Differences between subjective and objective sleep duration according to actual sleep duration and sleep-disordered breathing: the Nagahama Study

STUDY OBJECTIVES

Since subjective sleep duration (SSD) is considered to be longer than objective sleep duration (OSD), results of SSD minus OSD (SSD-OSD) might always be thought to be positive. Some recent reports showed different results, but exact results have not been obtained. The difference between SSD and OSD may change according to OSD. We investigated this difference and its association with sleep-disordered breathing (SDB) or nonrestorative sleep.

METHODS

This cross-sectional study evaluated 6,908 community residents in Nagahama, Japan. SSD was determined by self-administered questionnaire. OSD was measured by wrist actigraphy and sleep diary. SDB was assessed according to the 3% oxygen desaturation index adjusted for OSD.

RESULTS

Worthy of notice was that SSD was shorter than OSD for those with SSD longer than 6.98 hours in all participants, 7.36 hours in males, and 6.80 hours in females. However, SSD was longer than OSD (mean ± SD: 6.49 ± 1.07 vs 6.01 ± 0.96; P < .001) overall, as SSD is considered to be longer than OSD. In patients with SDB, the difference between SSD-OSD was greater when OSD was shorter. The difference also depended on SDB severity. The degree of positivity between OSD and SSD was a significant factor in nonrestorative sleep (odds ratio: 2.691; P < .001).

CONCLUSIONS

When OSD was slightly less than 7 (6.98) hours, participants reported or perceived SSD > OSD. When OSD was > 6.98 hours, participants reported or perceived SSD < OSD. Patients with SDB reported longer SSD than OSD according to severity of SDB. Evaluating SSD, OSD, and their differences may be useful for managing sleep disturbances, including nonrestorative sleep.

CITATION

Takahashi N, Matsumoto T, Nakatsuka Y, et al. Differences between subjective and objective sleep duration according to actual sleep duration and sleep-disordered breathing: the Nagahama Study. J Clin Sleep Med. 2022;18(3):851-859.

Ultrasonographic Changes of the Knee Joint Reflect Symptoms of Early Knee Osteoarthritis in General Population; The Nagahama Study

OBJECTIVE

Radiographic changes in knee osteoarthritis (OA) are not always associated with symptoms, especially in its early stages. Ultrasonography (US) can detect early changes in the knee joint, but the changes that reflect symptoms have not been fully elucidated. This study aimed to identify US-detectable changes in the knee that are often associated with knee symptoms and demonstrate the feasibility of early diagnosis in symptomatic knee OA using US.

DESIGN

In this cross-sectional community-based study, 1,667 participants aged ≥60 years (1,103 women [66%]) were included. All participants concurrently underwent US and radiography of the knee and completed the Knee Society Knee Scoring System (KSS) questionnaire. Simple and multiple regression analyses were used to examine the associations between US findings and KSS symptom subscales.

RESULTS

Among all participants, medial meniscus protrusion and medial osteophytes, age, and body mass index showed significant associations with KSS symptom scores. Among 894 participants with Kellgren-Lawrence (KL) grade ≤1, medial osteophytes and age were significantly associated with KSS symptom score. US measures were more related to KSS symptoms than KL grades.

CONCLUSIONS

Among the knee US-detectable changes, medial osteophytes were strongly associated with knee symptoms. Osteophytes are reliable predictors of symptomatic early knee OA, even in participants with few radiographic OA changes.

Gender Differences in Smoking Initiation and Cessation Associated with the Intergenerational Transfer of Smoking across Three Generations: The Nagahama Study

Global tobacco policies lowered overall and male smoking rates, but female smoking rates have remained unchanged. Parent–child studies revealed the effects of parental smoking, but gender differences had mixed results. We investigated the effects of long-term smoking behavior in families over three generations in order to clarify gender differences. A cross-sectional study in a community-based genome cohort was conducted using a self-reported questionnaire. A total of 8652 respondents were stratified by gender regarding smoking initiation. A logistic regression analysis was performed to analyze the family smoking history. A total of 2987 current smokers and ever-smokers were compared regarding smoking cessation. With respect to smoking initiation, women were affected by their smoking mothers (odds ratio (OR), 2.4; 95% confidence interval (CI), 1.8–3.2) and grandmothers (OR, 1.7; CI, 1.1–2.4). Women who continued smoking were affected only by their smoking mothers (OR, 1.6; CI, 1.05–2.49). In conclusion, gender differences in smoking initiation and cessation are possibly associated with family smoking history. Mothers and grandmothers were shown to have a strong influence on women with respect to both smoking initiation and cessation. Future research should focus on providing evidence for effective gender-specific intervention programs to curb long-term smoking in women.

