Background
: Although caffeine is commonly consumed substance and not seriously harmful as compared to alcohol and nicotine, Korea is planning to mark on the products which contain caffeine above a definite level with "containing large amounts caffeine". At this point in time, the study concerning caffeine related symptoms is in need.

Methods : After surveying university students by using self-administered questionnaires based on DSM-IV substance related disorder, healthy 810 subjects were assessed for socio-demographic characteristics and features of caffeine intake and its dependence, withdrawal, and intoxication.

Results : The mean amount of caffeine consumption in 810 subjects was 120.49 mg (median=93.0) per day. The major features of caffeine dependence were as follows: tolerance (61.1%), withdrawal (46.3%), using more or longer than intended (46.0%), and unsuccessful attempt to cut down or control use (12.6%). The prevalence was increased by daily caffeine consumption. Among 711 subjects who had experienced no caffeine consumption over 24 hours {amount of daily caffeine consumption was 116.0 mg (median=86.5)}, 6.19% showed significant distress in usual activity, and 22.1% used caffeine contents to avoid withdrawal symptoms. The prevalence of caffeine withdrawal based on DSM-IV research criteria was 2.67% and the frequency for symptoms were as follows: fatigue (37.7%), drowsiness (17.6%), headache (14.5%), an anxiety (8.3%). In addition, the prevalence of caffeine intoxication was 2.1% and the frequency for symptoms were as follows: insomnia (41.9%), diuresis (35.8%), tachycardia (26.7%), and gastrointestinal disturbance (23.3%).

Conclusion : The unwanted symptoms related to caffeine withdrawal or intoxication were common in students using caffeine. Therefore, major features of caffeine-related symptoms should be considered in primary care practice.

Background
: Regular colorectal cancer (CRC) screening is known to reduce the CRC incidence and mortality. Health care providers can play a key role in recommending screening to healthy people. However, data on providers' CRC screening knowledge, attitude, and practice are sparse in Korea. We investigated primary care physicians' perception and performance of practice guidelines for CRC screening recommendations, and their view of barriers to physicians' adherence to guidelines.

Methods : A questionnaire was administered to 760 primary care physicians of internal medicine, general surgery, and family medicine in Seoul, Korea. The data were collected from March 2 to April 30, 2004, and those of 106 respondents (response rate 14%) were analyzed.

Results : Forty seven percent of respondents reported they recommended CRC screening. The most common screening test equipment in primary care settings was the fecal occults blood test (22.6%) followed by sigmoidoscopy (16.0%), colonoscopy (16.0%), and double contrast barium enema (10.4%). However, colonoscopy was recommended the most as a CRC screening method (54%) and only 43% of respondents complied with the interval indicated on the guidelines. Awareness (64.8%) and agreement (93.2%) to CRC screening recommendation by primary care physicians in Seoul, Korea was high, but the screening delivery was suboptimal. Many primary care physicians regarded patient-related factors were more important barriers of CRC screening than environment-related factors.

Conclusion : There were many barriers to physicians' guideline adherence. It may be useful to develop and improve guidelines in considerationt these barriers to establish appropriate cancer screening.

Background
: 'Masked Hypertension' is a phenomenon of blood pressure that is normotensive by clinic measurement but proves to be hypertensive by 24 hour-AMBP and is associated with many cardiovascular complications and its clinical importance has become the center of public interest. However, in Korea no study concerning masked hypertension has ever been published so far. We investigated the frequency and the related factors of masked hypertension among Koreans.

Methods : Overall, 53 volunteers from Incheon and Seoul, Korea, who were 40 years old and abov were enrolled from August 2003 to August 2004. We checked their blood pressure and pulse rate every hour using an ambulatory blood pressure monitoring device [SpaceLabs 90207] for 24 hours. Masked hypertension was defined as office mean BP less than 140/90 mmHg and daytime mean BP over 135/85 mmHg.

Results : Among the total, 15 subjects met the criteria of masked hypertension (28.3%) Current smoking (P=0.021), higher clinic mean SBP (P=0.011) and DBP (P=0.027), and prehypertension (P=0.04) were identified as related factors. And when adjusted for sex by logistic regression, only current smoking was statistically significant (P=0.039) and prehypertension showed borderline significance (P=0.092) (CI=95%). Additionally, mean pulse pressures and mean standard deviation of individual mean SBP were higher in the masked hypertension group.

Conclusion : The frequency of masked hypertension was 28.3% the and related factors were current smoking and higher office BP, especially prehypertension that was introduced in JNC-7. The fact that the pulse pressure and the variability of individual SBP were higher in the masked hypertension group remains thought-provoking.

Background
: Recently, inflammation has been associated with insulin resistance and the development of type 2 diabetes mellitus. We investigated the relationship between white blood cell (WBC) count and the incidence of hyperglycemia and the interactive effects of smoking and elevated WBC count on hyperglycemia.

