Recent Advances in Anti-Aging Medicine

A rapidly aging population in Korea has led to increased attention in the field of anti-aging medicine. The purpose of anti-aging medicine is to slow, stop, or reverse the aging process and its associated effects, such as disability and frailty. Anti-aging medicine is emerging as a growing industry, but many supplements or protocols are available that do not have scientific evidence to support their claims. In this review, the mechanisms of action and the clinical implications of anti-aging interventions were examined and explained. Calorie restriction mimetics define compounds that imitate the outcome of calorie restriction, including an activator of AMP protein kinase (metformin), inhibitor of growth hormone/insulin-like growth factor-1 axis (pegvisomant), inhibitor of mammalian target of rapamycin (rapamycin), and activator of the sirtuin pathway (resveratrol). Hormonal replacement has also been widely used in the elderly population to improve their quality of life. Manipulating healthy gut microbiota through prebiotic/probiotics or fecal microbiota transplantation has significant potential in anti-aging medicine. Vitamin D is expected to be a primary anti-aging medicine in the near future due to its numerous positive effects in the elderly population.ope

U-Shaped Association Between Sleep Duration, C-Reactive Protein, and Uric Acid in Korean Women

Serum high-sensitivity C-reactive protein (hsCRP) and serum uric acid (SUA) are biomarkers that predict chronic inflammation and cardiovascular dysfunction. Therefore, we aimed to investigate the association between sleep duration, hsCRP, and SUA in Korean women. Cross-sectional data from the Seventh Korea National Health and Nutrition Examination Survey was analyzed. The odds ratio (OR) and 95% confidence intervals (CIs) for an association between higher hsCRP (>2.0 mg/L) or higher SUA (>5.6 mg/dL) and sleep duration were calculated using multiple logistic regression analyses after adjusting for potential confounders. In total, 6151 women were included in the analysis. There was a U-shaped relationship between continuous sleep duration, hsCRP, and SUA. Compared to those who slept for 7-8 h, the ORs (95% CIs) for higher hsCRP were 1.43 (0.95-2.16) in short sleepers and 1.64 (1.09-2.48) in long sleepers after adjusting for confounders. Compared with those who slept for 7-8 h, the ORs (95% CIs) for higher SUA were 1.54 (1.04-2.26) in short sleepers and 1.94 (1.27-2.96) in long sleepers after adjusting for confounders. We found a U-shaped association between sleep duration, hsCRP, and SUA in Korean women. 7-8 h sleep was associated with lower level of hsCRP and SUA in Korean women.ope

Association between oxidative balance score and new-onset hypertension in adults: A community-based prospective cohort study

Introduction: Oxidative stress plays a key role in the pathophysiology of hypertension development. The oxidative balance score (OBS) comprises dietary and lifestyle pro- and anti-oxidant components and reflects the overall oxidative stress burden. We aimed to evaluate the association between the OBS and new-onset hypertension (HTN) using large, community-based, prospective Korean cohort data. Methods: Among 10,030 participants aged 40-69 years included in the Korean Genome and Epidemiology Study, the data of 5,181 participants were analyzed. The hazard ratio (HR) and 95% confidence interval (CI) for new-onset HTN according to sex-specific OBS quartile groups were calculated using univariable and multivariable Cox proportional hazard regression analyses. Results: During the mean 13.6-year follow-up period, 1,157 men and 1,196 women developed new-onset HTN. Compared to the Q1 group, the adjusted HRs (95%CI) for new-onset HTN in the Q2, Q3, and Q4 groups were 0.96 (0.82-1.16), 0.85 (0.72-0.99), and 0.71 (0.59-0.86) in men and 0.81 (0.69-0.95), 0.81(0.68-0.95), and 0.70 (0.57-0.84) in women, respectively. Discussion: Individuals with high OBS are at lower risk of developing HTN. This study suggests that a healthy lifestyle and antioxidant rich diet could be a preventive strategy for HTN.ope

Relationship between Sedentary Time and Handgrip Strength in Healthy Korean Women: Korea National Health and Nutrition Examination Survey 2014-2016

