Effectiveness of mobile applications in improving insomnia symptoms among adults from multi-community: A systematic review and meta-analysis.

OBJECTIVE/BACKGROUND: To clarify whether mobile sleep applications alleviate insomnia symptoms among adults from multi-community. PATIENTS/METHODS: A literature search was conducted using the PubMed, Cochrane, PsycINFO, and Web of Science databases for articles related to mobile technology and sleep interventions published between database inceptions and March 27, 2023. We pooled relevant data using a random-effects model, and a meta-analysis was performed using a web version of the Cochrane Review Manager. The effect size was estimated and reported as the combined overall effect (weighted average). Forest plots were created, and the Cochrane risk-of-bias tool and Newcastle-Ottawa Scale were used to evaluate studies. RESULTS: After an initial screening and full-text reviews, seven studies were identified with a total of 10,139 participants (females n = 8844, 87.2 %) recruited from multi-community and not diagnosed with sleep disorders or taking medications. These studies included one cross-sectional study investigating mindfulness meditation apps and six randomized-controlled trials (RCTs), including one with sleep-feedback messaging, one comparing sleep applications with or without a wearable device, and four with multicomponent interventions based on cognitive theory and subsequent behavioral change techniques. In a meta-analysis of three cognitive behavior therapy (CBT)-based RCTs, the intervention group showed statistically significant improvements in insomnia symptoms according to the Pittsburgh Sleep Quality Index but with high heterogeneity, while two CBT-based RCTs showed no significant improvements in the Insomnia Severity Index with low heterogeneity. CONCLUSIONS: A small body of evidence supports the use of CBT-based sleep applications to improve insomnia symptoms among adults from multi-community.

Association Between Ego-Resilience and Social Isolation Among Urban Older People.

Social isolation among older adults affects their physical and mental health. Ego-resilience is associated with flexible adaptation to various environments and acceptable behaviors. However, its association with social isolation among older people is unclear. Therefore, a health survey was conducted with 510 adults aged 65 years or older to assess social isolation, its associated factors, and ego resilience. The results showed that the social isolation group had a lower median ego-resiliency scale score (42.0) compared to the non-social isolation group (38.0). The social isolation group were mostly males without spouses, took time to move, had more depressive moods, and poorer subjective health status. The non-social isolated group had faster maximum walking speed. Low ego-resilience was newly identified as a factor associated with social isolation among older people, as were being male, having no spouse, and depressive symptoms. Mediation analysis revealed that ego-resilience affected social isolation and was partially mediated by depressive symptoms.

Sex differences in the association between smoking and central sensitization: A cross-sectional study.

INTRODUCTION: Despite the acknowledged interconnection between smoking and pain, research on the relationship between smoking and central sensitization (CS) is scarce; this pain mechanism has attracted recent research attention. Considering potential sex differences, this cross-sectional study aimed to investigate the association between smoking and CS. METHODS: Overall, 415 adult participants from an outpatient clinic underwent evaluation. The analysis focused on determining the relationship between smoking status and CS by differentiating between sexes. Data were collected on smoking presence or absence (independent variable) and CS (dependent variable) for each sex, with age, education level, drinking history, depression, and anxiety as covariates. CS was evaluated using the Central Sensitization Inventory. Following a descriptive analysis of the study population's characteristics, logistic regression analysis was employed to assess the relationships. RESULTS: The average participant age was 42.3 years, with 59% being women. Among women, a significant association was found between smoking status and higher CS severity (AOR=3.21; 95% CI 1.29-7.99, p<0.01), after accounting for confounding variables. Conversely, no significant association was observed for men (AOR=1.50; 95% CI 0.63-3.60, p=0.36). Interaction by sex on the relationship between smoking and CS was not statistically significant (p=0.23). CONCLUSIONS: This study suggests a potential association between smoking and CS in women, whereas no conclusive relationship was observed among men. These findings indicate the necessity of considering CS when examining the relationship between smoking and pain.

Association of illness perception and alexithymia with fatigue in hemodialysis recipients: a single-center, cross-sectional study.