Differential Contribution of the Medial and the Lateral Side of the Joint to Symptoms in Knee Osteoarthritis: A Radiographic and Laboratory Analysis in the Nagahama Study

OBJECTIVE

This cross-sectional study aimed to explore the differences of the medial and lateral sides of the knee joint and precise radiographic abnormalities in contribution to the knee pain and clinical outcomes.

DESIGN

Participants 60 years or older who underwent radiographic evaluation were included. Knee radiography was assessed using grading systems of the Osteoarthritis Research Society International (OARSI) atlas. The Japanese Knee Osteoarthritis Measure (JKOM) was evaluated as clinical outcomes. Serum high-sensitivity C-reactive protein (hsCRP) was used to evaluate systemic inflammation. We divided the participants into normal, medial-, lateral-, and medial & lateral-OA types and compared their JKOM using an analysis of covariance. Furthermore, we analyzed the relationship between the knee pain and stiffness of JKOM and the grading of each radiographic feature using a multiple regression model.

RESULTS

Lateral- and medial & lateral-OA groups had a significantly worse symptoms in the total and the pain score, especially in movement subscales, in JKOM score. Lateral-OA groups had higher hsCRP than medial-OA group. Multivariate analysis showed that medial joint space narrowing (JSN), and lateral femoral and tibial osteophytes significantly affected knee pain (adjusted odds ratios: 1.73, 1.28, and 1.55, respectively). The radiographic changes are associated with pain more in JSN in the medial side and osteophytes in the lateral side.

CONCLUSION

Lateral- and medial & lateral-OA groups showed worth symptom. In addition, medial JSN and lateral osteophytes have potent effects on the knee pain.

The power of genetic diversity in genome-wide association studies of lipids

Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use1. Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels2, heart disease remains the leading cause of death worldwide3. Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS4-23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns24. Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine25, we anticipate that increased diversity of participants will lead to more accurate and equitable26 application of polygenic scores in clinical practice.

Body mass index, functional disability and all-cause mortality in 330 000 older adults: The Shizuoka study

AIM

A J-shaped association has been observed between body mass index (BMI) and all-cause mortality, but its relationship with functional disability is uncertain. We aim to clarify the association between BMI and functional disability, as well as all-cause mortality, by analyzing prefecture-wide annual health checkup data, and health and care insurance data.

METHODS

The dataset analyzed in this study consisted of 332 405 community residents aged ≥65 years who subscribed to the National Health Insurance. Basic clinical information was obtained from the annual health checkup data. The presence of comorbidities at baseline and the incidence of functional disability and all-cause mortality were obtained from the health insurance data.

RESULTS

The mean age and standard deviation of the study participants was 73.5 ± 6.0 years. During a 4-year follow-up period, we observed 31 508 incident cases of functional disability and 16 640 deaths. The incidence rates of functional disability and all-cause mortality were higher in both lower and higher BMI subgroups, and the lowest risk was observed in the range of 21-27 kg/m² in men and 20-25 kg/m² in women. These associations were independent of age, sex, current smoking and possible confounding factors, including a cardiovascular diseases history, hospitalization during the half-year period before baseline, and baseline comorbidities. A similar association was observed between BMI and all-cause mortality even when individuals who developed functional disabilities before death were excluded from the analysis.

CONCLUSIONS

Maintaining the bodyweight within the recommended range could be an effective method of reducing the risk of functional disability and mortality. Geriatr Gerontol Int 2021; 21: 1040-1046.

