertens. 2005;18:276-286. [Cited in This Article: ] |
| 30. | Xin X, He J, Frontini MG, Ogden LG, Motsamai OI, Whelton PK. Effects of alcohol reduction on blood pressure: a meta-analysis of randomized controlled trials. Hypertension. 2001;38:1112-1117. [Cited in This Article: ] |
| 31. | Carlsson S, Hammar N, Grill V. Alcohol consumption and type 2 diabetes Meta-analysis of epidemiological studies indicates a U-shaped relationship. Diabetologia. 2005;48:1051-1054. [Cited in This Article: ] |
| 32. | Sakai Y, Yamaji T, Tabata S, Ogawa S, Yamaguchi K, Mineshita M, Mizoue T, Kono S. Relation of alcohol use and smoking to glucose tolerance status in Japanese men. Diabetes Res Clin Pract. 2006;73:83-88. [Cited in This Article: ] |
| 33. | Djousse L, Biggs ML, Mukamal KJ, Siscovick DS. Alcohol consumption and type 2 diabetes among older adults: the Cardiovascular Health Study. Obesity (Silver Spring). 2007;15:1758-1765. [Cited in This Article: ] |
| 34. | Englund Ogge L, Brohall G, Behre CJ, Schmidt C, Fagerberg B. Alcohol consumption in relation to metabolic regulation, inflammation, and adiponectin in 64-year-old Caucasian women: a population-based study with a focus on impaired glucose regulation. Diabetes Care. 2006;29:908-913. [Cited in This Article: ] |
| 35. | Lucas DL, Brown RA, Wassef M, Giles TD. Alcohol and the cardiovascular system research challenges and opportunities. J Am Coll Cardiol. 2005;45:1916-1924. [Cited in This Article: ] |