Fatigue in hemodialysis recipients interferes with daily activities and renal rehabilitation, and its underlying causes and treatment remain unclear. Psychological factors, like illness perceptions and alexithymia, cause fatigue in other diseases; however, their contribution to hemodialysis-related fatigue is unknown. This cross-sectional study included 53 hemodialysis recipients. To assess participants' fatigue, we used a self-administered patient-reported outcome questionnaire whose items have shown correlation with those of established scales, such as the Profile of Mood States and Visual Analogue Scales. The associations among the scores of the revised Illness Perceptions Questionnaire (IPQ-R), Toronto Alexithymia Scale (TAS-20), and Hospital Anxiety and Depression Scale and fatigue were analyzed using bivariable and multivariable analyses. Patients with fatigue had significantly higher median scores for the IPQ-R subscales "Identity" and "Negative emotional representation about illness" than those without fatigue, suggesting the association of specific illness perception with fatigue. Median scores for the TAS-20 subscale "Difficulty identifying feelings" were also significantly higher among fatigued patients, suggesting the association of alexithymia with fatigue. Depression was not associated with fatigue. Multivariable logistic regression revealed the association of a high "Identity" score with the risk of fatigue (adjusted odds ratio, 1.32; 95% confidence interval, 1.00-1.73; P = 0.04), while there were no significant association between a high "Difficulty identifying feelings" score and the risk of fatigue (adjusted odds ratio, 1.09; 95% confidence interval, 0.95-1.24). Specific illness perception and alexithymia were slightly associated with hemodialysis-related fatigue. Cognitive-behavioral therapy for these conditions could reduce fatigue and promote renal rehabilitation.

Psychosomatic symptoms related to exacerbation of fatigue in patients with medically unexplained symptoms.

Background: Medically unexplained symptoms (MUS) are common conditions that cause various somatic complaints and are often avoided in primary care. Fatigue frequently occurs in patients with MUS. However, the somatic and psychiatric symptoms associated with fatigue in patients with MUS are unknown. This study aimed to clarify the intensity of fatigue and the related somatic and psychiatric symptoms in patients with MUS. Methods: A total of 120 patients with MUS aged 20-64 years who visited the Department of Psychosomatic Medicine, Toho University Medical Center Omori Hospital, between January and March 2021 were considered. The participants' medical conditions were assessed using the Chalder Fatigue Scale (CFS), Somatic Symptom Scale-8 (SSS-8), and Hospital Anxiety and Depression Scale (HADS). We estimated the relationship between CFS, SSS-8 and HADS by using Spearman's rank correlation. Additionally, linear multiple regression analysis with CFS as the objective variable was used to identify symptoms related to fatigue. Results: Fatigue was significantly associated with all symptoms observed (p < 0.01). Linear multiple regression analysis revealed that "dizziness," "headache," and "Sleep medication" were extracted as relevant somatic symptoms (p < 0.05), independent of anxiety and depression, which were already known to be associated with fatigue in MUS. Conclusion: The intensity of anxiety, depression, headache, and dizziness were all associated with the intensity of fatigue in MUS patients. On the contrary, sleeping medication was associated with lower levels of fatigue in MUS.

Utility and optimal cut-off point of the Somatic Symptom Scale-8 for central sensitization syndrome among outpatients with somatic symptoms and related disorders.

BACKGROUND: Central sensitization syndrome (CSS) involves severe functional symptoms due to central sensitization. for patients with severe somatic symptoms and related disorders (SSRDs), central sensitization may be responsible for their functional symptoms. We hypothesized that screening for CSS in patients with SSRDs would identify those with severe disease. The Somatic Symptom Scale-8 (SSS-8) is a simple tool to assess medical conditions related to SSRDs, but the cut-off point to identify severe cases of comorbid CSS is unknown. This study aimed to determine the optimal cut-off point of SSS-8 for screening the CSS of patients with severe SSRDs. METHODS: In total, 143 patients with SSRDs attending outpatient clinics of a university hospital in Japan were included in the study. The participants were evaluated using the SSS-8 for somatic symptoms, Hospital Anxiety and Depression Scale (HADS) for anxiety and depressive symptoms, Pain Catastrophizing Scale (PCS) for catastrophic thoughts, and Central Sensitization Inventory (CSI-A, B) for CSS. Receiver operating characteristic (ROC) curve analysis was performed using the propensity score. The area under the curve (AUC) was calculated using a propensity score considering PCS, age, sex, HADS, and CSI-B as confounders of SSS-8 and CSS to evaluate differences in diagnostic accuracy between patients with and without SSS-8. The sensitivity and specificity of the ROC analysis were then used to determine the cut-off point for discriminating severe cases of SSS-8. RESULTS: Of the 143 participants, 126 responded (51 CSS group and 75 non-CSS group), with a valid response rate of 88.1 percent. In the ROC analysis, the propensity score including SSS-8 was statistically more accurate. The optimal cut-off point was 13, with an AUC of 0.88, sensitivity of 84.3 percent, and specificity of 77.3 percent. CONCLUSIONS: The SSS-8 is a useful tool for discriminating severe cases of SSRDs comorbid with CSS.

