Height, body mass index, physical activity, and risk of colorectal cancer in relation to expression of insulin receptor: The Japan Public Health Center-based Prospective Study.

To ascertain the involvement of insulin receptors (IRs) in colorectal carcinogenesis, we investigated the association of height, body mass index (BMI), and physical activity with colorectal cancer (CRC) and two subtypes of CRC according to the expression level of IR. We utilized data from a large-scale, population-based prospective cohort study of 18,158 middle-aged and elderly subjects in Akita and Okinawa, Japan. In the statistical analysis, we used the Cox proportional hazards model and estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of CRC and its subtypes as defined by immunohistochemistry of IRß, a transmembrane subunit of IR. In the IRß-defined subtypes, height showed no apparent association with the risk of IRß-positive CRC. In contrast, a multivariable HR of IRß-positive CRC was 1.77 (95% CI = 1.04-3.03) with a BMI of ≥30.0 kg/m2 (i.e., obesity), compared to a BMI of <25.0 kg/m2. Further, an increase in physical activity was significantly associated with decreased risk of IRß-positive CRC (multivariable HR per 5 METs-hour/day = 0.93, 95% CI = 0.88-0.99). Meanwhile, we found no significant association between any exposure and IRß-negative CRC. Likewise, heterogeneity between the two subtypes of CRC was not statistically significant. These findings imply that obesity and physical activity exert promoting and suppressing effects on the development of CRC expressing IRs, respectively.

Third Report of the Japan Diabetes Society/Japanese Cancer Association Joint Committee on Diabetes and Cancer: Summary of the results of a questionnaire survey of oncologists and diabetologists-Secondary publication.

The Japan Diabetes Society and the Japan Cancer Association launched a joint committee and published their "First Joint Committee Report on Diabetes and Cancer" in 2013, compiling recommendations for physicians and health-care providers as well as for the general population. In 2016, the "Second Joint Committee Report on Diabetes and Cancer" summarized the current evidence on glycemic control and cancer risk in patients with diabetes. The current "Third Joint Committee Report on Diabetes and Cancer", for which the joint committee also enlisted the assistance of the Japanese Society of Clinical Oncology and the Japanese Society of Medical Oncology, reports on the results from the questionnaire survey, "Diabetes Management in Patients Receiving Cancer Therapy," which targeted oncologists responsible for cancer management and diabetologists in charge of glycemic control in cancer patients. The results of the current survey indicated that there is a general consensus among oncologists and diabetologists with regard to the need for guidelines on glycemic control goals, the relevance of glycemic control, and glycemic control during cancer therapy in cancer patients.

Preparation of Block Copolymer Self-Assemblies via Pisa in a Non-Polar Medium Based on RCMP.

Polymerization-induced self-assembly (PISA) is conducted in a non-polar medium (n-dodecane) via reversible complexation-mediated polymerization (RCMP). Stearyl methacrylate (SMA) is used to synthesize a macroinitiator, and subsequent block polymerization of benzyl methacrylate (BzMA) from the macroinitiator in n-dodecane afforded a PSMA-PBzMA block copolymer, where PSMA is poly(stearyl methacrylate) and PBzMA is poly(benzyl methacrylate). Because PSMA is soluble but PBzMA is insoluble in n-dodecane, the block copolymer formed a self-assembly during the block polymerization (PISA). Spherical micelles, worms, and vesicles are obtained, depending on the degrees of polymerization of PSMA and PBzMA. "One-pot" PISA is also attained; namely, BzMA is directly added to the reaction mixture of the macroinitiator synthesis, and PISA is conducted in the same pot without purification of the macroinitiator. The spherical micelle and vesicle structures are also fixed using a crosslinkable monomer during PISA. RCMP-PISA is highly attractive as it is odorless and metal-free. The "one-pot" synthesis does not require the purification of the macroinitiator. RCMP-PISA can provide a practical approach to synthesize self-assemblies in non-polar media.

Comparison of instrumental variable methods with continuous exposure and binary outcome: A simulation study.

