Relationship Between Asymptomatic Hyperuricemia and the Hypertriglyceridemic-Waist Phenotype in Korean Adults: A Cross-Sectional Study.

Purpose: Visceral fat accumulation can negatively affect uric acid metabolism in healthy adults. The hypertriglyceridemic-waist (HTGW) phenotype is a predictor of diabetes and cardiometabolic risk. This study aimed to investigate the association between the HTGW phenotype and asymptomatic hyperuricemia in Korean adults. Patients and Methods: The study included 23,240 adults, aged 20-80 years who underwent comprehensive health examinations at a general hospital in Gyeonggi Province, Korea, from January 2020 to December 2022. The HTGW phenotype was defined as the simultaneous presence of elevated serum triglyceride (TG) levels and increased waist circumference (WC). The diagnostic capability of the HTGW phenotype for hyperuricemia and its association with the condition were assessed using the receiver operating characteristic (ROC) curve and logistic regression analysis. Results: The prevalence of hyperuricemia in the HTGW phenotype was 3.44 times higher than that in the normal TG normal waist (NTNW) phenotype. Compared with those in the NTNW group, the hazard ratios for developing hyperuricemia in the HTGW group were 2.887 (2.566-3.249, P <0.001) for men and 7.341 (5.139-10.487, P <0.001) for women, and these values remained significant after adjusting for potential confounders. The stratified analysis revealed that the HTGW phenotype, coupled with diabetes, had the highest probability of developing asymptomatic hyperuricemia (2.55 times). ROC curve analysis revealed that the area under the curve values of the WC*TG index for hyperuricemia diagnosis were 0.702, 0.627, and 0.685 for all participants, men, and women, respectively. Conclusion: Among Korean adults, the HTGW phenotype was closely related to hyperuricemia in both men and women and showed a particularly strong association in patients with diabetes. It may be used in combination with an indicator that can complement its accuracy for identifying individuals at high risk of hyperuricemia.

Visceral Adiposity Index and Lipid Accumulation Product as Effective Markers of Different Obesity Phenotypes in Korean Adults: A Cross-Sectional Analysis.

Purpose: The visceral adiposity index (VAI) and lipid accumulation product (LAP) are useful for assessing visceral obesity. However, these indices were developed for Caucasians, and it is necessary to confirm whether the VAI and LAP are appropriate indicators for identifying obesity phenotypes in Asians. This study investigated whether the VAI and LAP are effective indicators for diagnosing four obesity phenotypes in South Korean adults. Patients and Methods: This cross-sectional study enrolled 23,310 adult participants (age ≥20 years) who had undergone a health checkup at a general hospital in Gyeonggi-do, South Korea from January 2017 to December 2020. VAI and LAP were calculated based on the presented mathematical model according to sex. According to the metabolic health status and presence or absence of obesity, the obesity phenotypes were classified into 4 groups: metabolically healthy non-obese (N=14,240, 61.1%), metabolically unhealthy non-obese (N=477, 2.0%), metabolically healthy obese (MHO; N=6796, 29.2%), and metabolically unhealthy obesity (MUO; N=1797, 7.7%). Results: The receiver operating characteristics curve analysis showed VAI best predicted MUO among the four obesity phenotypes, whereas the LAP showed excellent discriminating ability for the MUO group (area under the curve 0.877, 0.849, and 0.921 and 0.923, 0.907, and 0.954 for all participants, men, and women, respectively). The optimal VAI cutoff values for identifying the MUO group were 1.83 in men and 1.58 in women, and the optimal cutoff values for the LAP were 41.45 in men and 23.83 in women, with a higher value for men. After adjusting for potential confounding factors, the VAI and LAP were associated with an increased risk in the MHO and MUO groups among the obesity phenotypes in both sexes. Conclusion: In South Korean adults, the VAI and LAP are closely related to the MUO phenotype in both sexes and are effective indices for predicting the MUO phenotype.

Comparison of the differences in iron and anemia-related markers by ultramarathon distance.

