Alcohol Intake and Triglycerides/High-Density Lipoprotein Cholesterol Ratio in Men with Hypertension

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1 Original article Alcohol Intake and Triglycerides/High-Density Lipoprotein Cholesterol Ratio in Men with Hypertension Ichiro Wakabayashi 1 Background The triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) ratio has been proposed to be a good predictor of cardiovascular disease. The relationship between alcohol consumption and TG/HDL-C ratio in patients with hypertension is unknown. Methods Subjects were normotensive and hypertensive men aged years who were divided by daily ethanol intake into non-, light (<22 g/day), heavy ( 22 but <44 g/day), and very heavy ( 44 g/day) drinkers. Results The TG/HDL-C ratio was significantly higher in the hypertensive group than in the normotensive group. Both in the normotensive and hypertensive groups, TG/HDL-C ratio was significantly lower in light, heavy, and very heavy drinkers than in nondrinkers and was lowest in light drinkers. In the hypertensive group, odds ratios (ORs) for high TG/ HDL-C ratio ( 3.75) in light, heavy, and very heavy drinkers vs. nondrinkers were significantly lower (P < 0.01) than a reference level of 1.00 (light drinkers: OR = 0.49, 95% confidence interval (CI) = ; heavy drinkers: OR = 0.59, 95% CI = ; very heavy drinkers: OR = 0.70, 95% CI = ) and were significantly lower than the corresponding ORs in the normotensive group. The ORs for hypertension in subjects with vs. subjects without high TG/HDL-C ratio were significantly higher than the reference level in all the alcohol groups and were significantly lower in light, heavy, and very heavy drinkers than in nondrinkers. Conclusions The results suggest that there is an inverted J-shaped relationship between alcohol and TG/HDL-C ratio in individuals with hypertension and that alcohol weakens the positive association between TG/HDL-C ratio and hypertension. Keywords: alcohol; blood pressure; cardiovascular disease; dyslipidemia; hypertension; triglycerides/hdl cholesterol ratio. doi: /ajh/hpt033 Both hypertension and dyslipidemia are major risk factors for cardiovascular disease. Alcohol drinking, a modifiable risk factor, has diverse effects on the risk of atherosclerotic disease. Blood pressure is known to be higher in drinkers than in nondrinkers, and thus alcohol is a risk factor for hypertension. 1 According to a study analyzing World Health Organization global burden of disease, 16% of all hypertensive diseases were attributed to alcohol. 2 In particular, alcohol is positively associated with risks of hemorrhagic type of stroke, such as cerebral hemorrhage and subarachnoid hemorrhage. 3 On the other hand, the risks of ischemic vascular diseases, such as coronary artery disease, ischemic type of stroke, and peripheral arterial disease, are known to be lower in light-to-moderate drinkers than in nondrinkers. 4 6 Alcohol has favorable effects on the blood cholesterol profile: high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels are higher and lower, respectively, in drinkers than in nondrinkers. 7 9 About half of the protection and an additional 18% of the protection against coronary artery disease afforded by moderate alcohol consumption were reportedly mediated by increases in HDL-C and LDL-C, respectively. 8 However, heavy alcohol drinking causes hypertriglyceridemia, 7,10 which is thought to be a risk factor of cardiovascular disease. 11 The triglycerides/hdl-c (TG/HDL-C) ratio has been proposed to be a good predictor of cardiovascular disease and has been demonstrated to be an even better predictor of coronary arterial disease than LDL-C/HDL-C ratio, a classical atherogenic index. 12,13 TG/HDL-C ratio has been shown to reflect small dense LDL particles, 14 which are more atherogenic than larger buoyant ones, and to be associated with insulin resistance 19 and metabolic syndrome. 20 Thus, TG/HDL-C ratio, an easily measurable index, is useful for evaluation of cardiovascular risk in routine clinical examination and mass screening examination, instead of small dense LDL particles, the measurement of which requires complicated procedures (e.g., gradient gel electrophoresis). 21 Both HDL-C and triglyceride levels are higher in drinkers than in nondrinkers. 7 9,11 There has been limited information Correspondence: Ichiro Wakabayashi (wakabaya@hyo-med.ac.jp). Initially submitted September 10, 2012; date of first revision February 12, 2013; accepted for publication February 17, 2013; online publication March 21, Department of Environmental and Preventive Medicine, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan. American Journal of Hypertension, Ltd All rights reserved. For Permissions, please journals.permissions@oup.com 888 American Journal of Hypertension 26(7) July 2013