Background: This study aimed to examine the association between sitting time and handgrip strength in healthy Korean women. Methods: A total of 5,437 participants were included from the Korea National Health and Nutrition Examination Survey 2014-2016. The overall daily sitting time was estimated using health interview surveys, and handgrip strength was assessed using a digital hand dynamometer. The relationship between sitting time and handgrip strength was calculated with a weighted analysis of covariance after adjusting for confounding variables. Results: Participants in each age group (19-39, 40-64, ≥65 years) were divided into three categories according to sitting time: ≤5, 6-9, and ≥10 h/d. The handgrip strength tended to decrease as sitting time increased after adjusting for age, body mass index, alcohol intake, cigarette smoking, resistance exercise, aerobic physical activity, household income, education level, hypertension, diabetes mellitus, dyslipidemia, and depression in all age groups (all P<0.001). Conclusion: We observed the inverse relationship between sitting time and handgrip strength in healthy Korean women.ope

Association between Relative Handgrip Strength and Insulin Resistance in Korean Elderly Men without Diabetes: Findings of the 2015 Korea National Health Nutrition Examination Survey

Background: Evidence regarding the association between handgrip strength (HGS) and insulin resistance in a non-diabetic population is scarce. This study aimed to investigate the association between relative HGS and insulin resistance in older men without diabetes, using a representative sample of the Korean male population. Methods: The study population comprised 206 participants aged 65-80 years, selected from the 2015 Korea National Health and Nutrition Examination Survey. Insulin resistance was defined as the upper tertile of the homeostatic model assessment of insulin resistance (HOMA-IR). Odds ratios and 95% confidence intervals for insulin resistance were assessed using multiple logistic regression analyses after adjusting for confounding variables. Results: The prevalence of insulin resistance decreased with increasing relative HGS. The prevalence in the T1, T2, and T3 groups was 46.0%, 32.2%, and 26.4%, respectively. Compared with the individuals in the highest tertile of relative HGS, the odds ratio (95% confidence interval) for insulin resistance in individuals in the lowest quartile was 2.82 (1.10-7.21) after adjusting for age, smoking, alcohol consumption, aerobic exercise, resistance exercise, systolic blood pressure, total cholesterol, residential area, household income, and education level. Conclusion: Lower relative HGS was inversely associated with an increased risk of insulin resistance in older Korean men without diabetes. In clinical practice, relative HGS, which is a simple and inexpensive tool, could be a useful measure for identifying older men with insulin resistance. Moreover, these findings suggest that muscle strengthening exercises should be considered to reduce insulin resistance and increase insulin sensitivity.ope

Triglyceride Glucose-Waist Circumference (TyG-WC) Is a Reliable Marker to Predict Non-Alcoholic Fatty Liver Disease

The triglyceride and glucose index (TyG index), a marker of insulin resistance, is positively associated with NAFLD. Modified TyG indices, combining body composition markers including body-mass index (BMI) or waist circumference (WC) with the TyG index, are reported to enhance predictability of insulin resistance. This study aimed to compare the usefulness of modified TyG indices for predicting NAFLD with the TyG index and fatty liver index (FLI). This cross-sectional study included 12,757 Korean adults. The TyG index and FLI were calculated using established formulas, and TyG-BMI and TyG-WC were calculated as TyG × BMI and TyG × WC, respectively. All measures were divided into quartiles. NAFLD severity (grade 0-3) was compared using ANOVA by quartiles of each index. Odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD were calculated using a multiple logistic regression analysis. ROC and AUROC analyses were performed to compare the predictability of NAFLD using WC, BMI, TyG, TyG-BMI, TyG-WC, and FLI. A higher TyG index, TyG-BMI, TyG-WC, and FLI were associated with a higher grade of NAFLD. ORs (CIs) for NAFLD increased in all indices, especially in TyG-WC (39.251 (31.304-49.215)) and FLI (38.937 (31.145-48.678)). AUROC was 0.848 (0.840-0.855) for TyG-WC and 0.850 (0.842-0.857) for FLI. TyG-WC is a reliable indicator for the presence of NAFLD in Korean adults.ope

Association of optimal blood pressure with mortality in patients taking antihypertensive medications

We investigated the relationship between blood pressure (BP) and mortality in patients taking antihypertensive medications in the Korean using data from the 2007-2015 Korean National Health and Nutrition Examination Surveys. A total of 6601 patients aged 30-74 years were included. Systolic BP (SBP) and diastolic BP (DBP) were both divided into four groups as follows: SBP < 120, 120 ≤ SBP ≤ 129 130 ≤ SBP ≤ 139, and SBP ≥ 140; DBP < 70, 70 ≤ DBP ≤ 79, 80 ≤ DBP ≤ 89, and DBP ≥ 90. The survival rates and hazard ratios were evaluated using Kaplan-Meier curves and multivariable Cox regression analyses. To evaluate the predictability of all-cause mortality according to SBP and/or DBP, we calculated Harrell's concordance-index. The lowest DBP group had a high risk of mortality regardless of the SBP status. The group with DBP < 70 mm Hg and SBP ≥ 140 mm Hg showed the highest mortality. The discriminatory ability calculated using Harrell's C-indexes was greater for the combination of SBP and DBP compared to DBP or SBP alone. These results suggest that it is more effective to simultaneously evaluate the effect of SBP and DBP to predict mortality; clinicians should manage DBP < 70 mm Hg when treating hypertensive patients.ope

