The Relationship Between Heart Rate Recovery and Brain Natruretic Peptide in Patients With Chest Discomfort

BACKGROUND AND OBJECTIVES: The correlation between brain natruretic peptide (BNP) level and cardiac autonomic function has been studied in type 2 diabetic patients. However, there is limited data from patients with normal systolic function. We evaluated the association between heart rate recovery (HRR) representing autonomic dysfunction and three plasma BNP levels: pre-exercise, post-exercise, and change during exercise in patients with normal systolic function. SUBJECTS AND METHODS: Subjects included 105 patients with chest pain and normal systolic function. HRR was defined as the difference between the peak heart rate and the rate measured two minutes after completion of a treadmill exercise test. We measured plasma BNP levels before exercise, 5 minutes after completion of exercise, and during exercise (absolute value of difference between pre- and post-exercise BNP levels). RESULTS: Patients with abnormal HRR values (< or =24 beats for the first 2 minutes of HRR) had lower high-density lipoprotein, lower peak heart rates, and higher pre- and post-exercise BNP levels than patients with normal HRR values. The patients with coronary artery disease (CAD) had abnormal HRR. However, no significant differences were found between the two groups in terms of history of hypertension (HTN), diabetes, and peak systolic blood pressure (SBP) and diastolic blood pressure (DBP). HRR was significantly associated with pre-exercise BNP (r=-0.36, p=0.004) and post-exercise BNP (r=-0.27, p=0.006), but not BNP changes. Further, pre-exercise BNP levels showed a greater association with HRR than post-exercise BNP levels. CONCLUSION: HRR is independently associated with pre-exercise and post-exercise BNP levels, even in patients with normal systolic function.

Distribution of Serum Lipoprotein(a) Level and its Association with Other Risk Factors in Apparently Healthy Korean

BACKGROUND AND OBJECTIVES: Recent studies have demonstrated that lipoprotein (a) [Lp(a)] plays an important role in atherothrombogenesis and to be associated with an increased risk for cardiovascular disease. SUBJECTS AND METHODS: We evaluated the distribution of Lp (a) and its association with cardiovascular risk factors, by conducting a cross sectional survey of 14,516 apparently healthy Koreans. The study group consisted of 8,007 men and 6,509 women, aged 20 years and over. RESULTS: The mean, medium and 75th percentile Lp (a) levels were 20.1, 13.2 and 23.8 mg/dL, respectively. The distribution of Lp (a) was highly skewed toward a lower level. The Lp (a) level was positively associated with age (p<0.001) and low density lipoprotein (LDL)(p<0.001). The body mass index (BMI)(p=0.006), log (triglyceride)(p<0.001) and alcohol consumption more than 3 times per week (p<0.047) were inversely related to the Lp (a) level. However, no relationship was seen with smoking, gender, exercise, homeostatic model assessment-insulin resistance (HOMA-IR) and high sensitivity C reactive protein (hsCRP). CONCLUSION: The Lp (a) level was positively associated with age and low density lipoprotein (LDL). The body mass index (BMI) and log (triglyceride) were inversely related to the Lp (a) level. However, the association between Lp (a) and cardiovascular disease in the general Korean population should be confirmed via large scale prospective cohort studies.

Relationship between Heart Rate Turbulence and Heart Rate Variability in Korean Adults with Structurally Normal Heart

BACKGROUND AND OBJECTIVES: Heart rate variability (HRV) illustrates the autonomic integration of the heart. Depressed HRV has been proven to be associated with an increased risk of cardiac death, whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity and it was recently introduced as another noninvasive tool for risk stratification. The aim of this study was to determine the relationship between the HRT and HRV parameters in Korean adults with a structurally normal heart. SUBJECTS AND METHODS: We studied 61 adults (males: 31) who showed ventricular premature complexes on 24 hour Holter recording and who were found to have normal hearts on full noninvasive investigation. We calculated the mean heart rate (RR interval), the number of VPBs, the time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (To) and turbulence slope (Ts). RESULTS: Ts showed a strong correlation with the HRV parameters (LF/HF ratio: r=0.35, p=0.006; VLF: r=0.32, p=0.013; LF: r=0.27, p=0.035; SDNN: r=0.28, p=0.029; SDANN: r=0.32, p=0.012), but To showed no significant correlation with the HRV parameters. CONCLUSION: The HRT parameters, and especially Ts, correlate strongly with the HRV parameters; therefore, Ts should be considered as a parameter that reflects the overall cardiac autonomic tone.