BACKGROUND: Instrumental variable (IV) methods are widely employed to estimate causal effects when concerns regarding unmeasured confounders. Although comparisons among several IV methods for binary outcomes exist, comprehensive evaluations are insufficient. Therefore, in this study, we aimed to conduct a simulation with some settings for a detailed comparison of these methods, focusing on scenarios where IVs are valid and under effect homogeneity with different instrument strengths. METHODS: We compared six IV methods under 32 simulation scenarios: two-stage least squares (2SLS), two-stage predictor substitutions (2SPS), two-stage residual inclusions (2SRI), limited information maximum likelihood (LIML), inverse-variance weighted methods with a linear outcome model (IVWLI), and inverse-variance weighted methods with a non-linear model (IVWLL). By comparing these methods, we examined three key estimates: the parameter estimates of the exposure variable, the causal risk ratio, and the causal risk differences. RESULTS: Based on the results, six IV methods could be classified into three groups: 2SLS and IVWLI, 2SRI and 2SPS, and LIML and IVWLL. The first pair showed a clear bias owing to outcome model misspecification. The second pair showed a relatively good performance when strong IVs are available; however, the estimates suffered from a significant bias when only weak IVs are used. The third pair produced relatively conservative results, although they were less affected by weak IV issues. CONCLUSIONS: The findings indicate that no panacea is available for the bias associated with IV methods. We suggest using multiple IV methods: one for primary analysis and another for sensitivity analysis.

Confounder Selection and Sensitivity Analyses to Unmeasured Confounding from Epidemiological and Statistical Perspectives.

In observational studies, identifying and adjusting for a sufficient set of confounders is crucial for accurately estimating the causal effect of the exposure on the outcome. Even in studies with large sample sizes, which typically benefit from small variances in estimates, there is a risk of producing estimates that are precisely inaccurate if the study suffers from systematic errors or biases, including confounding bias. To date, several approaches have been developed for selecting confounders. In this article, we first summarize the epidemiological and statistical approaches to identify a sufficient set of confounders. Particularly, we introduce the modified disjunctive cause criterion as one of the most useful approaches, which involves controlling for any pre-exposure covariate that affects the exposure, outcome, or both. It then excludes instrumental variables but includes proxies for the shared common cause of exposure and outcome. Statistical confounder selection is also useful when dealing with a large number of covariates, even in studies with small sample sizes. After introducing several approaches, we discuss some pitfalls and considerations in confounder selection, such as the adjustment for instrumental variables, intermediate variables, and baseline outcome variables. Lastly, as it is often difficult to comprehensively measure key confounders, we introduce two statistics, E-value and Robustness value, for assessing sensitivity to unmeasured confounders. Illustrated examples are provided using the National Health and Nutritional Examination Survey Epidemiologic Follow-up Study. Integrating these principles and approaches will enhance our understanding of confounder selection and facilitate better reporting and interpretation of future epidemiological studies.

Importance of circulating leptin and adiponectin in the causal pathways between obesity and the development of colorectal cancer in Japanese men.

BACKGROUND: The mechanistic associations between obesity and risk of colorectal cancer (CRC) remain unclear. Here, using body mass index (BMI) as an obesity indicator, we decomposed the total effects of obesity on the risk of CRC into: (1) direct effects, which are possibly mediated by unmeasured or currently unknown factors; (2) indirect effects mediated by circulating leptin and adiponectin; and (3) indirect effects that are not mediated by circulating leptin and adiponectin but by hyperinsulinemia and chronic inflammation (assessed via circulating connecting peptide and C-reactive protein, respectively). METHODS: We adopted a causal mediation framework, using data from a large prospective cohort study of 44,271 Japanese men. RESULTS: BMI was not associated with the risk of CRC due to direct and indirect effects that were not mediated by circulating leptin and adiponectin. By contrast, individuals with BMIs of 25.0-27.4 kg/m2 (risk ratio, 1.29; 95% confidence interval, 0.98-1.69) and ≥27.5 kg/m2 (risk ratio, 1.28; 95% confidence interval, 0.98-1.68) had a higher risk of CRC due to indirect effects of circulating leptin and adiponectin. CONCLUSIONS: Our mediation analyses suggest that the association between BMI and CRC risk may be largely mediated by a pathway involving circulating leptin and adiponectin.