Prevalence and physical characteristics of locomotive syndrome stages as classified by the new criteria 2020 in older Japanese people: results from the Nagahama study

Background

The Japanese Orthopaedic Association (JOA) proposed the concept of locomotive syndrome (LS) in 2007 for detecting high-risk individuals with mobility limitation. In 2020, the JOA revised the clinical decision limits and introduced LS stage 3, which carried the highest-risk for LS compared to the conventional stages, 1 and 2. The purpose of this study was to characterize the prevalence, comorbidities, and physical characteristics in each LS stage, as per the LS criteria 2020.

Methods

We analyzed 2077 participants (64.9% women; mean age, 68.3 ± 5.4 years) from the Nagahama Study aged ≥60 years. Participants were classified into 4 groups, non-LS and LS stages 1, 2, and 3, based on a 25-question Geriatric Locomotive Function Scale. The prevalence of comorbidities (sarcopenia, osteoporosis, diabetes mellitus, low back pain [LBP], and knee pain) were investigated. Physical characteristics were measured based on the physical performance tests including gait speed, five-times chair-stand, single-leg stand, and short physical performance battery; muscle strength tests including grip, knee extension, hip flexion, and abduction; and body-composition analysis including muscle quantity and quality. Differences in the prevalence of comorbidities between LS stages were tested using the chi-square test. The general linear model was performed for univariate and multivariate analyses with post-hoc test to compare the differences in physical characteristics among the LS stages.

Results

The prevalence of LS increased with age, and the mean prevalence of LS stages 1, 2, and 3 were 24.4, 5.5, and 6.5%, respectively. The prevalence of comorbidities, including sarcopenia, osteoporosis, LBP, and knee pain, increased with worsening LS stage. Physical performance tests were significantly different between LS stages 2 and 3; and muscle strength differed significantly between LS stages 1 and 2. Additionally, in terms of body composition analysis, muscle quality but not muscle quantity showed significant differences among all the LS stages.

Conclusions

Our findings suggest that muscle strengthening and dynamic training, including balance training in LS stage 1 and 2, respectively, were needed for preventing the LS progression. Individuals with LS stage 3 should perform dynamic training and muscle strengthening exercises while receiving treatment for comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02440-2.

Tenderness of the knee is associated with thinning of the articular cartilage evaluated with ultrasonography in a community-based cohort: The Nagahama study

OBJECTIVES

This study aimed to elucidate the association between joint line tenderness (JLT) of the knee and knee joint structural changes evaluated with ultrasonography (US) for the early diagnosis of knee osteoarthritis (KOA).

METHODS

This cross-sectional study included 121 participants (age 71.7 ± 5.8 years, 75 women) from a community-based population. Bilateral structural changes in the knee joint were evaluated with US, and the presence or absence of JLT was evaluated using a pressure algometer. Logistic regression analysis was performed to evaluate the odds ratios (ORs) of US findings for the presence of JLT. Moreover, when the analysis was limited to knees with pre-/early radiographic KOA, the ORs were also calculated using logistic regression analysis.

RESULTS

Among the 242 knees, 38 had medial JLT, which was significantly associated with female sex (OR 11.87) and loss of cartilage thickness of the distal medial femoral condyle (CTh-MFC) (OR 0.12). Among 96 knees with Kellgren-Lawrence grade ≤ 2, 18 knees had medial JLT, which was also significantly associated with loss of CTh-MFC (OR 0.07) and medial osteophytes (OR 2.01).

CONCLUSIONS

JLT is significantly associated with thinning of the femoral cartilage and larger osteophytes in elderly patients, even in those with pre-/early radiographic KOA.

Estimation of Muscle Mass Using Creatinine/Cystatin C Ratio in Japanese Community-Dwelling Older People

OBJECTIVES

Sarcopenia is defined as a combination of low skeletal muscle mass index (SMI), weak muscle strength, and reduced physical function. Recently, many studies have reported that the creatinine/cystatin C ratio (Cr/CysC) is useful for evaluating muscle mass. We designed a cross-sectional study with separate model development and validation groups to develop a prediction equation to estimate bioimpedance analysis (BIA)-measured SMI with Cr/CysC.

DESIGN

The current study was a retrospective cross-sectional study.

SETTING AND PARTICIPANTS

The model development group included 908 subjects (288 men and 620 women) from the Frail Elderly in the Sasayama-Tamba Area (FESTA) study, and the validation group included 263 subjects (112 men and 151 women) from participants in the medical checkup program at the Anti-Aging Center in Ehime Prefecture.

