• Korean Journal of Animal Reproduction
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• v.9 no.1
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• pp.62-65
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• 1985

This study was conducted to investigate the effect of progesterone on the oxygen consumption of washed goat spermatozoa. The results obtained were summarized as follows: 1. Progesterone significantly depressed the respilation of the spermatozoa. 2. Caffeine and Di-cAMP greatly increased the oxygen consumption of the spermatozoa. 3. Caffeine plus progesterone and Di-cAMP plus progesterone significantly depressed the oxygen uptake of the cells. 4. There is some indication of a relationship between progesterone and its interference with metabolic behavior of sperm.

• Toxicological Research
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• v.33 no.2
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• pp.157-164
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• 2017

This study was to evaluate the age-dependent effects of caffeine exposure on the long bones and reproductive organs using male rats. A total of 15 immature male rats and 15 young adult male rats were allocated randomly to three groups: a control group and two groups fed caffeine with 120 and 180 mg/kg/day for 4 weeks. Exposure to caffeine at either dose significantly reduced body weight gain; a proportional reduction in muscle and fat mass in immature animals, whereas a selective reduction in fat mass with relatively preserved muscle mass in young adult animals. The long bones of immature rats exposed to caffeine were significantly shorter and lighter than those of control animals along with decreased bone minerals. However, there was no difference in the length or weight of the long bones in young adult rats exposed to caffeine. Exposure to caffeine reduced the size and absolute weight of the testes significantly in immature animals in comparison to control animals, but not in young adult animals exposed to caffeine. In contrast, the adrenal glands were significantly heavier in caffeine-fed young adult rats in comparison to control animals, but not in caffeine-fed immature rats. Our results clearly show that the negative effects of caffeine on the long bones and testes in rats are different according to the age of the rat at the time of exposure, and might therefore be caused by changes to organ sensitivity and metabolic rate at different developmental stages. Although the long bones and testes are more susceptible to caffeine during puberty, caffeine has negative effects on body fat, bone minerals and the adrenal glands when exposure occurs during young adulthood. There is a need, therefore, to educate the public the potential dangers of caffeine consumption during puberty and young adulthood.

• Korean Journal of Exercise Nutrition
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• v.15 no.4
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• pp.183-189
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• 2011

Caffeine and capsaicin increase resting energy metabolism. However, most measurements have been conducted in short-term studies. Therefore, we investigated the effects of caffeine and capsaicin on energy expenditure and energy substrate utilization in resting rats for 6 h. The caffeine (Experiment 1) experiment included four male rats aged 5 weeks and measured the effects of oral administration of caffeine (10 or 50 mg/kg) on respiratory gas, energy expenditure, and energy substrate oxidation for 6 h. Experiment 2 included four male rats aged 6 weeks to measure the effects of capsaicin (10 mg/kg) using the same method as in Experiment 1. The results of Experiment 1 indicated that O₂ uptake and carbohydrate oxidation after caffeine administration for 2 h was higher in the 10 mg trial than that in the 50 mg or placebo trials (P < 0.05). However fat oxidation was not significantly different. In contrast, capsaicin (Experiment 2) observed no differences between the placebo and the capsaicin trials. In conclusion, caffeine initially increased the resting energy consumption for 2 h, and this energy expenditure was due to carbohydrate oxidation. Capsaicin did not change oxygen uptake, respiratory exchange ratio, fat oxidation, or carbohydrate oxidation.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.3
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• pp.407-420
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• 2014

A survey was carried out regarding university students' recognition of high-caffeine energy drinks in an effort to identify and improve problems as well as provide basic data. Most of the subjects had previous experience of energy drink consumption. Studies showed that most students consumed energy drinks when studying. Regarding frequency of energy drink consumption, most students' responded "1~6 times a year"; female students showed lower frequency of energy drink consumption than male students. Both male and female students used convenience stores to purchase energy drinks. In most cases, students became aware of energy drinks through advertisements on TV, radio, newspapers, and magazines. The most important factor affecting their energy drink purchase and consumption status was taste. The most frequent adverse effect they experienced after drinking an energy drink was unusual heart-pounding, whereas the biggest problem caused by energy drink consumption was addiction. This study indicates that students should have a better understanding of the problems associated with excessive and prolonged high-caffeine intake. In addition, instructions for proper purchasing and consumption of high-caffeine energy drinks should be provided as well as education and campaigns concerning symptoms caused by high-caffeine energy drink consumption so that students may refrain from excessive consumption. Further, civil organizations and the government need to devise effective measures for proper regulation of high-caffeine energy drink consumption.

• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.275-282
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• 2016

Recently, increased caffeine intake has led to an increase in caffeine addiction and withdrawal symptoms. Coffee is surreptitiously consumed in as an additive to milk and caramel. There are few studies on how coffee affects the health of modern people. The purpose of this study is to determine the efficacy and side effects of coffee by awareness of coffee consumption patterns among college students, who are the principal consumers. A survey was conducted from May 11 to 17, 2015 and 302 questionnaires were analyzed. The respondents were 140 men (46.4%) and 162 women (53.6%). In terms of coffee additives, 151 (50.0%) respondents chose 'americano' and 111 (36.8%) 'variation'. The frequency of coffee intake and sleep time for college students was negatively correlated, with the correlation coefficient of -0.145 and significance probability of 0.019. The group that was 'positively' aware of the principal ingredients of coffee had a higher level of academic training than those with 'negative' awareness (p=0.000). Women recognized a larger number of side effects than men: 1.99 and 1.36, respectively, on average (p=0.001). 'Time for consumption' had statistically significant effects on the side effects of coffee consumption: consumption before/after lunch, before/after supper and before going to bed led to 0.4 times (p=0.048) and 0.3 times (p=0.023) more side effects, respectively, than consuming coffee after getting up and before/ after breakfast. Excessive caffeine intake through coffee led to limited sleep time and poorer learning concentration. The guidelines for proper coffee consumption should be created to help students consume coffee properly so that it will not affect sleep, learning concentration or adversely affect health.

• Journal of Preventive Medicine and Public Health
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• v.45 no.3
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• pp.204-208
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• 2012

Objectives: To investigate whether caffeine intake is associated with urinary incontinence (UI) among Japanese adults. Methods: A total of 683 men and 298 women aged 40 to 75 years were recruited from the community in middle and southern Japan. A validated food frequency questionnaire was administered face-to-face to obtain information on dietary intake and habitual beverage consumption. Urinary incontinence status was ascertained using the International Consultation on Incontinence Questionnaire-Short Form. Results: Mean daily caffeine intake was found to be similar between incontinent subjects (men 120 mg, women 94 mg) and others without the condition (men 106 mg, women 103 mg), $p$=0.33 for men and $p$=0.44 for women. The slight increases in risk of UI at the highest level of caffeine intake were not significant after adjusting for confounding factors. The adjusted odds ratios (95% confidence interval) were 1.36 (0.65 to 2.88) and 1.12 (0.57 to 2.22) for men and women, respectively. Conclusions: No association was evident between caffeine intake and UI in middle-aged and older Japanese adults. Further studies are required to confirm the effect of caffeine in the prevention of UI.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.459-466
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• 1998

To investigate the effect of coffee consumption during pregnancy on serum lipids in maternal and infants` umbilical cord blood, 76 cases of newborn infants and women delivered o f a child who had delivered at hospital located in Chung-Ju city from Feb. 1, 1996 to Aug. 31, 1996 were studied. The gestational ages of cases were 37 to 42 weeks and the average maternal ages were $28.3{\pm}4.63$ years old without any other medical or obstetric problems. Infants` Apgar scores and birth weights were decreased by above 3 cups per day of coffee consumption during pregnancy. No relationships between coffee consumption during pregnancy and maternal serum lipid levels were observed. However, serum total cholesterol and LDL-cholesterol levels in infants` umbilical cord were significantly increased with increasing coffee consumption during pregnancy. In contrary to coffee consumption, alcohol drinking habits affected maternal serum lipid levels but not serum lipid levels in infants` umbilical cord blood. Coffee consumption during pregnancy increased caffeine concentration in infants` umbilical cord blood. These results suggest that caffeine from maternal consumption of coffee can easily pass to the fetus and significantly affect serum lipids levels in infants` umbilical cord blood rather than those in maternal blood.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.197-202
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• 2020