Development and Validation of Prediction Models for the 5-year Risk of Type 2 Diabetes in a Japanese Population: Japan Public Health Center-based Prospective (JPHC) Diabetes Study.

BACKGROUND: This study aimed to develop models to predict the 5-year incidence of type 2 diabetes mellitus (T2DM) in a Japanese population and validate them externally in an independent Japanese population. METHODS: Data from 10,986 participants (aged 46-75 years) in the development cohort of the Japan Public Health Center-based Prospective Diabetes Study and 11,345 participants (aged 46-75 years) in the validation cohort of the Japan Epidemiology Collaboration on Occupational Health Study were used to develop and validate the risk scores in logistic regression models. RESULTS: We considered non-invasive (sex, body mass index, family history of diabetes mellitus, and diastolic blood pressure) and invasive (glycated hemoglobin [HbA1c] and fasting plasma glucose [FPG]) predictors to predict the 5-year probability of incident diabetes. The area under the receiver operating characteristic curve was 0.643 for the non-invasive risk model, 0.786 for the invasive risk model with HbA1c but not FPG, and 0.845 for the invasive risk model with HbA1c and FPG. The optimism for the performance of all models was small by internal validation. In the internal-external cross-validation, these models tended to show similar discriminative ability across different areas. The discriminative ability of each model was confirmed using external validation datasets. The invasive risk model with only HbA1c was well-calibrated in the validation cohort. CONCLUSION: Our invasive risk models are expected to discriminate between high- and low-risk individuals with T2DM in a Japanese population.

Validity of self-reported Helicobacter pylori eradication treatment from questionnaire and interview surveys of the JPHC-NEXT study: comparison with prescription history from insurance claims data.

BACKGROUND: We aimed to evaluate the validity of self-administered questionnaire surveys and face-to-face interview surveys for the detection of Helicobacter pylori eradication therapy. METHODS: Participants were a cohort, aged 40-74 years, living in three different locations of Japan, who took part in the baseline survey (2011-2012) of the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT). Five years after the baseline survey, a questionnaire and interview survey were independently conducted to determine the history of Helicobacter pylori eradication treatment over the 5-year period. Prescription of Helicobacter pylori eradication medications in national insurance claims data from the baseline survey to the 5-year survey was used as a reference standard. RESULTS: In total, 15,760 questionnaire surveys and 8,006 interview surveys were included in the analysis. There were 3,471 respondents to the questionnaire and 2,398 respondents to the interview who reported having received Helicobacter pylori eradication treatment within the past five years. Comparison of the questionnaire survey to national insurance claims data showed a sensitivity of 95.1% (2213/2328), specificity of 90.6% (12174/13432), positive predictive value of 63.8% (2213/3471), negative predictive value of 99.1% (12174/12289), and Cohen's Kappa value of 0.71. Respective values of the interview survey were 94.4% (1694/1795), 88.7% (5507/6211), 70.6% (1694/2398), 98.2% (5507/5608), and 0.74. CONCLUSION: Both the questionnaire and the interview showed high sensitivity, high specificity, and good agreement with the insurance claim prescriptions data. Some participants may have received eradication treatment without going through the public insurance claim database, resulting in a low positive predictive value.

GWAS meta-analysis of kidney function traits in Japanese populations.

BACKGROUND: Genetic epidemiological evidence for the kidney function traits in East Asian population including Japanese remain still relatively unclarified. Especially, the number of GWASs for kidney traits reported still remains limited, and the sample size of each independent study is relatively small. Given the genetic variability between ancestries/ethnicities, implementation of GWAS with sufficiently large sample sizes in specific population of Japanese is considered meaningful. METHODS: We conducted the GWAS meta-analyses of kidney traits by leveraging the GWAS summary data of the representative large genome cohort studies with about 200,000 Japanese participants (n = 202,406 for estimated glomerular filtration rate [eGFR] and n = 200,845 for serum creatinine [SCr]). RESULTS: In the present GWAS meta-analysis, we identified 110 loci with 169 variants significantly associated with eGFR (on chromosomes 1-13 and 15-22; p < 5×10-8), whereas we also identified 112 loci with 176 variants significantly associated with SCr (on chromosomes 1-22; p < 5×10-8), of which one locus (more than 1Mb distant from known loci) with one variant (CD36 rs146148222 on chromosome 7) for SCr was considered as the truly novel finding. CONCLUSIONS: The present GWAS meta-analysis of largest genome cohort studies in Japanese provided some original genomic loci associated with kidney function in Japanese, which may contribute to the possible development of personalized prevention of kidney diseases based on genomic information in the near future.

