Sleep disordered breathing and haemoglobin A1c levels within or over normal range and ageing or sex differences: the Nagahama study.

Recently an association between blood glucose dysregulation and sleep disruption was suggested. The association between sleep disordered breathing, most of which is due to obstructive sleep apnea (OSA) in the general population, and diabetic severity, as well as the impact of antidiabetic treatment, remains unclear. This study aimed to investigate these associations as well as age and sex differences. This cross-sectional study evaluated 7,680 community participants as the main cohort (population-based cohort). OSA was assessed by the 3% oxygen desaturation index from pulse oximetry, which was corrected for sleep duration obtained by wrist actigraphy. For arguing the limitations for using pulse oximetry, 597 hospitalised patients, who were assessed by the apnea-hypopnea index from attended polysomnography, were also evaluated as the validation cohort (hospital-based cohort). Moderate-to-severe OSA was more prevalent as haemoglobin A1c (HbA1c) levels increased (<5.6%/5.6%-<6.5%/6.5%-<7.5%/≥7.5%, respectively) in both cohorts (p < 0.001), but only in those without antidiabetic treatment. The HbA1c level was an independent factor for moderate-to-severe OSA (population-based cohort, odds ratio [OR] 1.26, 95% confidence interval [CI] 1.10-1.45; hospital-based cohort, OR 1.69, 95% CI 1.22-2.33, per 1% increase). These associations were more prominent in the middle-aged (aged <60 years) than in the elderly (aged ≥60 years) and in women than in men in both cohorts. The prevalence of moderate-to-severe OSA in patients with antidiabetic treatment in the hospital-based cohort was ≥75% regardless of HbA1c levels. In conclusion, an association between the prevalence of OSA and HbA1c level even within or over the normal range was found only in patients without antidiabetic treatment and was more prominent in the middle-aged and in women.

Development and validation of prediction model for incident overactive bladder: The Nagahama study.

OBJECTIVES: We aimed to develop models to predict new-onset overactive bladder in 5 years using a large prospective cohort of the general population. METHODS: This is a secondary analysis of a longitudinal cohort study in Japan. The baseline characteristics were measured between 2008 and 2010, with follow-ups every 5 years. We included subjects without overactive bladder at baseline and with follow-up data 5 years later. Overactive bladder was assessed using the overactive bladder symptom score. Baseline characteristics (demographics, health behaviors, comorbidities, and overactive bladder symptom scores) and blood test data were included as predictors. We developed two competing prediction models for each sex based on logistic regression with penalized likelihood (LASSO). We chose the best model separately for men and women after evaluating models' performance in terms of discrimination and calibration using an internal validation via 200 bootstrap resamples and a temporal validation. RESULTS: We analyzed 7218 participants (male: 2238, female: 4980). The median age was 60 and 55 years, and the number of new-onset overactive bladder was 223 (10.0%) and 288 (5.8%) per 5 years in males and females, respectively. The in-sample estimates for C-statistic, calibration intercept, and slope for the best performing models were 0.77 (95% confidence interval 0.74-0.80), 0.28 and 1.15 for males, and 0.77 (95% confidence interval 0.74-0.80), 0.20 and 1.08 for females. Internal and temporal validation gave broadly similar estimates of performance, indicating low optimism. CONCLUSION: We developed risk prediction models for new-onset overactive bladder among men and women with good predictive ability.

Genome-wide association study of individual differences of human lymphocyte profiles using large-scale cytometry data.

Human immune systems are very complex, and the basis for individual differences in immune phenotypes is largely unclear. One reason is that the phenotype of the immune system is so complex that it is very difficult to describe its features and quantify differences between samples. To identify the genetic factors that cause individual differences in whole lymphocyte profiles and their changes after vaccination without having to rely on biological assumptions, we performed a genome-wide association study (GWAS), using cytometry data. Here, we applied computational analysis to the cytometry data of 301 people before receiving an influenza vaccine, and 1, 7, and 90 days after the vaccination to extract the feature statistics of the lymphocyte profiles in a nonparametric and data-driven manner. We analyzed two types of cytometry data: measurements of six markers for B cell classification and seven markers for T cell classification. The coordinate values calculated by this method can be treated as feature statistics of the lymphocyte profile. Next, we examined the genetic basis of individual differences in human immune phenotypes with a GWAS for the feature statistics, and we newly identified seven significant and 36 suggestive single-nucleotide polymorphisms associated with the individual differences in lymphocyte profiles and their change after vaccination. This study provides a new workflow for performing combined analyses of cytometry data and other types of genomics data.

