Cancer as an Independent Mortality Risk in Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: The management of chronic thromboembolic pulmonary hypertension (CTEPH) has advanced significantly in recent years, thereby improving patient prognosis. However, the impact of cancer on the outcomes of patients with CTEPH under current treatment remains unclear. This study aimed to investigate the prevalence of cancer in patients with CTEPH and determine how comorbid cancer affects their prognosis and clinical course. METHODS: Data from an ongoing Japanese prospective cohort study were analyzed. Prevalence and primary cancer sites were evaluated. The association of a history of cancer with a composite endpoint, including all-cause death, lung transplantation, and worsening of CTEPH, as well as venous thromboembolism and bleeding events, was assessed. RESULTS: Of the 1,270 patients in the cohort, 134 (10.6%) had a history of cancer, with the most common primary sites being the breast in women and the prostate in men. The incidence of composite outcome and all-cause death was higher in those with a history of cancer (p<0.001, log-rank test). In the Cox proportional hazard model, age- and sex-adjusted hazard ratios for the composite outcome and all-cause death were 2.69 (95% confidence interval, 1.48-4.89, p=0.001) and 4.25 (95% confidence interval, 1.98-9.10, p<0.001), respectively, for patients with a history of cancer. No significant differences in venous thromboembolism and bleeding events were observed between patients with and those without a history of cancer. CONCLUSIONS: A history of cancer, with a prevalence of 10.6%, is an independent risk factor for mortality in patients with CTEPH undergoing the currently recommended treatment.

Association Between Time Since Smoking Cessation and Frailty Trajectory Among Community-Dwelling Older People: English Longitudinal Study of Ageing.

OBJECTIVES: To examine the associations of smoking cessation with the subsequent frailty status trajectory using data from a nationally representative sample of community-dwelling older adults living in England. DESIGN: A prospective panel study. SETTING AND PARTICIPANTS: A total of 2600 community-dwelling older adults aged 60 or older in England who used to smoke. METHODS: The past smokers were divided into 5 groups based on years since smoking cessation: 0-10, 11-20, 21-30, 31-40, and 41+ years. The Frailty Index (FI) was constructed using 60 deficits and repeatedly calculated every 2 years over 16 years. Trajectories of FI according to years since smoking cessation were estimated by a mixed-effects model. RESULTS: A mixed-effects model adjusted for age, sex, education, wealth, and alcohol use showed that FI increased over time in all groups and that longer duration since smoking cessation was significantly associated with lower FI. Those who quit 41 years earlier or more had the lowest frailty trajectory, however, there was still a gap between them and never smokers. CONCLUSIONS AND IMPLICATIONS: The current study showed that past smokers with a longer duration of quitting smoking had a significantly lower degree of frailty at baseline and over time. These findings highlight beneficial effects of smoking cessation on frailty even in middle or old age and could be used in public health education to promote the importance of quitting smoking.

Investigation of dog ownership and physical activity on weekdays and weekends using longitudinal data from the SOEP Cohort.

This study examines the association between dog ownership over a period of 5 years (always, sometimes and no ownership) with physical activity on weekdays and weekends over a period of 6 years using the nationally representative German Socio-Economic Panel. Participants were asked if they had any pets and how many hours they spend on sports, fitness, and exercise. We hypothesized that the length of dog ownership may have different effects on the physical activity of the owner. Overall, 15,240 participants completed the questionnaire on dog ownership in both 2011 and 2016, and reported their physical activity levels at least once between 2013 and 2018. Generalized estimating equation models showed that, compared to no ownership, always dog ownership was associated with higher physical activity on weekdays (Coefficient = 0.106, Standard Error: SE = 0.027, P < 0.001) and weekends (Coefficient = 0.121, SE = 0.033, P < 0.001) respectively, after controlling for related socio-demographic, physical, and psychological factors during the 6-year follow-up period. During the same follow-up period, sometimes dog ownership had no clear association with physical activity on both weekdays (Coefficient=-0.012, SE = 0.033, P = 0.706) and weekends (Coefficient = 0.049, SE = 0.039, P = 0.209) compared to no ownership. This study showed for the first time that longer dog ownership is associated with higher physical activity on both weekdays and weekends. Future research will be needed to investigate whether any causal relationships underlie the association.