The epidemiology of postoperative dobutamine and phosphodiesterase inhibitors after adult elective cardiac surgery and its impact on the length of hospital stay: a post hoc analysis from the multicenter retrospective observational study.

The optimal administration of inotrope after cardiac surgery is unknown. This study aimed to investigate the impact of postoperative inotrope on clinical outcomes in adult elective cardiac surgery patients. Data from the Blood Pressure and Relative Optimal Target after Heart Surgery in Epidemiologic Registry study were analyzed, employing propensity score considering the hospital of admission. The primary outcome was the length of hospital stay evaluated using quantile regression. Secondary outcomes were kidney injury progression, renal replacement therapy, atrial fibrillation, mortality, mechanical ventilation duration, and length of intensive care unit (ICU) stay. Among 870 patients from 14 ICUs in Japan, 535 received inotropes within 24 h of ICU admission, with usage rates ranging from 40 to 100% among facilities. After propensity score matching, 218 patients were included in each group. The inotrope group had a significantly longer hospital stay compared to the control group (16 days vs. 14 days; median difference 1.78 [95% confidence interval [CI] 0.31-3.24]; p = 0.018). However, no significant differences were observed in the secondary outcomes, except for mechanical ventilation duration. The results of the sensitivity analysis using a mixed-effects quantile regression analysis considering the hospital of admission for length of hospital stay in the original cohort were consistent with the results of the propensity analyses (median difference in days, 2.35 [95% CI, 0.35-4.36]; p = 0.022). The use of inotropes within 24 h of ICU admission in adult elective cardiac surgery patients was associated with an extended hospitalization period of approximately 2 days, without offering any prognostic benefit. Clinical trial registration: UMIN-CTR, https://www.umin.ac.jp/ctr/index-j.htm , UMIN000037074.

Valid instrumental variable selection method using negative control outcomes and constructing efficient estimator.

In observational studies, instrumental variable (IV) methods are commonly applied when there are unmeasured covariates. In Mendelian randomization, constructing an allele score using many single nucleotide polymorphisms is often implemented; however, estimating biased causal effects by including some invalid IVs poses some risks. Invalid IVs are those IV candidates that are associated with unobserved variables. To solve this problem, we developed a novel strategy using negative control outcomes (NCOs) as auxiliary variables. Using NCOs, we are able to select only valid IVs and exclude invalid IVs without knowing which of the instruments are invalid. We also developed a new two-step estimation procedure and proved the semiparametric efficiency of our estimator. The performance of our proposed method was superior to some previous methods through simulations. Subsequently, we applied the proposed method to the UK Biobank dataset. Our results demonstrate that the use of an auxiliary variable, such as an NCO, enables the selection of valid IVs with assumptions different from those used in previous methods.

One-Pot Reversible Complexation-Mediated Polymerization (RCMP) from Benzylic Alcohols for Facile Access to Polymer-Grafted Lignin.

One-pot synthesis of methacrylic and acrylic polymers from benzylic alcohols (R-OH) used as initiating moieties was developed. R-OH was converted to alkyl iodide (R-I), and the generated R-I was used as an initiator without purification or isolation in the subsequent reversible complexation mediated polymerization (RCMP), leading to one-pot RCMP from R-OH. As a useful application, this technique was exploited for one-pot polymer-grafting from lignin that is the second most abundant renewable carbon-source on earth and bears benzylic alcohols. The direct initiation from lignin eliminates tedious initiator attachment and purification, offering a facile access to polymer-grafted lignin. The obtained polymer-grafted lignin was utilized to form an efficient UV-absorbing film with high transparency in visible region. One-pot RCMP may serve as a practical method to obtain value-added functional lignin-polymer composites.