MEASURES

Multivariate regression analysis indicated that age, hemoglobin (Hb), body weight (BW), and Cr/CysC were independently associated with SMI in both men and women. The SMI prediction equation was developed as follows: Men:4.17-0.012×Age+1.24×(Cr/CysC)-0.0513×Hb+0.0598×BW Women:3.55-0.00765×Age+0.852×(Cr/CysC)-0.0627×Hb+0.0614×BW RESULTS: The SMI prediction equation was applied to the validation group and strong correlations were observed between the BIA-measured and predicted SMI (pSMI) in men and women. According to the receiver operator characteristic (ROC) analysis, the areas under the curve were 0.93 (specificity 89.0%, sensitivity 87.2%) among men and 0.88 (specificity 83.6%, sensitivity 79.6%) among women for using pSMI to identify low SMI in the model development group. The pSMI also indicated high accuracy in ROC analysis for low SMI in the validation group. The Bland-Altman plot regression showed good agreement between BIA-measured and pSMI.

CONCLUSIONS AND IMPLICATIONS

Our new prediction equation to estimate SMI is easy to calculate in daily clinical practice and would be useful for diagnosing sarcopenia.

Weak hip flexor strength predicts progression of functional capacity decline due to locomotor system dysfunction in community-dwelling older adults: A longitudinal cohort study

PURPOSE

It is critical to determine the risk factors for activities of daily living (ADL) disability caused by locomotor dysfunction. However, no longitudinal study has investigated the association between disability due to locomotive dysfunction and multidimensional factors. Therefore, we investigated the relationship between the progression of functional capacity decline due to locomotive dysfunction and multiple physical functions among older adults in a longitudinal study.

METHODS

The participants comprised of 433 community-dwelling older adults. Physical function was assessed at baseline, which included handgrip strength, maximal isometric strength of hip flexion, hip extension, hip abduction, knee extension, toe flexion (index for muscle strength), the 5-time chair-stand test (index for muscle power), the one-legged stance and timed ''Up & Go'' tests (index for balance function), the 30-s stair test (index for muscle endurance), and range of motion (ROM) (an index of joint condition). Functional capacity decline due to locomotive dysfunction was assessed using the 25-question Geriatric Locomotive Function Scale (GLFS-25) before and after a 12-month period. Based on changes in the GLFS-25 score compared with baseline, the non-decline and decline groups were operationally defined. Logistic regression analyses with the groups as the dependent variable and physical function as independent variables were performed.

RESULTS

Of the 433 participants, 189 (43.6%) were included in the decline group. Logistic regression analysis revealed hip flexor strength as a primary determinant in the progression of functional capacity decline.

CONCLUSION

These results suggest that among physical functions, hip flexor strength influences the progression of disability resulting from locomotive dysfunction in older adults.

Low Carotid Flow Pulsatility Index Correlates With the Presence of Unruptured Intracranial Aneurysms

Background

We assessed cases of incidental unruptured intracranial aneurysm (UIA) discovered on screening magnetic resonance angiography to identify hemodynamic and atherosclerotic risk factors.

Methods and Results

The data of 1376 healthy older subjects (age range, 31–91 years) without cerebro‐ or cardiovascular diseases who underwent brain magnetic resonance angiography as part of a medical checkup program at a health screening center were examined retrospectively. We looked for an increase in classical risk factors for UIAs (age, sex, hypertension, and smoking) and laboratory data related to lifestyle diseases among subjects with UIAs. Brachial‐ankle pulse wave velocity, central systolic blood pressure, radial augmentation index, and carotid flow pulsatility index were also compared between those with and without UIAs. We found UIAs in 79 (5.7%) of the subjects. Mean age was 67.1±9.0 years, and 55 (70%) were women. Of the 79 aneurysms, 75 (95%) were in the anterior circulation, with a mean diameter of 3.1 mm (range, 2.0–8.0 mm). Subjects with UIAs were significantly older and had more severe hypertension. The carotid flow pulsatility index was significantly lower in subjects with UIAs and negatively and independently correlated with UIAs. Tertile analysis stratified by carotid flow pulsatility index revealed that subjects with lower indices had higher levels of low‐density lipoprotein cholesterol.