Effect of central sensitization on dizziness-related symptoms of persistent postural-perceptual dizziness.

BACKGROUND: Persistent postural-perceptual dizziness (PPPD) is a chronic functional dizziness symptom triggered by psychological stress, but its pathophysiology is unknown. Central sensitization is considered the cause of functional diseases, such as medically unexplained symptoms, and is a psychosocially affected condition. However, the association between dizziness symptoms in PPPD and central sensitization remains unclear. Thus, we conducted a cross-sectional study on the relation between dizziness symptoms and central sensitization in PPPD. METHODS: We recruited 61 outpatients with dizziness who met the PPPD diagnostic criteria. In addition to the evaluation of dizziness symptoms using the Dizziness Handicap Inventory, the participants were evaluated using the Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, and Central Sensitization Inventory (CSI). A CSI score of 40 or higher was defined as central sensitization syndrome (CSS), and the severity of each condition in CSS and non-CSS participants was compared. We also evaluated the association between dizziness symptoms and central sensitization and coexisting symptoms using linear multiple regression analysis. RESULTS: We analyzed the data of 50 valid responses (valid response rate of 82.0 percent). Compared with the non-CSS group, the CSS group had a higher degree of disability owing to dizziness and a higher rate of complications of anxiety and depression. The regression analysis results showed that the severity of central sensitization was a related factor that could enhance the dizziness symptoms of PPPD. CONCLUSIONS: Central sensitization may affect the dizziness symptoms of PPPD as an exacerbating factor.

Effect of relaxation therapy on benzodiazepine use in patients with medically unexplained symptoms.

BACKGROUND: The change in the benzodiazepine (BZD) use of patients with medically unexplained symptoms (MUS) following the application of relaxation therapy were examined. METHODS: Of the 221 outpatients with MUS using BZD, 42 received relaxation therapy. Change in BZD use was compared using a relaxation group (n = 42) and a control group that had 84 MUS patients whose baseline was matched by optimal matching algorithms. Logistic regression analysis was done to evaluate the effect of BZD-dependent factors on the BZD dose of the relaxation group. RESULTS: Compared with the control group, the number of patients who decreased the amount of BZD and the number of patients whose subjective symptoms of MUS improved were significantly higher in the relaxation group (p < 0.05). In addition, a factor that made it difficult to reduce the BZD of MUS patients who had undergone relaxation was a long history of BZD use, for more than 6 months (odds ratio, 0.06, 95% confidence interval, 0.01-0.36). CONCLUSIONS: Relaxation therapy for patients with MUS may help reduce BZD use; however, early intervention is important to prevent BZD dependence.

Alexithymia and Somatosensory Amplification Link Perceived Psychosocial Stress and Somatic Symptoms in Outpatients with Psychosomatic Illness.

BACKGROUND: Psychosomatic patients often complain of a variety of somatic symptoms. We sought to clarify the role of clinical predictors of complaints of somatic symptoms. METHODS: We enrolled 604 patients visiting a psychosomatic outpatient clinic. The outcome was the total number of somatic symptoms, and the candidate clinical predictors were perceived psychosocial stress, alexithymia, somatosensory amplification, adaptation, anxiety, and depression. All participants completed questionnaires assessing the outcome and the predictors. RESULTS: The average number of reported somatic symptoms was 4.8; the most frequent was fatigue (75.3%), followed by insomnia (56.1%), low-back pain (49.5%), headache (44.7%), and palpitations (43.1%). Multiple regression analysis showed that the total number of somatic symptoms was significantly associated with the degree of perceived psychosocial stress, alexithymia, somatosensory amplification, and depression. Also, structural equation models indicated links between excessive adaptation (via perceived psychosocial stress, alexithymia, and somatosensory amplification) and the total number of somatic symptoms. CONCLUSION: The results suggested that the association between psychosocial stress and reported somatic symptoms is mediated by alexithymia and somatosensory amplification in psychosomatic patients.

Clinical features of outpatients with somatization symptoms treated at a Japanese psychosomatic medicine clinic.