2 Alcohol Intake and Triglycerides/High-Density Lipoprotein Cholesterol Ratio in Men with Hypertension on the relationship between alcohol intake and TG/HDL-C ratio. TG/HDL-C ratio has recently been reported to be lower in drinkers than in nondrinkers in a general population 22 and in patients with diabetes. 23 Hypertension and dyslipidemia are closely interrelated and often coexist in the same individual. 24,25 However, it remains to be determined whether and how TG/HDL-C ratio is influenced by alcohol in patients with hypertension. The purpose of this study was therefore to investigate relationships among alcohol, TG/ HDL-C ratio, and hypertension by using a large populationbased database of health checkup examinations. METHODS Subjects The subjects were Japanese men aged years (n = 21,572) who had received periodic health checkup examinations at workplaces in Yamagata Prefecture in Japan. Histories of alcohol consumption, cigarette smoking, regular exercise (almost every day for 30 minutes or longer per day), illness, and therapy for illness were surveyed by questionnaires. Those who had been receiving medication therapy for dyslipidemia (4.7%) were excluded from subjects of this study. A cross-sectional study was performed using a local population-based database for the above subjects. This study was approved by the Ethics Committee of Yamagata University School of Medicine. Evaluation of alcohol consumption Average alcohol consumption of each subject per week was reported on questionnaires. Among overall subjects who had annual health checkups in the original database, the percentages of nondrinkers, regular drinkers, and occasional drinkers were 21.8%, 51.2%, and 27.0%, respectively. Because it is difficult to know the correct average alcohol consumption of occasional drinkers, only regular drinkers who drink almost every day were used as drinkers for analysis in this study. Occasional drinkers were thus excluded from subjects for analysis. Usual daily alcohol consumption was calculated in terms of the equivalent number of go, a traditional Japanese unit of amount of sake (rice wine). The amounts of other alcoholic beverages, including beer, wine, whisky, and shochu (traditional Japanese distilled spirit), were converted and expressed as units of go. One go approximately corresponds to 180 ml of sake, 500 ml of beer, 240 ml of wine, 60 ml of whisky, and 80 ml of shochu. Amount of daily alcohol drinking was categorized as null, less than 1 go per day, 1 go or more but less than 2 go per day, 2 go or more but less than 3 go per day, and 3 go or more per day. One go contains about 22 g of ethanol, and this amount was used to separate heavy drinkers from light drinkers because it is generally accepted that alcohol intake should be reduced to less than 30 ml or g per day from the viewpoint of prevention of hypertension The subjects were divided into 4 groups according to ethanol consumption per day (nondrinkers; light drinkers: <22 g of ethanol per day; heavy drinkers: 22 g but <44 g of ethanol per day; very heavy drinkers: 44 g ethanol per day). Measurements Height and body weight were measured while subjects wore light clothes at the health checkup. Body mass index was calculated as weight in kilograms divided by the square of height in meters. Blood pressure was measured by trained nurses who were part of the local health checkup company with a mercury sphygmomanometer once on the day of the health checkup after each subject had rested quietly in a sitting position. Korotkoff phase V was used to define diastolic pressure. Normal blood pressure was defined as systolic blood pressure of <140 mm Hg and diastolic blood pressure of <90 mm Hg. Hypertension was defined as systolic blood pressure of 140 mm Hg and/or diastolic blood pressure of 90 mm Hg. Subjects receiving medication therapy for hypertension were also included in the hypertensive group. Fasted blood was sampled from each subject in the morning, and serum triglycerides, HDL-C, and LDL-C were measured by enzymatic methods using commercial kits, pureauto S TG-N, cholestest N-HDL, and cholestest LDL (Sekisui Medical, Tokyo, Japan), respectively. Coefficients of variation for reproducibility of each measurement were 3% for triglycerides, 5% for HDL-C, and 5% for LDL-C. The cutoff values of high triglycerides, low HDL-C, and high TG/ HDL-C ratio were defined as 150 mg/dl, 40 mg/dl, and 3.75, respectively. Statistical analysis Statistical analyses were performed using a computer software program (SPSS version 16.0 J for Windows, Chicago, IL). Percentages of smokers, drinkers, subjects doing exercise regularly, and subjects with high TG/HDL-C ratio were compared between the normotensive and hypertensive groups using the χ 2 test for independence. In univariable analysis, means of each variable were compared between the normotensive and hypertensive groups by using the unpaired Student t test. Because triglycerides and TG/HDL-C ratio did not show a normal distribution, they were compared between the groups nonparametrically by using the Mann Whitney U test. The trend of the relationship between alcohol quantity and TG/HDL-C ratio or blood pressure was analyzed using the Jonckheere Terpstra test. In multivariable analysis, mean levels of each variable were compared by using analysis of covariance followed by Student t test after Bonferroni correction, and data of triglycerides and TG/HDL-C ratio were used after logarithm transformation. In logistic regression analysis, crude and adjusted odds ratios (ORs) for high TG/HDL-C ratio or hypertension were calculated. Crude ORs were compared between the normotensive and hypertensive groups and between each drinker group and the nondrinker group by using the Breslow Day test. Age, smoking, alcohol drinking, regular exercise, and history of medication American Journal of Hypertension 26(7) July

3 Wakabayashi therapy for hypertension were used as other explanatory variables or covariables in multivariable analyses. P < 0.05 was defined as significant. RESULTS Characteristics of subjects Table 1 shows results of comparison of characteristics of the subject groups of normotensive and hypertensive men. Age was significantly higher in the hypertensive group than in the normotensive group. The percentages of heavy drinkers, very heavy drinkers, and total drinkers were significantly higher in the hypertensive group than in the normotensive group, whereas the percentage of light drinkers was significantly lower in the hypertensive group than in the normotensive group. The percentages of smokers and subjects doing regular exercise were significantly lower and lower with marginal significance, respectively, in the hypertensive group than in the normotensive group. Triglycerides, TG/HDL-C ratio, and percentage of subjects with high TG/HDL-C ratio were significantly higher in the hypertensive group than in the normotensive group. HDL-C and LDL-C were slightly but significantly lower and higher, respectively, in the hypertensive group than in the normotensive group. Means with standard errors of log-transformed TG/HDL-C ratio in non-, light, heavy, and very heavy drinkers were ± 0.004, ± 0.007, ± and ± 0.005, respectively. There was a significant trend (standardized Jonckheere Terpstra value = 5.80; P < 0.01) between drinker category (light, heavy, and very heavy drinkers) and log-transformed TG/HDL-C ratio. Thus, there was a positive relationship between alcohol quantity and TG/HDL-C ratio among drinkers. Comparison of systolic and diastolic blood pressure among the alcohol groups in overall subjects Means of systolic and diastolic blood pressure were compared among the alcohol groups in multivariable analysis with adjustment for age, smoking, regular exercise, and medication therapy for hypertension. In overall subjects, systolic and diastolic blood pressure was significantly