Prevalence and clinical characteristics of microalbuminuria in Koreans: a population-based cross-sectional study / 대한내과학회지

BACKGROUND: Microalbuminuria (MA) is independent predictor of cardiovascular disease and it cause mortality regardless of the presence of diabetes (DM) and hypertension (HTN). However, few published studies on this topic have been reported in Korea. Therefore, we investigated the MA prevalence and relationship between MA, insulin resistance and cardiovascular risk factor. METHODS: A total of 5,915 (3,053 men and 2,852 women) health screen examinees were enrolled in this study. We measured the anthropometric and biochemical parameters of the atherogenic indexes. RESULTS: The MA prevalence was 7.7% in all participants. The prevalence of MA in the men and women was 9.5% and 5.7%, respectively. Elevated levels of serum fasting glucose, serum fasting insulin, HOMA index, total cholesterols, LDL cholesterol, TG, Body Mass Index (BMI) and the systolic and diastolic blood pressure were significantly associated with MA. The results of multiple logistic regression analysis about MA showed that frequent drinking, low BMI, newly diagnosed DM and elevated levels of HOMA index and blood pressure were significantly associated with MA prevalence. Also, excluding newly diagnosed diabetic and hypertensive subjects, the MA prevalence was 5.7% (6.9% in men, 4.7% in women) and in multiple logistic regression analysis, the MA prevalence significantly increased in the individuals with pre-HTN rather than in the normotensives. CONCLUSIONS: The MA prevalence was 7.7% in all subjects. Except the newly diagnosed diabetic and hypertensive subjects, it was 5.7%. The MA prevalence was significantly increased in the individuals with pre-HTN rather than in the normotensives and MA was related with insulin resistance.

Concordance/Discordance between Apolipoprotein B Levels and the Cholesterol Indexes

BACKGROUND AND OBJECTIVES: Apolipoprotein B (Apo-B) has been reported to be a better predictor of the coronary artery disease (CAD) than the cholesterol indexes. The aim of this study was to examine the concordance/discordance between the apolipoprotein B levels and the cholesterol indexes, and to assess the factors affecting the discordance. SUBJECTS AND METHODS: A total of 11,816 participants (6,965 men and 4,851 women) were enrolled in this study from all the individuals who participated in medical screening examinations at the health promotion center in Kangbuk Samsung Hospital from January to December 2002. All the participants had no history of coronary artery disease. We assessed the concordance between the biochemical parameters of the atherogenic indexes, and we evaluated the factors affecting the discordance. RESULTS: Despite the fact that the Apo-B and the various cholesterol indexes were highly correlated, the concordance rate was merely 47-56%. Multinomial logistic regression analysis showed the possibility of an increased risk for the group of discordance in whom Apo-B level was disproportionately higher than LDL cholesterol in the elderly, the smokers, the men and the people having a larger waist circumference, a lower total cholesterol level, a higher triglyceride level and a higher HDL-C level. CONCLUSION: The measurement of apo B, along with the measurement of the standard lipid profile, could be a great help in evaluating the CAD risk and for aiding in the treatment of dyslipidemia in the elderly, the smokers, men and the people having a larger waist circumference, a lower total cholesterol level, a higher triglyceride level and a higher HDL-C level.

