Association between Japanese Diet Adherence and Muscle Weakness in Japanese Adults Aged ≥50 Years: Findings from the JSTAR Cohort Study

Japanese diet adherence has been inversely correlated with muscle weakness. In this study, we aimed to validate that association. Longitudinal data from 1699 individuals aged ≥50 years (mean age 62.5 ± 6.9 years, 50.4% female) at two time points (2007 and 2011) were used. Participants without muscle weakness from several regions in Japan were included. The 12-component revised Japanese Diet Index (rJDI12) classified by tertiles assessed adherence to the Japanese dietary pattern. Muscle weakness was defined as a handgrip strength of ˂18 kg for females and ˂28 kg for males based on the Asian Working Group for Sarcopenia criteria 2019. A multivariate logistic approach was used to determine the relationship between rJDI12 tertile and the occurrence of muscle weakness by calculating the odds ratio (OR) and its 95% confidence interval (95% CI) throughout the observation period. Muscle weakness was negatively correlated with the highest rJDI12 tertile (OR [95% CI] 0.891 [0.814, 0.973] for T3). This association was consistent in sensitivity analyses with multiple imputations of missing values. Closely following the Japanese dietary pattern appears to reduce the occurrence of muscle weakness among the aging population in this study, suggesting it may prevent frailty and sarcopenia in the aging population.

Association of Japanese and Mediterranean Dietary Patterns with Muscle Weakness in Japanese Community-Dwelling Middle-Aged and Older Adults: Post Hoc Cross-Sectional Analysis

The association of Japanese and Mediterranean dietary patterns with muscle weakness in middle-aged and older Japanese individuals is unclear. This cross-sectional study investigated the association between Japanese and Mediterranean dietary patterns and muscle weakness in community-dwelling, middle-aged, and older Japanese individuals (enrolled from 2007 to 2011). Based on the dietary consumption information obtained from the brief self-administered diet history questionnaire, we assessed adherence to the Japanese (12-component revised Japanese diet index (rJDI12)) and Mediterranean (alternate Mediterranean diet (aMed) score) dietary patterns. Muscle weakness was defined as handgrip strength <28 and <18 kg for men and women, respectively. Logistic regression was used to ascertain the relationship between dietary pattern and muscle weakness. In our study, with 6031 participants, the Japanese, but not Mediterranean, dietary pattern was inversely associated with muscle weakness (p for trend = 0.031 and 0.242, respectively). In the model adjusted for confounders, including energy intake, the highest quartile of rJDI12 scores (9-12 points), and the rJDI12 scores, entered as continuous variables, showed an independent association (odds ratio (95% CI), 0.703 (0.507-0.974), and 0.933 (0.891-0.977), respectively). Our findings showed that adherence to the Japanese dietary pattern is associated with a low prevalence of muscle weakness.

Nutritional Management in Adult Patients With Dysphagia: Position Paper From Japanese Working Group on Integrated Nutrition for Dysphagic People

This position paper prepared by the Japanese Working Group on Integrated Nutrition for Dysphagic People (JWIND) aims to summarize the need for nutritional management in adult patients with dysphagia, the issues that nutrition professionals should address, and the promising approaches as well as to propose a vision for the future of nutritional care for adult patients with dysphagia. JWIND is a joint certification system recognized by the Japan Dietetic Association and the Japanese Society of Dysphagia Rehabilitation; its members are mostly experts known as "Certified Specialist of Registered Dietitian for Dysphagia Rehabilitation." Malnutrition and dysphagia are associated with each other. Therefore, malnutrition detection and intervention are essential for patients with dysphagia. However, evidence on the usefulness nutritional assessment and intervention to ensure appropriate nutritional care remains insufficient. Here, we present current knowledge of the relationship between primary diseases causing dysphagia and malnutrition, the indicators used for nutritional assessment, and nutritional interventions such as texture-modified diet (TMD) quality improvement, oral nutritional supplementation, and comprehensive intervention. We also discuss the current status and issues in nutritional care for adult patients with dysphagia. Furthermore, we have proposed measures that nutrition professionals should consider based on 3 perspectives: nutritional assessment, TMD, and nutritional intervention. Individualized and specialized nutritional management by registered dietitians (RDs) through appropriate assessment of the nutritional status of adult patients with dysphagia is needed. To maintain and improve swallowing function and nutritional status, RDs should intervene from the state of risk or early dysphagia onset, providing individualized care per their expertise as part of a multidisciplinary team. However, systematic clinical practice and research regarding the association of nutrition with dysphagia are currently insufficient. Therefore, further clinical practice and evidence building, including the verification of the efficacy on nutritional support through intervention research, are needed.