higher (P < 0.01 compared with nondrinkers) in light, heavy, and very heavy drinkers than in nondrinkers and tended to be higher with an increase in alcohol intake (blood pressure (mmhg of means ± standard errors): systolic: ± 0.2 (nondrinkers) vs ± 0.3 (light drinkers) vs ± 0.2 (heavy drinkers) vs ± 0.2 (very heavy drinkers); diastolic blood pressure: 76.3 ± 0.1 (nondrinkers) vs ± 0.2 (light drinkers) vs ± 0.1 (heavy Table 1. Characteristics of normotensive and hypertensive subject groups Characteristic Normotensive Hypertensive No. 14,175 7,397 Age, years 47.0 ± ± 7.0* Drinkers, % Light, % * Heavy, % * Very heavy, % * Total, % * Smokers, % * Regular exercise, % ** Medical therapy for hypertension, % * Body mass index, kg/m ± ± 3.54* Systolic blood pressure, mm Hg ± ± 14.2* Diastolic blood pressure, mm Hg 73.7 ± ± 10.5* Triglycerides, mg/dl 110 (15 3,734) 137 (21 2,415)* Log(triglycerides) ± ± 0.281* HDL-C, mg/dl 57.7 ± ± 15.4* LDL-C, mg/dl ± ± 32.4* TG/HDL-C ratio 1.96 ( ) 2.49 ( )* Log(TG/HDL-C ratio) ± ± 0.349* High TG/HDL-C ratio, % * Data are given as numbers, percentages of subjects, means with standard deviations, and medians with ranges. Abbreviations: HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; TG/HDL-C, triglycerides/hdl-c. Asterisks denote significant differences from the normotensive group (* P < 0.01) or marginally significant difference (** P = 0.055) from the normotensive group. Þ Symbols denote significant differences (* P < 0.01) and a marginally significant difference (** P = 0.055) from the normotensive group. 890 American Journal of Hypertension 26(7) July 2013

4 Alcohol Intake and Triglycerides/High-Density Lipoprotein Cholesterol Ratio in Men with Hypertension Figure 1. Comparison of triglycerides, high-density lipoprotein cholesterol (HDL-C), triglycerides/hdl-c (TG/HDL-C) ratio, and low-density lipoprotein cholesterol (LDL-C) among non-, light, heavy, and very heavy drinkers in the normotensive or hypertensive group. Mean levels of log-transformed triglycerides (a), HDL-C (b), log-transformed TG/HDL-C ratio (c), and LDL-C (d) calculated after adjustment for age, history of smoking, and history of regular exercise are shown. In the hypertensive group, history of medication therapy for hypertension was also added as an explanatory covariable. Symbols denote significant differences from nondrinkers (* P < 0.01) and light drinkers (** P < 0.05; *** P < 0.01) and a marginally significant difference from light drinkers (**** P = 0.054). drinkers) vs ± 0.2 (very heavy drinkers)). There was a significant trend between drinker category (non-, light, heavy, and very heavy drinkers) and systolic or diastolic blood pressure (standardized Jonckheere Terpstra value = 27.56, P < 0.01 for systolic blood pressure; 26.27, P < 0.01 for diastolic blood pressure). Comparison of triglycerides, HDL-C, TG/HDL-C ratio, and LDL-C among the alcohol subgroups of the normotensive or hypertensive group Mean levels of log-transformed triglycerides, HDL- C, log-transformed TG/HDL-C ratio, and LDL-C in the multivariable analysis are shown in Figure 1. Both in the normotensive and hypertensive groups, mean logtransformed triglycerides was significantly lower in light drinkers than in nondrinkers and was significantly higher in very heavy drinkers than in nondrinkers (Figure 1a). Mean HDL-C was significantly higher in light, heavy, and very heavy drinkers than in nondrinkers and tended to be higher with an increase in alcohol intake both in the normotensive and hypertensive groups (Figure 1b). Both in the normotensive and hypertensive groups, mean log-transformed TG/ HDL-C ratio was significantly lower in light, heavy, and very heavy drinkers than in nondrinkers and was lowest in light drinkers (Figure 1c). Mean log-transformed TG/HDL-C ratio was significantly higher in very heavy drinkers than in light drinkers in the hypertensive group and was higher with marginal significance in very heavy drinkers than in light drinkers in the normotensive group. The difference in the mean log-transformed TG/HDL-C ratio compared with light drinkers was most prominent in nondrinkers both in the normotensive and hypertensive groups (Figure 1c). Mean LDL-C was significantly lower in light, heavy, and very American Journal of Hypertension 26(7) July