Conclusions

The presence of UIAs correlated with lower carotid flow pulsatility index and elevated low‐density lipoprotein cholesterol in the data from a population of healthy older volunteers. A reduced carotid flow pulsatility index may affect low‐density lipoprotein cholesterol elevation by some molecular pathways and influence the development of cerebral aneurysms. This may guide aneurysm screening indications for institutions where magnetic resonance angiography is not routine.

Markers of cardiovascular disease risk in sleep-disordered breathing with or without comorbidities: the Nagahama Study

STUDY OBJECTIVES

Whether the association between sleep-disordered breathing (SDB) and cardiovascular disease (CVD) is independent of comorbid risk factors for CVD is controversial. The objective of this study is to elucidate whether the association between SDB severity and the surrogate markers of CVD evets differs in relation to the number of comorbidities.

METHODS

This cross-sectional study included 7731 participants. Severity of SDB was determined by the oxygen desaturation index adjusted by actigraph-measured objective sleep time. Participants were stratified according to SDB severity and the number of comorbidities (hypertension, diabetes, dyslipidemia and obesity), and the associations between the maximum value of intima-media thickness of the common carotid artery (CCA-IMT-max), brachial-ankle pulse wave velocity (baPWV) and cardio-ankle vascular index (CAVI) were evaluated.

RESULTS

Among participants with no risk factor, CCA-IMT-max increased according to SDB severity (n = 1022, P <0.0001). Even after the matching of background, the median CCA-IMT-max value was 14% higher in moderate-severe SDB cases than those without SDB (n=45 in each group, P=0.020). The difference was not significant for baPWV and CAVI. On the other hand, a significant difference in CCA-IMT-max was not found in those with multiple comorbidities. Consistently, multiple regression analysis revealed an independent association between CCA-IMT-max and moderate-severe SDB for all study participants (β: 0.0222 (95% confidence interval: 0.0039-0.0405), P=0.017), but the association was not significant for stratified participants with multiple comorbidities.

CONCLUSIONS

SDB severity is associated with the CCA-IMT-max level, but the independent association becomes weaker for those with multiple comorbidities.

Distribution of Choroidal Thickness and Choroidal Vessel Dilation in Healthy Japanese Individuals

Purpose

To report fundamental epidemiologic data for choroidal parameters such as choroidal thickness and index of choroidal vascularity in Japanese individuals and to evaluate their correlations with age, sex, systemic parameters, and other ocular parameters.

Design

Population-based cohort study.

Participants

A total of 9850 individuals participated in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama Study) conducted between 2013 and 2016.

Methods

All participants underwent standardized ophthalmic examinations, including OCT with enhanced depth imaging (EDI; RS-3000 Advance; Nidek). We manually segmented the choroidoscleral interface to measure subfoveal choroidal thickness (SFCT) and calculated the normalized choroidal intensity obtained with EDI (NCI_EDI) and choroidal vascularity index (CVI). These are indices of choroidal brightness in OCT and reportedly represent the dilation of choroidal vessels. After summarizing the age-sex stratified distributions of SFCT, NCI_EDI, and CVI, their associations with age, sex, axial length (AL), and spherical equivalent (SE) were evaluated using linear regression analysis with adjustments for possible confounders.

Main Outcome Measures

Distribution of SFCT, NCI_EDI, and CVI in the healthy Japanese population and their characteristics.

Results

Age-sex standardized SFCT, NCI_EDI, and CVI were 291.2 μm, 0.653, and 66.88%, respectively. In both men and women, SFCT was associated negatively with age (P < 0.001) and NCI_EDI was associated positively with age (P < 0.001). Although both SFCT and NCI_EDI did not differ significantly between men and women overall (P = 0.87 and P = 0.21, respectively), among younger participants (35–50 years of age), men showed significantly greater SFCT than women (P < 0.001). Only in men was CVI associated positively with age (P < 0.001). In the multivariable analysis, SFCT was associated significantly with age, sex, AL, SE, and the interaction term of age and sex (P < 0.001). Independent of SFCT, NCI_EDI and CVI were associated significantly with age (P < 0.001).