Hospital Frailty Risk Score predicts adverse events in older patients with vertebral compression fractures: Analysis of data in a nationwide in-patient database in Japan

AIMS

This study investigated the usefulness of frailty for predicting adverse events in patients with vertebral compression fractures (VCFs) during hospitalization using data obtained from the Japanese health insurance system.

METHODS

This retrospective cohort study of patients with VCFs aged ≥65 years was conducted using a nationwide database in Japan. We examined the relationships between frailty risk, classified using the Hospital Frailty Risk Score (HFRS), in-hospital mortality, and complications such as pressure ulcers and pneumonia. Multivariate logistic regression analysis was used to estimate the association between the HFRS and the outcomes of patients with VCFs.

RESULTS

In this study, the data of 30 980 in-patients with VCFs were analyzed. Of these patients, 76.8%, 21.3%, and 1.9% had low, intermediate, and high risks of frailty, respectively. The higher the risk of frailty, the higher the rate of in-hospital mortality and the occurrence of all complications (P < 0.001 for trend). An intermediate risk of frailty was independently associated with in-hospital mortality (odds ratio [OR], 1.421; P < 0.001), whereas a high risk of frailty did not show statistical significance (OR, 1.385; P = 0.150). Each frailty risk was independently associated with the occurrence of all complications during hospitalization.

CONCLUSIONS

The HFRS, which can assess the risk of frailty based on routinely collected medical records, was predictive of adverse events in older patients with VCFs based on a nationwide database in Japan. Future studies need to assess approaches to preventing adverse events in frail VCF patients. Geriatr Gerontol Int 2022; ••: ••-••.

Short- and long-term effects of different exercise programs on the gait performance of older adults with subjective cognitive decline: A randomized controlled trial

BACKGROUND

Older adults, especially those with cognitive decline, often have poor gait performance, which results in poor clinical outcomes due to falls or decreased daily physical activity. The effects of various exercises on gait performance have been studied, whereas the short-term and long-term effects of different exercise modalities remain unknown.

OBJECTIVE

To compare the short- and long-term effects of aerobic training (AT), resistance training (RT), and combined training (CT) on the gait performance of community-dwelling older adults with subjective cognitive decline (SCD).

DESIGN

A four-arm, randomized controlled trial.

SETTING AND SUBJECTS

388 community-dwelling older adults with SCD (mean age, 72.3 years).

METHODS

Participants attended an exercise or education class twice a week for 26 weeks. 10 gait performance parameters were examined at baseline, post-intervention (Week 26), and after 26 weeks of follow-up (Week 52) using an electronic walkway system.

RESULTS

The mean adherence of exercise sessions was 82.5 to 85.9%. All exercise intervention induced an improvement in gait speed, stride time, cadence, stride length, and double-support time at Week 26 (p < .05), without significant intergroup differences among exercise interventions. However, only RT showed a significant effect on some spatiotemporal gait parameters at Week 52. The analyses for the gait variability parameters showed mild effects of all exercise interventions.

CONCLUSION

All of the exercise programs examined had a positive short-term effect on spatiotemporal gait parameters of older adults with SCD, despite no effect on gait variability parameters. RT are most recommended when long-lasting effects are the primary aim.