Medical history of nocturnal enuresis during school age is an independent risk factor for nocturia in adults: The Nagahama study.

AIM: To evaluate the relationship between nocturia and medical history of nocturnal enuresis: two conditions where diurnal urination rhythm is disturbed. METHODS: The Nagahama study is a longitudinal population-based health survey involving people aged 30-75 years in Nagahama city, Japan. Our analysis included 5,402 participants who completed enuresis and International Prostate Symptom Score questionnaires. Associations between nocturnal enuresis and nocturia were evaluated cross-sectionally and longitudinally with three models: (1) univariate analysis; (2) adjusted for basic characteristics (e.g., age, sex, body mass index, activity, alcohol, and smoking); and (3) adjusted for basic and clinical variables (e.g., hyperglycemia, hyperlipidemia, hypertension, renal insufficiency, insomnia, obstructive sleep apnea, and mental health). RESULTS: In total, 1,613 participants (29.9%) had a medical history of enuresis. The mean night-time frequency was 0.73 at baseline and 0.85 at the 5-year follow-up. The cross-sectional analysis showed participants with a medical history of enuresis had night-time frequency more often than those without this history (0.84 vs. 0.68, p < .0001). Significant differences were observed in Models 2 (p < .0001) and 3 (p < .0001). The longitudinal analysis showed nocturia progression was significantly related to a history of enuresis, with odds ratios of 1.32 (p < .0001) in Model 1, 1.21 (p < .01) in Model 2, and 1.22 (p < .01) in Model 3. CONCLUSIONS: Medical history of enuresis during school age was significantly related to nocturia in adulthood in the cross-sectional analysis, and to progression to nocturia in the longitudinal analysis. These two conditions may possess a common causative association.

Protocol for development and validation of a prediction model for 5-year risk of incident overactive bladder in the general population: the Nagahama study.

BACKGROUND: An accurate prediction model could identify high-risk subjects of incident Overactive bladder (OAB) among the general population and enable early prevention which may save on the related medical costs. However, no efficient model has been developed for predicting incident OAB. In this study, we will develop a model for predicting the onset of OAB at 5-year in the general population setting. METHODS: Data will be obtained from the Nagahama Cohort Project, a longitudinal, general population cohort study. The baseline characteristics were measured between Nov 28, 2008 and Nov 28, 2010, and follow-up was performed every 5 years. From the total of 9,764 participants (male: 3,208, female: 6,556) at baseline, we will exclude participants who could not attend the follow-up assessment and those who were defined as having OAB at baseline. The outcome will be incident OAB defined using the Overactive Bladder Symptom Score (OABSS) at follow-up assessment. Baseline questionnaires (demographic, health behavior, comorbidities and OABSS) and blood test data will be included as predictors. We will develop a logistic regression model utilizing shrinkage methods (LASSO penalization method). Model performance will be evaluated by discrimination and calibration. Net benefit will be evaluated by decision curve analysis. We will perform an internal validation and a temporal validation of the model. We will develop a web-based application to visualize the prediction model and facilitate its use in clinical practice. DISCUSSION: This will be the first study to develop a model to predict the incidence of OAB.

Genetic determinants and an epistasis of LILRA3 and HLA-B*52 in Takayasu arteritis.