Assessment of Factors Influencing Plasma BNP Level in Patients with Chronic Atrial Fibrillation and Preserved Left Ventricular Systolic Function

BACKGROUND AND OBJECTIVES: Several studies have reported that Brain Natriuretic Peptide (BNP) were increased in patients with chronic atrial fibrillation (AF). The objective of this study was to assess the factors influencing plasma BNP levels in patients with chronic AF and preserved left ventricular (LV) systolic function. SUBJECTS AND METHODS: Transthoracic echocardiography was performed in 55 patients (25 men, 30 women; mean age 66.6+/-11.5 years) with chronic AF. At the same time, plasma BNP was measured with a Triage(r) kit (Biosite, San Diego, California). RESULTS: Women, long duration of AF and hypertension were more prevalent in the highest quartile group of BNP levels than in the lowest quartile group of BNP levels. Significant correlations were observed between plasma BNP levels and the following: mitral E velocity (r=0.339), mitral annular E'-velocity (r=-0.396), ratio of mitral E-velocity and mitral annular E' velocity (r=0.473), left atrium (LA) size (r=0.648), LA volume index (r=0.744), right atrium (RA) volume index (r=0.554), maximal velocity (Vmax) of mitral regurgitation (MR) (r=0.444), tricuspid regurgitation (TR) Vmax (r=0.544), MR grade (r=0.431), TR grade (r=0.427) and LV mass index (r=0.570). In stepwise multiple linear regression analysis, LA volume index (beta=0.299, p=0.014), LV mass index (beta=0.404, p<0.001) and duration of AF (beta=0.488, p<0.001) independently predicted plasma BNP levels in this study subjects. The patients with increased LA volume index exhibited longer duration of AF, larger RA volume index and LV mass index, higher MR Vmax, TR Vmax, MR and TR grade and plasma BNP level. CONCLUSION: LA volume index, LV mass index and duration of AF were independent predictors of plama BNP level in patients with chronic AF and preserved LV systolic function.

Effect of Exercise on Serum C-Reactive Protein

BACKGROUND AND OBJECTIVES: Regular exercise protects us against numerous chronic diseases, and reduces the risk of cardiovascular disease. Also, C-reactive protein, a marker of inflammation, is known to be associated with the risk and prognosis of cardiovascular disease. The present study was designed to assess the effects of regular exercise on the level of high sensitive C-reactive protein (hsCRP). SUBJECTS AND METHODS: The serum level of hsCRP and the anthropometric indices of adiposity, metabolic variables, blood pressure (BP) and several cardiovascular risk factors were measured in 18445 subjects. A prospective study of 42 subjects with high baseline levels of hsCRP was conducted. After 3 months of regular aerobic exercise their hsCRP levels were rechecked and the association between regular exercise and hsCRP analyzed using a cross sectional and prospective study. RESULTS: Age, smoking, hypertension, diabetes and body mass index were found to be independent determinants of an elevated hsCRP level, but exercise was not found to be associated with a decreased hsCRP level in the cross-sectional study. In the prospective study, the mean serum hsCRP value was significantly reduced after 3 months in the exercise group (3.02+/-1.06 vs. 2.05+/-1.23 p=0.015), but not in the controls (3.03+/-1.09 vs. 2.57+/-1.11 p=0.104). However, the interval changes in hsCRP levels were not different in the exercise compared to the control group (p=0.660). CONCLUSION: These results suggest that exercise is not an independent determinant of the CRP level. Three months of regular aerobic exercise show a tendency to be associated with a reduction in the hsCRP level, but this putative effect of exercise on the hsCRP level was not significant in healthy subjects. Further larger sample, prospective cohort studies will be required to establish the effect of exercise on the hsCRP level.

Relationship between Heart Rate Reduction and Insulin Resistance in Normoglycemic Individuals

BACKGROUND AND OBJECTIVES: It is well known that, regardless of whether a person has cardiovascular diseases, the reduction of heart rate after exercise reflects the impairment of the autonomic nervous system. It is also a predictive factor of death rate and it correlates to insulin resistance. Therefore, we assessed these correlations in normoglycemic subjects. SUBJECTS AND METHODS: Exercise stress testing was performed according to the Bruce protocol. Anthropometric indices of adiposity, metabolic variables, blood pressure (BP) and several cardiovascular risk factors were measured. The HOMA index was used as the insulin resistance, and the impairment of the autonomic nervous system was assessed by measuring the reduction of heart rate for 2 minutes after the cessation of exercise. RESULTS: The reduction of heart rate during 2 minutes after the cessation of exercise statistically correlated with the HOMA index, gender, age, body mass index, the waist circumference, heart rate during rest, the maximum heart rate, serum total cholesterol concentration, serum high density lipoprotein cholesterol concentration and serum low density lipoprotein cholesterol concentration, (p<0.05). However, on multiple regression analysis, the HOMA index, gender, heart rate during rest, and the maximum heart rate significantly correlated to the reduction of heart rate during 2 minutes after the cessation of exercise. CONCLUSION: In individuals with normal serum glucose levels, even after adjustment was made for other factors, the reduction of heart rate after the cessation of exercise correlated to insulin resistance. Hence, in individuals with normal serum glucose levels, efforts to improve insulin resistance have to be made, and prospective study on this subject is required.