Hospital Frailty Risk Score predicts adverse events in older patients with hip fractures after surgery: Analysis of a nationwide inpatient database in Japan

BACKGROUND

Frailty may predict adverse events in patients with hip fractures. This study aimed to investigate the association between frailty and adverse events in patients with hip fractures after surgery using information from Japanese health insurance.

METHODS

This retrospective cohort study included patients with hip fractures aged ≥ 65 years using a nationwide database in Japan. We examined the relationship of the frailty risk, which was defined using the Hospital Frailty Risk Score (HFRS), with in-hospital mortality, complications such as delirium and pneumonia, and functional outcomes. We used descriptive analysis, logistic regression, and linear regression analysis to estimate the association between the HFRS and outcomes in patients with hip fracture.

RESULTS

We analysed data from 36,192 patients with hip fractures after surgery (mean age: 83.6 ± 6.7 years, female: 79.5%). The proportions of low, intermediate, and high risk of frailty were 68.4%, 28.1%, and 3.5%, respectively. The frailty risk was independently associated with in-hospital mortality (intermediate risk: odds ratio [OR] 1.385, P < 0.001; high risk: OR 1.572; P < 0.001) and the occurrence of complications. Furthermore, each frailty risk was negatively associated with the Barthel Index score at discharge (intermediate risk: coefficient -11.919, P < 0.001; high risk: coefficient -18.044; P < 0.001).

CONCLUSIONS

The HFRS could predict adverse events, including in-hospital mortality, in Japanese older patients with hip fractures. This finding supports the validity of using the HFRS in clinical practice for patients with hip fractures.

The association of social frailty with intrinsic capacity in community-dwelling older adults: a prospective cohort study

Background

Social frailty is associated with poor health outcomes; however, its effects on healthy aging indicators have not been adequately investigated. This study assessed the longitudinal association between social frailty and the intrinsic capacity of community-dwelling older adults.

Methods

A total of 663 participants (56.7% women) aged ≥60 years from in Nagoya, Japan, were included in the study. The first measurement occurred in 2014, and annual follow-ups occurred until 2017. Social frailty was determined based on four items: financial difficulty, household status, social activity, and regular contact with others. A deficit score of 0 represented social robustness, 1 represented social prefrailty, and ≥ 2 represented social frailty. Intrinsic capacity was evaluated by the locomotion, cognition, psychological function, vitality, and sensory function domains. The longitudinal association was analyzed using generalized estimating equations.

Results

The prevalence of social prefrailty and social frailty at baseline was 31.2 and 6.3%, respectively. The social prefrailty group (β = − 0.132, P < 0.001) and social frailty group (β = − 0.258, P < 0.001) were associated with a greater reduction in the composite intrinsic capacity scores than the social robustness group, especially in the cognition, psychological function, and vitality domains. Men with social prefrailty/social frailty demonstrated a greater decrease in the psychological function domain score (− 0.512 vs. − 0.278) than women. Additionally, the cognition domain score only decreased in men in the social prefrailty/social frailty group (β = − 0.122, P = 0.016).

Conclusions

Social frailty was associated with intrinsic capacity and its subdomains longitudinally. Men with social frailty were more vulnerable than women to a decline in their psychological function and cognition domains. Therefore, the advanced management of social frailty is necessary to facilitate healthy aging.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02466-6.

Dietary Patterns and Muscle Mass, Muscle Strength, and Physical Performance in the Elderly: A 3-Year Cohort Study

OBJECTIVES

Nutritional support effectively prevents and treats sarcopenia; however, the influence of overall dietary patterns on sarcopenia parameters is less investigated. This study aimed to determine the association between adherence to Mediterranean-style diet (MD), Dietary Approaches to Stop Hypertension (DASH), Japanese Food Guide Spinning Top (JFG-ST), and modified JFG-ST (mJFG-ST) and muscle mass, muscle strength, and physical performance in community-dwelling Japanese elderly.