5 Wakabayashi heavy drinkers than in nondrinkers and tended to be lower with an increase in alcohol intake both in the normotensive and hypertensive groups (Figure 1d). Relationships between alcohol intake and prevalence of high TG/HDL-C ratio in the normotensive and hypertensive groups ORs of each drinker group vs. the nondrinker group for high TG/HDL-C ratio in subjects with normal blood pressure and those with hypertension are shown in Table 2. Both in the normotensive and hypertensive groups, the crude and adjusted ORs vs. the nondrinker group for high TG/HDL-C ratio were significantly lower than a reference level of 1.00 in light, heavy, and very heavy drinkers except for the crude OR of very heavy drinkers in the normotensive group. The crude ORs of light, heavy, and very heavy drinkers vs. nondrinkers were significantly lower in the hypertensive group than in the normotensive group. ORs for high TG/ HDL-C ratio of the interaction term consisting of alcohol (each drinker group vs. nondrinkers) and blood pressure status (normotensive vs. hypertensive) were calculated using alcohol, blood pressure status, age, history of smoking, and history of regular exercise as other explanatory variables. As shown in Table 2, the ORs of the interaction term for high TG/HDL-C ratio were significantly lower than a reference level of 1.00 in light, heavy, and very heavy drinkers. Table 2 also shows ORs for high TG/HDL-C ratio of each drinker subgroup vs. the light drinker subgroup. The OR vs. light drinkers for high TG/HDL-C ratio was significantly higher than a reference level of 1.00 in nondrinkers and very heavy drinkers both in the normotensive and hypertensive groups. In addition, the OR vs. light drinkers for high TG/ HDL-C ratio was significantly higher than a reference level of 1.00 in heavy drinkers in the hypertensive group. ORs of the interaction term consisting of drinker category (each drinker group vs. the light drinker group) and hypertension (yes vs. no) were also calculated by using drinker category, hypertension, age, smoking, and regular exercise as other explanatory variables. As shown in Table 2, the OR of the interaction term consisting of the drinker category (nondrinkers vs. light drinkers) and hypertension was significantly higher than a reference level of This result indicated that the difference in the prevalence of high TG/ HDL-C ratio between nondrinkers and light drinkers is greater in individuals with hypertension than in individuals with normal blood pressure. Relationships between TG/HDL-C ratio and hypertension in the different alcohol groups ORs for hypertension in subjects with vs. subjects without high TG/HDL-C ratio in each drinker group and overall subjects are shown in Table 3. The crude and adjusted ORs were significantly higher than a reference level of 1.00 in non-, light, heavy, and very heavy drinkers and in overall subjects. The crude ORs were significantly lower in light, heavy, and very heavy drinkers than in nondrinkers. The ORs of the interaction term consisting of alcohol (each drinker group vs. nondrinkers) and TG/HDL-C ratio (high vs. not high) were calculated using alcohol, TG/HDL-C ratio status, age, history Table 2. Odds ratios (ORs) for high triglycerides/high-density lipoprotein cholesterol ratio of each drinker subgroup vs. the nondrinker subgroup or the light drinker subgroup in normotensive and hypertensive groups. ORs Nondrinkers Light drinkers Heavy drinkers Very heavy drinkers Normotensive Crude OR ( )** 0.76 ( )** 0.96 ( ) Adjusted OR ( )** 0.73 ( )** 0.89 ( )* Crude OR 1.47 ( )** ( ) 1.40 ( )** Adjusted OR 1.50 ( )** ( ) 1.36 ( )** Hypertensive Crude OR ( )**, *** 0.59 ( )**, *** 0.70 ( )**, *** Adjusted OR ( )** 0.61 ( )** 0.71 ( )** Crude OR 2.05 ( )**, *** ( )* 1.44 ( )** Adjusted OR 2.04 ( )** ( )* 1.42 ( )** Overall OR of interaction term ( )** 0.77 ( )** 0.73 ( )** OR of interaction term 1.41 ( )** ( ) 1.02 ( ) Crude and adjusted ORs with their 95% confidence intervals in the parentheses are shown. Adjusted ORs for high triglycerides/high-density lipoprotein cholesterol ratio of each drinker subgroup vs. the nondrinker or light drinker subgroup in normotensive and hypertensive groups were calculated using age, smoking, regular exercise, and history of medication therapy for hypertension as other explanatory variables. ORs of the interaction term consisting of drinker category (each drinker group vs. the nondrinker or light drinker group) and hypertension (yes vs. no) were calculated by using drinker category, hypertension, age, smoking, and regular exercise as other explanatory variables. Symbols denote significantly lower or higher odds ratios compared with a reference level of 1.00 (* P < 0.05; ** P < 0.01) and significant differences from the normotensive group (*** P < 0.01). 