Objective: Some reports have described the effects of sleep on development of diabetes mellitus and cardiovascular diseases; however, the importance of appropriate sleep is not well understood by health care workers at Ningen Dock.

Methods: We obtained data from 8,124 examinees who underwent the annual Ningen Dock in both 2015 and 2020 fiscal years and analyzed their laboratory data and responses to medical interviews, including responses regarding sleep time and bedtime irregularity.

Results: The median sleep duration was 6 hours, and sleep duration was less than 6 hours in 26.6% of the examinees. We observed newly diagnosed diabetes mellitus in 136 examinees (1.7%) and newly diagnosed cardiovascular disease in 179 examinees (2.2%) during the study period. On multivariate analysis of age, sex, smoking status, BMI, systolic blood pressure, LDL cholesterol, HbA1c, and 6 lifestyle habits including sleep duration less than 6 hours and sleep irregularity, sleep duration less than 6 hours (odds ratio 1.87) was identified as a predictor of diabetes mellitus and bedtime irregularity (odds ratio 1.74) as a predictor of cardiovascular disease. Lifestyle habits related to diet and exercise were not proven to be predictors of these diseases.

Conclusions: Short sleep duration less than 6 hours and bedtime irregularity may be predictors of diabetes and cardiovascular disease, respectively.

Objective: At our center, persons identified during a detailed medical checkup as requiring medical care or more detailed examination are issued a referral letter on the day of the checkup. They are also advised to undergo medical examination during an interview to communicate the checkup results and in health guidance sessions, as well as by telephone or letter on a later date. The objectives of this study were to compare the timing of undergoing close examinations and factors promoting consultation behavior; to determine the effectiveness of our efforts and areas that need to be reinforced in order to further improve the rate of undergoing close examination; and to investigate those methods of recommending detailed examination that best lead to consultation behavior.

Methods: Among those who underwent thorough medical checkups between June 9, 2020 and September 30, 2020, 354 examinees who had been issued a referral letter in the previous year (380 examination items) were included in the study. The subjects were classified by the interval from the time they underwent the health checkup to the time they underwent detailed examination. They were also administered a questionnaire to determine the factors that influenced their decision to undergo detailed examination.

Results: Among the items examined in detailed examinations, 90.9% were examined less than 3 months after the health checkup. After 3 months, many of the items recommended for detailed examination remained unexamined. The most common factor influencing the decision to undergo detailed examination was “recommendation by the center to undergo examination on the day of the health checkup”, regardless of the timing of undergoing detailed examination. Other factors influencing the decision to undergo detailed examinations within 3 months were “information on medical institutions,” “awareness of the need to undergo examination,” and “surrounding environment.”

Conclusion: Patients were more likely to undergo detailed medical examination within 3 months after a health checkup. The recommendation to undergo examination on the day of the health checkup was the most important factor that led to consultation behavior. These results suggest that increasing examinees’ willingness to undergo detailed examination on the day of their health checkup and encouraging them to do so within 3 months after the checkups are effective methods of recommending detailed examination that lead to consultation behavior.

Objective: Although hypertension is an important cause of cardiovascular disease, there are many people with untreated hypertension for whom health checkups play an important role. In this study, we investigated the effect of recommending medical examinations to persons with untreated hypertension on the day of occupational health checkups.

Methods: Persons with untreated hypertension of grade II-III (JSH2019) were interviewed on the day of a health checkup and advised to undergo a medical examination. At the interview, a specific plan for visiting the clinic in accordance with their work style and living environment was made, and health guidance on lifestyle modification and home blood pressure measurement was given. Subjects were contacted by telephone 1 month later to confirm their hypertension treatment status. A follow-up survey was also conducted at the next year’s health checkup.

Results: Of the 7,717 persons who underwent health checkups, 315 (4.1%) had untreated hypertension of grade II-III, of whom 278 were interviewed and recommended to undergo medical examination. Of the 241 persons who could be followed 1 month later, 108 (44.8%) had already undergone a medical examination, 60 (24.9%) planned to undergo an examination, 56 (23.2%) were considering undergoing an examination, and 17 (7.1%) had no intention to undergo an examination. The rate of undergoing medical examinations tended to be higher in women, persons of advanced age, those with grade III hypertension, and those with other risk factors for arteriosclerosis. One month after the interview, efforts to improve lifestyle habits were improved compared with those before the interview, and efforts to reduce salt intake and increase vegetable intake were also significantly improved, even in persons who had not undergone medical examinations. In the follow-up survey conducted at the next year’s health checkup, the hypertension treatment rate was significantly higher among those who were interviewed compared to those who were not, and a significant improvement in blood pressure level was also observed among those who had not received treatment.

Conclusion: Interviews and health guidance on the day of occupational health checkups were effective in improving the hypertension treatment rate and modifying lifestyle habits. They also led to lifestyle modification and blood pressure improvement in persons who had not received treatment.