Takayasu arteritis (TAK) is a systemic vasculitis with severe complications that affects the aorta and its large branches. HLA-B*52 is an established susceptibility locus to TAK. To date, there are still only a limited number of reports concerning non-HLA susceptibility loci to TAK. We conducted a genome-wide association study (GWAS) and a follow-up study in a total of 633 TAK cases and 5,928 controls. A total of 510,879 SNPs were genotyped, and 5,875,450 SNPs were imputed together with HLA-B*52. Functional annotation of significant loci, enhancer enrichment, and pathway analyses were conducted. We identified four unreported significant loci, namely rs2322599, rs103294, rs17133698, and rs1713450, in PTK2B, LILRA3/LILRB2, DUSP22, and KLHL33, respectively. Two additional significant loci unreported in non-European GWAS were identified, namely HSPA6/FCGR3A and chr21q.22. We found that a single variant associated with the expression of MICB, a ligand for natural killer (NK) cell receptor, could explain the entire association with the HLA-B region. Rs2322599 is strongly associated with the expression of PTK2B Rs103294 risk allele in LILRA3/LILRB2 is known to be a tagging SNP for the deletion of LILRA3, a soluble receptor of HLA class I molecules. We found a significant epistasis effect between HLA-B*52 and rs103294 (P = 1.2 × 10-3). Enhancer enrichment analysis and pathway analysis suggested the involvement of NK cells (P = 8.8 × 10-5, enhancer enrichment). In conclusion, four unreported TAK susceptibility loci and an epistasis effect between LILRA3 and HLA-B*52 were identified. HLA and non-HLA regions suggested a critical role for NK cells in TAK.

Sleep disordered breathing and metabolic comorbidities across sex and menopausal status in East Asians: the Nagahama Study.

It is well known that the prevalence of sleep disordered breathing (SDB) is increased in patients with obesity or metabolic comorbidities. However, the way in which the prevalence of SDB increases in relation to comorbidities according to the severity of obesity remains unclear.This cross-sectional study evaluated 7713 community participants using nocturnal oximetry ≥2 nights. SDB was assessed by the 3% oxygen desaturation index corrected for sleep duration obtained by wrist actigraphy (acti-ODI3%). SDB severity was defined by acti-ODI3%. Obesity was defined as body mass index ≥25 kg·m-2The prevalence of SDB was 41.0% (95% CI 39.9-42.1%), 46.9% (45.8-48.0%), 10.1% (9.5-10.8%) and 2.0% (1.7-2.3%) in normal, mild, moderate and severe SDB, respectively, with notable sex differences evident (males>post-menopausal females>premenopausal females). Comorbidities such as hypertension, diabetes and metabolic syndrome were independently associated with the prevalence of moderate-to-severe SDB, and coincidence of any one of these with obesity was associated with a higher probability of moderate-to-severe SDB (hypertension OR 8.2, 95% CI 6.6-10.2; diabetes OR 7.8, 95% CI 5.6-10.9; metabolic syndrome OR 6.7, 95% CI 5.2-8.6). Dyslipidaemia in addition to obesity was not additively associated with the prevalence of moderate-to-severe SDB. The number of antihypertensive drugs was associated with SDB (p for trend <0.001). Proportion of a high cumulative percentage of sleep time with oxygen saturation measured by pulse oximetry <90% increased, even among moderate-to-severe SDB with increases in obesity.Metabolic comorbidities contribute to SDB regardless of the degree of obesity. We should recognise the extremely high prevalence of moderate-to-severe SDB in patients with obesity and metabolic comorbidities.

Impact of Nocturia on Mortality: The Nagahama Study.

PURPOSE: Nocturia has been reported as a risk factor for mortality. However, evidence is limited and has a high risk of bias. We evaluated the association between nocturia and mortality using longitudinal data from the general Japanese population. MATERIALS AND METHODS: Data were obtained from the Nagahama Cohort Project, a longitudinal, general population cohort study. Nocturia was measured using the International Prostate Symptom Score. Mortality data were obtained from the Basic Resident Register in Nagahama City. We used Cox proportional hazard models and time-varying covariates at baseline and 5-year followup to analyze the association between nocturia and mortality. RESULTS: We analyzed 9,762 participants (median age 56.8 years, male 32.8%). The prevalence rates of nocturnal voiding at 0, 1, 2 and 3 or more times were 44.3%, 39.1%, 11.7% and 4.9%, respectively. A total of 263 participants died. Followup assessment was performed 3,224 (SD 537) days after baseline. According to multivariable Cox proportional hazard regressions, mortality increased dose dependently with the nocturnal voiding frequency as HR 1.46 for 1 time (95% CI 1.02-2.09), HR 1.85 for 2 times (95% CI 1.23-2.77) and HR 2.06 (95% CI 1.28-3.32) for 3 or more times in comparison with 0 times (p for trend=0.00084). In the time varying Cox proportional hazard regression the association was still significant (p for trend=0.0017). CONCLUSIONS: According to this longitudinal study with a low incidence of missing data and high representation of the general population, nocturia is associated with mortality.