BACKGROUND: Somatization is produced due to the summation of psychological factors, irrespective of the presence or absence of physical factors. A group of diseases with severe pain and other disorders exhibit so-called Medically Unexplained Symptoms (MUS), and the characteristics of patients with MUS are largely unexplained. In this paper, the characteristics of a series of new patients with somatization treated in a Japanese university hospital are discussed. METHOD: The subjects were 871 patients who newly visited the Department of Psychosomatic Medicine, Toho University Omori Medical Center between January and December of 2015. Under the assumption that the definition of somatization is same as that of MUS, the correlation between somatization and the age, sex, academic background, chief complaints, reasons for visiting the medical center, diagnosis, symptoms, presence or absence of a referral form, continued treatment after the first visit, and marital status of these patients at the time of their respective examinations were evaluated. RESULTS: Of the patients studied, 68% suffered from somatization. Among them, 11% met the definition of Functional Somatic Symptoms (FSS) and 74% had somatization associated with mood disorder or anxiety disorder. Digestive symptoms were reported by 33%, headaches by 24%, and unusual sensations by 21%. Whereas no correlation was found between somatization symptoms and the patients' academic background, marital history, or medical history after the first visit, a positive correlation (p < 0.05) was found between somatization and patients who had been referred by their doctor. CONCLUSION: Many of the studied patients who suffered from somatization, regardless of age and sex, were referred to us by doctors from other hospitals. It was concluded that many patients difficult to diagnose or deal with are referred the Department of Psychosomatic Medicine of Japanese university hospitals, thus these hospitals must assume great responsibility for preventing mistaken diagnoses by conducting effective psychological treatment and thorough medical examinations.

Pre-pregnancy body mass index as a predictor of low birth weight infants in Japan.

BACKGROUND AND OBJECTIVES: The prevalence of low birth weight (LBW) infants in Japan has doubled in the last several decades. The objective of this study was to examine the effects of pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on LBW infants of Japanese women. METHODS AND STUDY DESIGN: This retrospective study was conducted using data on 1,336 mothers (mean age, 34.0 years)whose pre-pregnancy BMI was less than 23 kg/m2 and their singleton infants were born at full term between January and December in 2011. The outcome of interest was LBW infants (less than 2,500 g). The main exposure variables were pre-pregnancy BMI and GWG. The effects of these two variables on LBW were determined after adjusting for confounder variables such as maternal age, smoking, drinking, parity, gestational week at birth and infant gender. RESULTS: The proportion of LBW infants was 4.2% in total, 6.1% among underweight mothers (<18.5 kg/m2) and 3.5% among normal weight mothers (18.5-22.9 kg/m2).A stepwise multivariable logistic regression model showed that underweight mother were more likely [odds ratio (OR) 1.86, 95% confidence interval (CI), 1.04-3.31] than normal weight mother to deliver a LBW infant. Mothers with inadequate GWG <8.5 kg were more likely to deliver a LBW infant (OR 1.66, 95% CI: 0.80-3.45) compared with mothers who gained 10.5-12.4 kg (the third lowest quartile) but this did not reach statistical significance. CONCLUSIONS: This study demonstrated that mothers who were underweight before pregnancy were independently associated with the delivery of LBW infants.

Behavioral medicine in Teikyo University and Toho University.

Behavioral medicine has increased in importance to become a promising field in medical education. The Teikyo University Graduate School of Public Health and Toho University School of Medicine were evaluated in terms of their educational emphasis on behavioral medicine. The Teikyo University Graduate School of Public Health has the following five core requirements, as in the global standards: behavioral medicine, biostatistics, epidemiology, occupational health, and health policy management. Behavioral medicine mainly encompasses psychology in normal populations, working as a gateway to the medical world among non-medical professionals who are interested in medicine. The Toho University School of Medicine aims to produce "good clinicians" who have a thorough knowledge, a deep sense of professional ethics, and a profound humanity to contribute to human welfare through medicine. In behavioral medicine here, systematic knowledge based on human behavior in medicine is taught from the first to sixth year. Psychosomatic physicians could be among the most optimal professionals for behavioral medicine because of the similarities between psychosomatic medicine and behavioral medicine. The establishment of a Center of Behavioral Medicine is a potential solution to tackle forthcoming medical problems, such as increasing medical costs and an aging society. We must focus on the importance of behavior change as a way for preventive medicine to connect hospitals and communities in Japan.

Clinical Characteristics and Referral Patterns of Outpatients Visiting a Japanese Psychosomatic Medicine Clinic.

