Background: The prevalence of impaired fasting glucose (IFG) in Korea is increasing. Few studies have investigated the relationship between handgrip strength (HGS) and type 2 diabetes among Koreans; however, no study has investigated the relationship between IFG and HGS among Koreans. Therefore, we examined the relationship between relative IFG and HGS to evaluate HGS as a marker of prediabetes. Methods: This cross-sectional study analyzed data from participants aged 20 years or older (n=9,190) who did not have diabetes and had had their body mass index, fasting plasma glucose (FPG), and HGS measured in the 2016–2017 Korea National Health and Nutrition Examination Survey. The association between relative HGS and IFG was analyzed using complex sample logistic regression analyses after adjusting for age, education, strengthening exercise, aerobic exercise, smoking, excessive drinking, and chronic diseases. Results: The prevalence of IFG was 31.5 (0.9)% and 19.6 (0.7)% for men and women, respectively. According to the increase in quartile of relative HGS, FPG and HbA1c significantly decreased in both men and women (Ptrend<0.001). In multivariate logistic regression, the odds of IFG significantly decreased with the increase in quartile of relative HGS in both men and women (Ptrend=0.001 for men, Ptrend=0.002 for women). Conclusion This population-based, nationally representative study suggests that higher relative HGS is associated with a decreased risk of IFG for both men and women.

Background: Dietary intake of n-3 fatty acids have been suggested for their protective role against cardiovascular disease. However, findings from recent studies have been inconsistent. Thus, we investigated the association between dietary intake of n-3 fatty acids and the 10-year risk of cardiovascular disease (CVD). Methods: We analyzed data from 17,390 adults who were aged 30–64 years and free of CVD using the Korea National Health and Nutrition Examination Survey, 2012–2016. Dietary intake of n-3 fatty acids was calculated by using food-frequency questionnaire, and the 10 year risk of CVD was calculated by Framingham general cardiovascular disease risk score (2008) model. We analyzed the odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression to evaluate the association between dietary intake of n-3 fatty acids and the 10-year risk of CVD. Results: Logistic regression anlaysis showed that dietary intake of n-3 fatty acids was not significantly associated with the 10-year risk of CVD, after adjusting for confounders (OR=0.91; 95% CI, 0.77–1.07). But higher dietary intake of n-3 fatty acids was associated with reduced the 10-year risk of CVD for the female (OR=0.74; 95% CI, 0.58–0.95). Conclusion Our research indicated no significant association between dietary intake of n-3 fatty acids and the 10-year risk of CVD. But the inverse association was observed in the female.

Background: Polypharmacy, the use of multiple drugs, is a growing concern in older adults. It has been reported that the prevalence of polypharmacy in elderly patients is higher in Korea than in other countries. The objective of this study was to investigate the prevalence and associated factors of polypharmacy in elderly outpatients who visited a Seoul Medical Center. Methods: We retrospectively reviewed medical records of 12,551 elderly patients aged ≥65 years who visited outpatient clinics in a public hospital in Seoul between January 1, 2018 and December 31, 2018. We defined “polypharmacy” as the use of ≥6 medications per person; “major polypharmacy,” ≥11 medications per person; and “excessive polypharmacy,” ≥21 medications per person. Multivariate logistic regression analysis was performed to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to investigate the risk factors for polypharmacy. Results: Among the elderly outpatients studied, 40.7% had polypharmacy, 11.9% major polypharmacy, and 0.8% excessive polypharmacy. The lowerincome medical aid population is associated with polypharmacy (OR, 1.70; 95% CI, 1.47–1.97). Conclusion We observed a high prevalence of polypharmacy in elderly outpatients, especially the medical aid population, who visited a Korean public hospital. Nationwide vigorous efforts to assess and reduce the prevalence of polypharmacy are urgently required for the Korean older population.