DESIGN AND SETTINGS

This prospective cohort study recruited individuals aged over 60 years from a community college in Nagoya, Japan.

PARTICIPANTS AND MEASUREMENTS

A total of 666 participants were followed up annually from 2014 to 2017. Demographic data, anthropometric measurements, and sarcopenia parameters including walking speed (WS), hand grip strength in the dominant hand (HGS), and skeletal mass index (SMI) were recorded. Self-recall dietary intake was assessed using a validated food frequency questionnaire comprising 29 food groups. Adherence to MD, DASH, JFG-ST, and mJFG-ST was determined by tertiles.

RESULTS

At baseline, the mean age of all participants (56.5% women) was 69.4±4.4 years. WS, HGS, and SMI were 1.4±0.2 (m/s), 28.9±8.1 (kg), and 6.7±1.0 (kg/m2), respectively. In longitudinal analysis, participants with higher JFG-ST adherence scores were more likely to have higher SMI (Q3 vs. Q1: mean difference, 0.048; p=0.04) after adjustment, and its benefits were more evident in men (Q2 vs. Q1: mean difference, 0.098; p=0.047; Q3 vs. Q1: mean difference, 0.091; p=0.017) than in women. WS and HGS were not associated with any type of dietary pattern.

CONCLUSIONS

Adherence to JFG-ST was positively associated with SMI in Japanese community-dwelling elderly adults aged over 60 years, specifically in men. The country-specific dietary recommendations are required to be developed for sarcopenia prevention.

Sex-Specific Association between Social Frailty and Diet Quality, Diet Quantity, and Nutrition in Community-Dwelling Elderly

The effects of social frailty on diet and nutrition are under-investigated. Our study aimed to assess the association between social frailty and diet quality, diet quantity, and nutrition over a 3-year period in community-dwelling older Japanese adults. This prospective cohort study recruited individuals aged ≥60 years from a community college and followed up 666 participants annually. Social frailty was determined using a 4-item questionnaire. Diet quantity (energy and macronutrient intake) and diet quality (dietary diversity score and Diet Quality Index-International) were assessed using a food frequency questionnaire. Nutrition was evaluated using the Mini-Nutritional Assessment (MNA). Out of the 666 participants (56.5% women), 250 (37.5%) were categorized as having social prefrailty or frailty. Regarding diet quantity, energy intake (β = −1.59kcal/kg/day, p < 0.01) and nutrient intake (protein intake, β = −0.08g/kg/day; fat intake, β = −0.06g/kg/day; carbohydrate intake, β = −0.18g/kg/day; fiber intake, β = −0.01g/kg/day; all p < 0.05) were lower in men with social prefrailty or frailty than in men with social robustness. Dietary diversity score (β = −0.25, p = 0.01) and MNA score (β = −0.32, p = 0.04) decreased in men with social prefrailty or frailty. However, these associations were not observed in women. Social frailty is associated with lower dietary intake, poor diet quality, and poor nutrition among community-dwelling older men. Future studies are required to determine the benefits of sex-specific interventions targeting social frailty on nutritional outcomes.

Built Environment and Frailty: Neighborhood Perceptions and Associations With Frailty, Experience From the Nagoya Longitudinal Study

Neighborhood physical characteristics have been consistently associated with the health of older adults. This article investigates links between frailty and perceptions of the neighborhood environment. Using a cross-sectional analysis of 370 community-dwelling older adults from Nagoya, Japan, neighborhood perceptions were assessed using the Neighborhood Environmental Walkability Scale (NEWS) in addition to frailty, using a frailty index. Frailty was associated with the NEWS composite index, land use mix diversity, land use mix access, street connectivity, walking infrastructure, aesthetics, and crime safety, after adjustment for covariates. Older adults with increasing frailty have poorer perceptions of their neighborhoods, which could lead to further constriction of the life-space, less social and physical engagement, and worsening of frailty status.