Seasonal Variation in Insulin Resistance in Koreans

BACKGROUND AND OBJECTIVES: There is a seasonal variation in the incidence of diabetes mellitus and cardiovascular disease. Insulin resistance is important in the development of both non-insulin dependent diabetes mellitus (Type II DM) and cardiovascular disease. Hyperinsulinemia, induced by an insulin resistant state, causes the development of a chronic inflammatory response in vascular structures, which is one of the main causes of cardiovascular disease. There have been several studies on seasonal variation in insulin resistance. Therefore, seasonal variation in insulin resistance were investigated to discover if any relationship existed. SUBJECTS AND METHODS: Korean people examined at a health care center were included. The subjects were divided into four groups, according to the season, and a homeostasis model assessment index (HOMA) calculated, as an indicator of insulin resistance, and compared between the groups. RESULTS: Using the homeostasis model assessment, the highest insulin resistance was observed during winter. Also, the body mass index and waist-hip ratio were highest during winter. CONCLUSION: Compensating for other metabolic factors (age, gender, body mass index, waist-hip ratio and season), insulin resistance was still found to be higher during winter. Seasonal variation in insulin resistance can be associated with the incidence of DM or cardiovascular disease. Therefore, a prospective study will be needed.

The Relationship between Cardiovascular Risk Factors and the Serum Ferritin Level in Relation to C-Reactive Protein in Korean

BACKGROUND AND OBJECTIVES: Iron is a key component in the production of oxidized low density lipoprotein (LDL), which increases cardiovascular disease through inflammation. However, there is little data to suggest that oxidative stress is positively correlated with C-reactive protein (CRP). The purpose of this study was to examine the influence of the serum ferritin level and cardiovascular risk factors on CRP in a Korean population. SUBJECTS AND METHODS: A total of 808 subjects (465 men, 343 women), who had undergone a medical check-up at the health promotion center at Kangbuk Samsung Hospital, between September 2002 and November 2002, were included in this study. Logistic regression models were computed using elevated or nonelevated hsCRP, as dependent variable, with cardiovascular risk factors, such as, serum ferritin, total, LDL and HDL cholesterols, controlling for potential confounders, including age, gender, body mass index (BMI), hypertension, diabetes and smoking. RESULTS: Significant positive correlations were found between hsCRP and age, BMI, triglyceride and the level of serum ferritin, with a negative correlation found between hsCRP and HDL cholesterol. In age, gender, BMI, hypertension, diabetes, a smoking-adjusted model, an elevated ferritin level were not significantly associated with elevated hsCRP in low LDL subjects (OR=1.68, 95% CI=0.81-3.48), but significant associations were observed in high LDL subjects (OR=11.21, 95% CI=1.14-110.27). And we observed the significant effect modification of the association of hsCRP with serum ferritin level by LDL-cholesterol (p=0.002). CONCLUSION: Our results suggest that increased LDL cholesterol and ferritin have an effect on the increment of hsCRP. Thus, iron-catalyzed oxidation of LDL cholesterol may be an important step of the development of the inflammatory process. Further prospective studies will need to be performed to establish the relationship between the decreasing of the serum ferritin level and CRP for the prevention of cardiovascular disease.

