Background: In cross-sectional and retrospective cohort studies, we examined comparative associations between nonalcoholic fatty liver disease (NAFLD) and metabolic dysfunction–associated fatty liver disease (MAFLD) and risk of having or developing coronary artery calcification (CAC). Methods: Participants who had health examinations between 2010 and 2019 were analyzed. Liver ultrasonography and coronary artery computed tomography were used to diagnose fatty liver and CAC. Participants were divided into a MAFLD and no-MAFLD group and then NAFLD and no-NAFLD groups. Participants were further divided into no fatty liver disease (reference), NAFLD-only, MAFLD-only, and both NAFLD and MAFLD groups. Logistic regression modeling was performed. Cox proportional hazard model was used to examine the risk of incident CAC in participants without CAC at baseline and who had at least two CAC measurements. Results: In cross-sectional analyses, 162 180 participants were included. Compared with either the no-NAFLD or no-MAFLD groups, the NAFLD and MAFLD groups were associated with a higher risk of prevalent CAC (NAFLD: adjusted odds ratio [OR], 1.34 [95% CI, 1.29–1.39]; MAFLD: adjusted OR, 1.44 [95% CI, 1.39–1.48]). Among the 4 groups, the MAFLD-only group had the strongest association with risk of prevalent CAC (adjusted OR, 1.60 [95% CI, 1.52–1.69]). Conversely, the NAFLD-only group was associated with a lower risk of prevalent CAC (adjusted OR, 0.76 [95% CI, 0.66–0.87]). In longitudinal analyses, 34 233 participants were included. Compared with either the no-NAFLD or no-MAFLD groups, the NAFLD and MAFLD groups were associated with a higher risk of incident CAC (NAFLD: adjusted hazard ratio, 1.68 [95% CI, 1.43–1.99]; MAFLD: adjusted hazard ratio, 1.82 [95% CI, 1.56–2.13]). Among these 4 groups, the MAFLD-only group had the strongest associations with risk of incident CAC (adjusted hazard ratio, 2.03,[95% CI, 1.62–2.55]). The NAFLD-only group was not independently associated with risk of incident CAC (adjusted hazard ratio, 0.88 [95% CI, 0.44–1.78]) Conclusions: Both NAFLD and MAFLD are significantly associated with an increased prevalence and incidence of CAC. These associations tended to be stronger for MAFLD.

Only a few studies have evaluated the relationship between physical activity (PA) and Homeostatic model assessment for insulin resistance (HOMA-IR). Therefore, we aimed to analyze the association between HOMA-IR and PA. We included 280,194 Korean without diabetes who underwent health examinations. The short form of the International Physical Activity Questionnaire was completed. PA level was divided into sedentary, mild PA, and health-enhancing PA (HEPA). The HOMA-IR levels were calculated. Confounding factors including waist circumference were adjusted. The median follow-up duration was 4.13 years. A significant inverse relationship was observed between PA level and HOMA-IR (p < 0.001). Compared with the sedentary group, HOMA-IR was lower in the HEPA group (p < 0.001), even when HEPA group decreased PA level over time (p < 0.001). Mild PA (p < 0.001) or HEPA showed a lower risk of HOMA-IR progression (p < 0.001). Increasing PA or maintaining HEPA was significantly associated with a lower HOMA-IR (p < 0.001), HOMA-IR improvement (p < 0.001), and a lower risk of HOMA-IR progression (p < 0.001). Our findings support the inverse relationship between PA and HOMA-IR in a population without diabetes. PA might improve IR and prevent its progression among populations without diabetes, independent of the waist circumference.