BACKGROUND: Iron and anemia-related markers in long-distance runners have mostly been investigated following single distance marathons, with contradictory findings. This study compared iron and anemia-related markers according to marathon distance. METHODS: Iron and anemia-related markers were analyzed from blood samples of healthy, adult male (aged ≥40-60 years) long-distance runners before and after ultramarathon races of 100 km (N.=14), 308 km (N.=14), and 622 km (N.=10). Fe, total iron-binding capacity (TIBC), unsaturated iron-binding capacity (UIBC), transferrin saturation, ferritin, high-sensitivity C-reactive protein (hs-CRP), white blood cell (WBC), red blood cell (RBC), hemoglobin (Hb), and hematocrit (Hct) levels were analyzed. RESULTS: On completion of all races, the iron levels and transferrin saturation decreased (P<0.05), while the ferritin and hs-CRP levels and WBC counts significantly increased (P<0.05). The Hb concentrations increased after the 100-km race (P<0.05), although the Hb levels and Hct decreased after the 308- and 622-km races (P<0.05). The highest-to-lowest levels of unsaturated iron-binding capacity were found following the 100-km, 622-km, and 308-km races, whereas those of the RBC count were found following the 622-km, 100-km, and 308-km races. Ferritin levels were significantly higher following the 308-km race than after the 100-km race (P<0.05); hs-CRP levels in the 308- and 622-km races were higher than those in the 100-km race. CONCLUSIONS: Ferritin levels increased due to inflammation following distance races, and runners experienced transient iron deficiency without anemia. However, the differences in iron and anemia-related markers according to the ultramarathon distance remain unclear.

Association between thyroid hormone and components of metabolic syndrome in euthyroid Korean adults: A population-based study.

ABSTRACT: Thyroid dysfunction increases the prevalence of metabolic syndrome. However, the link between thyroid hormones and metabolic syndrome remains debatable, and the effect of sex on their relationship is not completely understood. To elucidate the relationship of thyroid hormones with metabolic syndrome and its components according to sex in euthyroid individuals in South Korea. Adult participants who underwent thyroid tests at our institution between January 2015 and December 2018 and had thyroid-stimulating hormone (TSH; 0.270-4.200 µIU/mL) and free thyroxine (FT4; 0.93-1.70 ng/dL) levels in the normal range were included. After correcting for age and body mass index, multiple linear regression was performed to assess the association of TSH and FT4 with metabolic syndrome and its components, and logistic regression was performed to estimate the risk of developing metabolic syndrome and its components according to different thyroid hormone quartiles. We included 12,478 men and 7,575 women in this study. The prevalence of metabolic syndrome was 9.68%. In men, TSH was positively associated with blood pressure and triglycerides, and the odds ratio for high blood pressure and hypertriglyceridemia was approximately 1.3 times higher in the fourth quartile than in the first quartile. FT4 associated positively with waist circumference, and a high odds ratio for abdominal obesity in the fourth quartile was observed in both men (odds ratio [OR], 1.239; 95% confidence interval [CI], 1.045-1.470) and women (OR, 1.302; 95% CI, 1.029-1.649). A negative association was found between FT4 and triglycerides, and concurrently, the odds ratios for hypertriglyceridemia were lower in the fourth quartile in both men (OR, 0.692; 95% CI, 0.619-0.774) and women (OR: 0.641; 95% CI: 0.512-0.803). In addition, a higher odds ratio for high blood pressure was observed in the fourth quartiles of FT4 and TSH in women. However, there was no association between TSH and FT4 levels and the onset of metabolic syndrome in either of the sexes. Serum TSH and FT4 levels were associated with different metabolic syndrome components in men and women, but there was no association with the onset of metabolic syndrome.

Usefulness Of Surrogate Markers Of Body Fat Distribution For Predicting Metabolic Syndrome In Middle-Aged And Older Korean Populations.