Serum C-Reactive Protein Level and its Association with Atrial Fibrillation in Korean Adults

BACKGROUND AND OBJECTIVES: Recent studies have implicated inflammation as playing an important role in the occurrence, persistence and recurrence of atrial fibrillation and that C-reactive protein is a useful marker of the inflammation. The purpose of this study is to evaluate the association between serum CRP levels and the risk of atrial fibrillation. SUBJECTS AND METHODS: This study was performed on 9,487 subjects (5,263 men and 4,224 women; mean age: 58.8+/-6.6 years) who underwent medical check-ups at the Health Promotion Center in Kanbuk Samsung Hospital. 9,438 normal control subjects and 49 atrial fibrillation patients were included in the study. The CRP was measured using a highly sensitive Behring Nephelometer II. RESULTS: When comparing the two groups, there were significant differences in age, gender and the presence of hypertension and cerebrovascular accident, and these are the previously known risk factors for atrial fibrillation. After adjustment was made for the clinical significant variables of atrial fibrillation, multiple regression analysis revealed that the hsCRP levels were not associated with the risk for atrial fibrillation (p=0.52). CONCLUSION: The inflammatory markers (CRP, WBC count) were not predictive of a higher risk for atrial fibrillation in the Korean population.

The Relationship of the Hypertension, Insulin Resistance, and Metabolic Syndrome in the Serum Uric Acid Level

BACKGROUND AND OBJECTIVE: The relationship between serum uric acid and metabolic syndrome variables has not been reported in Korea. Therefore, whether the circulating levels of serum uric acid are independently related to hypertension, insulin resistance and the variables of metabolic syndrome were assessed. SUCJECTS AND METHODS: A total of 53,477 health screen examinees were enrolled and divided into four groups (Quartile 1:6.29 mg/dL) according to their serum uric acid level. The blood pressure, lipid profiles, fasting plasma glucose, waist circumference, HOMA, high sensitivity CRP and apolipoprotein were compared between the four groups. RESULTS: There was a positive association between blood pressure and the serum uric acid level (p<0.001). After adjustment for covariates the prevalence of hypertension due to uric acid was 1.192 (95% CI, 1.038-1.368 p=0.013), and 1.408 (95% CI, 1.221-1.623 p<0.001) times higher in subjects in the third and fourth uric acid level quartiles, respectively, compared to the subjects in the first quartile. Insulin resistance and metabolic syndrome variables were positively correlated with the serum uric acid level. The number of metabolic syndrome variables was also increased with an elevated serum uric acid level. CONCLUSION: Our study suggests that serum uric acid levels were independently associated with hypertension, insulin resistance and the variables of metabolic syndrome in the Korean population. Although the serum uric acid level was normal value, the risk of metabolic syndrome was increased with an elevated serum uric acid level. However, because of the cross-sectional nature of our study, these findings should be confirmed in prospective cohort studies.

Associations between White Blood Cell Count and Features of the Metabolic Syndrome

BACKGROUND AND OBJECTIVES: The proinflammatory state is considered to be a risk factor for develop atherosclerosis. Recently, certain components of the metabolic syndrome have been related to inflammatory markers. The purpose of this study was to assess the association of white blood cell (WBC) count with different components of the metabolic syndrome (MS). SUBJECTS AND METHODS: We performed this study to investigate the relationships of white blood cell count, uric acid, and C-reactive protein (CRP) to components of metabolic syndrome (MS), such as abdominal obesity, elevated triglyceride, low high-density lipoprotein cholesterol (HDL), high blood pressure, and impaired fasting glucose in 3134 koreans. RESULTS: WBC count, uric acid, and CRP were associated with several components of MS. WBC count increased, as did the number of MS. CONCLUSION: Our data suggests an association between the metabolic syndrome and WBC count.