Methods : We prospectively examined 6,734 Korean males without IFG (fasting plasma glucose concentration of ≥ 110 mg/dL) or type 2 diabetes mellitus from 1994 to 2002. We divided WBC counts into 4 groups: 2.9∼5.9 (reference quartile), 6.0∼6.9, 7.0∼8.1, 8.2∼16.5 (×10³ cells/μL), respectively. The odds ratios were calculated by multiple logistic regression according to WBC quartiles after adjusting for predictive risk factors of type 2 diabetes mellitus. Also the odds ratios were calculated after stratification according to smoking status.

Results : Compaired to reference quartile, the odds ratio for hyperglycemia was 1.09 (95% CI, 0.91∼1.30), 1.17 (95% CI, 0.99∼1.40), 1.34 (95% CI, 1.12∼1.60) (P value for trend=0.0009), respectively. And the odds ratio for IFG or type 2 diabetes mellitus was 1.08 (95% CI, 0.83∼1.42), 1.16 (95% CI, 0.89∼1.50), 1.28 (95% CI, 1.00∼1.65) (P value for trend=0.0395) among the current smoking group, respectively.

Conclusion : Our findings demonstrate that an elevated WBC count is associated with an increased risk of hyperglycemia, particularly in current and former smokers. These results support our hypothesis that inflammation increases the risk of hyperglycemia.

Background
: We conducted a cross-sectional survey to determine the associated factors with successful smoking cessation, longer than 1 year, as compared with current smokers who had made at least one attempt to quit in the past and failed.

Methods : Smokers and ex-smokers were randomly selected by stratification at three levels (geographic location of home, age and sex). Among the subjects were 97 ex- smokers who had stopped smoking longer than 1 year and 71 current smokers, who had made at least one prior attempt to quit. Nicotine dependence and number of the smokers in the 5 closest friends were measured.

Results : A high Fagerstrom score (OR=0.784; CI 0.667∼0.921) and the number of the smokers among their 5 closest friends (OR=0.681; CI 0.511∼0.909) were significantly associated with a relapse in smoking adjusting confounding factors such as age, sex, alcohol consumption and so on.

Conclusion : In Korean ex-smokers, lower nicotine dependence and the number of friends who smoked were associated factors in successful smoking cessation longer than 1 year.

Background
: Serum Gamma-glutamyltransferase (GGT) has been used clinically as a marker for excessive alcohol consumption or liver diseases, but it was reported recently that GGT is associated with cardiovascular disease. This study was done to verify the association between GGT and the metabolic syndrome in Korean male workers.

Methods : Total cholesterol, triglycerides, HDL cholesterol, body mass index (BMI), waist circumference, blood pressure, fasting glucose, uric acid, and GGT were measured and liver US was performed in 1,215 male workers who underwent annual health check up in a university health promotion center from May to October 2003. The association of GGT with the metabolic syndrome was assessed.

Results : The mean age of subjects was 41.9±7.2 years and the mean BMI was 24.1±2.7 kg/m². A raised GGT level (GGT＞75 IU/L) was seen in 172 of 1,136 (15.1%) and the prevalence of the metabolic syndrome was 9.9% (112/1,136). Individuals with the metabolic syndrome had a higher mean GGT concentration (53.4 IU/L) than individuals without the metabolic syndrome (34.4 IU/L; P＜0.001). The subjects with increased GGT showed more risk of metabolic syndrome than the subjects with normal GGT by multivariate analysis (OR=2.835). Subgroup analyses did not change the association between the GGT and the metabolic syndrome.

Conclusion : This study showed that the serum GGT was associated with the metabolic syndrome and that increased GGT was another feature of the metabolic syndrome.

Background
: This study was designed to evaluate the validity of the Cyriax's selective tension examination as a diagnostic tool in young male with shoulder pain compared to ultrasonographic findings.

Methods : Twenty young male patients with 26 shoulder pain cases were prospectively included in this study. All had a physical examination performed by Cyriax's selective tension method. As a diagnostic gold standard, ultrasonographic examination was carried out within one week of the physical examination by two specialists.

Results : The most common findings by sonographic evaluation were sub-deltoid bursitis (65.4%). Sub-deltoid bursal effusion without rotator cuff injury were 10 cases (58.8%) and 17 cases (41.2%) showed combined rotator cuff lesion. The most common diagnoses by physical examination were sub-deltoid bursitis (46.2%) followed by supraspinatus tendon lesion (19.2%). Clinical assessment by physical examination showed low sensitivity in the diagnosis of rotator cuff lesion (42.9%) and sub-deltoid bursitis (70.6%) but high sensitivity and specificity in the diagnosis of shoulder joint instability (sensitivity 100%, specificity 91.7%).

Conclusion : This study suggest that the validity of Cyriax's selective tension test for the diagnosis of shoulder pain are questionable.