Nutritional status change and activities of daily living in elderly pneumonia patients admitted to acute care hospital: A retrospective cohort study from the Japan Rehabilitation Nutrition Database

OBJECTIVE

The aim of this study was to examine the effect of improved nutritional status on activities of daily living (ADLs) and dysphagia in elderly patients with pneumonia who were admitted to acute care hospitals.

METHODS

A retrospective cohort study was conducted using registry data from the Japan Rehabilitation Nutrition Database of patients with pneumonia who were admitted to acute care hospitals. Patients were divided into two groups based on the Mini Nutritional Assessment Short-Form (MNA-SF) status at discharge: Patients with no status change or with decreased status were allocated to the unimproved nutritional status (UN) group and those with increased status were assigned to the improved nutritional status (IN) group. The primary outcome was ADLs as assessed by Barthel Index (BI) score at hospital discharge. Secondary outcomes included dysphagia as assessed by the Food Intake Level Scale (FILS) at discharge.

RESULTS

The study included 143 patients with a mean age of 84.7 ± 7.8 y. Based on the MNA-SF categories at discharge, 127 (88.8%) patients were assigned to the UN group and 16 (11.2%) to the IN group. Patients in the IN group had significantly higher BI and FILS scores than those in the UN group. Multiple regression analysis indicated that improvement in nutritional status was independently associated with BI gain (B = 9.916; β = 0.153; 95% confidence interval [CI], 1.929-11.761; P = 0.017) and FILS gain (B = 1.259; β = 0.167; 95% CI, 1.224-2.814; P = 0.044).

CONCLUSIONS

Nutritional improvement is associated with improvements in ADL and dysphagia in patients with pneumonia and malnutrition.

Frailty prevalence using Frailty Index, associated factors and level of agreement among frailty tools in a cohort of Japanese older adults

Frailty prevalence defined by the deficit accumulation model (Frailty Index) has limited exploration in a Japanese population. The objective of this paper is to investigate the prevalence of frailty by Frailty Index among a cohort of healthy Japanese older adults, define risk factors associated with pre-frailty and frailty status and evaluate Frailty Index's agreement with Frailty Phenotype and Kihon checklist.

METHODS

Data from 673 participants of the 2014 wave of the Nagoya Longitudinal Study - Healthy Elderly were used. Annual assessments include investigation of mood, memory, health status, nutrition, physical performance and oral health. The Frailty Index was compared to Frailty Phenotype and Kihon Checklist, and factors associated to Frailty Index were investigated through univariate and multivariate logistic regression.

RESULTS

Frailty prevalence was 13.5% (n = 91) by Frailty Index, 1.5% (n = 10) by Frailty Phenotype and 4% (n = 27) by Kihon Checklist. Although the correlations between the three scales were moderate to high, the agreement between the scales was poor. In terms of risk factors, age, polypharmacy and physical activity level were associated with being pre-frail and frail. Having a higher waist circumference was associated with being pre-frail, and lower handgrip strength and lower walking speed were associated with being frail.

CONCLUSIONS

The Frailty Index showed similar metrics and agreement comparable to findings of previous studies, and was able to identify a higher number of individuals who were pre-frail and frail. Age, polypharmacy, physical activity, waking speed and waist circumference were associated with pre-frailty and frailty by frailty index.

Purification and characterization of lipoxygenase from Pleurotus ostreatus

Lipoxygenase was purified homogeneously from cups of Pleurotus ostreatus by Sephacryl S-400 HR gel filtration, Dyematrex Green A affinity, and DEAE-Toyopearl 650M ion-exchange chromatographies. The molecular weight of the enzyme was estimated to be 67,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 66,000 by gel filtration; the isoelectric point was pH 5.1. The optimum pH and temperature of the enzymatic activity were 8.0 and 25 degrees C, respectively. The enzyme contained non-heme iron, and a thiol group seemed to be involved in its activity. The K(m), V(max), and k(cat) values of the enzyme for linoleic acid were 0.13 mM, 23.4 micromol.min(-1).mg(-1), and 25.7 s(-1), respectively. The enzyme showed high specificity toward linoleic acid. When linoleic acid was incubated with the enzyme, 13-hydroperoxy-9Z,11E-octadecadienoic acid was found to be the main oxidative product.

