Koichi Shinchi

Green tea consumption and serum lipid profiles: A cross-sectional study in Northern Kyushu, Japan☆

METHODS. The relation between green tea consumption and serum lipid concentrations was examined using cross-sectional data on 1,306 males who received the retirement health examination at the Self-Defense Forces Fukuoka Hospital between October 1986 and December 1988. RESULTS. After adjustment for rank, smoking, alcohol use, physical activity, and body mass index, serum total cholesterol levels were found to be inversely related to the consumption of green tea while no association was noted with serum triglycerides and high-density lipoprotein cholesterol. Adjusted mean concentrations of total cholesterol were 8 mg/dl lower in men drinking nine cups or more per day than in those consuming zero to two cups per day. Serum cholesterol levels were inversely associated with traditional Japanese dietary habits (intake of rice and soy bean paste soup) and positively associated with Westernized habits. Additional adjustment for these dietary variables did not alter the inverse relation between green tea and total cholesterol.

Physical activity, dietary habits and adenomatous polyps of the sigmoid colon: a study of self-defense officials in Japan.

Physical activity and dietary habits were compared between 80 men with adenomatous polyps of the sigmoid colon and 1148 men with normal colonoscopy among male retiring self-defense officials. Physical activity as expressed in terms of time spent doing strenuous activities during leisure time was inversely related to the risk of adenomatous polyps. Controlling for rank, smoking, alcohol and body mass index (BMI), odds ratios for the categories of 0, 1-59, 60-119 and greater than or equal to 120 minutes per week were 1.0, 0.88, 0.70 and 0.44, respectively (trend p = 0.015). Among a limited range of foods and beverages, the consumption of rice, green tea and instant coffee tended to be associated with a decreased risk of adenomatous polyps. Although the associations observed with dietary habits still need to be substantiated, the findings on physical activity lend further evidence to the hypothesis that physical activity may be protective in the development of colon cancer.

Epidemiology of Gallbladder Polyps: An Ultrasonographic Study of Male Self-Defense Officials in Japan

The prevalence and risk factors of gallbladder polyps diagnosed by ultrasonography were investigated in 2739 male self-defense officials who received a retirement health examination at the Self-Defense Forces Fukuoka Hospital, Japan, between October 1986 and December 1990. Excluding 38 men whose gallbladder had been removed previously, 143 men were found to have gallbladder polyps. The overall prevalence of gallbladder polyps was 5.3%. The relation between gallbladder polyps and smoking, alcohol use, body mass index, glucose tolerance, and serum lipids was examined in 137 men with stoneless polyps and 2495 normal subjects. Whereas smoking tended to be inversely associated with gallbladder polyps, none of the other lifestyle and clinical variables were related to this condition. Thus the reported risk factors of gallstones had no relation to gallbladder polyps.

Coffee consumption and serum aminotransferases in middle-aged Japanese men

We investigated the relation between coffee drinking and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations among 7313 Japanese men receiving a health examination, excluding former alcohol drinkers and men with a history of chronic liver disease. Serum AST > 40 and/or ALT > 40 U/L was defined as liver inflammation. Adjustment was made for alcohol use, smoking, body mass index, serum marker for hepatitis virus infection, and other possible confounders. Adjusted odds ratios of liver inflammation were 1.00 (reference), 0.80, 0.69, and 0.61 for men drinking < 1, 1-2, 3-4, and > or = 5 cups of coffee daily, respectively. Among 6898 men without liver inflammation, serum AST and ALT were inversely associated with coffee consumption, and alcohol-related rise in AST was attenuated with coffee drinking. These findings suggest coffee may have an effect of suppressing the rise of serum aminotransferase, partly by inhibiting the alcohol-related elevation. Studies regarding biological mechanism are warranted.

