Measurements of elemental iodine in soy sauces in Taiwan using a modified microplate method.

Background: Soy sauce is widely used in a variety of Asian dishes to enhance flavor. Soybean and most soybean products, including soy sauces, are listed as prohibited foods in a low iodine diet. However, the iodine content in soy sauces is largely unknown. The aim of this study was to determine the iodine content in domestic soy sauces in Taiwan. Methods: Twenty-five different kinds of soy sauces were diluted with distilled water and with a dilution factor of fifty or above. Iodine concentrations of the diluted samples were measured colourimetrically based on the Sandell-Kolthoff reaction by a modified microplate method. All the measurements were repeated twelve times on three different days for determination of mean and standard deviation (SD), and coefficients of variance (CV). Serial dilution and recovery tests were also performed for validation. The results were confirmed by an inductively coupled plasma mass spectrometry (ICP-MS) method. Results: Among the twenty-five surveyed soy sauces, most of them (n=22) were iodine-free (<16 ug/L, and thus un-detectable). The iodine concentrations (mean ± SD) of the three iodine-containing soy sauces were 2.7 ± 0.1, 5.1 ± 0.2, and 10.8 ± 0.6 mg/L, respectively. The inter-assay, intra-assay and total CVs were all <5.3% for the modified microplate method. The results obtained by ICP-MS were consistent with those of the modified microplate method. The recovery rates in the serial dilution test and recovery test ranged from 94.7% to 118.6%. Two of the three iodine-containing soy sauces were supplemented with kelp extract, while the other one without kelp extract had the highest amount of salt among the three iodine-containing soy sauces. Therefore, we postulate that iodized salt instead of kelp extract is the source of higher iodine content in that sauce. Conclusion: The results suggest that most soy sauces are iodine-free and may be allowed during low iodine diets.

ER ribosomal-binding protein 1 regulates blood pressure and potassium homeostasis by modulating intracellular renin trafficking.

BACKGROUND: Genome-wide association studies (GWASs) have linked RRBP1 (ribosomal-binding protein 1) genetic variants to atherosclerotic cardiovascular diseases and serum lipoprotein levels. However, how RRBP1 regulates blood pressure is unknown. METHODS: To identify genetic variants associated with blood pressure, we performed a genome-wide linkage analysis with regional fine mapping in the Stanford Asia-Pacific Program for Hypertension and Insulin Resistance (SAPPHIRe) cohort. We further investigated the role of the RRBP1 gene using a transgenic mouse model and a human cell model. RESULTS: In the SAPPHIRe cohort, we discovered that genetic variants of the RRBP1 gene were associated with blood pressure variation, which was confirmed by other GWASs for blood pressure. Rrbp1- knockout (KO) mice had lower blood pressure and were more likely to die suddenly from severe hyperkalemia caused by phenotypically hyporeninemic hypoaldosteronism than wild-type controls. The survival of Rrbp1-KO mice significantly decreased under high potassium intake due to lethal hyperkalemia-induced arrhythmia and persistent hypoaldosteronism, which could be rescued by fludrocortisone. An immunohistochemical study revealed renin accumulation in the juxtaglomerular cells of Rrbp1-KO mice. In the RRBP1-knockdown Calu-6 cells, a human renin-producing cell line, transmission electron and confocal microscopy revealed that renin was primarily retained in the endoplasmic reticulum and was unable to efficiently target the Golgi apparatus for secretion. CONCLUSIONS: RRBP1 deficiency in mice caused hyporeninemic hypoaldosteronism, resulting in lower blood pressure, severe hyperkalemia, and sudden cardiac death. In juxtaglomerular cells, deficiency of RRBP1 reduced renin intracellular trafficking from ER to Golgi apparatus. RRBP1 is a brand-new regulator of blood pressure and potassium homeostasis discovered in this study.

Iodine nutritional status of pregnant women in an urban area of northern Taiwan in 2018.