Background: Previous studies have reported that abnormal glucose metabolism is associated with poor cancer outcomes. Glycated hemoglobin A1c (HbA1c) is an important indicator of glucose metabolism. This study aimed to investigate the relationship between nondiabetic HbA1c levels and cancer-related mortality. Methods: This was a retrospective cohort study of Koreans who attended an annual or biennial health checkup program. The study group was categorized based on the quintile of HbA1c level (Q1, 3.0–5.1%; Q2, 5.2–5.3%; Q3, 5.4%; Q4, 5.5–5.6%, Q5, 5.7–6.4%). Cancer-related mortality was determined using the mortality data from the Korea National Statistical Office. Participants with an established diagnosis of diabetes or cancer were excluded. Cancer-related mortality was assessed depending on each HbA1c level with adjustment for factors that could influence mortality. Results: A total of 589,457 participants were included in this study. During a median follow-up duration of 6.99 years, 1712 cancer-related deaths were reported. The risk of cancer-related mortality was significantly higher in the Q5 group (hazard ratio (HR) 1.23, range 1.02–1.47 in model 1; HR 1.25, range 1.04–1.50 in model 2). HbA1c levels were linearly associated with cancer-related deaths (Ptrend = 0.021 in model 1; 0.013 in model 2). HbA1c level and colorectal, stomach, and lung cancer mortality exhibited a positive relationship, whereas liver cancer-related mortality showed an inverse relationship with HbA1c level (Ptrend = 0.001). Conclusions: Our study showed that abnormal glucose metabolism is significantly associated with cancer-related mortality, and its relationship varies with each type of cancer.

We investigated the relationship between high carcinoembryonic antigen (CEA) levels and low skeletal muscle mass (LMM) in asymptomatic adults in a population-based study. A total of 202,602 adults (mean age 41.7 years) without malignancy, stroke, cardiovascular disease, or chronic lung/liver disease were included. A high CEA level was defined as ≥5 ng/mL. Skeletal muscle mass index (SMI) was calculated based on appendicular muscle mass (kg)/height (m)². Participants were classified into three groups based on SMI: “normal”, “mild LMM”, and “severe LMM.” The prevalence of elevated CEA levels was the highest in subjects with severe LMM (4.2%), followed by those with mild LMM (1.6%) and normal muscle mass (1.1%) (p for trend < 0.001). In multivariate logistic regression analysis, high CEA was independently associated with having mild LMM (adjusted odds ratio, 1.139 [95% confidence interval, 1.092–1.188]) and severe LMM (2.611 [2.055–3.319]) compared to normal muscle mass. Furthermore, the association between high CEA and severe LMM was stronger in women than that in men (women, 5.373 [2.705–10.669]; men, 2.273 [1.762–2.933]). Elevated CEA levels were significantly associated with a higher prevalence of LMM. Therefore, increased CEA could be used as a biomarker for detecting LMM in adults without cancer.

Background and Objectives: Flexibility is one of the most important physical fitness parameters in the geriatric population. Brachial–ankle pulse wave velocity (baPWV) is a measure of systemic arterial stiffness. However, data on the association between flexibility and arterial stiffness in the older adult population are limited. Therefore, we aim to investigate this association by using the sit-and-reach test (SRT) and measuring baPWV. Materials and Methods: We reviewed data from the 2014–2015 Korean Institute of Sports Science Fitness Standards Project. Individuals older than 65 years with SRT and baPWV data were included. A generalized linear regression analysis was conducted to assess the association between flexibility and arterial stiffness. Multiple relevant confounding factors were adjusted. Results: A total of 615 individuals were included in the analysis. The mean age of the male and female participants was 71.44 ± 4.42 and 70.64 ± 4.13 years, respectively. The mean SRT result was 6.58 ± 9.97 and 18.04 ± 7.48 cm, respectively. After multivariable adjustment among the male participants, the higher SRT result tertiles were inversely associated with baPWV (β (95% confidence interval): 3.11–11.00 cm, −74.45 (−140.93, −8.55); ≥11.01 cm, −108.17 (−177.65, −38.70)) in comparison with the lowest tertile. The female participants did not show any significant correlation between the SRT result and baPWV. Conclusions: Our results suggest an inverse association between trunk flexibility and systemic arterial stiffness, expressed as the SRT result and baPWV, respectively, in older Korean men but no association in older Korean women. Sex differences might influence the association between flexibility and arterial stiffness in the older adult population.