Sugar intake and colorectal cancer risk: A prospective Japanese cohort study.

The influence of sugar consumption on the risk of colorectal cancer (CRC) remains controversial. Prospective cohort studies focusing on total and specific types of sugar intake among the Asian population who have different patterns of sugar intake sources than American and European populations are scarce. We intended to examine the association of sugar intake with CRC risk among middle-aged adults in a Japanese large-scale population-based cohort study. The participants (42,405 men and 48,600 women) who were 45-74 years old and answered the questionnaire in 1995-1999 in the Japan Public Health Center-based Prospective Study were followed up until December 2013. Total sugars, total fructose, and specific types of sugar intake were estimated using a validated 147-item food frequency questionnaire and divided into quintiles (Q1-Q5). We used Cox proportional hazard regression models adjusted for potential confounders to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During the follow-up, 2118 CRC cases (1226 men and 892 women) were identified. We did not observe any clear association between all types of sugar intake and an increased risk of CRC. Analyses by tumor sites yielded a positive association of total sugar consumption with rectal cancer in women (1.75 [1.07-2.87] for Q1 vs. Q5; p linear trend  = 0.03), but no statistically significant trend was detected among men. Sugar intake was not associated with CRC risk in middle-aged Japanese adults. However, for rectal cancer, the probability of an increased risk among women with a higher total sugar intake cannot be excluded.

Association of body mass index and weight change with pneumonia mortality in a Japanese population: Japan Public Health Center-based Prospective Study.

BACKGROUND: Accumulating evidence suggests that pneumonia mortality is lower for individuals with high body mass index (BMI) compared to normal BMI, but it remains unclear whether weight change during adulthood influences subsequent mortality due to pneumonia in Asian populations, who have a relatively lean body mass. This study aimed to examine the association of BMI and weight change over 5 years with the subsequent risk of pneumonia mortality in a Japanese population. METHODS: The present analysis included 79,564 Japan Public Health Center (JPHC)-based Prospective Study participants who completed a questionnaire between 1995 and 1998 were followed for death through 2016. BMI was categorized into four groups: underweight (<18.5 kg/m2), normal weight (BMI: 18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (BMI: ≥30.0 kg/m2). Weight change was defined as the difference of body weight between questionnaire surveys with a 5-year interval. Cox proportional hazards regression was used to estimate hazard ratios of baseline BMI and weight change for pneumonia mortality. RESULTS: During a median follow-up of 18.9 y, we identified 994 deaths from pneumonia. Compared with participants with normal weight, an elevated risk was observed among those who were underweight (hazard ratio = 2.29, 95% confidence interval [CI]: 1.83-2.87), whereas a decreased risk was found among those who were overweight (hazard ratio = 0.63, 95% CI: 0.53-0.75). Regarding weight change, the multivariable-adjusted hazard ratio (95% CI) of pneumonia mortality for a weight loss of 5 kg or more versus a weight change of less than 2.5 kg was 1.75 (1.46-2.10), whereas that for a weight gain of 5 kg or more was 1.59 (1.27-2.00). CONCLUSION: Underweight and greater weight change was associated with an increase in the risk of pneumonia mortality in Japanese adults.

Association of chronic kidney disease with total and site-specific cancer incidence in participants of the Japan Public Health Center-based Prospective Study.

BACKGROUND: Although studies have found an association between chronic kidney disease (CKD) and cancer incidence, the results are inconsistent. METHODS: This study included participants in the Japan Public Health Center-based Prospective Study who had data on serum creatinine measurements. We assessed the association between estimated glomerular filtration rate (eGFR) and the risk of total and site-specific cancer incidence using a systematic survey in Japan. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment for participant demographics and lifestyle factors. RESULTS: A total of 21 978 participants who met the inclusion criteria were followed up for a mean period of 12.9 years, during which a total of 2997 incident cancer cases were reported. In the multivariable adjusted models, an eGFR of <45 mL/min/1.73 m2 was not significantly associated with total cancer incidence (adjusted HR 1.22, 95% CI 0.94-1.60), compared with an eGFR of 60-89 mL/min/1.73 m2 (reference). The HR among those with eGFRs of ≥90 mL/min/1.73 m2 was 1.10 (95% CI 1.00-1.22). CONCLUSIONS: In this large prospective study, a low eGFR was not significantly associated with an increased risk of total cancer incidence in patients with CKD, which may be partly due to an underpowered sample size. This finding may be due to the many shared risk factors between CKD and cancer.

