Korean frailty and aging cohort study (KFACS): cohort profile.

PURPOSE: The purpose of the Korean Frailty and Aging Cohort Study (KFACS) is to initiate a nationwide, population-based prospective cohort study of older adults living in the community to assess their frailty status and explore transitions between frailty states over time in Korea. PARTICIPANTS: The KFACS is a multicentre longitudinal study with the baseline survey conducted from May 2016 to November 2017. Each centre recruited participants using quota sampling stratified by age and sex. The number of participants recruited through 2 years of baseline study from 10 centres was 3014, with each site accounting for approximately 300 participants. The inclusion criteria were: having an age of 70-84 years, currently living in the community, having no plans to move out in the next 2 years, having no problems with communication and no prior dementia diagnosis. FINDINGS TO DATE: To define physical frailty, the KFACS used a modified version of the Fried Frailty Phenotype (FFP) consisting of five components of frailty: unintended weight loss, weakness, self-reported exhaustion, slowness and low physical activity. In the baseline study of 2016-2017, 2907 of 3014 individuals fulfilled all five components of FFP. The results indicated that 7.8% of the participants (n=228) were frail, 47.0% (n=1366) were prefrail and 45.2% (n=1313) were robust. The prevalence of frailty increased with age in both sexes; in the group aged 70-74 years, 1.8% of men and 3.7% of women were frail, whereas in the 80-84 years age group, 14.9% of men and 16.7% of women were frail. Women tended to exhibit a higher prevalence of frailty than men in all age groups. FUTURE PLANS: The KFACS plans to identify outcomes and risk factors associated with frailty by conducting a 10-year cohort study, with a follow-up every 2 years, using 3014 baseline participants.

Comprehensive assessment of lipoprotein subfraction profiles according to glucose metabolism status, and association with insulin resistance in subjects with early-stage impaired glucose metabolism.

BACKGROUND: Early detection of atherogenic dyslipidemia is crucial. We investigated lipoprotein subfraction parameters according to glucose metabolism status. METHODS: We recruited 1255 lipid-lowering drug-naïve subjects with normal fasting glucose (NFG; n=200, 15.9%), impaired fasting glucose (IFG; n=443, 35.3%), or type 2 diabetes (T2D; n=612, 48.8%). Lipoprotein subfractions (1-7) were determined by polyacrylamide gel electrophoresis, separating low-density lipoprotein (LDL) into large buoyant LDL (lbLDL, LDL1-2) and small dense LDL (sdLDL, LDL3-7). Lipoprotein subfraction parameters including the sdLDL% (LDL3-7/LDL1-7), the sdLDL/lbLDL ratio (LDL3-7/LDL1-2), and weighted LDL subfraction (LDLSF) scores, were compared between groups. Their associations with insulin resistance, estimated using the homeostasis model assessment of insulin resistance, were examined. RESULTS: The concentrations of sdLDL particles were significantly higher in subjects with T2D and IFG than in those with NFG (15.78±13.47mg/dl and 14.60±14.33mg/dl, respectively, vs. 12.22±12.31mg/dl). Compared with those with NFG, subjects with IFG or T2D had significantly a higher sdLDL% (15.98±15.26% vs. 19.50±16.21% or 21.46±16.81%, respectively), a higher sdLDL/lbLDL ratio (0.24±0.30 vs. 0.31±0.37 or 0.35±0.39), and a higher LDLSF score (2.08±0.91 vs. 2.30±1.14 or 2.36±1.17). These lipoprotein subfraction parameters had stronger associations with insulin resistance compared to conventional lipid profiles in the IFG and T2D groups. CONCLUSIONS: Atherogenic dyslipidemia is initiated in an early stage of impaired glucose metabolism, when early intervention might be required.

Role of various indices derived from an oral glucose tolerance test in the prediction of conversion from prediabetes to type 2 diabetes.

AIMS: The clinical implications of prediabetes for development of type 2 diabetes may differ for Asian ethnicity. We investigated various indices derived from a 2-h oral glucose tolerance test (OGTT) in people with prediabetes to predict their future risk of diabetes. METHODS: We recruited 406 consecutive subjects with prediabetes from 2005 to 2006 and followed them up every 3-6 months for up to 9 years. Prediabetes was defined as isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), combined glucose intolerance (CGI), or isolated elevated HbA1c (5.7-6.4%, 39-46 mmol/mol) without IFG or IGT. The rate of diabetes conversion was compared between prediabetes categories. The association of glycemic indices with development of diabetes was also investigated. RESULTS: Eighty-one patients were diagnosed with diabetes during the 9-year follow-up (median 46.0 months). The rate of diabetes conversion was higher in subjects with CGI (31.9%), or isolated IGT (18.5%) than in those with isolated IFG (15.2%) or isolated elevated HbA1c (10.9%). Surrogate markers reflecting ß-cell dysfunction were more closely associated with diabetes conversion than insulin resistance indices. Subjects with a 30-min postload glucose ≥ 165 mg/dL and a 30-min C-peptide < 5 ng/mL had 8.83 times greater risk (95% confidence interval 2.98-26.16) of developing diabetes than other prediabetic subjects. CONCLUSIONS: In Asians, at least Koreans, ß-cell dysfunction seems to be the major determinant for diabetes conversion. A combination of high glucose and low C-peptide levels at 30 min after OGTT may be a good predictor for diabetes conversion in this population.