Association of ALPL variants with serum alkaline phosphatase and bone traits in the general Japanese population: The Nagahama Study.

Although alkaline phosphatase (ALP) activity is relatively low in carriers of recessive type hypophosphatasia (HPP), most are asymptomatic and therefore do not undergo medical evaluations. We analyzed the association of ALP-encoding ALPL variants with serum ALP and bone traits in the general Japanese population. Study participants (n = 9671) were from the Nagahama Study, which was a longitudinal cohort study of an apparently healthy general Japanese population. ALPL variants were analyzed by whole-genome sequencing or TaqMan probe assays using DNA extracted from peripheral blood samples. The speed of sound in calcaneal bone was assessed by quantitative ultrasound (QUS) and used as surrogate measures of bone mineral density. We identified 13 ALPL variants. Minor allele frequencies of three variants were higher than expected. Variant c.529G > A has been reported as a possible pathogenic variant for adult type HPP. Variants c.979C > T and c.1559delT are reported as pathogenic variants for perinatal severe HPP or infantile HPP. The allele frequencies of c.529G > A, c.979C > T, and c.1559delT were 0.0107, 0.0040, and 0.0014, respectively. Serum ALP activity was significantly lower and differed among the three variants (P < 0.001), as well as between individuals with and without any of the three variants (P < 0.001). Serum ALP activity was inversely associated with QUS values, although no direct association was observed between the ALPL variants and QUS values. An association between serum ALP activity and QUS was confirmed; however, we failed to detect an association between ALPL variants and bone traits in the general Japanese population.

Lifestyle habits associated with nocturnal urination frequency: The Nagahama study.

BACKGROUND: Nocturia is a risk factor for poor quality of life and increased mortality. This study was aimed to clarifying dietary habits, eating behaviors, and sleep characteristics associated with nocturia to identify modifiable lifestyle factors for nocturia. METHODS: This cross-sectional study included 5683 community residents (64.5 ± 7.7 years old). The frequency of nocturnal urination was recorded for 1 week using a sleep diary. The frequency of food intake, unfavorable eating behaviors, and sleep characteristics that may have influence on salt intake and wasting were obtained using a structured questionnaire. RESULTS: The frequency of nocturnal urination was increased with age (ß = .312, P < .001). Other basic factors associated with the frequency were the male sex (ß = .090), hypertension (ß = .038), sleep apnea (ß = .030), B-type natriuretic peptide level (ß = .089), and spot urine sodium excretion (ß = -.058). Dietary factors independently associated with nocturnal urination frequency were coffee (≥1 time/day: ß = -.059, P < .001) and green vegetable consumption (≥1 time/week: ß = -.042, P = .001), whereas habitual intake of dairy products, miso soup, and alcohol were not associated with urination frequency. Later bedtime was inversely associated with nocturnal urination frequency independent of sleep duration (before 23:00: ß = -.096; before 24:00: ß = -.225; after midnight: ß = -.240; all P < .001). CONCLUSION: Coffee and green vegetable consumption and later bedtime but not sleep duration are lifestyle factors associated with nocturnal urination frequency.

Sleep blood pressure measured using a home blood pressure monitor was independently associated with cardiovascular disease incidence: the Nagahama study.

