•Pool boiling heat transfer performance of low GWP refrigerants was investigated.•The HTCs of low GWP refrigerants were compared with empirical correlations.•The enhanced 2 tube is effective for low ...pressure R-1233zd(E).
Low GWP refrigerants have drawn increasing attention as an alternative to HFC refrigerants that are regulated as a leading cause of global warming. The present study was focused on R-1234ze(E) and R-1233zd(E) refrigerants among other alternative refrigerant candidates and experimented on three types of tubes, i.e., a plain tube and two type of enhanced tubes, in terms of pool boiling heat transfer performance. The investigation was conducted under the experimental condition at saturated temperatures 4.4°C and 26.7°C and heat flux of 10–50kW/m2. The heat transfer coefficients of R-1234ze(E) and R-1233zd(E) for the plain tube showed approximately 10.8–19.0%, 54.1–62.8% lower than those of R-134a respectively. Also, the results were compared against the previous empirical correlations, which proved satisfactory predictability for all conditions. For the enhanced 1 tube, the heat transfer coefficients of R-1234ze(E) and R-1233zd(E) showed 9.8–14.0%, 60.0–75.0% lower than those of R-134a, while the heat transfer coefficients of R-1234ze(E) and R-1233zd(E) for enhanced 2 tube showed 13.3–17.9%, 39.5–43.7% lower than those of R-134a respectively.
Metabolic syndrome (MetS) is considered very important because of the increased risk for cardiovascular diseases. Identifying modifiable factors may help prevent MetS. We aimed to investigate the ...relationship between iodine intake as a dietary factor and MetS in euthyroid adult in an iodine-replete area. A total of 4,277 adult aged ≥19 years from the Korea National Health and Nutrition Examination Survey VI (2013–2015) with urinary iodine concentration (UIC) results and normal thyroid function were included. Participants were grouped according to their iodine nutrition status based on the WHO recommendations and modifications: insufficient (<100 μg/L), adequate (100–299 μg/L), and excessive (≥300 μg/L) iodine intake. We estimated the odds ratios (ORs) for MetS according to the UIC groups using logistic regression models. Of the study participants, 27.2% men and 23.9% women had MetS. Men with excessive iodine intake had a significantly lower risk of elevated triglycerides OR 0.733, 95% confidence interval (CI) 0.603–0.890, p = 0.010, as compared to those with adequate iodine intake. Women with insufficient iodine intake had a significantly greater risk of elevated blood glucose (OR 1.519, 95% CI 1.011–2.282, p = 0.044), as compared to those with adequate iodine intake. In women, insufficient iodine intake was a significant risk factor for MetS compared to adequate iodine intake, even after adjusting for confounding variables including age, smoking, alcohol consumption, walking activity, serum thyroid-stimulating hormone, free thyroxine, and anti-thyroid peroxidase antibody (OR 1.544, 95% CI 1.031–2.311, p = 0.035). There was no association between iodine intake and risk of MetS in men. In conclusion, insufficient iodine intake was associated with an increased risk of MetS only in euthyroid adult women. Our data support that sex differences may influence the relationship between iodine intake as a dietary pattern and MetS.
Diabetic nephropathy (DN) is associated with high risk of cardiovascular disease and mortality. Exosomal microRNAs (miRNAs) regulate gene expression in a variety of tissues and play important roles ...in the pathology of various diseases. We hypothesized that the exosomal miRNA profile would differ between DN patients and patients without nephropathy.
We prospectively enrolled 74 participants, including healthy volunteers (HVs), diabetic patients without nephropathy, and those with DN. The serum exosomal miRNA profiles of participants were examined using RNA sequencing.
The expression levels of 107 miRNAs differed between HVs and patients without DN, whereas the expression levels of 95 miRNAs differed between HVs and patients with DN. Among these miRNAs, we found 7 miRNAs (miR-1246, miR-642a-3p, let-7c-5p, miR-1255b-5p, let-7i-3p, miR-5010-5p, miR-150-3p) that were uniquely up-regulated in DN patients compared to HVs, and miR-4449 that was highly expressed in DN patients compared to patients without DN. A pathway analysis revealed that these eight miRNAs are likely involved in MAPK signaling, integrin function in angiogenesis, and regulation of the AP-1 transcription factor. Moreover, they were all significantly correlated with the degree of albuminuria.