The Effect of Systemic Inflammation on the Elevation of Troponin I after Percutaneous Transluminal Coronary Angioplasty with Stent in Patients with Stable Angina

BACKGROUND AND OBJECTIVES: There is growing evidence that inflammation plays an important role in atherosclerosis and in the elevation of cardiac troponin I (cTnI) after coronary intervention. The aim of this study was to evaluate the relationship between inflammatory markers and the elevation of cTnI after coronary intervention in patients with stable angina. SUBJECTS AND METHODS: Twenty-three patients who underwent successful percutaneous transluminal coronary angioplasty with stent were examined as the subjects. Serial blood samples were obtained for High Sensitivity C-reactive protein (hs-CRP), which served as markers of systemic inflammation, and cTnI. The difference of cTnI before and 24 hours after coronary intervention was defined as the gradient of cTnI. RESULTS: The mean gradient of cTnI was 1.77+/-3.4 ng/mL. The concentrations of baseline and post-procedural hs-CRP were 1.57+/-1.3 mg/L and 6.31+/-3.8 mg/L, respectively (p=0.001). There were no significant differences in the gradient of cTnI with hypertention, diabetes, smoking, and hypercholesterolemia. The variable that significantly correlated with the gradient of cTnI was the baseline hs-CRP (R2=0.374, p=0.048). CONCLUSION: Systemic inflammation correlated with periprocedural elevation of cTnI in stable angina patients. These results suggest that inflammation plays a pivotal role in the predictive value of myocardial injury after coronary intervention.

Relationship between Peripheral Leukocyte Count and the Severity of Stable Angina Determined by Coronary Angiography

BACKGROUND: Inflammation has been demonstrated to be an important risk factor for the development of cardiovascular disease (CVD). The relationship of the peripheral leukocyte count to the severity of stable angina remains to be clarified. The present study analyzed the relationship of the peripheral leukocyte count to the severity of stable angina determined by coronary angiography. METHODS: The data from 108 patients with stable angina, and 92 subjects with normal coronary angiograms were reviewed, and the role of the peripheral leukocyte count as a risk factor for stable angina evaluated. In addition, the correlation of the peripheral leukocyte count and the severity of stable angina, as assessed by the Gensini's score in the stable angina group, were analyzed. RESULTS: Age, the prevalence of hypertension and diabetes, and the fasting blood sugar were significantly higher, and the HDL was lower in the stable angina than the control group. A multivariate analysis showed that a peripheral leukocyte count over 6, 800/mm3 was an independent variable, but with no statistical significance (p=0.067), and diabetes (OR=3.02, 95% CI: 1.29~7.02) and old age (OR=3.62, 95% CI: 1.33~9.87) were independent risk factors for stable angina. A positive correlation between peripheral leukocyte count and Gensini's score was noted in the stable angina group even after adjusting for age, fasting blood sugar, blood pressure and lipid profiles (R2=0.198, p=0.015). CONCLUSION: An increased peripheral leukocyte count is considered not so much an indicator of the pathogenesis of stable angina, but as a predictor for disease progression. Furthermore, it is considered that the above correlation will be helpful in screening high-risk groups that require relatively active interventional therapy.

Insulin resistance and apolipoprotein B as a metabolic syndrome risk factor in normal glucose tolerance / 대한내과학회지

BACKGROUND: Insulin resistance is associated with greatly increased risk of coronary artery disease. Serum apolipoprotein B and the ratio of apo A-1/Apo B are important markers of the coronary artery disease. The aim of this study was to assess the association of serum apolipoprotein B and the ratio of apo A-1/Apo B with insulin resistance in normal glucose tolerance. METHODS: From individual, who participated in medical screening at health promotion center in Kangbuk Samsung Hospital from Jan. to Dec. 2002, total 7427 participants (4356 men, 3071 women) were enrolled in this study. All participants was no personal history of diabetes and normal fasting glucose. We assess the clinical characteristics and biochemical parameters of subjects. RESULTS: Apolipoprotein B, total cholesterol/HDL-C and LDL-C/HDL-C show an positive correlation with metabolic syndrome and insulin resistance (p<0.001). Apo A-I, Apo A-I/Apo B, LDL/Apo B and HDL/Apo A-I show an negative correlation with metabolic syndrome and insulin resistance (p<0.001). CONCLUSION: These data suggest that insulin resistance are associated with serum apolipoprotein B and the ratio of apo A-1/Apo B in normal glucose tolerance. And early diagnosis and tight control of insulin resistance in normal glucose tolerance should be administered for the prevention of coronary artery disease.