BACKGROUND: Obesity markers, the lipid accumulation product (LAP), visceral adiposity index (VAI), triglyceride and glucose (TyG) index, and waist-to-height ratio (WHtR) are useful for assessing the risk of obesity-related cardiovascular disease. However, no previous study has assessed the usefulness of these four indices as predictors of metabolic syndrome among middle-aged and older Korean populations. PURPOSE: To investigate the usefulness of LAP, VAI, TyG index, and WHtR as predictors of metabolic syndrome in middle-aged and older Korean populations. METHODS: This study included 15,490 male and female adults aged 40 years or older who underwent a medical check-up in a general hospital located in a Korean metropolitan area between January 2015 and December 2016. The diagnostic criteria for metabolic syndrome suggested by the American Heart Association/National Heart Lung and Blood Institute were used. LAP, VAI, and TyG index were computed based on the suggested mathematical models. WHtR was computed by dividing waist circumference by height. The independent sample t-test, one-way analysis of variance, Scheffe test, chi-square test, Pearson's correlation analysis, and logistic regression were used to analyze the data. RESULTS: LAP, VAI, TyG index, and WHtR were significantly related to metabolic syndrome in both sexes. Receiver operating characteristic curve analysis showed the following optimal cutoffs for LAP, VAI, TyG index, and WHtR: 33.97, 1.84, 8.81, and 0.51, respectively. After adjusting for latent confounding variables (age, systolic blood pressure, diastolic blood pressure, and waist circumference), LAP, VAI, TyG index, and WHtR were significantly correlated with metabolic syndrome. Area under the curve (AUC) values based on ROC curves showed that LAP, VAI, TyG index, and WHtR were reliable predictors of metabolic syndrome. LAP had the greatest AUC, suggesting that it was a more useful predictor than the other markers (AUC=0.917, 95% confidence interval: 0.913-0.922). CONCLUSION: LAP, VAI, TyG index, and WHtR are useful predictors of metabolic syndrome in middle-aged and older Koreans, but LAP had the greatest diagnostic accuracy.

Changes in hormone levels of participants in a 622-km ultramarathon race based on distance and recovery period.

BACKGROUND: Runners who participate in endurance sports such as marathons or ultramarathons have superior physical capabilities and health benefits compared to others. However, they may suffer long-term effects of the negative physiological changes during long-distance running. This study aimed to examine the effects of an ultramarathon on hormone levels, and the associated risks. METHODS: Ten participants who completed a 622-km ultramarathon were included. Blood was collected prerace, at the 300-km mark, the 622-km mark, and on the 3rd day of recovery (RD3) and the 6th day of recovery (RD6) and analyzed for human growth hormone (HGH), cortisol, beta-endorphin, serotonin, testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels. RESULTS: HGH and beta-endorphin showed the highest increase at the 300-km mark compared to prerace levels, with recovery on RD3 and RD6, respectively. LH, cortisol, and serotonin showed the highest levels of increase at the 622-km mark, with recovery on RD6 for LH, and RD3 for cortisol and serotonin. FSH showed the highest level of decrease at both 300-km and 622-km marks compared to prerace levels, with recovery on RD3. Testosterone decreased the most at the 300-km mark compared to the prerace level and this decrease was below the normal levels; however, it recovered to normal levels on RD3. CONCLUSIONS: Hormone levels after the 622-km ultramarathon were within their normal ranges, except for testosterone. However, all the hormones recovered to prerace levels on RD3 or RD6. This study showed that running ultramarathons does not cause abnormal hormone levels.

Effects of Long-Distance Running on Cardiac Markers and Biomarkers in Exercise-Induced Hypertension Runners: An Observational Study.