Patients with DN have a different serum exosomal miRNA profile compared to HVs. These miRNAs may be promising candidates for the diagnosis and treatment of DN and cardiovascular disease.
Recent studies have indicated that the triglyceride-glucose (TyG) index or subclinical thyroid dysfunction is associated with carotid plaques, a predictor of cardiovascular disease risk. However, ...evidence for this association is limited and inconsistent. This study aimed to evaluate the risk of carotid plaques according to TyG index and thyroid function status in the general population.
A total of 2,931 individuals who underwent carotid ultrasound as part of a comprehensive health examination at the Health Promotion Center of Soonchunhyang University Hospital were retrospectively reviewed. Based on the TyG index and thyroid function status, the participants were divided into six groups: LoTyG-SHyper (low TyG index with subclinical hyperthyroidism), LoTyG-Eu (low TyG index with euthyroidism), LoTyG-SHypo (low TyG index with subclinical hypothyroidism), HiTyG-SHyper (high TyG index with subclinical hyperthyroidism), HiTyG-Eu (high TyG index with euthyroidism), and HiTyG-SHypo (high TyG index with subclinical hypothyroidism). A multivariate logistic regression analysis was conducted to determine the risk of carotid plaques.
The proportion of participants with significant carotid plaques was significantly different among the six groups (p<0.001, p for trend<0.001). The odds ratio (OR) and 95% confidence interval (CI) for significant carotid plaques were significantly higher in the HiTyG-SHypo group than in the LoTyG-Eu group, even after adjusting for confounding variables including sex, age, smoking, obesity, hypertension and diabetes mellitus (OR 1.506, 95% CI 1.045-2.170, p = 0.028). The OR of significant carotid plaques was higher in the HiTyG-Eu group than in the LoTyG-Eu group; however no associations were observed after additional adjustment for confounding variables.
The TyG index and thyroid function status are important predictors of the risk of carotid plaques in healthy individuals. Early evaluation of carotid plaques may be necessary for subjects with high insulin resistance and subclinical hypothyroidism.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objective Recent studies have reported that thyroid hormone levels are associated with metabolic syndrome (MetS) even in euthyroid subjects. However, the association between thyroid autoimmunity and ...MetS is uncertain. This study aimed to investigate the relationship between thyroid autoimmunity and MetS in a large cohort study of euthyroid subjects. Methods A total of 4775 participants aged ≥19 years from the Korea National Health and Nutrition Examination Survey VI (2013–2015) with anti-thyroid peroxidase antibody (TPOAb) results and normal thyroid functions were included in this study. Subjects were grouped according to thyroid autoimmunity (positivity of TPOAb). We estimated the odds ratios (ORs) for MetS according to TPOAb positivity using logistic regression models, adjusted for potential confounders. Results Of the study subjects, 25% (n = 1206) were diagnosed with MetS. Subjects with MetS showed higher median TPOAb levels (6.3 vs 6.8 IU/mL, P < 0.001) and higher positivity of TPOAb (5 vs 7%, P = 0.002) than those without MetS. There was a significant difference in prevalence of MetS depending on the TPOAb positivity (25% vs 33%, P = 0.002). Subjects with TPOAb positive had a significantly greater risk of abdominal obesity (OR 1.675, 95% CI: 1.302–2.154, P < 0.001), low high-density lipoprotein cholesterol (OR: 1.603, 95% CI: 1.244–2.066, P < 0.001) and elevated blood pressure (OR: 1.418, 95% CI: 1.099–1.829, P = 0.007) as compared to those with TPOAb negative. Positivity of TPOAb was a significant risk factor for MetS even after adjusting for confounding variables including age, sex, household income, education, smoking, alcohol consumption, walking activity, thyroid-stimulating hormone and free thyroxine (OR: 1.389, 95% CI: 1.048–1.841, P = 0.022). Conclusion In euthyroid subjects, thyroid autoimmunity is associated with MetS. Further large longitudinal studies are needed to clarify causality.