Structure-activity relationships of saponins and cardiac glycosides. III. Beta-L-xylopyranosyl-(1-->6)-alpha- and -beta-D-glucopyranosides

Comparisons of the biological activities of diosgenyl, methyl glycyrrhetinate or digitoxigenyl 3-O-beta-L-xylopyranosyl-(1-->6)-beta-D-glucopyranoside with those of other previously tested glycosides confirmed our assumption that both the hemolytic and antifungal activities of steroid saponins are generally parallel to each other, while almost all hemolytic triterpenoid saponins and nonhemolytic ones have no antifungal activity, and that cardiac diglycosides having a (1-->4) sugar linkage have stronger activities than those with a (1-->6) or a (1-->2) linkage. On the other hand, the case of the diosgenyl 3-O-beta-L-xylopyranosyl-(1-->6)-alpha-D-glucopyranoside didn't conform to the above assumption, but those of methyl glycyrrhetinate and digitoxigenyl did.

Biological activities of synthetic triterpenoid and steroid beta-D-glucopyranosyl-(1-->2)-alpha-D-glucopyranosides

Comparisons of the biological activities of diosgenyl, methyl glycyrrhetinate, or digitoxigenyl 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-D-glucopyranoside with those of other previously tested glycosides confirmed our assumption that both haemolytic and antifungal activities of steroid saponins are generally parallel to each other, while almost all haemolytic triterpenoid saponins have no antifungal activity. The earlier supposition that cardiac diglycosides having a (1-->4) sugar linkage have stronger activities than those with a (1-->6) linkage has been extended by the demonstration of reduced activity also in those with a (1-->2) linkage.

Biological activities of synthetic triterpenoid and steroid beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranosides

Comparisons of the activities of diosgenyl, methyl glycyrrhetinate or digitoxigenyl 3-O-beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside with those of our previous glycosides supported our assumptions that both haemolytic and antifungal activities of steroid saponins are generally parallel to each other, while almost all haemolytic triterpenoid saponins show no antifungal activity, and that both antiviral and anti-ATPase activities of cardiac glycosides having a (1-->6) sugar linkage are much lower than those of the others.

Structure-activity relationships of synthetic saponins

The haemolytic and antifungal activities of synthetic diosgenyl, tigogenyl, hecogenyl, methyl oleanolate, methyl ursolate and methyl glycyrrhetinate glycosides were compared with each other. Both activities of the steroid glycosides were generally parallel to each other, while almost all haemolytic triterpenoid glycosides showed no antifungal activity.

Structure-activity relationships of synthetic cardiac glycosides

The antiviral, cytotoxic and anti-ATPase activities of 14 synthetic bufalyl glycosides were compared with each other. Among these glycosides, the activities of the gentiobioside and the melibioside were much weaker than those of the others. On the other hand, these three activities were found to be highly correlated with each other. These were parallel to the case of the digitoxigenyl glycosides in our previous paper.