Background: Decreased glomerular filtration rate (GFR) was associated with increased mortality and decreased quality of life in previous studies. In Korean adults, the prevalence rates of cardiometabolic risk factors are higher in women than in men after middle age. We evaluated the association between cardiometabolic risk factors and decreased GFR in Korean women. Methods: We evaluated 2,339 subjects using data from the Korea National Health and Nutrition Examination Survey VII-1 (2016) after excluding participants with GFRs of <15 mL/min/1.73 m2. Normal GFR was ≥60 mL/min/1.73 m2, and decreased GFR was 15–59 mL/min/1.73 m2. Socioeconomic status, lifestyle factors, body mass index, waist circumference, and comorbidities were evaluated to analyze the association between cardiometabolic risk factors and decreased GFR. The odds ratio (OR) and 95% confidence interval (CI) were calculated using multivariate logistic regression analyses. Results: As age increased, the OR for decreased GFR increased. In comparison with women with waist circumferences of <85 cm, the women with waist circumferences of ≥85 cm (OR, 1.94; 95% CI, 1.22–3.10) had a significant increase in the OR for decreased GFR. In women with diabetes mellitus, the OR for decreased GFR significantly increased (OR, 3.14; 95% CI, 1.70–5.81). Conclusion Decreased GFR was associated with age, abdominal obesity, and diabetes mellitus in Korean women. Control of abdominal obesity and appropriate management of diabetes mellitus are needed to prevent chronic kidney disease in Korean women.

Background: Recent evidence has reported the relationships between 25-hydroxyvitamin D (25[OH]D) insufficiency and chronic diseases. This study examined the association of physical activity and sitting time with vitamin D status. Methods: This study analyzed the data of 1,598 adults aged ≥19 who participated in the 2014 Korea National Health and Nutrition Examination Survey. Vitamin D insufficiency was defined as a serum 25(OH)D level of ≤20 ng/mL. The odds ratios and 95% confidence intervals of vitamin D insufficiency according to physical activity and sitting time were calculated using a multivariable logistic regression analysis. Results: The mean levels of serum 25(OH)D were 16.5 ng/mL in males and 15.2 ng/mL in females, respectively and was significantly higher in the participants with sitting times of <5 hours/day than those with sitting times of ≥5 hours/day. After adjusting for confounding variables, sitting time of <5 hours/day was associated with decreased odds of vitamin D insufficiency as compared with sitting time of ≥5 hours/day in the total participants and females. In addition, the odds ratio for vitamin D insufficiency was significantly lower in the group with sitting times of <5 hours/ day than in the group with sitting times of ≥5 hours/day even among people with low physical activity in the total participants and females. Conclusion Serum 25(OH)D level was insufficient in the Korean adults and shorter sitting time was related to lower odds ratio of vitamin D insufficiency. Our findings suggest that sitting time is an independent factor of serum vitamin D status.

Background: Previous studies suggested the correlation between thyroid and kidney functions, especially the high prevalence of hypothyroidism in chronic kidney disease. This study aimed to evaluate the influence of hypothyroidism on kidney function in Korean adults by using data from a representative nationwide survey. Methods: This was a cross-sectional study composed of 5,250 individuals aged ≥19 years who were enrolled in the sixth Korea National Health and Nutrition Examination Survey. The participants were classified into three groups of patients with euthyroidism, subclinical hypothyroidism, and overt hypothyroidism according to thyroid function. Chronic kidney disease was defined as having a decreased estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2. Univariate and multivariate logistic regression analyses were used to evaluate the prevalence and adjusted odds ratio (aOR) of chronic kidney disease. Results: Compared with the euthyroidism group, the subclinical and overt hypothyroidism groups showed higher prevalence rates of chronic kidney disease in both sexes. This tendency was significant in the elderly people aged ≥65 years. In the multivariate logistic regression analysis, the subclinical hypothyroidism group did not show a significant difference (adjusted odds ratio [aOR], 1.78; 95% confidence interval [CI], 0.82–3.87) from the euthyroidism group. In the overt hypothyroidism group, the aOR of chronic kidney disease was significantly higher (aOR, 5.90; 95% CI, 1.73– 20.15) than that in the euthyroidism group. Conclusion Overt hypothyroidism was associated with decreased eGFR and may be considered as an independent risk factor of chronic kidney disease.