BACKGROUND: The definition of psychosomatic medicine is not consistent across countries. PURPOSE: The study purpose was to clarify the applicability of the definition of psychosomatic illness issued by the Japanese Society of Psychosomatic Medicine to different types of referral in a university hospital. METHODS: The sample consisted of 1067 outpatients visiting a psychosomatic clinic. Participants completed questionnaires to assess degrees of somatization, depression, anxiety, and psychosocial stress after completing clinical interviews based on the Diagnostic and Statistical Manual, Fourth Edition, Text Revision. All subjects were classified into psychosomatic and non-psychosomatic groups, and the non-psychosomatic group was further divided into three additional groups: depression, anxiety, and other. RESULTS: In total, 398 (37 %) of the subjects were placed in the psychosomatic group. The percentage of the psychosomatic group was 46 % in those referred within the hospital, 37 % in those referred outside the hospital, and 28 % in those without referral from physicians. Concerning the non-psychosomatic group, 269 (25 %) were placed in the depression group, 229 (22 %) in the anxiety group, and 171 (16 %) in the other group. Membership in the psychosomatic group was positively associated with age and the severity of somatosensory amplification (both p < 0.05), but negatively associated with the severity of depression and anxiety as well as the classification of non-referral (all p < 0.05). CONCLUSIONS: Although patients with psychiatric disorders, including depressive and anxiety disorders, are frequently seen in the Japanese psychosomatic clinic, patients who are diagnosed with psychosomatic illnesses tend to have been referred by physicians within the hospital. The concept of psychosomatic medicine needs to be further developed to assist both clinical practitioners and patients.

The relationship between suicidal ideation and symptoms of depression in Japanese workers: a cross-sectional study.

OBJECTIVES: The prevalence of suicidal ideation and predictors for suicidal ideation among Japanese workers is unknown, although a previous study reported a 30% prevalence rate of suicidal ideation in a psychosomatic clinical setting. Hence, we evaluated the prevalence of suicidal ideation and its relationship with depressive symptoms among Japanese workers. METHODS: For this purpose, a cross-sectional design was used. Major depressive disorder (MDD) and suicidal ideation in 1266 workers (1100 men and 166 women, aged 20-69 years) were assessed through clinical interviews conducted in accordance with the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders. RESULTS: A total of 34 and 70 participants were diagnosed with suicidal ideation and MDD, respectively. Suicidal ideation was especially prevalent in 40-year-olds to 49-year-olds. Six of the eight symptoms of MDD (depressive mood, loss of interest, weight loss, psychomotor agitation, worthlessness and concentration loss) were related to suicidal ideation. Depressive mood had the strongest relationship with suicidal ideation, followed by worthlessness and concentration loss. Worthlessness had the highest area under the curve in predicting suicidal ideation, followed by concentration loss and depressive mood. CONCLUSIONS: We conclude that MDD symptoms-particularly depressive mood, worthlessness and concentration loss-are potential predictors of suicidal ideation in Japanese workers.

Association of metabolic syndrome with atypical features of depression in Japanese people.

AIM: It has been controversial whether metabolic syndrome (MetS) is associated with depression. We aimed to clarify the correlation between MetS and depression, considering atypical features of depression. METHODS: Participants were 1011 Japanese men aged 20-59 years. MetS was diagnosed according to criteria set by the International Diabetes Federation. Clinical interviews for major depressive disorder (MDD) employed the DSM-IV; MDD was classified into atypical and non-atypical types. The prevalence of MetS was compared between the groups with no MDD, atypical depression, and non-atypical depression via trend analyses. Multiple logistic regression analyses examined the association of MetS with atypical depression and the features thereof. RESULTS: In total, 141 (14.0%) participants were diagnosed with MetS and 57 (5.6%) were diagnosed with MDD (14 had atypical and 43 had non-atypicalMDD). The prevalence of MetS was the highest in the group with atypical depression, followed by the non-atypical depression and no MDD groups, respectively, with a marginally significant trend (P = 0.07). The adjusted odds ratios of MetS associated with depression were 3.8 (95% confidence interval [CI] 1.1-13.2) for atypical depression and 1.6 (95% CI 0.7-3.6) for non-atypical depression. Among the five features of atypical depression, only hyperphagia was significantly related to MetS (odds ratio 2.7, 95% CI 1.8-4.1). CONCLUSION: There was a positive association between MetS and atypical depression, but not between MetS and non-atypical depression. Specifically, hyperphagia seems to be an important factor affecting the correlation between MetS and atypical depression.

An overview of the China National Tobacco Corporation and State Tobacco Monopoly Administration.