OBJECTIVE: To investigate changes of cardiac and muscle damage markers in exercise-induced hypertension (EIH) runners before running (pre-race), immediately after completing a 100-km ultramarathon race, and during the recovery period (24, 72, and 120 hours post-race). METHODS: In this observational study, volunteers were divided into EIH group (n=11) whose maximum systolic blood pressure was ≥210 mmHg in graded exercise testing and normal exercise blood pressure response (NEBPR) group (n=11). Their blood samples were collected at pre-race, immediately after race, and at 24, 72, and 120 hours post-race. RESULTS: Creatine kinase (CK) and cardiac troponin I (cTnI) levels were significantly higher in EIH group than those in the NEBPR group immediately after race and at 24 hours post-race (all p<0.05). However, lactate dehydrogenase (LDH), creatine kinase-myocardial band (CKMB), or CKMB/CK levels did not show any significant differences between the two groups in each period. N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were significantly higher in EIH group than those in NEBPR group immediately after race and at 24 and 72 hours postrace (all p<0.05). A high sensitivity C-reactive protein (hs-CRP) level was significantly higher in EIH group than that in NEBPR group at 24 hours post-race (p<0.05). CONCLUSION: The phenomenon of higher inflammatory and cardiac marker levels in EIH group may exaggerate cardiac volume pressure and blood flow restrictions which in turn can result in cardiac muscle damage. Further prospective studies are needed to investigate the chronic effect of such phenomenon on the cardiovascular system in EIH runners.

Comparison of Changes in Biochemical Markers for Skeletal Muscles, Hepatic Metabolism, and Renal Function after Three Types of Long-distance Running: Observational Study.

The purpose of this study is to compare changes in biochemical markers for the skeletal muscles, hepatic metabolism, and renal function based on extreme long-distance running.Among healthy amateur endurance athletes who participated in a marathon, 100 km-, or 308 km ultramarathon, 15 athletes with similar physical and demographic characteristics were chosen to be the subjects in this study, upon completion of each course. The subjects' blood was collected before and after the course to identify biochemical markers for the skeletal muscles, hepatic metabolism, and renal function.After all of the courses, creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine transaminase (ALT), blood urea nitrogen (BUN), and creatinine were found to be significantly increased compared with values obtained before the race (P <0.05 for each marker). CK, LDH, AST, and LDH were significantly higher after completion of the 100 km race than the marathon (P <0.05) and were significantly higher after the 308 km race than the marathon or 100 km race (P <0.05). Total protein was significantly lower after the 308 km race than the marathon or 100 km race (P <0.05). Albumin significantly increased after the marathon but significantly decreased after the 308 km course (P <0.05). Total and direct bilirubin were significantly increased after the 100 km and 308 km races (P <0.05), and were significantly higher after the 308 km than the marathon or 100 km course (P <0.05). BUN was significantly higher after the 100 km race than the marathon (P <0.05) and was significantly lower after the 308 km than the 100 km race (P <0.05). Creatinine was significantly higher after the marathon and 100 km than the 308 km race (P <0.05). Uric acid significantly increased after the marathon and 100 km race (P <0.05); it was significantly higher after completing the marathon and 100 km than the 308 km race (P <0.05).Muscular damage, decline in hepatic function, and hemolysis in the blood were higher after running a 308 km race, which is low-intensity running compared with a marathon, and a temporary decline in renal function was higher after completing a 100 km race, which is medium-to-high intensity.

Changes in the markers of cardiac damage in men following long-distance and ultra-long-distance running races.

BACKGROUND: The aim of this study was to compare pre- and postcompetition markers of cardiac damage in ultraendurance athletes. METHODS: All the subjects had blood samples collected before starting and immediately after completing the running race, in order to analyze CK, hs-CRP, cTnI, and NT-proBNP. RESULTS: Before starting the marathon, there were no differences between the groups for all of the tests. CK was significantly higher after the 308 km ultra-marathon than after the marathon and the 100 km ultra-marathon (P<0.001). In cTnI, the value after the 100 km ultra-marathon was significantly higher than that after the marathon and 308 km ultra-marathon, respectively (P<0.05, P<0.01). NT-proBNP was significantly higher after the 100 km and 308 km ultra-marathons than after the marathon (P<0.01, P<0.01). Hs-CRP was significantly higher after the 308 km ultra-marathon than after the marathon and the 100 km ultra-marathon (P<0.001). CONCLUSIONS: cTnI was expressed after marathon and the 100 km ultra-marathon, and NT-proBNP exceeding the upper reference limit (URL) was expressed in long-distance races such as the 100 km and 308 km ultra-marathons. The highest expression of cTnI and NT-proBNP exceeding the URL was in the 100 km ultra-marathon, which may be caused by a combination of the moderate intensity of the exercise and the long-running distance.