Association between Basal Metabolic Rate and Handgrip Strength in Older Koreans

We investigated the relationship between the basal metabolic rate (BMR) and muscle strength through measurement of handgrip strength. We conducted a cross-sectional study of a population representative of older Korean from the 2014–2016 Korean National Health and Nutrition Examination Survey. A total of 2512 community-dwelling men and women aged 65 years and older were included. The BMR was calculated with the Singapore equation and handgrip strength was measured using a digital dynamometer. The patients were categorized into handgrip strength quartiles and a weighted one-way analysis of variance (ANOVA) for continuous variables and a weighted chi-squared test for categorical variables were performed. Pearson, Spearman correlation analysis, univariate, and multivariate linear regression were performed. Analysis of covariance (ANCOVA) was also performed to determine the association between basal metabolic rate and handgrip strength quartiles after adjusting for confounding factors. The BMR increased according to handgrip strength quartile after adjusting for age, BMI, relative fat mass, comorbidity number, resistance exercise, aerobic physical activity, household income, educational level, smoking status, and alcohol ingestion in both sexes (p < 0.001). Handgrip strength has a positive association with the BMR in older Korean people. Therefore, muscle strength exercises should be considered for regulating the BMR in the older people.ope

Effects of a Calorie-Restricted Mediterranean-Style Diet on Plasma Lipids in Hypercholesterolemic South Korean Patients

The objective of this randomized cross-over trial was to evaluate the short term effects of a calorie-restricted Korean style Mediterranean diet (KMD) versus a calorie-restricted conventional diet on lipid profile and other metabolic parameters in hypercholesterolemic patients. Ninety-two patients with hypercholesterolemia were randomly assigned to two groups and switched to the other group following a 4-week intervention after a 2-week washout period. While participants during KMD intervention period received home delivery of two meals daily except for weekends, those during the control group were advised to consume a conventional diet. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) significantly decreased in KMD group even after adjusting for age, sex, total energy intake changes, alcohol consumption, smoking status, and physical activity changes (all p < 0.05). Anthropometric parameters, white blood cell (WBC), fasting glucose, fasting insulin, HOMA-IR, and fatty liver index (FLI) also significantly decreased after KMD intervention (all p < 0.05). In addition, WBC, fasting glucose, total cholesterol, LDL-C and FLI were significantly decreased even after adjusting for weight reduction changes. Calorie-restricted KMD not only helps to treat dyslipidemia by improving the lipid parameters but also has beneficial effects on reducing cardiovascular risk by improving chronic inflammation, insulin resistance, and fatty liver.ope

Association between the Oxidative Balance Score and Incident Chronic Kidney Disease in Adults

Oxidative stress is a novel risk factor for chronic kidney disease (CKD). The oxidative balance score (OBS) was developed to represent the overall oxidative balance based on dietary and lifestyle pro-oxidant and antioxidant components. The aim of this study is to verify the relationship between the OBS and the incidence of CKD. Data from 5795 participants without CKD at the baseline survey of the Korean Genome and Epidemiology Study were analyzed. Participants were classified into sex-specific OBS tertiles. During the mean follow-up period of 13.6 years, 286 men and 382 women newly developed CKD. The Cox proportional hazard spline curve revealed an inverse dose-response association between the OBS and incident CKD in both men and women. Multiple Cox proportional hazard regression analysis revealed that the adjusted hazard ratios (95% confidence intervals) for sex-specific highest (T3) and middle (T2) OBS tertile groups were 0.80 (0.59-1.08) and 0.70 (0.51-0.95), respectively, in men and 0.76 (0.59-0.98) and 0.73 (0.55-0.96), respectively, in women, with the sex-specific lowest OBS tertile group (T1) as the reference. These results suggest that a healthy diet and lifestyle that increases the OBS may help prevent CKD in both men and women.ope