Hepatitis B virus infection and its relation to cardiovascular risk factors such as lipid profile, hsCRP in Korean adults / 대한내과학회지

BACKGROUND: Among the recent advances in understanding atherogenesis, the "infection hypothesis" is one of the most compelling but remains controversial. Recent experimental and epidemiologic findings suggest that some infectious agents play a role in the development and promotion of atherosclerosis. But very few data are available on the relation between HBV infection and atherosclerosis. We have investigated the possible association between hepatitis B virus surface antigen (HBsAg) positivity and cardiovascular risk factors including hsCRP in healthy Korean adults. METHODS: In 48,423 healthy subjects, the proportion of seropositive subjects for HBsAg and its association with cardiovascular disease risk factors were evaluated in participants in health screening program. Hepatitis B virus infection status was tested with HBsAg test with IRMA (immunoradiometric method) and serum lipid profiles, hsCRP were tested. RESULTS: Of the 48,423 study subjects, 4.5% were positive for HBsAg, indicating that they were hepatitis B virus carriers. In male, HBsAg positive group showed higher mean values for high density lipoprotein (HDL) and lower values for triglycerides, low density lipoprotein (LDL), total cholesterol. They were statistically significant (p<0.001). In female, HBsAg positive group showed higher mean values for high density lipoprotein (HDL) and lower values for triglycerides (p<0.001). In multivariate analysis of covariance (MANCOVA), adjusted by age and other variables, triglyceride, total cholesterol and low density lipoprotein were inversly associated with HBsAg seropositivity in male while only triglyceride and total cholesterol were inversly associated in female. HBsAg seropositivity and other risk factors including hsCRP level which is markers for inflammation were not correlated(p=0.055, p=0.074). CONCLSUION: The result of this study suggest no significant association between hepatitis B infection and hsCRP which is markers for inflammation but possible association with some cardiovascular risk factors such as triglyceride, total cholesterol, HDL, and LDL. Relationship between HBV infection and atherosclerosis has no definitive answer and is disputed issue therefore should stimulate the initiation of further studies to determine whether hepatitis B virus is indeed a causative factor in atherogenesis.

B-Type Natriuretic Peptide Blood Concentrations in Differential Diagnosis of Dyspnea and its Association to 6 Minute Walk

BACKGROUND AND OBJECTIVES: This study was performed to, 1) evaluate the diagnostic value of the Brain Natriuretic Peptide (BNP), which is known to be present in the heart ventricle, for patients with dyspnea for the assessing its causes;diastolic or systolic heart failure or pulmonary disease, and 2) find if the BNP is correlated with the distance walked in 6 minutes, which is known to be a prognostic indicator for heart failure. SUBJECTS AND METHODS: Fifty-seven patients who admitted to the Kangbuk Samsung Medical Center, with the chief complaint of dyspnea, were enrolled in the study. The subjects were classified into three groups according to the causes of their dyspnea, which were systolic heart failure, diastolic heart failure and chronic obstructive pulmonary disease. The plasma BNP levels were measured by a radioimmunoassay, both at admission and discharge. The BNP levels at admission were compared among the three groups. The presence of a correlation between the distance walked in 6 minutes and the BNP at discharge were also evaluated. RESULTS: The patients group with systolic heart failure had the highest mean BNP concentration of 934.6+/-386.7 pg/mL. The other two groups had significantly lower levels of BNP. The patients group with chronic obstructive pulmonary disease had significantly lower level than the group with diastolic heart failure (33.2+/-25.6 vs. 181.8+/-222.2 pg/mL). The BNP concentrations at discharge, and the distance walked in 6 minutes, between the three groups showed no statistical significance (p=0.69). CONCLUSION: This study showed that the mean plasma BNP level was highest in the group with systolic heart failure, followed by diastolic heart failure and lastly chronic obstructive pulmonary disease. These findings suggest that diagnostic value of the plasma BNP concentration in the assessment of the causes of dyspnea. Although this study has failed to show a correlation between the plasma BNP concentration at discharge and the distance walked in 6 minutes, prospective cohort studies, with larger sample sizes, need to be performed to establish the relationship, if any.