BACKGROUND: Nocturnal blood pressure (BP) is associated with cardiovascular disease independently of awake BP. However, nocturnal BP measured using an ambulatory monitoring device has limited reproducibility because it is a single-day measurement. We investigated the association between sleep BP measured on multiple days using a timer-equipped home BP monitor and cardiovascular diseases in a general population. METHODS: The study population comprised 5814 community residents. Participants were required to sleep with wrapping cuffs on their upper arm and BP was measured automatically at 0 : 00, 2 : 00, and 4 : 00. Actigraph was used to determine BP measured during sleep. Participants were also measured home morning and evening BP manually using the same device. RESULTS: During the 7.3-year mean follow-up period, we observed 117 cases of cardiovascular diseases. The association between sleep BP (per 10 mmHg hazard ratio = 1.31, P  < 0.001) and cardiovascular events remained significant (hazard ratio = 1.22, P  = 0.036) even after adjusting for office BP and confounding factors, such as sleep-disordered breathing. Individuals with sleep-only hypertension ( n  = 1047; hazard ratio = 2.23, P  = 0.005) had a significant cardiovascular risk. Daytime-only hypertension ( n  = 264; hazard ratio = 3.57, P  = 0.001) and combined sleep and daytime hypertension ( n  = 1216; hazard ratio = 3.69, P  < 0.001) was associated with cardiovascular events to the same extent. Sleep BP dipping was not identified as a significant determinant of cardiovascular events. CONCLUSION: Sleep BP measured using a home BP monitor was independently associated with the incidence of cardiovascular disease in a general population.

Transcriptomic Analysis Reveals Sixteen Potential Genes Associated with the Successful Differentiation of Antibody-Secreting Cells through the Utilization of Unfolded Protein Response Mechanisms in Robust Responders to the Influenza Vaccine.

The seasonal influenza vaccine remains one of the vital recommended infection control measures for the elderly with chronic illnesses. We investigated the immunogenicity of a single dose of influenza vaccine in 123 seronegative participants and classified them into four distinct groups, determined by the promptness of vaccine response, the longevity of humoral immunity, and the likelihood of exhibiting cross-reactivity. Subsequently, we used transcriptional profiling and differential gene expression analysis to identify potential genes directly associated with the robust response to the vaccine. The group of exemplary vaccine responders differentially expressed 16 genes, namely: MZB1, MYDGF, TXNDC5, TXNDC11, HSP90B1, FKBP11, PDIA5, PRDX4, CD38, SDC1, TNFRSF17, TNFRSF13B, PAX5, POU2AF1, IRF4, and XBP1. Our findings point out a list of expressed proteins that are related to B cell proliferation, unfolded protein response, and cellular haemostasis, as well as a linkage of these expressions to the survival of long-lived plasma cells.

Genetic architecture of alcohol consumption identified by a genotype-stratified GWAS and impact on esophageal cancer risk in Japanese people.

An East Asian-specific variant on aldehyde dehydrogenase 2 (ALDH2 rs671, G>A) is the major genetic determinant of alcohol consumption. We performed an rs671 genotype-stratified genome-wide association study meta-analysis of alcohol consumption in 175,672 Japanese individuals to explore gene-gene interactions with rs671 behind drinking behavior. The analysis identified three genome-wide significant loci (GCKR, KLB, and ADH1B) in wild-type homozygotes and six (GCKR, ADH1B, ALDH1B1, ALDH1A1, ALDH2, and GOT2) in heterozygotes, with five showing genome-wide significant interaction with rs671. Genetic correlation analyses revealed ancestry-specific genetic architecture in heterozygotes. Of the discovered loci, four (GCKR, ADH1B, ALDH1A1, and ALDH2) were suggested to interact with rs671 in the risk of esophageal cancer, a representative alcohol-related disease. Our results identify the genotype-specific genetic architecture of alcohol consumption and reveal its potential impact on alcohol-related disease risk.

Development of a plasma-free amino acid-based risk score for the incidence of cardiovascular diseases in a general population: The Nagahama study.