Production of an anti-allergic triterpene bryonolic acid, by plant cell cultures

Cell suspension cultures of Luffa cylindrica, Citrullus lanatus, and related cucurbitaceous plants accumulate large quantities of bryonolic acid (3 beta-hydroxy-D:C-friedoolean-8-en-29-oic acid) [1], an acidic, pentacyclic triterpene found exclusively in the roots of the intact plants. This compound could readily be isolated from cultured cells with CHCl3 and purified simply by recrystallization. Pharmacological tests using mice demonstrated that bryonolic acid or its derivative is active against at least three types of allergies and that its activity could be increased significantly by preparing synthetic derivatives, in particular a potassium salt of its succinate ester. The biosynthesis of bryonolic acid from mevalonic acid via isomultiflorenol has been elucidated by tracer and enzymological experiments using cultured cells of watermelon both in vitro and in vivo. Furthermore, cell fractionation and electron microscopic studies on subcellular structures of luffa cells suggested that minute vesicles originating from elongated, rough endoplasmic reticulum probably play an important role in the transport of bryonolic acid which largely accumulates in the cell wall of cultured cells. The results obtained from the present study indicate that plant cell culture would be useful not only as a biological system for elucidating biosynthetic mechanisms but also as a potential source of new pharmacologically active compounds.

Activity of thyroid stimulating antibody and thyroid stimulation blocking antibody determined by radioiodine uptake into FRTL-5 cells

To investigate the pathophysiology of patients with autoimmune thyroid diseases, we measured serum thyroid stimulating antibody (TSAb) activity and thyroid stimulation blocking antibody (TSBAb) activity by determining the radioiodine (125I) uptake into FRTL-5 cells. FRTL-5 cells were pre-incubated for seven days with 5H medium and then incubated for 48 hours with patients' crude IgG prepared by polyethylene glycol precipitation. In order to measure TSBAb, 10 microU/ml TSH was also added. 125I was added one hour before the end of the 48 hour incubation period. After the incubation, the medium was aspirated, and the radioactivity in the cells was counted. In patients with untreated hyperthyroid Graves' disease, TSAb was detectable in 18 of 20 patients, the detectability being 90%, and activity showed a statistically significant positive correlation with TSAb activity determined by c-AMP accumulation. Out of 41 patients with hypothyroidism, TSBAb determined by 125I uptake was positive in six cases, the detectability being 14.6%. The inhibition of 125I uptake by one of these six IgGs was suggested to be at the TSH receptor level because it inhibited TSH induced c-AMP accumulation and showed positive thyrotropin binding inhibitor immunoglobulin (TBI I) activity, but did not inhibit the forskolin- and (Bu)2cAMP-induced 125I uptake. Inhibition of another IgG was suggested at the post-receptor level because it did not inhibit TSH induced cAMP accumulation and showed negative TBI I activity, but inhibited forskolin- and (Bu)2cAMP-induced 125I uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship among thyrotropin (TSH), thyroid stimulating immunoglobulins, and results of triiodothyronine (T3) suppression test in patients with Graves' disease

To investigate the relationship between TSH and abnormal thyroid stimulator(s) in patients with hyperthyroid Graves' disease in whom normal thyroid hormone levels in the serum were maintained by antithyroid drug therapy and in patients with euthyroid Graves' disease, determinations were made of the TSH concentration, action of thyroid stimulating immunoglobulins (TSAb and TBII), and T3 suppression. Out of thirty-three patients with hyperthyroid Graves' disease, twelve patients with subnormal TSH levels were all non-suppressible according to the T3 suppression test results and the detectability of TSAb and/or TBII was as high as 75%. In three out of five patients with euthyroid Graves' disease, the serum TSH level was subnormal. All three showed non-suppressibility in the T3 suppression test and positive action of either TSAb or TBII. One of them became clinically thyrotoxic when the TSAb activity was further increased and TBII became positive, and was therefore diagnosed as having hyperthyroid Graves' disease. The present findings suggest that there are still abnormal thyroid stimulator(s) in patients with hyperthyroid Graves' disease who have low TSH, even if their thyroid hormone concentrations remain normal. Moreover, it is likely that some of the patients with euthyroid Graves' disease are actually in a state of subclinical hyperthyroidism because of the presence of abnormal thyroid stimulator(s).