OBJECTIVES: China is facing a serious public health problem in active and passive smokers. Confronted with this, China has taken some measures to control tobacco. However, this information has not been surveyed at academic level. Our aim is to investigate information relating to tobacco controls in China. METHODS: To find information relating to tobacco control, we reviewed and analysed the China National Tobacco Corporation (CNTC) and State Tobacco Monopoly Administration (STMA) mainly by systematic examination of documents made available in the University of California, San Francisco Legacy Tobacco Documents Library and China Tobacco database. RESULTS: Eleven relevant documents met our research purpose, and 18 further relevant documents were found on the CNTC, STMA and Tobacco China database websites. As a result, 29 relevant articles were included in our analysis. We describe the CNTC and STMA's history, structure, and relation to the Chinese Government ministry and to other tobacco companies, and China's tobacco control in detail. CONCLUSIONS: The Chinese cigarette market is dominated by a state-owned monopoly, the STMA. Under the protection of the Law of the People's Republic of China on Tobacco Monopoly, the STMA controls all aspects of the tobacco industry. As far as the Chinese tobacco monopoly is concerned, although smoking harms people's health, restraining smoking threatens social stability and government income, which may be more serious problems for any government. China still has a long way to go in creating smoke-free environments.

Job stress strengthens the link between metabolic risk factors and renal dysfunction in adult men.

Chronic kidney disease (CKD) is an important risk factor for cardiovascular disease. The metabolic risk factors obesity, hypertension, diabetes, and dyslipidemia are closely associated with renal dysfunction. As psychosocial stress affects these risk factors, here, we examined relationships between metabolic risk factors and renal function, and their association with job stress. The participants were 1,231 Japanese male office workers attending annual health examinations. The estimated glomerular filtration rate (eGFR) was determined using the equation recommended by the Japanese Society for Nephrology: eGFR (mL/min/1.73 m(2)) = 194 × age(-0.287) × Cr(-1.094). Job stress was measured using the Job Content Questionnaire based on the job demand-control model. The job strain index equaled the job demand scores divided by the job control scores. The participants were classified into four ordinal groups of job strain index, based on previous studies (i.e., ≤ 0.4 the lowest, 0.4-0.5 lower, 0.5-0.6 higher, or ≥ 0.6 the highest). A significant correlation was found between lowered eGFR and each of the metabolic risk factors waist circumference, systolic and diastolic blood pressure, and total cholesterol (p < 0.001). Furthermore, job stress had an interactive effect on the relationships between eGFR and systolic and diastolic blood pressure, and triglycerides, depending on the job strain index (highest vs. lowest) (p < 0.05). The highly stressed workers exhibited a close association of eGFR with metabolic risk factors like hypertension and dyslipidemia. Therefore, intensive management may be important for preventing the progression of renal dysfunction and cardiovascular complications in those experiencing stress.

Association between insomnia symptoms and hemoglobin A1c level in Japanese men.

BACKGROUND: The evidence for an association between insomnia symptoms and blood hemoglobin A(1c) (HbA(1c)) level has been limited and inconclusive. The aim of this study was to assess whether each symptom of initial, middle, and terminal insomnia influences HbA(1c) level in Japanese men. METHODS: This cross-sectional study examined 1,022 male workers aged 22-69 years with no history of diabetes at a Japanese company's annual health check-up in April 2010. High HbA(1c) was defined as a blood level of HbA(1c) ≥6.0%. Three types of insomnia symptoms (i.e., difficulty in initiating sleep, difficulty in maintaining sleep, and early morning awakening) from the previous month were assessed by 3 responses (i.e., lasting more than 2 weeks, sometimes, and seldom or never [reference group]). RESULTS: The overall prevalence of high HbA(1c) was 5.2%. High HbA(1c) was positively and linearly associated with both difficulty in maintaining sleep (P for trend  = .002) and early morning awakening (P for trend  = .007). More specifically, after adjusting for potential confounding factors, high HbA(1c) was significantly associated with difficulty in maintaining sleep lasting more than 2 weeks (adjusted odds ratio, 6.79 [95% confidence interval, 1.86-24.85]) or sometimes (2.33 [1.19-4.55]). High HbA(1c) was also significantly associated with early morning awakening lasting more than 2 weeks (3.96 [1.24-12.59]). CONCLUSION: Insomnia symptoms, particularly difficulty in maintaining sleep and early morning awakening, were found to have a close association with high HbA(1c) in a dose-response relationship.