Dog, cat, bird, fish, and other pet ownership and mortality: Evidence from the HILDA cohort.

This study used the nationally representative prospective study of the Household, Income and Labour Dynamics in Australia (HILDA) survey cohort to examine the association of pet ownership (dog, cat, bird, fish, and others) with the risk of all-cause mortality using propensity score matching based on a wide range of factors. The study sample included 15,735 participants who completed the questionnaire on pet ownership in 2018. The HILDA survey sample was matched to the National Death Index through 2022 to assess death during the follow-up period. Statistical analysis was weighted by the inverse of the propensity score in the generalized estimating equation. During the 4-year follow-up period, 377 of 15,735 (2.4%) participants died. The odds ratios (ORs) for all-cause mortality were 0.77 (95%CI: 0.59-0.99) for dog owners compared to non-pet owners after controlling for related socio-demographic, physical, psychological, and social factors. The Sobel test showed a partial mediating effect of physical activity level on the relationship between dog ownership and all-cause mortality. Ownership of cats, birds, fish, and others showed no clear association with mortality, despite owners having similar socio-demographics characteristics to dog owners. Companionship and exercise of a pet dog may be recommended as a component of health promotion policy, and may have an important role to play in promoting health aging.

Efficacy, safety, and pharmacokinetics of inhaled treprostinil in Japanese patients with pulmonary hypertension associated with interstitial lung disease.

BACKGROUND: The INCREASE trial, conducted in the United States, showed that inhaled treprostinil improved exercise capacity in pulmonary hypertension associated with interstitial lung disease (PH-ILD). However, hemodynamic and pharmacokinetic measurements were not performed in the trial. The objective of this trial was to evaluate the efficacy on hemodynamics and exercise capacity, safety, and pharmacokinetics (PK) of inhaled treprostinil in Japanese patients with PH-ILD. METHODS: This trial was a multicenter, non-randomized, open-label, single-arm trial of patients with PH-ILD. Inhaled treprostinil was administered at 3 breaths (18 µg)/session four times daily, and the dose was gradually increased to a maximum of 12 breaths (72 µg)/session. The primary endpoints were the change of pulmonary vascular resistance index (PVRI) and peak 6-min walking distance (6MWD) from baseline to week 16. Endpoints also included other efficacy parameters, safety, and PK. RESULTS: Twenty patients received inhaled treprostinil. At week 16, PVRI decreased from baseline by -40.1% (95% CI, -53.1 to -27.2) and peak 6MWD increased by 13.0 m (95% CI, -15.0 to 49.0). The most frequently reported adverse events related with treprostinil were cough, malaise and blood pressure decreased. PK was similar to those in pulmonary arterial hypertension (PAH) patients. CONCLUSIONS: Treatment with inhaled treprostinil using the same dosing regimen as in the INCREASE trial resulted in improvements in hemodynamics and exercise capacity with a favorable tolerability and safety profile in Japanese patients with PH-ILD.

Outcomes of Chronic Thromboembolic Pulmonary Hypertension After Balloon Pulmonary Angioplasty and Pulmonary Endarterectomy.

Background: The contemporary outcome of balloon pulmonary angioplasty (BPA) and pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are unclear. Objectives: This study aimed to clarify the characteristics and outcomes of CTEPH patients treated with BPA and PEA in Japan. Methods: Among 1,270 participants enrolled between 2018 and 2023 in the CTEPH AC (Chronic Thromboembolic Pulmonary Hypertension Anticoagulant) registry, a Japanese nationwide CTEPH registry, 369 treatment-naive patients (BPA strategy: n = 313; PEA strategy: n = 56) and 690 on-treatment patients (BPA strategy: n = 561; PEA strategy: n = 129) were classified according to the presence of prior reperfusion therapy. Morbidity and mortality events (all-cause death, rescue mechanical reperfusion therapy, and/or initiation of parenteral pulmonary vasodilators), pulmonary hemodynamics, exercise tolerance, and relevant laboratory test results were evaluated. Results: The BPA strategy was chosen in older patients than the PEA strategy (mean age, BPA vs PEA: 66.5 ± 12.6 years vs 62.5 ± 11.8 years; P = 0.028). Median follow-up period was 615 (Q1-Q3: 311-997) days in treatment-naive patients and 1,136 (Q1-Q3: 684-1,300) days in on-treatment patients. BPA strategy had as acceptable morbidity and mortality as PEA strategy (5-year morbidity and mortality event rate, BPA vs PEA: 10.2% [95% CI: 5.2%-19.5%] vs 16.1% [95% CI: 4.3%-50.6%] in treatment-naive patients; 9.7% [95% CI: 6.7%-13.8%] vs 6.9% [95% CI: 2.7%-17.3%] in on-treatment patients), with greater improvement of renal function; glomerular filtration rate in propensity score-matched population (difference between change: 4.9 [95% CI: 0.5-9.3] mL/min/1.73 m2; P = 0.030). Conclusions: BPA strategy was more frequently chosen in older patients compared with PEA strategy and showed acceptable outcomes for efficacy with greater advantage for improvement in renal function. (Multicenter registry of chronic thromboembolic pulmonary hypertension in Japan; UMIN000033784).