Cooperation between artificial intelligence and endoscopists for diagnosing invasion depth of early gastric cancer.

BACKGROUND AND STUDY AIMS: The diagnostic ability of endoscopists to determine invasion depth of early gastric cancer is not favorable. We designed an artificial intelligence (AI) classifier for differentiating intramucosal and submucosal gastric cancers and examined it to establish a diagnostic method based on cooperation between AI and endoscopists. PATIENTS AND METHODS: We prepared 500 training images using cases of mainly depressed-type early gastric cancer from 250 intramucosal cancers and 250 submucosal cancers. We also prepared 200 test images each of 100 cancers from another institution. We designed an AI classifier to differentiate between intramucosal and submucosal cancers by deep learning. We examined the performance of the AI classifier and the majority vote of the endoscopists as high confidence and low confidence diagnostic probability, respectively, and cooperatively combined them to establish a diagnostic method providing high accuracy. RESULTS: Internal evaluation of the training images showed that accuracy, sensitivity, specificity, and F1 measure by the AI classifier were 77%, 76%, 78%, and 0.768, and those of the majority vote of the endoscopists were 72.6%, 53.6%, 91.6%, and 0.662, respectively. A diagnostic method based on cooperation between AI and the endoscopists showed that the respective values were 78.0%, 76.0%, 80.0%, and 0.776 for the test images. The value of F1 measure was especially higher than those by AI or the endoscopists alone. CONCLUSIONS: Cooperation between AI and endoscopists improved the diagnostic ability to determine invasion depth of early gastric cancer.

Topology-Dependent pH-Responsive Actuation and Shape Memory Programming for Biomimetic 4D Printing.

Biomimetic actuators are critical components of bionics research and have found applications in the fields of biomedical devices, soft robotics, and smart biosensors. This paper reports the first study of nanoassembly topology-dependent actuation and shape memory programming in biomimetic 4D printing. Multi-responsive flower-like block copolymer nanoassemblies (vesicles) are utilized as photocurable printing materials for digital light processing (DLP) 4D printing. The flower-like nanoassemblies enhance thermal stability, attributed to their surface loop structures on the shell surfaces. Actuators prepared from these nanoassemblies display topology-dependent bending in response to pH and temperature-programmable shape memory properties. Biomimetic octopus-like soft actuators are programmed with multiple actuation patterns, large bending angles (≈500°), excellent weight-to-lift ratios (≈60), and moderate response time (≈5 min). Thus, nanoassembly topology-dependent and shape-programmable intelligent materials are successfully developed for biomimetic 4D printing.

Vitamin D intake and all-cause and cause-specific mortality in Japanese men and women: the Japan Public Health Center-based prospective study.

While higher circulating 25-hydroxyvitamin D concentrations have been reported to be associated with decreased risk of all-cause mortality, evidence on dietary vitamin D intake is limited and inconsistent. We investigated whether vitamin D intake is associated with all-cause and cause-specific mortality among Japanese adults. Participants were 42,992 men and 50,693 women who responded to the second survey of the Japan Public Health Center-based Prospective Study (1995-1998) and who were followed up for mortality through 2018. Dietary intake was ascertained using a validated food frequency questionnaire. Hazard ratios of deaths from the second survey to December 2018 were estimated using Cox proportional hazard regression analysis. During follow-up, we identified 22,630 deaths. Overall, the third and fourth quintiles, but not the highest quintile, of vitamin D intake were each associated with a significantly lower risk of all-cause mortality. In subgroups characterized by low sunlight exposure, risk of all-cause mortality decreased linearly with increasing vitamin D intake. The multivariable-adjusted hazard ratios (95% confidence intervals) of all-cause mortality for the highest versus lowest quintile of vitamin D intake were 0.87 (0.79-0.95) in women and 0.88 (0.79-0.97) in residents of higher latitude areas. Lower risk was also observed for all-cause mortality in participants with hypertension and for heart disease mortality in those with higher calcium intake. Higher vitamin D intake was associated with decreased risk of ischemic stroke and pneumonia mortality. Higher dietary vitamin D was associated with a lower risk of mortality among individuals with low sunlight exposure or hypertension. Individuals with potentially low vitamin D may benefit from increasing dietary vitamin D intake for the prevention of premature death.