Correlation of Cardiac Markers and Biomarkers With Blood Pressure of Middle-Aged Marathon Runners.

Runners with exercise-induced high blood pressure have recently been reported to exhibit higher levels of cardiac markers, vasoconstrictors, and inflammation. The authors attempted to identify correlations between exercise-related personal characteristics and the levels of biochemical/cardiac markers in marathon runners in this study. Forty healthy runners were enrolled. Blood samples were taken both before and after finishing a full marathon. The change in each cardiac/biochemical marker over the course of the marathon was determined. All markers were significantly (P<.001) increased immediately after the marathon (creatine kinase-MB [CK-MB]: 7.9 ± 2.7 ng/mL, cardiac troponin I (cTnI): 0.06 ± 0.10 ng/mL, N-terminal pro-B-type natriuretic peptide (NT-proBNP): 95.7 ± 76.4, endothelin-1: 2.7 ± 1.16, high-sensitivity C-reactive protein [hs-CRP]: 0.1 ± 0.09, creatine kinase [CK]: 315.7 ± 94.0, lactate dehydrogenase [LDH]: 552.8 ± 130.3) compared with their premarathon values (CK-MB: 4.3 ± 1.3, cTnI: 0.01 ± 0.003, NT-proBNP: 27.6 ± 31.1, endothelin-1: 1.11 ± 0.5, hs-CRP: 0.06 ± 0.07, CK: 149.2 ± 66.0, LDH: 399 ± 75.1). In middle-aged marathon runners, factors related to increased blood pressure were correlated with marathon-induced increases in cTnI, NT-proBNP, endothelin-1, and hs-CRP. These correlations were observed independent of running history, records of finishing, and peak oxygen uptake.

The effects of running a 308 km ultra-marathon on cardiac markers.

The aim of this study was to investigate the expression of cardiac strain and damage in 18 male marathoners with average age of 52.8 ± 5.0 years running at a 308 km ultra-marathon. Blood samples were collected at pre-race, 100 km, 200 km and 308 km check points for the analysis of cardiac muscle injury markers, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), cardiac troponin I (cTnI) and cardiac muscle strain marker, N-terminal pro-brain natriuretic peptide (NT-proBNP). The CK levels increased 1127.2 ± 507.9 IU/L, 5133.8 ± 2492.7 IU/L and 4958.4 ± 2087.9 IU/L at 100 km, 200 km and 308 km, respectively, compared to the pre-race levels. The CK-MB levels increased 20.2 ± 11.2 ng/mL, 73.3 ± 35.6 ng/mL and 68.6 ± 42.6 ng/mL at 100, 200 and 308 km, respectively, compared to the pre-race levels. The CK-MB/CK ratio showed that the CK-MB mass index was within the normal range (<2.5%) at 100 km, 200 km and 308 km. The cTnI levels showed no significant difference in all check points. The NT-proBNP levels increased 146.55 ± 92.7 pg/mL, 167.95 ± 111.9 pg/mL and 241.23 ± 121.2 pg/mL at 100, 200 and 308 km, respectively, compared to the pre-race levels. The normal CK-MB mass index (<5.0 ng/mL) and the absence of an increase in the cTnI levels during the 308 km ultra-marathon suggested that no myocardial injury despite an elevation in CK-MB. The increase in NT-proBNP levels probably resulted from continuous hemodynamic cardiac stress and represents a transient physiological myocardial protective response.

Effects of six-week cardiac rehabilitation and exercise on adiponectin in patients with acute coronary syndrome.