Pregnant women are considered as one of the most vulnerable groups for iodine deficiency. The Nutrition and Health Survey in Taiwan 2013 revealed that the median urinary iodine concentration (UIC) of non-pregnant women of child-bearing age of 15-44 years was 124 µg/L, which was adequate in general, but insufficient according to pregnancy criteria. The aim of this study was to determine the iodine nutritional status of pregnant women in an urban area of Northern Taiwan. A hospital-based cross-sectional survey was conducted in Taipei Veterans General Hospital. Random spot urine samples were collected from January to October, 2018 and UIC was determined by inductively coupled plasma mass-spectrometry. A food frequency questionnaire was also delivered to the participants. The overall median UIC was 225.3 µg/L (IQR: 109.1-514.2 µg/L) for 257 pregnant women ranging from 21-47 years-old. The distribution of UIC was as follows: 35.4% with UIC <150 µg/L, 17.1% with UIC within 150-249 µg/L, 21.8% with UIC within 250-499 µg/L, and 25.7% with UIC ≥500 µg/L. The use of prenatal multivitamin was very common among the participants: 79.4% (n = 204) took multivitamin either every day or less frequently, with 52.5% (n = 135) taking one pill every day, and only 20.6% (n = 53) never took multivitamin during their pregnancy. Other commonly consumed iodine-containing foods were dairy products and fish. Our results indicate that the iodine status in the studied women is adequate. However, efforts are still needed to avoid iodine deficiency as well as iodine excess.

Hospitalization in patients with type 2 diabetes mellitus in Taiwan: A nationwide population-based observational study.

BACKGROUND/PURPOSE: We investigated hospitalization rates of patients with type 2 diabetes mellitus (T2DM) and individuals without diabetes mellitus (non-DM) in a disease-specific manner from 2005 to 2014 in Taiwan. METHODS: This population-based study was conducted using data from the National Health Insurance Research Database. We analyzed the hospitalization rates of patients with and without T2DM. We collected up to five diagnostic codes given at discharge for each hospitalization, and the first one was considered the main diagnosis. Odds ratios were determined to assess the risk of hospitalization according to disease-specific classifications in patients with T2DM compared with those without T2DM. RESULTS: The hospitalization rates of non-DM patients was stable from 2005 to 2014. By contrast, the rate of hospitalization among patients with T2DM decreased from 395.4 (per 1000 person-years) in 2005 to 336.9 (per 1000 person-years) in 2014. An increase in hospitalization rates for malignancies and sepsis/infection (other than pneumonia) was observed from 2005 to 2014 in both patients with and without T2DM. Although patients with T2DM had a higher hospitalization risk for all the disease-specific classifications than non-DM patients, this difference in risk decreased from 2005 to 2014 for all diseases except pneumonia. CONCLUSION: Hospitalization rates for malignancies and sepsis/infection (other than pneumonia) continually increased from 2005 to 2014 in Taiwan. Although patients with T2DM had a greater risk of disease-specific hospitalization than those without, this difference in risk decreased from 2005 to 2014 for all diseases except for pneumonia.

Effect of growth hormone on dawn phenomenon in patients with type 2 diabetes.

We aimed to investigate the involvement of growth hormone in dawn phenomenon and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM). On six occasions separated by intervals of at least 3 days, subjects received early evening (16:00 hours) or late night (23:00 hours) pretreatment with subcutaneous injection of normal saline, human growth hormone, or octreotide. Modified euglycemic insulin clamp test was done 16 hours later and variable glucose infusion (M values) was determined. Plasma glucose, serum insulin, insulin-like growth factor-1, non-esterified fatty acids, and metabolic clearance rate of insulin (MCRI) were measured. Early evening application of growth hormone decreased MCRI 16 hours later, suggesting reduction in insulin sensitivity. Exogenous growth hormone injection reduced insulin sensitivity in T2DM patients. Results provide direct evidence for the role of growth hormone in regulating the insulin sensitivity in insulin-resistant patients.

Acarbose improves glycemic control in insulin-treated Asian type 2 diabetic patients: results from a multinational, placebo-controlled study.

The purpose of the study was to determine the efficacy and tolerability of acarbose in Asian type 2 diabetic patients insufficiently controlled by insulin. Asian type 2 diabetic patients on stable insulin dosages were enrolled into a multinational, double-blind, placebo-controlled parallel arm study. After a 2-week screening phase, patients were randomly assigned to 50 mg acarbose t.i.d. or matching placebo for 6 weeks, followed by 100 mg acarbose t.i.d. or placebo for 12 weeks. The primary efficacy parameter was change from baseline in HbA(1c); secondary variables included the changes in fasting and postprandial blood glucose. After 18 weeks of treatment there was a difference in HbA(1c) levels between the two treatment groups (-0.69%, 95% CI (-1.18; -0.2), P=0.008) in favour of acarbose. Reductions in 1-h postprandial glucose levels from baseline to endpoint were observed with acarbose treatment (P=0.029). There were no differences in fasting blood glucose, total triglyceride and cholesterol between the two groups. Safety profiles were similar for both treatment arms except for the higher incidence of flatulence in the acarbose group (28.6% vs. 16.4% for placebo). Adjunctive acarbose therapy offers an efficacious and safe means for improvement of glycemic control in Asian type 2 diabetic patients insufficiently controlled by insulin.