The association between thyroid hormone levels and pulmonary function in euthyroid population is still unclear. We aimed to examine the relationship between thyroid function and lung function in a ...large cohort study of euthyroid subjects. We analyzed biochemical and spirometry data from a nationwide, population-based, cross-sectional survey (KNHANES VI). A total of 1,261 middle-aged participants aged 45-65 years with spirometry tests and normal thyroid function were included in this study. The subjects were grouped according to free thyroxine (fT4) (ng/dL) quartiles (Q1, 0.89-1.09; Q2, 1.10-1.19; Q3, 1.20-1.30; Q4, 1.31-1.76). Obstructive lung pattern was defined as forced expiratory volume in one second (FEV.sub.1 )/forced vital capacity (FVC) <0.7. The probability of obstructive lung patterns according to fT4 quartiles was assessed using logistic regression models, adjusted for potential confounders. Overall, 10.9% of the subjects had an obstructive lung pattern. The mean fT4 levels were significantly higher in those with obstructive lung pattern than in those with normal lung function (1.26 vs. 1.20 ng/dL, p<0.001). The proportion of participants with obstructive lung pattern increased across the fT4 quartile categories (p<0.001). With the Q1 group as reference, the multivariate-adjusted odds ratios (95% confidence intervals) for obstructive lung pattern in the Q3 and Q4 groups were 2.875 (1.265-6.535) and 2.970 (1.287-6.854), respectively, even after adjusting for confounding variables. High fT4 levels are an independent predictor of obstructive lung pattern in euthyroid middle-aged subjects. Further prospective studies are needed to confirm these findings.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recent studies have correlated serum cystatin C (CysC) with vascular complications, but few studies have investigated this correlation in diabetes patients without nephropathy. This study aimed to ...evaluate if higher serum CysC levels increase the risk for vascular complications in type 2 diabetes mellitus patients with normal renal function or mild renal impairment.
A total of 806 consecutive patients with type 2 diabetes mellitus who were admitted to the diabetes center of Soonchunhyang University Hospital for blood glucose control were retrospectively reviewed. Patients with nephropathy were excluded. Subjects were categorized into quartiles of serum CysC levels (Q1, ≤0.65 mg/L; Q2, 0.66 to 0.79 mg/L; Q3, 0.80 to 0.94 mg/L; and Q4, ≥0.95 mg/L).
The proportion of patients with diabetic retinopathy (DR) (
for trend <0.001), coronary heart disease (CHD) (
for trend <0.001), and stroke (
for trend <0.001) increased across the serum CysC quartiles. After adjustment for confounding factors, the highest serum CysC level remained a significant risk factor for DR (odds ratio OR, 1.929; 95% confidence interval CI, 1.007 to 4.144;
=0.040). Compared with Q1, a significant positive association was observed between serum CysC and CHD in Q2 (OR, 7.321; 95% CI, 1.114 to 48.114;
=0.012), Q3 (OR, 6.027; 95% CI, 0.952 to 38.161;
=0.020), and Q4 (OR, 8.122; 95% CI, 1.258 to 52.453;
=0.007). No associations were observed between CysC and stroke after additional adjustment for confounding variables.
Serum CysC levels are independently associated with DR and CHD, suggesting that CysC may be useful for identifying type 2 diabetes mellitus patients without nephropathy who are at high risk for vascular complications.
Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular and renal outcomes in type 2 diabetes mellitus (T2DM) patients. However, the mechanisms by which SGLT2 inhibitors improve the ...clinical outcomes remain elusive. We evaluated whether empagliflozin, an SGLT2 inhibitor, ameliorates mitochondrial dysfunction and inflammatory milieu of the kidneys in T2DM patients. We prospectively measured copy numbers of urinary and serum mitochondrial DNA (mtDNA) nicotinamide adenine dinucleotide dehydrogenase subunit-1 (mtND-1) and cytochrome-c oxidase 3 (mtCOX-3) and urinary interleukin-1β (IL-1β) in healthy volunteers (n = 22), in SGLT2 inhibitor-naïve T2DM patients (n = 21) at baseline, and in T2DM patients after 3 months of treatment with empagliflozin (10 mg, n = 17 or 25 mg, n = 4). Both urinary mtDNA copy numbers and IL-1β levels were higher in the T2DM group than in healthy volunteers. Baseline copy numbers of serum mtCOX-3 in the T2DM group were lower than those in healthy volunteers. Empagliflozin induced marked reduction in both urinary and serum mtND-1 and mtCOX-3 copy numbers, as well as in urinary IL-1β. Empagliflozin could attenuate mitochondrial damage and inhibit inflammatory response in T2DM patients. This would explain the beneficial effects of SGLT2 inhibitors on cardiovascular and renal outcomes.
Purpose
Both deficient and excessive iodine intake leads to thyroid disease, which shows
U
-shaped curves. Our previous study showed that a relatively low urinary iodine concentration (UIC) <300 μg/L ...and extremely excessive (UIC ≥ 2500 μg/L) iodine intake were associated with thyroid cancer in Korea, an iodine-replete area. Papillary thyroid cancer (PTC) accounts for more than 97 % of thyroid cancer and 80% or more PTC cases harbor the
BRAF
mutation in Korea. We aimed to investigate the relationship between iodine intake and the prevalence of the
BRAF
mutation in PTC in Korea.
Methods
UIC was measured by inductively coupled plasma mass spectrometry. The
BRAF
mutation was detected using both allele-specific polymerase chain reaction and mutant enrichment with 3′-modified oligonucleotide sequencing. Risk factors for the occurrence of
BRAF
mutations in PTC were evaluated using multivariate logistic regression models.
Results
The median UIC in all patients with PTC was 287 μg/L (range from 7 to 7, 426 μg/L). Nearly half of the patients (102/215, 47%) belonged to the excessive iodine intake category (UIC ≥ 300 μg/L) according to the WHO iodine recommendations. The frequency of
BRAF
mutations was lowest in the 300–499 μg/L UIC group; it was significantly different compared to the relatively low (UIC < 300 μg/L) and more than excessive (UIC ≥ 500 μg/L) iodine intake groups. UIC was an independent predictor for
BRAF
mutations in PTC. The multivariate-adjusted odds ratios (95% confidence intervals) in the relatively low and more than excessive iodine intake groups for the
BRAF
mutation were 4.761 (1.764–12.850) and 6.240 (2.080–18.726), respectively, compared to the 300–499 μg/L UIC group.
Conclusion
Relatively low iodine intake and more than excessive iodine intake seem to be significant risk factors for the occurrence of
BRAF
mutations in the thyroid and, therefore, may be risk factors for the development of PTC in an iodine-replete area.
Inadequate calcium and vitamin D intake is a possible risk factor of osteoporosis. Our purposes were to estimate calcium and vitamin D intake in Korean women, and to determine associated risk factors ...for low calcium and vitamin D intake. This is a multicenter, hospital-based, and cross-sectional study on osteoporosis. In this study, 1516 women of 50 years or older were involved. Dietary calcium and vitamin D intake were evaluated using the self-reporting KCAT questionnaire. Average daily calcium intake was 662.8 ± 473.8 mg, and vitamin D intake 9.5 ± 10.7 μg. In multivariate analysis, older age (OR 1.02, 95 % CI 1.00–1.04,
p
= 0.001), and rural residence (OR 2.43, 95 % CI 1.34–4.43,
p
= 0.004) were significant risk factors for lower calcium intake, and older age (OR 1.03, 95 % CI 1.02–1.04,
p
< 0.001), and rural residence (OR 1.85, 95 % CI 1.10–3.11,
p
< 0.001) were significant risk factors for lower vitamin D intake. About 70 % of women aged 50 years or older had calcium and vitamin D intake below the recommended dietary intake. Older age and rural residence were significant risk factors for lower calcium and vitamin D intake in Korean women.
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