Assessment of appendicular skeletal muscle mass by bioimpedance in older community-dwelling Korean adults.

It is crucial to investigate age-related body composition changes in geriatric medicine. Bioelectrical impedance analysis (BIA) is easy to perform, non-invasive, relatively inexpensive, and portable. However, the accuracy of measurement by BIA is questionable. To develop and cross-validate the predictive equation for estimated appendicular skeletal muscle mass (ASM) using BIA in older community-dwelling Korean adults, we include two cohorts: study participants aged 65-80 years in the Ansung cohort for the Korean Health and Genome Study (men, n=285; women, n=435) used as equation-generating group, and Korean Longitudinal Study of Health Aging (KLoSHA) as cross-validation group (men, n=202; women, n=208). Dual energy X-ray absorptiometry (DXA) and BIA were performed in both cohorts. Using multiple linear regression analysis, we drew a predictive equation for DXA-measured ASM by BIA resistance. From DXA and BIA measurements in the Ansung cohort, we generated the estimated equation ASM (kg)=[(Ht(2)/R×0.104)+(age×-0.050)+(gender×2.954)+(weight×0.055)]+5.663 where Ht is height in centimeters; R is BIA resistance in 250Ω; for gender, men=1 and women=0; and age is in years. We validated this equation in the KLoSHA. The r(2) of the estimated ASM was 0.890. This BIA equation provides valid estimates of ASM in older Korean adults.

Managing diabetes in Asia: overcoming obstacles and the role of DPP-IV inhibitors.

Asia bears the world's greatest burden of type 2 diabetes (T2DM) and prevalence is increasing rapidly. Compared to other races, Asians develop T2DM younger, at a lower degree of obesity, suffer longer from its complications and die earlier. Curbing this epidemic requires an integrated, risk-based, and multidisciplinary approach. Inadequately managed T2DM has macrovascular and microvascular sequelae, Asians with T2DM being particularly susceptible to diabetic nephropathy. Earlier and more intensive monitoring and management of risk factors are required, especially for patients with, or at risk of, renal impairment. Particular challenges of T2DM management in Asia include: lack of access to specialist healthcare, insufficient clinical evaluation and delayed diagnosis. As in Caucasians, conventional treatment modalities are limited by deteriorating glycaemic control with disease progression and there is an unmet need for efficacious, safe, cost-effective and convenient pharmacotherapies for treating different stages of T2DM and preventing its complications, particularly in high-risk patients. There is a trend towards increasing use of DPP-IV inhibitors, which are no less efficacious and safe in Asians than Caucasians and may have some advantages over existing oral antidiabetic agents, particularly for certain high-risk groups. Such agents may play a significant future role in the management of T2DM.

Assessment of subclinical coronary atherosclerosis in asymptomatic patients with type 2 diabetes mellitus with single photon emission computed tomography and coronary computed tomography angiography.

We evaluated the characteristics of coronary artery disease in asymptomatic patients with type 2 diabetes mellitus (DM) using single photon emission computed tomography (SPECT) and coronary computed tomographic angiography (CCTA). A total of 116 patients with DM without abnormal electrocardiographic findings or evidence of peripheral arterial disease (number of risk factors > or =2; 62 +/- 7 years, 59% men) underwent CCTA and SPECT. Of the 116 patients with DM, 88 (76%) had a normal single photon emission computed tomographic findings, and 28 (24%) had abnormal perfusion defects. Of the 116 patients, 92 (79%) had atherosclerotic plaques (2 +/- 2 segments per subject), and 20 (17%) had significant stenosis seen on CCTA. Patients with DM and normal findings on SPECT had a similar prevalence of atherosclerotic plaque (78% vs 82%), significant stenosis (15% vs 25%), severe stenosis (7% vs 7%), and calcified (40% vs 43%), mixed (49% vs 57%), and noncalcified plaques (26% vs 29%) and a high (>100) coronary artery calcium score (32% vs 29%; all p >0.05) compared to those with abnormal findings on SPECT. During the mid-term follow-up (24 +/- 4 months), 5 cardiac events occurred in patients with DM and normal findings on SPECT, only in those with occult CAD on CCTA: 1 sudden cardiac death and 4 revascularization procedures. In conclusion, a significant percentage of patients with DM and normal eletrocardiographic findings, no peripheral arterial disease, and normal findings on SPECT have evidence of occult CAD on CCTA. Furthermore, a small percentage had had a cardiac event by mid-term follow-up. SPECT showed limited capability to differentiate the coronary risks between patients with DM and no coronary plaque and from those with a certain degree of disease; 2 circumstances that represent different coronary risks.