Conclusions

We report normative Japanese SFCT, NCI_EDI, and CVI data using a large general Japanese cohort. The association analysis of SFCT with NCI_EDI and CVI suggested that younger individuals have a more lumen-rich choroid for their choroidal thickness than older individuals.

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 × 10-8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.

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.

Association of Creatinine-to-Cystatin C Ratio with Myosteatosis and Physical Performance in Older Adults: The Japan Shimanami Health Promoting Program

OBJECTIVE

Sarcopenia is a risk factor for poor outcomes in older adults. Identification of plasma markers may facilitate screening of sarcopenia. We previously reported that creatinine-to-cystatin C ratio is a simple marker of muscle mass. To further assess the clinical relevance of the creatinine-to-cystatin C ratio, we investigated its association with myosteatosis and physical performance.

DESIGN

Observational study.

SETTING AND PARTICIPANTS

Cross-sectional analysis of the dataset obtained from a Japanese population consisting of 1468 older (≥60 years of age) community residents.

METHODS

The mean attenuation values of the skeletal muscle calculated from computed tomography images of the midthigh were used as an index of myosteatosis, while the cross-sectional area of the muscle was used as a proxy for muscle mass. Physical performance was assessed by 1-leg standing time.

RESULTS

Creatinine-to-cystatin C ratio was positively associated with the cross-sectional area of muscle fiber-rich muscles, while it showed an inverse association with fat-rich muscle areas, resulting in the positive association between creatinine-to-cystatin C ratio and the mean attenuation value of the skeletal muscle [creatinine-to-cystatin C ratio quartiles (Q), Q1: 47.4 ± 4.8, Q2: 48.9 ± 4.4, Q3: 49.8 ± 4.1, Q4: 50.9 ± 3.7, P < .001]. The results of the linear regression analysis adjusted for major covariates (including muscle cross-sectional area) identified creatinine-to-cystatin C ratio as an independent determinant of the mean attenuation value (Q1: reference, Q2: β = 0.07, P = .019, Q3: β = 0.11, P < .001, Q4: β = 0.16, P < .001). Low creatinine-to-cystatin C ratio was independently associated with 1-leg standing time, although the association was attenuated substantially by adjusting for skeletal muscle cross-sectional area and mean attenuation value.

CONCLUSION AND IMPLICATIONS

Creatinine-to-cystatin C ratio was associated with myosteatosis in older adults, independent of the muscle mass. Creatinine-to-cystatin C ratio may serve as a convenient marker of sarcopenia.

Age-related changes in gait speeds and asymmetry during circular gait and straight-line gait in older individuals aged 60-79 years

AIM

The present study aimed to investigate the age-related changes in gait speeds and asymmetry during circular and straight-line gaits among older adults aged 60-79 years.

METHODS

The study included 391 community-dwelling older adults aged >60 years, who participated in the Nagahama cohort study. They were assigned to four age groups: 60-64 years (early 60s), 65-69 years (late 60s), 70-74 years (early 70s) and 75-79 years (late 70s). For the circular gait test, the time required to walk twice around a 1-m diameter circle for right and left rotations were measured. The average time of the two trials was measured as the circular gait time, and the side-to-side difference in the circular gait times was calculated as an asymmetry index. Walking speed, asymmetry of step length, and asymmetry of stance duration time during straight-line gait at comfortable and maximal walking pace were measured.

RESULTS

Circular gait time in older women in the late 70s group was significantly slower than that in other age groups; however, no age-related change was observed in older men. Maximal gait speeds in the early and late 70s groups were significantly slower than those in the early 60s group.

CONCLUSIONS

Age-related decline in circular gait speed was observed in older women aged ≥75 years, but not in older men. Maximal straight-line gait speed decreased significantly in both genders after the age of 70 years. Geriatr Gerontol Int 2021; 21: 404-410.

Coexistence of low back pain and lumbar kyphosis is associated with increased functional disability in knee osteoarthritis: the Nagahama Study

OBJECTIVE

To examine the association of low back pain (LBP) and lumbar kyphosis with functional disabilities and knee symptoms in patients with knee osteoarthritis (OA).