The Effectiveness of Leukocyte-Poor Platelet-Rich Plasma Injections for Symptomatic Mild to Moderate Osteoarthritis of the Knee With Joint Effusion or Bone Marrow Lesions in a Japanese Population: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

BACKGROUND: Intra-articular platelet-rich plasma (PRP) injections have been proposed for the treatment of knee osteoarthritis (OA); however, their effectiveness in Japanese patients remains unclear. PURPOSE: To investigate whether 3 intra-articular injections of leukocyte-poor PRP (LP-PRP) improve symptoms and joint function in symptomatic Japanese patients with mild to moderate knee OA. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Of 72 patients screened, 30 were included and randomized to receive LP-PRP (n = 15) or saline (placebo; n = 15) injections between March 2019 and February 2023. Patients attended a screening visit and 3 treatment visits at 1 week apart, followed by 3 follow-up visits (at 4, 12, and 24 weeks) after the initial treatment visit. The primary efficacy outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, whereas the secondary efficacy outcome measures were the proportion of patients showing a visual analog scale (VAS) improvement of ≥50%. Magnetic resonance imaging was performed to evaluate joint effusion and bone marrow lesions using the Whole-Organ Magnetic Resonance Imaging Score. Patients were followed for 24 weeks. RESULTS: Patients in the PRP group (mean age, 65.9 years) had a mean hip-knee-ankle angle of 5.1°, with 7 and 8 patients demonstrating Kellgren-Lawrence grade 2 and 3 knee OA, respectively. Patients in the placebo group (mean age, 67.9 years) had a mean hip-knee-ankle angle of 3.8°, with 6 and 9 patients showing Kellgren-Lawrence grade 2 and 3 knee OA, respectively. No significant differences were identified in any baseline factors. The percentage change in Western Ontario and McMaster Universities Osteoarthritis Index scores from baseline to 24 weeks was significantly different (P= .032) between the PRP (median, 75.9%; quantile 1 [Q1], 49.6; quantile 3 [Q3], 94.1]) and placebo (median, 27.7%; Q1, -9.4; Q3, 80.9]) groups. Overall, 73.3% and 28.6% of the PRP group and placebo group, respectively, exhibited an improvement in visual analog scale scores of ≥50%, with a significant improvement observed in the PRP group (P = .027). Changes in bone marrow lesions from baseline to 24 weeks, as assessed on magnetic resonance imaging, significantly differed between groups (P = .017), with no significant differences in other secondary endpoints. CONCLUSION: In Japanese patients with knee OA, 3 intra-articular LP-PRP injections led to clinical improvements at 24-week follow-up and significant functional improvements and pain relief after 24 weeks.

Overview of the 88th Annual Scientific Meeting of the Japanese Circulation Society (JCS2024)　- The Future of Cardiology - Challenges in Overcoming Cardiovascular Disease.

The 88thAnnual Scientific Meeting of the Japanese Circulation Society (JCS2024) was held from Friday, March 8thto Sunday, March 10thin Kobe, Japan. The main theme of this 3-day meeting was "The Future of Cardiology: Challenges in Overcoming Cardiovascular Disease". As COVID-19 has been finally conquered, with revision of its categorization under the Infectious Disease Control Law and relaxation of infection prevention measures, it was once again possible to have face-to-face presentations and lively discussion. JCS2024 was a major success, with 19,209 participants and attendees, thanks to the greatly appreciated cooperation and support from all affiliates.

