Survey of the current status of subclinical coronavirus disease 2019 (COVID-19).

OBJECTIVES: We investigated relationships between subclinical COVID-19 (coronavirus disease 2019) and background factors. METHODS: We determined SARS-CoV-2 antibody (IgG) prevalence in 1603 patients, doctors, and nurses in 65 medical institutions in Kanagawa Prefecture, Japan and investigated their background factors. Antibodies (IgG) against SARS-CoV-2 were analyzed by Immunochromatographic test. RESULTS: The 39 subjects (2.4%) were found to be IgG antibody-positive: 29 in the patient group (2.9%), 10 in the doctor/nurse group (2.0%), and 0 in the control group. After adjustment for age, sex, and the antibody prevalence in the control group, antibody prevalence was 2.7% in the patient group and 2.1% in the doctor/nurse group. There was no significant difference between the antibody-positive subjects and the antibody-negative subjects in any background factors investigated including overseas travel, contact with overseas travelers, presence/absence of infected individuals in the living area, use of trains 5 times a week or more, BCG vaccination, and use of ACE inhibitor and ARB. CONCLUSIONS: Antibody prevalence in the present survey at medical institution is higher than that in Tokyo and in Osaka measured by the government suggesting that subclinical infections are occurring more frequently than expected. No background factor that influenced antibody-positive status due to subclinical infection was identified.

Population-based cross-sectional study on insulin resistance and insulin-secretory capacity in Japanese school children.

AIMS/INTRODUCTION: Little information is available regarding the status of insulin resistance (IR) and insulin deficiency (ID), as well as their relationship with obesity in children using the homeostasis model assessment (HOMA) in a population-based setting. MATERIALS AND METHODS: The study included a total of 445 ninth-grade children participating in health check-up programs implemented in Tsunan Town, Niigata, Japan (boys/girls, 252/193 [participation rates: 98.1/95.5%]). HOMA of insulin resistance ≥2.5 was defined as IR, and HOMA of ß-cell function <40 defined as ID. RESULTS: The medians (25-75th percentiles) of HOMA of insulin resistance, HOMA of ß-cell function, Disposition Index and body mass index in boys were 1.2 (0.8-1.7), 64 (44-93), 52 (43-64) and 19.2 (18.0-20.7) kg/m2 , respectively, vs 1.5 (1.0-2.0), 86 (63-120), 60 (50-74) and 20.4 (18.9-22.0) kg/m2 , respectively, in girls. The HOMA of insulin resistance, HOMA of ß-cell function and Disposition Index values were significantly higher in the girls (P = 0.002, P < 0.001 and P < 0.001, respectively). Those with IR accounted for a significantly higher proportion of girls than boys (15.5/8.7%; P = 0.027); those with obesity accounted for 9.9/10.7% (boys/girls); and those with IR and obesity accounted for 2.4/4.7%. Those with ID accounted for a significantly higher proportion of boys than girls (20.6/8.8%; P = 0.001), whereas those with ID and obesity accounted for a very small proportion of either group (0.4/0.5%). CONCLUSIONS: The presence of IR was higher among the girls. In contrast, ID was more frequent among the boys. The infrequent presence of ID among children might support the presence of non-obese type 2 diabetes adults in Japan.

Validity of salt intake assessment system based on a 24-h dietary recall method using a touch panel computer.

BACKGROUND: An electronic system for salt intake assessment using a 24-h dietary recall method has been developed in Japan. We evaluated the validity of this salt intake system for assessing salt intake. METHODS: We prospectively obtained data on estimated salt intake using 24-hour urinary sodium excretion (24-hUNaCl) and salt intake by the salt intake assessment system from 203 consecutive outpatients with essential hypertension (age: 67.8 ± 10.7 years; 53.7% men). RESULTS: Mean values were 9.7 ± 2.9 g/day for 24-hUNaCl and 9.1 ± 2.9 g/day for the salt intake assessment system before corrections. The salt intake estimated by the present system was significantly correlated with 24-hUNaCl (r = 0.66, p < 0.0001). After corrections for habitual use of discretionary seasonings, habitual intake of salty foods, and physical activity, correlation coefficients between salt intake and 24-hUNaCl increased from 0.60 to 0.66 in men <65 years, from 0.80 to 0.81 in men ≥ 65 years, from 0.64 to 0.75 in women <65 years, and from 0.52 to 0.59 in women ≥ 65 years. After further correction for regional differences in average salt intake, the correlation coefficient reached 0.72 in all patients. CONCLUSION: After correction for dietary habits, lifestyle factors, and differences in average salt intake by region, this system may be a useful tool in Japan to encourage salt restriction in the clinical treatment of hypertension and improve public health in terms of salt restriction overall.

Low prevalence of metabolic syndrome and its components in rural Japan.

Tsunan, Niigata is a non-westernized rural Japanese town, known for heavy snowfalls and as a rice-producing area, whose inhabitants have a long life expectancy. We investigated the prevalence of obesity, metabolic syndrome (MetS) and its components in Tsunan. A total of 1,155 men and women, 40-69 years of age were recruited from participants in the 2005 public-health program in Tsunan. Obesity was defined as body-mass index (BMI) >or= 25 kg/m(2). MetS was defined as BMI >or= 25 kg/m(2) as well as at least two of the following three items: (1) high glycosylated hemoglobin (HbA1c >or= 5.5%); (2) high blood pressure (HBP: systolic blood pressure >or= 130 mmHg or diastolic blood pressure >or= 85 mmHg), and (3) low high-density lipoprotein cholesterol (HDL-C < 40 mg/dL). If an individual was diagnosed with diabetes, hypertension, or dyslipidemia, each item was recorded as a positive finding. The prevalence of MetS and its components among Tsunan inhabitants were compared to the results of the 2005 Japanese nationwide survey. The prevalence of MetS was 4.6% in males and 4.2% in females. The prevalence of obesity, high HbA1c, HBP, and low HDL-C were 22.1/22.2%, 13.4/16.4%, 46.6/40.0%, and 9.2/3.9% in males/females, respectively. All values were significantly lower than the national results, except for the rate of female obesity. The lower prevalence of MetS and its components in Tsunan may be due to the consumption of traditional Japanese food, which is still commonly eaten there, and the higher levels of regular physical activity of farmers.