In this study, we investigate the effect of twenties female caffeine addiction on cardiorespiratory capacity. For this study, we divided 35 female students at H university into caffeine addict group(n=17) and none caffeine addict group(n=18). Measure maximal oxygen uptake, maximal energy consumption and METs using Cycle Ergometer to assess cardiac capacity. Measure peak inspiratory pressure, peak inspiratory flow rate, peak inspiratory capacity, average inspiratory pressure, average inspiratory flow rate, average inspiratory capacity using Power Breathe K5 to assess respiratory capacity. As a result, cardiac capacity showed a statistically significant decrease in maximal oxgen uptake and METs compared caffeine addict group to none caffeine addict group(p<.001). respiratory capacity showed a statistically significant decrease in peak inspiratory pressure(p<.05), peak inspiratory flow rate(p<.01), average inspiratory pressure(p<.01), average inspiratory flow rate(p<.01), compared caffeine addict group to none caffeine addict group. Combining the results of the study, we could see that caffeine addiction reduces the cardiorespiratory capacity in twenties female. Therefore, it could be used as a basis date to prevent caffeine addiction for twenties female.

• Journal of the Korean Dietetic Association
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• v.25 no.2
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• pp.115-128
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• 2019

This study evaluated the nutrient intake with increasing coffee consumption for 403 adults aged over 30 years in Korea. The 403 subjects were national health screening examinees, who visited Sahmyook Seoul Hospital's Comprehensive Check-up Center between 2017.11.01 and 2018.12.18. The subjects were asked to answer questionnaires covering a 24-hour recall fluid and dietary intake before the health examination. The research ethics council of Sahmyook University (2-7001793-AB-N-012019036HR) approved this study. Coffee consumption exceeding two servings daily was more likely in males, in those aged between 30 and 40 years, and in the smoking, drinking, non-exercise, non-breakfast groups compared to each counterpart. The correlation between the coffee consumption frequency and current nutrient density showed negative correlations in most micronutrients. The mean nutrient density decreased gradually with increasing coffee consumption (<1 serving daily, ${\leq}1{\sim}2$ servings daily, >2 servings daily) in the ANOVA analysis. Therefore, the progressive adverse health effects of excessive coffee consumption needs to be researched further, and a daily total caffeine limit should be suggested in education of the nation levels.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.367-377
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• 2016

Purpose: This study analyzed the degree of job stress and caffeine intake in workers in industrial positions in order to determine the relationships between job stress and caffeine intake. Methods: For this purpose, this study conducted a survey targeting 361 blue collar workers working for K manufacturing company, Gwangju. Results: The total score for job stress in subjects was $72.7{\pm}6.8points$/100points. According to job stress, subjects were categorized as follows: Q1 for the group who had the least stress; Q2 for the group who had little stress; Q3 for the group who had a lot of stress, and Q4 for the group who had the most stress. As for the effects of caffeine on health, 57.1% thought that caffeine is helpful and not harmful if taken properly while 17.3% responded that less caffeine consumption is better. Daily intake of caffeine according to stress was presented as: $172.0{\pm}85.3mg$ in Q1, $179.0{\pm}83.7mg$ in Q2, $187.9{\pm}81.4mg$ in Q3, and $214.2{\pm}147.3mg$ in Q4 (p < 0.05). The percentages of caffeine consumption compared to the daily safe limit in subjects were: $43.0{\pm}21.3$, $44.8{\pm}20.9$, $47.1{\pm}20.4$, and $53.6{\pm}36.8%$ in Q1, Q2, Q3, and Q4, respectively (p < 0.05). Adverse effects such as nausea or vomiting from caffeine were most common in Q4 (p < 0.05). Conclusion: As a result, higher stress in blue collar workers working for K manufacturing company was associated with more caffeine consumption. Groups with a lot of stress (Q4) consumed approximately 50% of daily safe limit of caffeine. Considering the results above, this study suggests that further research on more precise caffeine intake and its effects is needed.