Use of Unidirectional Porous ß-Tricalcium Phosphate in the Tibial Tunnel for Anterior Cruciate Ligament Reconstruction: A Case Series.

Bone defects in the tibial tunnel for anterior cruciate ligament (ACL) reconstruction can cause adverse events. The unidirectional porous tricalcium ß-phosphate (UDPTCP) has the potential to be used as a filling substitute for bone defects. In this case series, we present the first nine cases in which UDPTCP was used as a bone substitute in the tibial tunnel during ACL reconstruction. The patients comprised six males and three females, with an average age of 32 years (range: 16-50 years). A cylindrical UDPTCP measuring 10 x 20 mm was molded to fit the tibial tunnel and then implanted. At the one-year postoperative follow-up, none of the patients demonstrated any complications, and bone remodeling was observed on radiographs. Therefore, UDPTCP may provide a safe and reliable filling substitute for the tibial tunnel in ACL reconstruction.

Pulmonary Hypertension With Interstitial Pneumonia: Initial Treatment Effectiveness and Severity in a Japan Registry.

Background: Recent guidelines discourage the use of pulmonary arterial hypertension (PAH)-targeted therapies in patients with pulmonary hypertension (PH) associated with respiratory diseases. Therefore, stratifications of the effectiveness of PAH-targeted therapies are important for this group. Objectives: The authors aimed to identify phenotypes that might benefit from initial PAH-targeted therapies in patients with PH associated with interstitial pneumonia and combined pulmonary fibrosis and emphysema. Methods: We categorized 270 patients with precapillary PH (192 interstitial pneumonia, 78 combined pulmonary fibrosis and emphysema) into severe and mild PH using a pulmonary vascular resistance of 5 WU. We investigated the prognostic factors and compared the prognoses of initial (within 2 months after diagnosis) and noninitial treatment groups, as well as responders (improvements in World Health Organization functional class, pulmonary vascular resistance, and 6-minute walk distance) and nonresponders. Results: Among 239 treatment-naive patients, 46.0% had severe PH, 51.8% had mild ventilatory impairment (VI), and 40.6% received initial treatment. In the severe PH with mild VI subgroup, the initial treatment group had a favorable prognosis compared with the noninitial treatment group. The response rate in this group was significantly higher than the others (48.2% vs 21.8%, ratio 2.21 [95% CI: 1.17-4.16]). In multivariate analysis, initial treatment was a better prognostic factor for severe PH but not for mild PH. Within the severe PH subgroup, responders had a favorable prognosis. Conclusions: This study demonstrated an increased number of responders to initial PAH-targeted therapy, with a favorable prognosis in severe PH cases with mild VI. A survival benefit was not observed in mild PH cases. (Multi-institutional Prospective Registry in Pulmonary Hypertension associated with Respiratory Disease; UMIN000011541).

Switching from Beraprost to Selexipag in the Treatment of Pulmonary Arterial Hypertension: Insights from a Phase IV Study of the Japanese Registry (The EXCEL Study: EXChange from bEraprost to seLexipag Study).

Pulmonary arterial hypertension (PAH) remains a significant challenge in cardiology, necessitating advancements in treatment strategies. This study explores the safety and efficacy of transitioning patients from beraprost to selexipag, a novel selective prostacyclin receptor agonist, within a Japanese cohort. Employing a multicenter, open-label, prospective design, 25 PAH patients inadequately managed on beraprost were switched to selexipag. Key inclusion criteria included ongoing beraprost therapy for ≥3 months, a diagnosis of PAH confirmed by mean pulmonary artery pressure (mPAP) ≥ 25 mmHg, and current treatment with endothelin receptor antagonists and/or phosphodiesterase type 5 inhibitors. Outcomes assessed were changes in hemodynamic parameters (mPAP, cardiac index, pulmonary vascular resistance) and the 6 min walk distance (6-MWD) over 3-6 months. The study found no statistically significant changes in these parameters post-switch. However, a subset of patients, defined as responders, demonstrated improvements in all measured hemodynamic parameters, suggesting a potential benefit in carefully selected patients. The transition was generally well-tolerated with no serious adverse events reported. This investigation underscores the importance of personalized treatment strategies in PAH, highlighting that certain patients may benefit from switching to selexipag, particularly those previously on higher doses of beraprost. Further research is needed to elucidate the predictors of positive response to selexipag and optimize treatment regimens for this complex condition.