METHODS

We analyzed 586 participants (80.1% female; age, 68.8 ± 5.2 years) from the Nagahama Study who were aged ≥60 years and had radiographically confirmed knee OA. The Knee Scoring System (KSS) was used to assess functional disabilities and knee symptoms. LBP was defined as the presence of any persistent back pain for more than 3 months. Lumbar kyphosis was determined by skin-surface methods using a computer-aided electronic device called the Spinal Mouse. Multiple linear regression analysis was used for assessing the association of LBP and lumbar kyphosis with the KSS scores. Subgroup analyses based on sex were also performed.

RESULTS

LBP and lumbar kyphosis were independently associated with a lower KSS function score after adjustment for covariates (mean difference [95%CI, confidence interval] = -4.96 [-7.56 to -2.36] points for LBP alone, -4.47 [-8.51 to -0.43] points for lumbar kyphosis alone, and -13.86 [-18.86 to -8.86] points for the coexistence of LBP and lumbar kyphosis, respectively). The coexistence of LBP and lumbar kyphosis in women was associated with a lower KSS symptom score (mean difference [95%CI] = -4.49 [-6.42 to -2.55] points).

CONCLUSION

These findings suggest that both LBP and lumbar kyphosis are useful clinical signals indicating functional disability and knee symptoms in patients with knee OA.

Relationship between Intraocular Pressure and Coffee Consumption in a Japanese Population without Glaucoma: The Nagahama Study

PURPOSE

To evaluate the association between daily coffee consumption and intraocular pressure (IOP) in healthy persons without glaucoma and the association between daily coffee consumption and history of glaucoma.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 9850 individuals participated in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama Study) conducted between 2013 and 2016.

METHODS

All participants underwent a standardized ophthalmic examination. Self-reporting questionnaires were completed by all participants. First, the association between habitual coffee consumption and IOP among nonglaucoma individuals was evaluated by a multivariate linear regression analysis, adjusting for possible confounders. Second, the association between habitual coffee consumption and history of glaucoma also was evaluated using a multivariate logistic regression analysis.

MAIN OUTCOME MEASURES

The association between habitual coffee consumption and IOP among nonglaucoma individuals.

RESULTS

Of 9850 participants, 9418 did not have history of glaucoma. Among these participants, the mean ± standard deviation IOP of both eyes was 14.7 ± 2.9 mmHg. The multivariate regression analysis revealed that habitual coffee consumption was associated significantly with IOP (P < 0.001): the higher the consumption of coffee, the lower the IOP of an individual. The IOP of the group who consumed coffee most frequently (3 times daily or more) was 0.4 mmHg lower (95% confidence interval, 0.2-0.5 mmHg lower) than that of the group that consumed coffee least frequently (less than once daily). However, the logistic regression analysis showed that habitual coffee consumption was not associated significantly with history of glaucoma (P = 0.53).

CONCLUSIONS

Frequent coffee consumption was associated with a slightly lower IOP in people without glaucoma but was not associated with a decreased risk of glaucoma developing. Additional experimental studies are needed to examine the effects of coffee on IOP and glaucoma risk.

Impact of sleep-disordered breathing on glucose metabolism among individuals with a family history of diabetes: the Nagahama study

STUDY OBJECTIVES

It is well known that a family history of diabetes (FHD) is a definitive risk factor for type 2 diabetes. It has not been known whether sleep-disordered breathing (SDB) increases the prevalence of diabetes in those with an FHD.

METHODS

We assessed SDB severity in 7,477 study participants by oximetry corrected by objective sleep duration determined by wrist actigraphy. Glycated hemoglobin ≥6.5% and/or current medication for diabetes indicated the presence of diabetes. In addition to the overall prevalence, the prevalence of recent-onset diabetes during the nearly 5 years before the SDB measurements were made was investigated.