[Clinical studies on abnormal thyroid stimulators in patients with Graves' disease. I. A sensitive assay for thyroid-stimulating antibodies using cultured porcine thyroid cells and polyethylene glycol precipitation of serum]

The activities of thyroid-stimulating antibody (TSAb) in serum from patients with Graves' disease were measured by a sensitive assay, using cultured porcine thyroid cells and the precipitation from serum with polyethylene glycol (PEG), and the activities were compared with those of thyrotropin binding inhibitor immunoglobulin (TBII), measured by the commercial assay kit. Porcine thyroid cells after digestion were cultured for 15-18 hours with TSH of 1-10,000 microU/ml or the precipitations of sera from normal subjects and patients with Graves' disease or Hashimoto's thyroiditis, and then the cAMP levels in the culture medium were determined by the commercial RIA assay kit (Yamasa). The precipitation was obtained by adding 0.5 ml of 30% PEG solution to 0.5 ml serum, and was resuspended with 0.6 ml of Hanks' medium without NaCl, containing 1.5% bovine serum albumin, 20mM Hepes and 0.5 mM 3-isobutyl-1-methylxanthine. The precipitation contained about 85% of immunoglobulin and 63% of albumin of the original amount of the serum, as well as substantial TSH, when the original serum contained TSH more than 40 microU/ml. When the PEG precipitations from 10 normal subjects were incubated with the thyroid cells of 4 X 10(5) cells, the cAMP releases into the medium ranged from 83 to 124%, when the mean value was calculated as 100%. Therefore, the cAMP release of more than 130% of the amount released into the culture medium incubated with normal IgG was judged as positive TSAb activity. The minimum detectable quantities were regarded as about 5 microU/ml TSH equivalent. TSAb and TBII activities were detected in 48 (92%) and 50 (96%) of 52 patients with untreated hyperthyroid Graves' disease, respectively, and either TSAb or TBII activities were detected in 16 (80%) of 20 patients with Graves' disease maintained in a clinically euthyroid state by treatment with antithyroid drugs. TBII was positive in 10(50%) of these patients. Some patients showed distinct discrepancies in these two activities, although there was a significant positive correlation between TSAb and TBII activities (r = 0.53, p less than 0.01) in patients with untreated Graves' disease. In these patients, TSAb activities showed a significant positive correlation with values for 99mTc thyroid uptake, determined 30 min after the injection. However, they did not show any significant correlation with serum T4 or T3 concentrations. Similarly, TBII showed significant correlations with goiter size and 99mTc thyroid uptake. To conclude, the present assay for TSAb is sensitive and reproducible.(ABSTRACT TRUNCATED AT 400 WORDS)

[Clinical studies on abnormal thyroid stimulators in patients with Graves' disease. II. Clinical significance of measuring TSAb and TBII in patients with euthyroid Graves' disease and patients with hyperthyroid Graves' disease during antithyroid drug treatment]

To evaluate the clinical significance of TBII and TSAb activities in euthyroid and hyperthyroid Graves' disease, these two activities were measured in 8 patients with euthyroid Graves' disease and 29 patients with hyperthyroid Graves' disease during treatment with antithyroid drugs. In 8 patients with euthyroid Graves' disease, TBII activity was detectable only in one patient and TSAb activity detected in 3 patients, these detectabilities being much lower than those in hyperthyroid Graves' disease. However, 2 of 4 patients who had either TSAb or TBII came to have both activities, and one of them became overt hyperthyroid. In patients with hyperthyroid Graves' disease, detectabilities of these activities became lower as they became euthyroid with antithyroid drug treatment, but TSAb tended to be higher than TBII when they remained euthyroid for more than 4 months. Although the majority of the patients who had TSAb and/or TBII activities were T3 non-suppressible, patients with no TSAb and TBII activities did not necessarily show remission of the disease. The present results suggest that patients with euthyroid Graves' disease with both TBII and TSAb may be apt to become hyperthyroid, and that TSAb and TBII activities and T3 suppressibility may not be a definite criteria for the remission of Graves' disease.