Development and web deployment of prediction model for pulmonary arterial pressure in chronic thromboembolic pulmonary hypertension using machine learning.

BACKGROUND AND PURPOSE: Mean pulmonary artery pressure (mPAP) is a key index for chronic thromboembolic pulmonary hypertension (CTEPH). Using machine learning, we attempted to construct an accurate prediction model for mPAP in patients with CTEPH. METHODS: A total of 136 patients diagnosed with CTEPH were included, for whom mPAP was measured. The following patient data were used as explanatory variables in the model: basic patient information (age and sex), blood tests (brain natriuretic peptide (BNP)), echocardiography (tricuspid valve pressure gradient (TRPG)), and chest radiography (cardiothoracic ratio (CTR), right second arc ratio, and presence of avascular area). Seven machine learning methods including linear regression were used for the multivariable prediction models. Additionally, prediction models were constructed using the AutoML software. Among the 136 patients, 2/3 and 1/3 were used as training and validation sets, respectively. The average of R squared was obtained from 10 different data splittings of the training and validation sets. RESULTS: The optimal machine learning model was linear regression (averaged R squared, 0.360). The optimal combination of explanatory variables with linear regression was age, BNP level, TRPG level, and CTR (averaged R squared, 0.388). The R squared of the optimal multivariable linear regression model was higher than that of the univariable linear regression model with only TRPG. CONCLUSION: We constructed a more accurate prediction model for mPAP in patients with CTEPH than a model of TRPG only. The prediction performance of our model was improved by selecting the optimal machine learning method and combination of explanatory variables.

Synovial Folds Impingement After Unicondylar Knee Arthroplasty.

Soft tissue impingement after total knee arthroplasty has been reported; however, complications after unicondylar knee arthroplasty (UKA) have rarely been reported. We report a rare case of synovial fold impingement that occurred after UKA and caused severe pain with clicking during knee flexion and extension. Diagnostic arthroscopy was performed 3 weeks after UKA and found that a hypertrophied and congested synovial fold in the medial compartment impinged on the femoral component during knee flexion and extension. After excising the synovial fold, the patient's symptoms improved. Synovial fold impingement is a complication that should be considered when patients complain of severe pain with clicking in the knee after UKA.

Pulmonary tumor thrombotic microangiopathy due to early gastric carcinoma in a patient with no antemortem findings suggestive of primary malignancy.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare and critical malignancy-related disease characterized by acute progressive pulmonary hypertension (PH). In most cases of PTTM, the cancer can be diagnosed in advance. Identification of the primary cancer is valuable for PTTM diagnosis. Here, we present the case of a patient with PTTM due to early gastric carcinoma in whom the diagnosis of malignant cancer was not revealed until macroscopic autopsy findings. This case highlights the importance of recognizing causative occult early gastric cancer leading to PTTM in cases of acute progressive PH.

Association between maternal blood or cord blood metal concentrations and catch-up growth in children born small for gestational age: an analysis by the Japan environment and children's study.