BACKGROUND & AIMS: Levels of circulating amino acids (AAs) have been suggested to be associated with cardiovascular diseases (CVDs). This study aimed to develop a plasma-free amino acid (PFAA)-based CVD risk-prediction model in a general population. METHODS: The study participants consisted of 9220 community residents (mean age, 53.2 years; standard deviation, 13.3 years). Circulating levels of 19 PFAAs were measured via high-performance liquid chromatography/electrospray ionization mass spectrometry. The incidence of CVDs was determined by reviewing participants' clinical records. The prediction model was developed using the Cox proportional hazards model with the brute force variable selection and then cross-validated. RESULTS: During the 8.5-year follow-up, 220 CVD events were observed. Six AAs (alanine, citrulline, glycine, histidine, serine, and tyrosine) were identified as components of the prediction model, of which the C-index was 0.72. The association between the fourth quartile of the risk score calculated using the prediction model and the CVD events was independent of conventional risk factors (adjusted hazard ratio [HR], 1.9; 95 % confidence interval, 1.1-3.3). When examining crude relationships between conventional risk factors and the PFAA-based risk score by subgroup analyses, the association was significant for most subpopulations, men [crude HR = 6.4 (2.0-20.2)] and women [crude HR = 4.9 (2.6-9.3)], and individuals with [crude HR = 4.7 (2.5-8.9)] and without [crude HR = 7.2 (2.7-18.9)] lifestyle-related diseases, but not for older (≥70 years) participants [crude HR = 3.3 (0.8-13.5)]. The risk score successfully identified at-risk individuals [HR = 2.1 (1.2-3.5)] from participants who were classified as low risk by a conventional CVD risk score. CONCLUSIONS: The PFAA-based risk score predicted CVD events independently of conventional risk factors.

Trivalent inactivated influenza vaccine response and immunogenicity assessment after one week and three months in repeatedly vaccinated adults.

BACKGROUND: The influenza vaccine administrated every year is a recommended infection control procedure for individuals above the age of six months. However, the effectiveness of repeated annual vaccination is still an active research topic. Therefore, we investigated the vaccine immunogenicity in two independent groups: previously vaccinated versus non-vaccinated individuals at three time points; prior vaccination, one week and three months post vaccination. The assessment enabled us to evaluate the elicited immune responses and the durability of the induced protection in both groups. RESEARCH DESIGN AND METHODS: A research study was conducted to assess the immunogenicity of a single dose of Trivalent Inactivated Influenza Vaccine (A/H1N1, A/H3N2, and B) in 278 healthy adults aged between 32 and 66 years. Almost half of the participants, 140 (50·36%), received influenza vaccination at least once precursor to past influenza seasons. One blood sample was taken prior to vaccination for complete blood analysis and baseline immunogenicity assessment. The selected study participants received a single vaccine dose on the first day, and then followed up for three months. Two blood samples were taken after one week and three months post vaccination, respectively, for vaccine immunogenicity assessment. RESULTS: Before vaccination, the seroprotection, defined as a hemagglutination-inhibiting titer of =>1:40, was detected for the three vaccine virus strains in 20 previously vaccinated participants (14·29%) [8·95%, 21·2%]. We compared the overall vaccine response for the three virus strains using a normalized response score calculated from linearly transformed titer measurements; the score before vaccination was 84% higher in the previously vaccinated group and the mean difference between the two groups was statistically significant. Three months post-vaccination, we didn't find a significant difference in vaccine responses; the number of fully seroprotected individuals became 48 (34·29%) [26·48%, 42·77%] in the previously vaccinated group and 59 (42·75%) [34·37%, 51·45%] in the non-vaccinated group. The calculated response score was almost equal in both groups and the mean difference was no longer statistically significant. CONCLUSION: Our findings suggest that a single dose of influenza vaccine is equally protective after three months for annually vaccinated adults and first-time vaccine receivers.

Sleep-related factors associated with masked hypertension: the Nagahama study.