Obesity and adenomatous polyps of the sigmoid colon

The relation between obesity and adenomatous polyps of the sigmoid colon was investigated in male self‐defense officials who received a retirement health examination at three hospitals of the Self‐Defense Forces in Japan between January 1991 and December 1992. Body mass index (BMI) and waist‐hip circumference ratio (WHR) were used as indices of obesity. A total of 228 adenoma cases and 1484 controls with normal sigmoidoscopy were identified in 2228 men: cases having small adenomas (<5 mm in diameter) and those with large adenomas (5 mm or greater) numbered 115 and 102, respectively. Smoking, alcohol use, physical activity, rank, and hospital were controlled for by multiple logistic regression analysis. BMI and WHR were classified into four levels using the 30th, 60th, and 90th percentiles of each distribution in the control as cut‐off points. There was a significant two‐fold elevation in the overall adenoma risk among men at the highest BMI level (≥26.95) compared with those at the lowest level (<22.48), but the risk did not linearly increase: a similar increase was also noted for large adenomas. While WHR was only weakly related to the overall adenoma risk, the risk of large adenomas progressively increased with increasing levels of WHR: odds ratio (OR) 2.9 (95% confidence interval (CI) 1.4–5.9) for the highest (≥0.958) versus lowest (<0.878) levels. BMI was not materially associated with adenoma risk after additional adjustment for WHR, but a positive association between WHR and large adenomas was independent of BMI: OR 3.4 (95%CI 1.5–7.6) for the highest versus lowest levels. These findings suggest that obesity is associated with an increased risk of colon adenomas, probably with adenoma growth.

Relationship of Diet to Small and Large Adenomas of the Sigmoid Colon

The relation of dietary factors to the risk of adenomas of the sigmoid colon was examined in men receiving a retirement health examination at the Self‐Defense Forces Fukuoka Hospital between October 1986 and 1990. A total of 187 adenoma cases and 1557 controls with normal colonoscopy were identified in the series. Cases were further classified into small‐adenoma (<5 mm, n=78) and large‐adenoma (≥5 mm, n=67) groups. The consumptions of selected foods and beverages were ascertained before colonoscopy by means of a self‐administered questionnaire. After adjustment for smoking, alcohol use, rank and body mass index, low rice consumption and high meat intake were independently associated with an increased risk of large adenomas. The risk of small adenomas was not related to either rice consumption or meat intake. Adjusted odds ratios of large adenomas for the low, intermediate and high consumption levels of rice were estimated to be 1.0 (referent), 0.83 and 0.43, respectively (trend P= 0.08), and the corresponding figures for meat consumption were 1.0 (referent), 1.58 and 2.38, respectively (trend P=0.02). The findings suggest that low rice consumption and high meat intake may promote the growth of colon adenomas, thereby increasing the risk of colon cancer.

Gallstone disease among Japanese men in relation to obesity, glucose intolerance, exercise, alcohol use, and smoking

BACKGROUND Risk factors for gallstones are not fully understood, especially in men. Obesity and other risk factors for gallstone disease were investigated in Japanese men based on gallbladder ultrasonography. METHODS Forty-one men with gallstones, 31 with postcholecystectomy state, and 2044 with a normal gallbladder were identified among 2228 men aged 49-55 years who received a retirement health examination at three hospitals of the Japan Self-Defense Forces between 1991 and 1992. Glucose tolerance was determined with a 75-g oral glucose tolerance test. RESULTS Body mass index was not associated with gallstones, although it was significantly, positively related to postcholecystectomy. Waist to hip circumference ratio tended to be weakly associated with gallstones. Diabetes mellitus was associated only with postcholecystectomy. Smoking, alcohol intake, and physical activity were not measurably related to either gallstones or postcholecystectomy. CONCLUSIONS The present study failed to substantiate an association of gallstone risk with either obesity or any other risk factor. Further observation is needed in view of the limited study power.

Cigarette smoking, alcohol use and adenomatous polyps of the sigmoid colon.