BACKGROUND: Catch-up growth issues among children born small for gestational age (SGA) present a substantial public health challenge. Prenatal exposure to heavy metals can cause adverse effects on birth weight. However, comprehensive studies on the accurate assessment of individual blood concentrations of heavy metals and their effect on the failure to achieve catch-up growth remain unavailable. This study aimed to evaluate the effects of uterine exposure to toxic metals cadmium, lead, and mercury and essential trace metals manganese and selenium at low concentrations on the postnatal growth of children born SGA. METHODS: Data on newborn birth size and other factors were obtained from the medical record transcripts and self-administered questionnaires of participants in the Japan Environment and Children's Study. The blood concentrations of lead, cadmium, mercury, selenium, and manganese in pregnant women in their second or third trimester were determined by inductively coupled plasma mass spectrometry. These heavy metal concentrations were also assessed in pregnant women's cord blood. Furthermore, the relationship between each heavy metal and height measure/catch-up growth in SGA children aged 4 years was analyzed using linear and logistic regression methods. These models were adjusted for confounders. RESULTS: We studied 4683 mother-child pairings from 103,060 pregnancies included in the Japan Environment and Children's Study. Of these, 278 pairs were also analyzed using cord blood. At 3 and 4 years old, 10.7% and 9.0% of children who were born below the 10th percentile of body weight had height standard deviation scores (SDSs) below 2, respectively. Cord blood cadmium concentrations were associated with the inability to catch up in growth by 3 or 4 years old and the height SDS at 3 years old. In maternal blood, only manganese was positively associated with the height SDS of SGA children aged 2 years; however, it was not significantly associated with catch-up growth in these children. CONCLUSION: Cadmium exposure is associated with failed catch-up development in SGA children. These new findings could help identify children highly at risk of failing to catch up in growth, and could motivate the elimination of heavy metal (especially cadmium) pollution to improve SGA children's growth.

Adult-onset idiopathic peripheral pulmonary artery stenosis.

BACKGROUND: Peripheral pulmonary artery stenosis (PPS) refers to stenosis of the pulmonary artery from the trunk to the peripheral arteries. Although paediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Our objectives in this study were to characterise the disease profile of adult-onset PPS. METHODS: We collected data in Japanese centres. This cohort included patients who underwent pulmonary angiography (PAG) and excluded patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis. Patient backgrounds, right heart catheterisation (RHC) findings, imaging findings and treatment profiles were collected. RESULTS: 44 patients (median (interquartile range) age 39 (29-57) years; 29 females (65.9%)) with PPS were enrolled from 20 centres. In PAG, stenosis of segmental and peripheral pulmonary arteries was observed in 41 (93.2%) and 36 patients (81.8%), respectively. 35 patients (79.5%) received medications approved for pulmonary arterial hypertension (PAH) and 22 patients (50.0%) received combination therapy. 25 patients (56.8%) underwent transcatheter pulmonary angioplasty. RHC data showed improvements in both mean pulmonary arterial pressure (44 versus 40 mmHg; p<0.001) and pulmonary vascular resistance (760 versus 514 dyn·s·cm-5; p<0.001) from baseline to final follow-up. The 3-, 5- and 10-year survival rates of patients with PPS were 97.5% (95% CI 83.5-99.6%), 89.0% (95% CI 68.9-96.4%) and 67.0% (95% CI 41.4-83.3%), respectively. CONCLUSIONS: In this study, patients with adult-onset idiopathic PPS presented with segmental and peripheral pulmonary artery stenosis. Although patients had severe pulmonary hypertension at baseline, they showed a favourable treatment response to PAH drugs combined with transcatheter pulmonary angioplasty.

Protective effects of dog ownership against the onset of disabling dementia in older community-dwelling Japanese: A longitudinal study.

This prospective study examined the associations of dog/cat ownership with incident disabling dementia using propensity score matching based on the physical, social, and psychological characteristics of dog and cat owners. We also examined associations of the interaction between dog/cat ownership and exercise habit and social isolation with dementia. Overall, 11,194 older adults selected using stratified and random sampling strategies in 2016 were analyzed. Dog/cat ownership was defined as "current" or "past and never". Disabling dementia was defined according to physicians' rating in the long-term care insurance system in Japan during the approximately 4-year follow-up period. Statistical analysis was weighted by the inverse of the propensity score in the generalized estimating equation after adjusting for follow-up period. Current dog owners (8.6 %) had an odds ratio (OR) of 0.60 (95 %CI: 0.37-0.977) of having disabling dementia compared to past and never owners. For cat ownership, the corresponding OR was 0.98 (95 %CI: 0.62-1.55). Current dog owners with a regular exercise habit had an OR of 0.37 (0.20-0.68) compared to past and never dog owners with no exercise habit. Further, current dog owners with no social isolation had an OR of 0.41 (0.23-0.73) compared to past and never dog owners with social isolation. Dog ownership had a suppressive effect on incident disabling dementia after adjusting for background factors over a 4-year follow-up period. Specifically, dog owners with an exercise habit and no social isolation had a significantly lower risk of disabling dementia.