RESULTS

Of the 7,477 participants (mean age: 57.9; range: 34.2-80.7; SD: 12.1 years; 67.7% females), 1,569 had an FHD. The prevalence of diabetes in FHD participants with moderate-to-severe SDB (MS-SDB) was higher than in those without SDB (MS-SDB vs without SDB: all, 29.3% vs 3.3% [P < .001]; females, 32.6% vs 1.9% [P < .001]; males, 26.2% vs 11.7% [P = .037]). However, multivariate analysis showed that MS-SDB was significantly associated with a higher prevalence of diabetes only in FHD-positive females (odds ratio [95% confidence interval]: females, 7.43 [3.16-17.45]; males, 0.92 [0.37-2.31]). Among the FHD-positive participants, the prevalence of recent-onset diabetes was higher in those with MS-SDB than those without SDB, but only in females (MS-SDB vs without SDB: 21.4% vs 1.1%; P < 0.001).

CONCLUSIONS

MS-SDB was associated with diabetes risk in females with an FHD, and future studies are needed on whether treatment of SDB in females with an FHD would prevent the onset of diabetes.

Data resource profile of Shizuoka Kokuho Database (SKDB) using integrated health- and care-insurance claims and health checkups: the Shizuoka Study

Background

Analyzing real-world data, including health insurance claims, may help provide insights into preventing and treating various diseases. We developed a database covering Shizuoka Prefecture (Shizuoka Kokuho Database [SKDB]) in Japan, which included individual-level linked data on health- and care-insurance claims and health checkup results.

Methods

Anonymized claims data on health insurance (National Health Insurance [age <75 years] and Latter-Stage Elderly Medical Care System [age ≥75 years]), care insurance, subscriber lists, annual health checkups, and all dates of death were collected from 35 municipalities in Shizuoka Prefecture. To efficiently link claims and health checkups, unique individual IDs were assigned using a novel procedure.

Results

From April 2012 to September 2018, the SKDB included 2,230,848 individuals (men, 1,019,687; 45.7%). The median age (min–max) of men and women was 60 (0–106) and 62 (0–111) years, respectively. During the study period, the median subscription time was 4.4 years; 40.8% of individuals continuously subscribed for the 6.5 years; 213,566 individuals died. Health checkup data were available for 654,035 individuals, amounting to 2,469,648 records. Care-service recipient data were available for 283,537 individuals; they used care insurance to pay for care costs.

Conclusion

SKDB, a population-based longitudinal cohort, provides a comprehensive dataset covering health checkups, disorders, medication, and care service. This database may provide a robust platform to identify epidemiological problems and generate hypotheses for preventing and treating disorders in the elderly.

Extracellular-to-intracellular water ratios are associated with functional disability levels in patients with knee osteoarthritis: results from the Nagahama Study

INTRODUCTION/OBJECTIVES

To test the hypothesis that greater extracellular-to-intracellular water (ECW/ICW) ratios in lower-limb muscles are associated with worsened functional abilities in patients with knee osteoarthritis (OA).

METHODS

We analyzed data from 787 participants (82.2% female; mean age, 69.6 ± 5.3 years) from the Nagahama Prospective Cohort who were ≥60 years old and had radiographically confirmed bilateral knee OA. The Knee Scoring System (KSS) was used to assess functional abilities. Lower-limb ECW/ICW ratios and skeletal mass index values were determined with multi-frequency bioelectrical impedance analysis (BIA). Multiple linear regression analysis was used to test for associations between ECW/ICW ratios and functional abilities. Subgroup analyses based on OA severities and symptomaticity were also conducted.

RESULTS

Increased ECW/ICW ratios were associated with a 4.38-point decrease in the KSS function scores (95% confidence interval [CI], 3.15-5.62 points) after adjusting for covariates. This association varied according to the degree of knee symptoms, especially in individuals with radiologically mild OA. ECW/ICW ratios in individuals with asymptomatic mild OA were associated with a 2.14-point decrease in the KSS function score (95% CI, 0.32-3.96 points), whereas those in individuals with severe symptomatic mild OA were associated with a 6.16-point decrease (95% CI, 2.13-10.19 points).

CONCLUSIONS

Our findings indicate that higher ECW/ICW ratios are associated with greater functional disability in patients with knee OA. Therefore, ECW/ICW ratio measurements with multi-frequency BIA can serve as valuable indicators for functional disability in patients with knee OA. Key Points • Higher extracellular-to-intracellular water (ECW/ICW) ratios are associated with greater functional disability levels in patients with knee osteoarthritis (OA). • ECW/ICW ratios are useful clinical signs as a biomarker for poor functional abilities in patients with knee OA.