892 American Journal of Hypertension 26(7) July 2013

6 Alcohol Intake and Triglycerides/High-Density Lipoprotein Cholesterol Ratio in Men with Hypertension Table 3. Odds ratios (ORs) for hypertension of subjects with vs. subjects without high triglycerides/high-density lipoprotein cholesterol ratio ORs Nondrinkers Light drinkers Heavy drinkers Very heavy drinkers Overall Crude OR 2.02 ( )* 1.44 ( )*, ** 1.56 ( )*, ** 1.48 ( )*, ** 1.60 ( )* Adjusted OR 2.13 ( )* 1.53 ( )* 1.66 ( )* 1.57 ( )* 1.74 ( )* OR of interaction term ( )* 0.77 ( )* 0.73 ( )* Crude and adjusted ORs with their 95% confidence intervals in the parentheses are shown. Adjusted ORs for hypertension were calculated using age, smoking, and regular exercise as other explanatory variables. In analysis of overall subjects, alcohol drinking was also included in the explanatory variables. ORs of the interaction term consisting of drinker category (each drinker group vs. nondrinkers) and triglycerides/highdensity lipoprotein cholesterol (TG/HDL-C) ratio (high vs. not high) were calculated by using drinker category, TG/HDL-C ratio, age, smoking, and regular exercise as other explanatory variables. Symbols denote significantly lower or higher odds ratios compared with a reference level of 1.00 (* P < 0.01) and significant differences from nondrinkers (** P < 0.01). of smoking, and history of regular exercise as other explanatory variables. As shown in Table 3, the ORs of the interaction term for hypertension were significantly lower than a reference level of 1.00 in light, heavy, and very heavy drinkers. Discussion TG/HDL-C ratio, a good predictor of cardiovascular disease, was significantly lower in light, heavy, and very heavy drinkers than in nondrinkers and was lowest in light drinkers in hypertensive men as well as in normotensive men. Thus, there is an inverted J-shaped relationship between alcohol intake and TG/HDL-C ratio. Logistic regression analysis using the interaction term demonstrated that the difference in TG/HDL-C ratio between each drinker group (light, heavy, or very heavy drinkers) and the nondrinker group was greater in hypertensive men than in normotensive men. This finding was also confirmed by linear regression analysis (data not shown). Accordingly, the inverted J-shaped relationship between alcohol intake and TG/HDL-C ratio is thought to be more prominent in individuals with hypertension than in those without hypertension. There was a positive association between TG/HDL-C ratio and risk of hypertension, which was weaker in drinkers than in nondrinkers. Therefore, chronic drinking is thought to lower TG/HDL-C ratio in hypertensive men and confound the relationship between TG/HDL-C ratio and blood pressure. This is the first study among individuals with hypertension to show an inverted J-shaped relationship between alcohol and TG/HDL-C ratio. In another analysis using occasional drinkers and nondrinkers, TG/HDL-C ratio tended to be lower in occasional light drinkers (<22 g ethanol per drinking day) and heavy drinkers ( 22 and <44 g ethanol per drinking day) than in nondrinkers, and these associations were more prominent in individuals with hypertension than in individuals with normal blood pressure (data not shown). Thus, the associations between alcohol intake and TG/HDL-C ratio in occasional drinkers were similar to the associations found in regular drinkers. Both in the normotensive and hypertensive groups, the relationship between alcohol and triglycerides differed among the drinker categories. Mean log-transformed value of triglycerides was lower in light drinkers, not