Background: Non-alcoholic fatty liver disease fibrosis score (NFS) is a scoring system applied in clinical practice to predict advanced fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Evidence shows that progression of steatohepatitis and liver fibrosis reduces the production of verylow- density lipoprotein. The aim of this study was to identify the association of NFS and serum low-density lipoprotein cholesterol (LDL-C) levels and in adults with NAFLD. Methods: Data were gathered from 24,889 subjects who had visited a health promotion center. NFS was calculated to assess the severity of fibrosis in all the subjects. Serum LDL-C levels were measured using a direct method. Results: Serum LDL-C levels tended to decrease with increasing NFS quartiles (P for trend<0.01). NFS was one of the major determinants of serum LDL-C level after adjusting for age, sex, lifestyle-related factors, and other covariates. The estimated mean serum LDL-C level was significantly lower in the highest quartile of NFS than in the lowest quartile of NFS. Conclusion NFS had a negative association with serum LDL-C levels in adults with NAFLD. Elevated LDL-C level is not only a risk factor of cardiovascular disease but also a predictive indicator of NAFLD severity.

Background: Smartphone usage time has been increasing every year causing smartphone addiction, also known as cell phone dependency. This study investigated and analyzed the effects of family characteristics on adolescent smartphone use. Methods: The subjects were 908 middle school students in Gangneung whose legal guardians agreed to participate in the study. We investigated general characteristics, family structure, smartphone usage time of family members, using Korean Smartphone Addiction Proneness Scale (K-SAPS), Family APGAR, and Family Adaptability and Cohesion Evaluation Scale III (FACES III). The participants were classified into three groups according to the scores of the SAPS: addiction proneness, addiction tendency group, and normal user. Results: The prevalence of the addiction proneness group was 47 (5.2%). The K-SAPS scores were higher in the following categories: female (P<0.001); more monthly allowance (P<0.05); lower academic performance (P<0.001); fewer hours of exercise (P<0.001); longer smartphone usage time (P<0.001); and younger owners of smartphones (P<0.05). In family characteristics, the K-SAPS scores were significantly higher in single parent families (P<0.05), longer smartphone usage time of mother and siblings (P<0.05), less time spent watching TV with family members (P<0.05), more exposure to smartphones in childhood (P<0.05), and less time spent with mother (P<0.05). The K-SAPS scores were significantly higher when family APGAR, family adaptability, and cohesion scores were lower (P<0.001). Conclusion This study indicated that the smartphone addiction in middle school students is closely related to smartphone usage of family members and family functions. Therefore, family behavior that can be corrected should be considered for counseling to prevent smartphone addiction.

Background: Postmenopausal status increases the risk of cardiovascular disease, and C-reactive protein (CRP) constitutes an independent cardiovascular risk factor. This study aimed to investigate the factors associated with increased high-sensitivity CRP (hs-CRP) level in postmenopausal women. Methods: We included postmenopausal women without laboratory test results that suggested acute inflammation who participated in the Korea National Health and Nutrition Examination Survey between 2016 and 2017. The participants were divided into high and low hs-CRP groups (cutoff value, 3.0 mg/L). We investigated factors that influenced the hs-CRP level with logistic regression analysis. Results: The total number of subjects was 2,739, of whom 76.4% had low hs-CRP levels and 23.6% had high hs-CRP levels. The mean age and body mass index were higher in the high than in the low hs-CRP group. In the simple logistic regression analysis, high hs-CRP level was associated with smoking, whereas low hs-CRP level was associated with aerobic exercise, use of oral contraceptives, and history of pregnancy in postmenopausal women. When the analysis was adjusted for confounding variables, histories of smoking and pregnancy had a statistically significant association with high hs-CRP level. Conclusion This study showed that the important modifiable risk factors of elevated hs-CRP level in postmenopausal women of Korea include obesity, smoking, and lack of aerobic exercise, but well-controlled prospective investigations should be considered.

Infectious diseases caused by the novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2), the first outbreak in China, are currently pandemic in the world, including in Korea. Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has not been proven and there has been no proper target medicine and vaccine, so it is virtually unprotected and is a serious health problem. A mitigation strategy that lowers and slows the peak of the epidemic is required to ensure efficient distribution of medical resources and time to development of therapeutic medicines and preventive vaccine. For this, close cooperation between the government and medical practitioners are required, and national prevention and prevention of the spread of the community and preparation for inflow from abroad will be required. In addition, large-scale studies on drugs including hydroxychloroquine, remdesivir, etc., which are known to be effective as therapeutic agents for COVID-19, are required to develop a vaccine for prevention. The authors hope that this review will assist primary care physicians currently engaged in patient care.