Shinsaku Ogawa

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.

Coffee consumption and glucose tolerance status in middle-aged Japanese men.

Aims/hypothesisSeveral studies have reported that coffee has a protective effect against the development of type 2 diabetes. However, few of these studies used the standard glucose tolerance test to diagnose type 2 diabetes. The aim of this study was to investigate the relationship between coffee and green tea consumption and glucose tolerance status as determined using a 75-g OGTT.MethodsWe performed a cross-sectional study of 3224 male officials of the self-defence forces. Glucose tolerance status was determined in accordance with the 1998 World Health Organization criteria, and average intakes of coffee and green tea over the previous year were assessed by a self-administered questionnaire. The figures obtained were adjusted for BMI, physical activity and other factors.ResultsA total of 1130 men were identified as having glucose intolerance (IFG, IGT or type 2 diabetes). Compared with those who did not consume coffee on a daily basis, fasting and 2-h post-load plasma glucose levels were 1.5% and 4.3% lower in those who drank 5 cups of coffee or more per day respectively. The adjusted odds ratios of glucose intolerance for categories of <1, 1–2, 3–4 and ≥5 cups of coffee per day were 1.0 (referent), 0.8 (95% CI 0.6–1.0), 0.7 (95% CI 0.6–0.9) and 0.7 (95% CI 0.5–0.9) respectively (p=0.0001 for trend). No clear association was observed between green tea drinking and glucose tolerance status.Conclusions/interpretationCoffee consumption may inhibit postprandial hyperglycaemia and thereby protect against the development of type 2 diabetes mellitus.

Inverse association between coffee drinking and serum uric acid concentrations in middle-aged Japanese males

Consumption of caffeine-rich beverages, which have diuretic properties, may decrease serum uric acid concentrations. We examined cross-sectionally the relationship of coffee and green tea consumption to serum uric acid concentrations in 2240 male self-defence officials who received a pre-retirement health examination at four hospitals of the Self-Defence Forces between 1993 and 1994. The mean levels of coffee and green tea consumption were 2.3 and 3.1 cups/d respectively. There was a clear inverse relationship between coffee consumption and serum uric acid concentration. When adjusted for hospital only, those consuming less than one cup of coffee daily had a mean serum uric acid concentration of 60 mg/l, while that of those drinking five or more cups of coffee daily was 56 mg/l (P < 0.0001). No such relationship was observed for green tea, another major dietary source of caffeine in Japan. The relationship between coffee consumption and serum uric acid concentration was independent of age, rank in the Self-Defence Forces, BMI, systolic blood pressure, serum creatinine, serum total cholesterol and serum HDL-cholesterol concentrations, smoking status, alcohol use, beer consumption and intake of dairy products. These findings suggest that coffee drinking may be associated with lower concentrations of serum uric acid, and further studies are needed to confirm the association.

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.

Relation of cigarette smoking and alcohol use to colorectal adenomas by subsite: the self-defense forces health study.

While smoking has consistently been shown to be related to increased risk of colorectal adenomas, few studies have addressed the association between smoking and site‐specific colorectal adenomas. The reported association between alcohol use and colorectal adenomas has been inconsistent. We evaluated risks of adenomas at the proximal colon, distal colon, and rectum in relation to cigarette smoking and alcohol use, and their interaction. Subjects were 754 cases with histologically proven colorectal adenomas and 1547 controls with normal colonoscopy among male officials of the Self‐Defense Forces (SDF) undergoing total colonoscopy at two SDF hospitals. Statistical adjustment was made for hospital, rank, body mass index, physical activity, and either smoking or alcohol drinking. Cigarette smoking was significantly associated with an increased risk of adenomas, regardless of the location of the adenomas, but the increased risk associated with smoking was more pronounced for rectal adenomas. Alcohol use was associated with moderately increased risks of distal colon and rectal adenomas, but not of proximal colon adenomas. Cigarette smoking, but not alcohol drinking, was associated with greater increases in the risk of large adenomas and of multiple adenomas across the colorectum. There was no measurable interaction of cigarette smoking and alcohol drinking on colorectal adenomas. The findings corroborate an increased risk of colorectal adenomas associated with smoking and a weak association between alcohol use and colorectal adenomas. Further studies are needed to confirm whether smoking is more strongly related to rectal adenomas, large adenomas, or multiple adenomas. (Cancer Sci 2004; 95: 72–76)

Glucose intolerance and adenomas of the sigmoid colon in Japanese men (Japan)

Objectives: The purpose was to investigate the relation between glucose tolerance and risk of sigmoid colon adenomas, a well-established precancerous lesion, in Japanese men.Methods: In the consecutive series of 7,637 men aged 48 to 59 years who received a preretirement health examination at four hospitals of the Self Defense Forces (SDF) in Japan from 1986 to 1994, we identified 821 cases of sigmoid colon adenomas and 4,372 controls with normal sigmoidoscopy or colonoscopy at 60 cm or more from the anus. Glucose tolerance status was classified as normal, impaired glucose tolerance (IGT), newly diagnosed non-insulin dependent diabetes mellitus (NIDDM), or diabetes mellitus under treatment, based on␣a␣75g oral glucose tolerance test and medical history. Statistical adjustment was made for body mass index (wt/ht2), cigarette smoking, alcohol use, rank of the SDF, and hospital.Results: Modest increases in adenoma risk were observed for newly diagnosed NIDDM and diabetes mellitus under treatment while there was no association between IGT and adenoma risk. When small (< 5 mm in diameter) and large (5+ mm) adenomas were analyzed separately, increased risk associated with newly diagnosed NIDDM was more pronounced for small adenomas, and diabetes mellitus under treatment showed a slightly stronger association with large adenomas.Conclusions: The findings suggest that NIDDM is associated with modestly increased risk of sigmoid colon adenomas, and add to evidence that hyperinsulinemia increases colon cancer risk.

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.

Relation of total and beverage-specific alcohol intake to body mass index and waist-to-hip ratio: A study of self-defense officials in Japan

We investigated the independent associations of total and beverage-specific ethanol consumption with body mass index (BMI) and waist-to-hip ratio (WHR) in middle-aged Japanese males, because of the scarcity of epidemiologic data in Japan. The subjects were 2227 male self-defense officials who received a pre-retirement health examination at the Self-Defense Forces Fukuoka, Kumamoto, and Sapporo Hospitals. Data on alcohol intake, smoking, physical activity, and past medical history were obtained from a self-reported questionnaire. Height, weight, and waist and hip girth measurements were obtained at the examination. Multiple linear regression analysis was employed. Alcohol intake was positively and strongly associated with WHR (p = 0.0001), but not associated with BMI after adjustment for lifestyle variables, including either BMI or WHR. Subjects who consumed 15 ml per day or more of shochu ethanol showed a larger WHR than never drinkers, and a dose-response relationship was found. Dose-response relationships to other beverages were not found. Dose-response relationships to other beverages were not found. These findings suggest that alcohol intake is strongly and independently associated with WHR, but not with BMI. Abdominal obesity was positively associated with shochu ethanol, but not with other types of alcohol.