OBJECTIVES: Masked hypertension, which is characterized by out-of-office hypertension but normal office blood pressure, is a risk factor for cardiovascular disease. However, the factors that contribute to masked hypertension are unclear. We aimed to determine the involvement of sleep-related characteristics in masked hypertension. METHODS: The study included 3844 normotensive (systolic/diastolic blood pressure < 140/90 mmHg) community residents with no antihypertensive drug use at baseline (mean age 54.3 years). Home morning and evening blood pressure, oxygen desaturation during sleep (pulse oximetry), and sleep efficiency (actigraphy) were measured for 1 week. The number of nocturnal urinations during this period was obtained using a sleep diary. RESULTS: Masked hypertension (mean morning and evening blood pressure ≥135/85 mmHg) was detected in 11.7% of study participants, and 79.0% of the participants with masked hypertension had sleep hypertension (≥120/70 mmHg). Multinominal logistic regression analysis identified different factors involved in masked hypertension with and without sleep hypertension; factors for masked hypertension with sleep hypertension included the frequency of at least 3% oxygen desaturation (coefficient = 0.038, P  = 0.001), nocturia (coefficient = 0.607, P  < 0.001), and carotid intima-media thickness (coefficient = 3.592, P  < 0.001). Only carotid intima-media thickness and measurement season were associated with masked hypertension without sleep hypertension. Low sleep efficiency was associated with isolated sleep hypertension but not masked hypertension. CONCLUSION: Sleep-related factors associated with masked hypertension differed depending on the presence of sleep hypertension. Sleep-disordered breathing and nocturnal urination frequency may help identify individuals who need home blood pressure monitoring.

Associations Among Tooth Loss, Periodontitis, and Carotid Intima-Media Thickness: the Nagahama Study.

AIMS: This study aimed to clarify the relationships among tooth loss, periodontal condition, and subclinical atherosclerosis from the aspect of intensity, extent, and duration of inflammation. METHODS: This cross-sectional study included 9,778 people from the Nagahama Study, a large-scale, general population-based study conducted in Japan. The number of teeth and periodontal status, including the attachment level (AL) and pocket depth (PD) of representative teeth from six regions, were evaluated by dentists. The maximum intima-media thickness (IMT) of the common carotid artery was used as an index of atherosclerosis. RESULTS: In the multivariate analysis adjusted for conventional risk factors, a large number of missing teeth (＜9 remaining teeth), which related to long-lasting inflammation indicative of the highest stage of periodontitis, was identified as an independent determinant of IMT in a general population (coefficient: 0.042; 95% confidence interval [CI]: 0.016 to 0.068). The presence of two or more regions with an AL ≥4 mm, which is indicative of the progressing, long-lasting stages of periodontal inflammation, was also independently associated with IMT (coefficient: 0.016; 95% CI: 0.004 to 0.028). On the contrary, PD, a measure of the early and reversible phases of periodontal inflammation, and loss of AL in the group without tooth loss were not significantly associated with IMT, because of the limited degree of accumulated periodontitis. CONCLUSION: The present results suggest that the association between periodontitis and atherosclerosis depends on the inflammation intensity, extent, and duration.

Risk analyses of nocturia on incident poor sleep and vice versa: the Nagahama study.

Cross-sectional relationships between nocturia and sleep problems have been well evaluated but the risk association for each incidence is scarcely reported. This analysis included 8076 participants of the Nagahama study in Japan (median age 57, 31.0% male) and associations between nocturia and self-reported, sleep-related problems (poor sleep) were evaluated cross-sectionally. Causal effects on each new-onset case were analyzed longitudinally after 5 years. Three models were applied: univariable analysis, adjustment for basic variables (i.e., demographic and lifestyle variables) and full adjustment for basic and clinical variables. The overall prevalences of poor sleep and nocturia were 18.6% and 15.5%, while poor sleep was positively associated with nocturia (OR = 1.85, p < 0.001) and vice versa (OR = 1.90, p < 0.001). Among 6579 good sleep participants, 18.5% developed poor sleep. Baseline nocturia was positively associated with this incident poor sleep (OR = 1.49, p < 0.001, full adjustment). Among 6824 non-nocturia participants, the nocturia incidence was 11.3%. Baseline poor sleep was positively associated with this incident nocturia (OR = 1.26, p = 0.026); such associations were significant only in women (OR = 1.44, p = 0.004) and under-50-year-old groups (OR = 2.82, p < 0.001), after full adjustment. Nocturia and poor sleep associate with each other. Baseline nocturia can induce new-onset poor sleep while baseline poor sleep may induce new-onset nocturia only in women.