Validation Study of Diabetes Definitions Using Japanese Diagnosis Procedure Combination Data Among Hospitalized Patients.

BACKGROUND: Validation studies of diabetes definitions using nationwide healthcare databases are scarce. We evaluated the validity of diabetes definitions using disease codes and antidiabetic drug prescriptions in the Japanese Diagnosis Procedure Combination (DPC) data via medical chart review. METHODS: We randomly selected 500 records among 15,334 patients who participated in the Japan Public Health Center-Based Prospective Study for the Next Generation in Yokote City and who had visited a general hospital in Akita between October 2011 and August 2018. Of the 500 patients, 98 were linked to DPC data; however, only 72 had sufficient information in the medical chart. Gold standard confirmation was performed by board-certified diabetologists. DPC-based diabetes definitions were based on the International Classification of Diseases, 10th Revision codes and antidiabetic prescriptions. Sensitivity, specificity, and the positive and negative predictive values (PPV and NPV, respectively) of DPC-based diabetes definitions were evaluated. RESULTS: Of 72 patients, 23 were diagnosed with diabetes using chart review; 19 had a diabetes code, and 13 had both a diabetes code and antidiabetic prescriptions. The sensitivity, specificity, PPV, and NPV were 89.5% (95% confidence interval [CI], 66.9-98.7%), 96.2% (95% CI, 87.0-99.5%), 89.5% (95% CI, 66.9-98.7%), and 96.2% (95% CI, 87.0-99.5%), respectively, for (i) diabetes codes alone; 89.5% (95% CI, 66.9-98.7%), 94.3% (95% CI, 84.3-98.8%), 85.0% (95% CI, 62.1-96.8%), and 96.2% (95% CI, 86.8-99.5%) for (ii) diabetes codes and/or prescriptions; 68.4% (95% CI, 43.4-87.4%), 100% (95% CI, 93.3-100%), 100% (95% CI, 75.3-100%), and 89.8% (95% CI, 79.2-96.2%) for (iii) both diabetes codes and prescriptions. CONCLUSION: Our results suggest that DPC data can accurately identify diabetes among inpatients using (i) diabetes codes alone or (ii) diabetes codes and/or prescriptions.

Long-term Response of Helicobacter pylori Antibody Titer After Eradication Treatment in Middle-aged Japanese: JPHC-NEXT Study.

BACKGROUND: Helicobacter pylori (H. pylori) is an established causative factor of gastric cancer. Although the expansion of insurance coverage has led to an increase in the number of patients treated for H. pylori, the population impact of eradication treatment for H. pylori has been scarcely investigated. This study aimed to clarify the long-term responses of H. pylori antibody titer after eradication treatment using large scale cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT Study). METHODS: A total of 55,282 Japanese participants aged 40 to 74 years residing in 16 areas provided blood samples from 2011 through 2016. From these, treated (n = 6,276) and untreated subjects who were seropositive for H. pylori or had serological atrophy (n = 22,420) formed the study population (n = 28,696). Seropositivity was defined as an anti-H. pylori IgG titer of ≥10 U/mL. Antibody level was compared among subjects according to self-reported treatment history as untreated, and treated for less than 1 year (<1Y), 1 through 5 years (1-5Y), and 6 or more years ago (6Y+). RESULTS: Median serum antibody titer was 34.0 U/mL, 7.9 U/mL, 4.0 U/mL, and 2.9 U/mL for the untreated, <1Y, 1-5Y, and 6Y+ groups, respectively. While those treated for H. pylori within the previous year had a 76.8% lower antibody titer compared to untreated subjects, approximately 41% of subjects were still seropositive. CONCLUSION: A significant reduction in H. pylori antibody titer occurs within 1 year after eradication treatment, but that a long period is needed to achieve complete negative conversion.