Sex difference in the relationship between insulin resistance and QTc interval in Korean non-diabetic subjects / 대한내과학회지

BACKGROUND: Men with prolonged corrected QT interval (QTc) are at increased risk for cardiovascular mortality and sudden death, even in healthy person. Also prolonged QTc predicts the mortality in diabetic persons. However the relationship between insulin resistance and QTc is not well known in healthy people without diabetes. This study was performed to observe the association between QTc and insulin resistance in Korean non-diabetic subjects. METHODS: Total 874 subjects (520 men, 354 women, mean age 45.9+/-11.0 years) who underwent medical check-up at health promotion center in Kangbuk Samsung Hospital from January 2002 to May 2002 were included in this study. Age, sex, height, body weight, blood pressure, blood cholesterol, triglyceride, HDL cholesterol, fasting insulin, and fasting glucose levels were measured. QT intervals were corrected with Bazett's formula (QTc=QT/ RR). HOMA (Homeostasis model assessment) were calculated in order to assess the correlations between insulin resistance indices and QTc interval. RESULTS: The means of QTc intervals were significantly longer in females (417.0+/-24.0 msec) compared to males (402.4+/-22.7 msec)(p<0.001). Significant positive correlation were found between QTc and age, glucose, blood pressure in male subjects. There were a positive correlation between QTc and age, glucose, blood pressure, blood chlesterol, LDL-cholesterol, triglyceride, fasting insulin, HOMA index and negative correlation between QTc and HDL-cholesterol in female subjects. With multiple regression analysis, age (beta=0.480, p<0.001) and diastolic blood pressure (beta=0.280, p<0.001) were predictors of QTc in men, age (beta=0.321, p=0.008), diastolic blood pressure (beta=0.324, p=0.006) and HOMA index (beta=3.508, p=0.033) were predictors of QTc in women. CONCLUSION: This study shows that QTc was more prolonged in female than in male among Korean healthy persons. In normoglycemic female subjects, there was correlation between insulin resistance and the prolongation of QTc.

Thyroid Dysfunction and Their Relation to Cardiovascular Risk Factors such as Lipid Profile, hsCRP, and Waist Hip Ratio in Korea

BACKGROUND: Thyroid abnormalities affect a considerable portion of the population, and overt hypothyroidism is associated with an elevated risk of cardiovascular disease and adverse changes in blood lipids. Subclinical hypothyroidism is also associated with an increase risk of cardiovascular disease. So, we undertook this study to investigate the prevalence of overt and subclinical thyroid disorders and their associations with cardiovascular risk factors. METHODS: This study involved 66260 subjects (43588 men, 22672 women ; between 20~80 years of age, mean age 41.5 +/- 9.6). Serum free thyroxine (FT4), thyroid stimulating hormone (TSH), total cholesterol, low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C) were measured by RIA using commercial kits. High sensitivity C-reactive protein (hsCRP) levels were determined by nephelometry. RESULTS: The prevalences of overt thyrotoxicosis, subclinical thyrotoxicosis, overt hypothyroidism and subclinical hypothyroidism were 5/1000 (334 subjects), 6.4/1000 (426 subjects), 1.6/1000 (108 subjects), and 6.4/1000 (375 subjects). Mean plasma total cholesterol and LDL-C were elevated in overt hypothyroidism than in normal controls (202.1 mg/dL and 121.8 mg/dL versus 197.1 mg/dL and 120.1 mg/dL, respectively) (p< 0.05). In subclinical hypothyroidism, mean total cholesterol and LDL-C levels were also elevated (201.9 mg/dL and 123.7 mg/dL) (p=0.015, p=0.047). Waist-to-hip ratio (WHR) was lower in overt thyrotoxicosis and higher in hypothyroidism. CONCLUSION: The prevalence of thyroid dysfunction in Korea is not significantly different from that reported by other countries. It was also age dependent and higher in women, but this elevation in women was lower than expected. Patients with hypothyroidism exhibited higher waist-to-hip ratios, an index of obesity. Patients with subclinical hypothyroidism exhibited elevated atherogenic parameters (Total cholesterol, LDL-C). Therefore screening and treatment for subclinical hypothyroidism may be warranted due to its adverse effects on lipid metabolism.