Objective: The objective of this study was to examine the significance of measuring serum 25(OH) vitamin D concentration at Ningen Dock.

Methods: We examined the relationships between 25(OH)D and bone mineral density, age, BMI, nutrition, renal function, bone metabolism, and glucose metabolism in 1,333 subjects whose serum 25(OH) vitamin D (25(OH)D) was measured during the year from April 2021 at our clinic’s Ningen Dock.

Results: Vitamin D deficiency (serum 25(OH)D: <20 ng/mL) and insufficiency (≥20 and <30 ng/mL) were common in both sexes and were found in 82% of all subjects. Multiple regression analysis showed that 25(OH)D and Cr were factors that increased bone mineral density in women <50 years. In addition, 25(OH)D was significantly lower in the group with abnormal glucose metabolism (HbA1c≥5.6%) than in subjects with normal levels. In addition, the number of cases with abnormal glucose metabolism were higher in those aged ≥50 years, and HbA1c was one of the factors for decreasing bone mineral density in male ≥ 50 years.

Conclusion: The overall frequency of vitamin D deficiency/insufficiency was high, at more than 80%. At Ningen Dock, it may be worthwhile to measure 25(OH)D in women <50 years and to provide dietary and sun exposure guidance in patients with deficiencies. Future studies on the relationships among abnormal glucose metabolism, 25(OH)D, and bone mineral density are warranted.

  Gastroesophageal reflux disease is a condition in which gastric contents flow back into the esophagus due to dysfunction of the lower esophageal sphincter. The number of patients with this disease is increasing worldwide, and reflux symptoms can lead to a decline in quality of life. Although proton pump inhibitors are effective, many patients are refractory to treatment. In these cases, cardioplasty may be an option, but is associated with the risk of complications and is often ineffective. The LINX Reflux Management System was approved by the U.S. Food and Drug Administration in 2012 as a treatment to bridge the gap between medical and surgical therapies. This system consists of a ring-shaped device made of multiple magnetic titanium beads tied together with a wire which is laparoscopically placed around the esophagogastric junction to enhance the function of the lower esophageal sphincter by magnetic force, thereby preventing reflux. Although not covered by health insurance in Japan, this system is widely used overseas with documented efficacy and safety. In this report, we performed upper gastrointestinal series on a health checkup examinee with an implanted LINX device and confirmed by imaging that there was no problem with the open/close function of the LINX device. In Japan, the opportunity to perform upper gastrointestinal series on patients with an implanted LINX device at health checkup facilities is expected to increase. Knowledge of the LINX Reflux Management System should be deepened to allow such patients to be accepted without hesitation.

Objective: To investigate the number of ventilations under various ventilation conditions of a cardiovascular medical examination car and to propose appropriate ventilation methods.

Methods: A cardiovascular medical examination car was filled up with high-concentration CO₂ gas with dry ice under the following conditions: (1) each window opened at 5 cm, (2) “Low” front and rear ventilation fans, (3) “High” front ventilation fan and “Low” rear ventilation fan, (4) “Low” front and rear ventilation fans and each window opened at 5cm and (5) “High” front ventilation fan and “Low” rear ventilation fan and each window opened at 5cm. CO₂ ventilation is performed under five conditions of window opening 5 cm. The number of ventilations was determined using the Seidel equation based on the change in the gas concentration.

Results: Conditions (1), (4), and (5) resulted in more than 12 ventilations per hour in the US Centers for Disease Control and Prevention (CDC) and infection isolation wards in Japan. Specifically, conditions (4) and (5) demonstrated at least 20 ventilations per hour.

Conclusions: If conditions (1), (4), and (5) represent sufficient ventilation frequency and the adverse effects due to the noise of the ventilation fan are minimal, condition (4) can be recommended for use in a cardiovascular medical examination car.

Objective: This study examined the effectiveness and challenges of the PDCA cycle-based operational improvement process over time. The aim was to increase the same-day implementation rate of specific health guidance (hereinafter referred to as “implementation rate”).

Methods: The implementation rate for FY2017-2020 was calculated. Business improvement processes aimed at increasing the implementation rate were summarized according to fiscal year. Furthermore, reasons for not implementing same-day specific health guidance in FY2019-2020 were ascertained from health guidance records and categorized.

Results: The implementation rates (number of persons implemented/year) for FY2017-2020 were 8% (73 persons/2017), 21% (158 persons/2018), 49% (384 persons/2019), and 54% (483 persons/2020). Although the implementation rate was steadily increasing, 40% of the reasons for non-implementation in 2019 were due to facility-side causes: omission of eligible patients, staff availability (staff schedule conflicts), and time required for stratification. As a result of focusing on the facility side and improving operations, the number of reasons for non-implementation in FY2020 due to the facility side decreased to 7%.

Conclusion: It is suggested that the increase in implementation rate may have been effected by the continuous improvement of business operations and systems per the PDCA cycle, strengthening the structure, system utilization, and increased manpower from the viewpoint of the target person.