BACKGROUND: Increased adiponectin is a result of an anti-arteriosclerotic effect and is related to the prevention of arteriosclerosis. However, it is uncertain whether cardiac rehabilitation and exercise (CRE) increase adiponectin in patients after acute coronary syndrome (ACS). AIM: To assess the effects of CRE intervention on adiponectin in patients after ACS. METHODS: Forty four patients participated in a cardiac rehabilitation programme after receiving percutaneous coronary intervention. The participants were divided into either an intervention (CRE) or a control (CON) group. Assessments were made at baseline and six weeks after the intervention for adiponectin, interleukin-6 (IL-6), tumour necrosis factor-a (TNF-a); high sensitivity C-reactive protein (hs-CRP), waist-to-hip ratio (WHR), and exercise duration. RESULTS: After six weeks of exercise training, adiponectin significantly increased in both CRE and CON (p < 0.001 and p = 0.009, respectively). Adiponectin showed a significantly greater increase in CRE than in CON (p = 0.032). Significant differences were not observed in IL-6, TNF-a, and hs-CRP between the groups. However, VO(2max) and exercise duration significantly increased in CRE (p < 0.001). Significant increases in VO(2max) and exercise duration were also observed in CRE but not in CON (p < 0.001). WHR significantly decreased in CRE, with no significant change in CON (p < 0.05). The difference in adiponectin between the groups showed a significantly inverse relationship with the difference in WHR (R² = -0.376, p = 0.034). CONCLUSIONS: Adiponectin and cardiopulmonary fitness were significantly increased in CRE after six weeks of intervention. Although reductions in inflammatory markers were not observed, a significant inverse correlation was observed between the changes in adiponectin and WHR in CRE. Therefore, six weeks of short-term CRE intervention had a significant anti-inflammatory effect.

Effect of a prolonged endurance marathon on vascular endothelial and inflammation markers in runners with exercise-induced hypertension.

OBJECTIVE: The aim of this study was to observe the changes in endothelial and inflammatory markers in middle-aged male runners with exercise-induced hypertension (EIH) at baseline and at 100-km, 200-km, and 308-km checkpoints during a prolonged endurance ultramarathon. DESIGN: Among a total of 62 ultramarathon volunteers, 8 with systolic blood pressure higher than 210 mm Hg and 8 with normal systolic blood pressure were selected for this study. The subjects were designated to EIH and control (CON) groups. Blood was collected for the analysis of soluble vascular cell adhesion molecule-1, soluble E-selectin, leukocytes, creatine kinase, and high-sensitivity C-reactive protein. RESULTS: Soluble vascular cell adhesion molecule-1 showed a significantly greater increase in the EIH group than in the CON group at 100 km and 200 km. Soluble E-selectin also showed a significantly greater increase in the EIH group than in the CON group at 100 km. Leukocytes significantly increased in the EIH group than in the CON group at 308 km. Creatine kinase and high-sensitivity C-reactive protein showed no group differences. CONCLUSIONS: Leukocytes, creatine kinase, and high-sensitivity C-reactive protein showed delayed-onset increases in both groups. Increased exercise intensity may stimulate greater endothelial responses independent of the inflammatory markers in EIH. The loss of a protective effect may be greater in those with EIH than in CONs. Acknowledging and prescribing proper exercise intensity may be critical in preventing possible vascular-related complications in runners with EIH.

Effect of Ultra-marathon (308 km) Race on Bone Metabolism and Cartilage Damage Biomarkers.

OBJECTIVE: To evaluate the potential effects of a 308-km ultra-marathon on bone and cartilage biomarkers. METHOD: Venous blood samples were collected at pre-race, 100 km, 200 km, and 308 km checkpoints. The following markers of cartilage damage and bone metabolism were studied: osteocalcin (OC), osteoprotegerin (OPG), and calcium, phosphorous, and cartilage oligomeric matrix protein (COMP). RESULTS: Blood samples were taken from 20 male runners at four different checkpoints. Serum COMP was increased by 194.1% (130.7% at 100 km and 160.4% at 200 km). Serum OPG was significantly increased by 158.57% at 100 km and 114.1% at 200 km compared to the pre-race measures. OC was transiently suppressed at 200 km. Serum calcium and phosphorous concentrations decreased compared to the pre-race measures. CONCLUSION: This study showed that the 308-km ultra-marathon induced several changes, including transient uncoupling of bone metabolism, increased bone resorption, suppressed bone formation, and bone turnover and had a major impact on cartilage structure.