different in heavy drinkers, and higher in very heavy drinkers when each of these categories was compared with nondrinkers. HDL-C was consistently higher in all of the drinker groups than in nondrinkers and tended to be higher with an increase in alcohol intake. These relationships of alcohol with triglycerides and HDL-C resulted in lower TG/HDL-C ratios in all of the drinker groups than in nondrinkers and the lowest TG/ HDL-C ratio in light drinkers among the 4 alcohol groups. TG/HDL-C ratio was higher in the hypertensive group than in the normotensive group, and there was a positive association between TG/HDL-C ratio and hypertension, which was significantly weakened by alcohol. This confounding effect of alcohol is plausible because TG/HDL-C ratio and blood pressure are modified by alcohol in opposite directions. Thus, alcohol should be taken into account as a potent confounding factor when TG/HDL-C ratio is used as a predictor of cardiovascular risk in persons with hypertension. In hypertensive men as well as in normotensive men, TG/ HDL-C ratio was lower in drinkers than in nondrinkers. Because TG/HDL-C ratio reflects small dense LDL particles, small dense LDL is thought to be decreased by alcohol. Moreover, LDL-C level became lower with an increase in alcohol intake (Figure 1d). Thus, alcohol shows beneficial effects on LDL metabolism in both hypertensive and normotensive people. This agrees with the lower risk of coronary heart disease in modest drinkers. 4 However, there is a positive association between alcohol intake and blood pressure. 1 In fact, blood pressure was significantly higher in all of the drinker groups than in nondrinkers and tended to be higher with an increase in alcohol intake in this study. Therefore, even light alcohol drinking should not be recommended for patients with hypertension. There are limitations of this study. Data on several possible confounding factors for the relationship between alcohol and TG/HDL-C ratio, such as diet, socioeconomic factors, and polymorphism of alcohol-metabolizing enzymes, were not available in this study. In particular, dietary sodium is an important factor influencing blood pressure, triglycerides, and cholesterol 29 and confounds their relations to alcohol. There is a possibility of an information bias of data on blood pressure, which was measured only once at the health checkup. Ethnicity-related difference in the relationship between TG/HDL-C ratio and insulin resistance has been suggested: TG/HDL-C American Journal of Hypertension 26(7) July

7 Wakabayashi ratio failed to predict insulin resistance in black women. 30 In addition, TG/HDL-C ratio that identifies patients with insulin resistance has recently been shown to be higher in men than in women. 31 The subjects of this study were middle-aged Japanese men. Therefore, further studies on the alcohol TG/HDL-C ratio relationship in different sex, age, and ethnicity groups are needed to confirm the findings of this study. In this study, using a database of health checkup examinations, subjects with stage 2 hypertension according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 26 accounted for only 6.1% of overall subjects, and the number of light drinkers in the stage 2 hypertension group (n = 113) was too small for statistical analysis. Therefore, analysis of data for subjects in different hypertension categories was not performed, and further studies are needed to determine whether severity of hypertension modifies the relationship between alcohol intake and TG/HDL-C ratio. Future longitudinal studies are also needed to clarify causality of the association between alcohol and TG/HDL-C ratio. In conclusion, there was an inverted J-shaped relationship between TG/HDL-C ratio and alcohol intake both in hypertensive and normotensive men, and the positive association between TG/HDL-C ratio and hypertension was weaker in drinkers than in nondrinkers. Thus, alcohol may modify TG/HDL-C ratio and its relation to hypertension. ACKNOWLEDGMENT This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (No ). DISCLOSURE The author declared no conflict of interest. References 1. Klatsky AL. Alcohol and hypertension. 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