The relationship of adenomatous polyps of the sigmoid colon with cigarette smoking and alcohol use was investigated in male self‐defense officials in Japan. In the comparison between 116 cases and 930 controls, total ethanol intake was not at all associated with the risk of adenomatous polyps, but cigarette smoking was strongly related to adenomatous polyps. After adjustment for total ethanol intake, body mass index and rank, odds ratios (and 95% confidence interval) for the categories of 0, 1–399, 400–799, and 800 or more cigarette‐years were 1.0 (referent), 2.3 (1.1–4.6), 2.9 (1.5–5.4) and 3.2 (1.6–6.5), respectively. Among five alcoholic beverages (sake, shochu, beer, whiskey including brandy, and wine), only whiskey consumption was weakly related to the risk of adenomatous polyps. Because the present findings disagree with an earlier observation on self‐defense officials, we examined the association with smoking and alcohol use separately for small (<5 mm) and large (≥5 mm) adenomas, combining data from these two studies. Cigarette smoking was more strongly associated with small adenomas while the positive association with certain alcoholic beverages were largely confined to large adenomas. These findings suggest that cigarette smoking and alcohol use may be linked with the development of adenoma at different stages of colon tumorigenesis.

Coffee Drinking and Serum Gamma-Glutamyltransferase: An Extended Study of Self-Defense Officials of Japan

PURPOSE To examine the effect of coffee drinking on serum gamma-glutamyltransferase (GGT) level in relation to alcohol drinking, smoking, and degree of obesity in middle-aged Japanese men. METHODS From 1986 to 1994, a total of 7,637 male officials of the Self-Defense Forces of Japan aged 48-59 years received a preretirement health examination. Coffee drinking was ascertained by a self-administered questionnaire, and serum GGT level was measured. After excluding 1,360 men with a possible pathologic condition influencing liver enzyme levels and 182 former alcohol drinkers, effect of coffee drinking on serum GGT was examined by a multiple linear regression model and analysis of variance adjusting for alcohol drinking, smoking, and body mass index (BMI). RESULTS The adjusted percentage of difference in serum GGT was -4.3 (95% CI = -5.0; -3.5) per cup of coffee. The inverse coffee-GGT relation was most prominent among men drinking > or = 30 ml of ethanol and smoking > or = 15 cigarettes daily; and positive associations of alcohol and smoking with GGT were attenuated by coffee drinking, more clearly among men with BMI > or = 25.00 kg/m2. Adjusted percentages of difference in serum GGT were -2.6% (p = 0.0003) per cup of brewed coffee, and -5.1% (p = 0.0001) per cup of instant coffee, independently of each other. CONCLUSIONS The present study suggests that coffee consumption may weaken GGT-induction by alcohol, and possibly by smoking. These effect modifications by coffee may differ according to the degree of obesity.

The Relation of Smoking, Alcohol Use and Obesity to Risk of Sigmoid Colon and Rectal Adenomas

We conducted a case‐control study, using 429 cases with histologically confirmed sigmoid adenoma, 75 cases with rectal adenoma, and 3101 controls showing normal colonoscopy at least up to 60 cm from the anus. The subjects were male Self‐Defense Forces personnel aged 48–56 who received a retirement health examination including a routine sigmoid‐ or colonoscopy. Lifestyle characteristics were ascertained by a self‐administered questionnaire. Smoking in the recent past (ġ 10 years preceding the colonoscopy) and smoking in the remote past (>10 years before the colonoscopy) were both significantly associated with risk of sigmoid adenoma but not with rectal adenoma as a whole. After reciprocal adjustment for smoking in the two periods, only smoking in the recent past was associated with both sigmoid colon and rectal adenomas. Odds ratios (OR) of sigmoid adenoma (and 95% confidence interval) for the categories of 0, 1‐150, 151‐250 and ġ251 cigarette‐years were 1.0 (reference), 1.9 (1.3‐2,8), 2.1 (1.4‐3.0) and 3.0 (1.9‐4.7), respectively (P for trend < 0.01), and those for rectal adenoma were 1.0 (reference), 1.2 (0.4‐3.2), 3.5 (1.4‐8.5) and 2.0 (0.6‐6.7), respectively (P for trend = 0.03). Alcohol use was significantly positively associated with sigmoid adenoma, and insignificantly associated with rectal adenoma. Body mass index was significantly positively associated with sigmoid adenoma, especially large ones. No such association was found for rectal adenoma. These findings suggest that smoking, especially in the recent past, and alcohol use are common risk factors for sigmoid colon and rectal adenomas while obesity may be exclusively related to the growth of sigmoid adenoma.