Molecular composition of adiponectin in urine is a useful biomarker for detecting early stage of diabetic kidney disease.

We previously developed two immune complex transfer enzyme immunoassays (ICT-EIA) to measure total adiponectin (T-AN) and high molecular weight adiponectin (H-AN) in urine and have verified their usefulness as biomarkers for diabetic kidney disease. In this study, we developed T-AN and H-AN assays using the sandwich EIA (Sand-EIA). The reactivities of Sand-EIAs were compared with ICT-EIAs by measuring size exclusion chromatography (SEC) fractions of urine and adiponectin standard. As a result, ICT-EIAs showed higher macromolecular specificity. We then analyzed the molecular profile of adiponectin in the urine of 5 patients with different eGFR stages by measuring SEC fractions of urine. The results showed that smaller adiponectin correlated relatively well with eGFR stage. Finally, because SEC is time-consuming, we investigated that the ratio of T-ANs by Sand-EIA and ICT-EIA could be a good indicator of the monomer adiponectin. The ratio was evaluated using 77 urine samples from patients with diabetes and showed a significant decrease at an earlier stage compared with other biomarkers. In conclusion, we demonstrated a new index to estimate monomer adiponectin in urine by using Sand-EIA and ICT-EIA, and urinary monomer adiponectin can be a good early indicator of deterioration of renal function in diabetic patients. J. Med. Invest. 70 : 464-470, August, 2023.

Coffee and metabolic phenotypes: A cross-sectional analysis of the Japan multi-institutional collaborative cohort (J-MICC) study.

BACKGROUND AND AIMS: To date, the relationship between coffee consumption and metabolic phenotypes has hardly been investigated and remains controversial. Therefore, the aim of this cross-sectional study is to examine the associations between coffee consumption and metabolic phenotypes in a Japanese population. METHODS AND RESULTS: We analyzed the data of 26,363 subjects (aged 35-69 years) in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. Coffee consumption was assessed using a questionnaire. Metabolic Syndrome (MetS) was defined according to the Joint Interim Statement Criteria of 2009, using body mass index (BMI) instead of waist circumference. Subjects stratified by the presence or absence of obesity (normal weight: BMI <25 kg/m2; obesity: BMI ≥25 kg/m2) were classified by the number of MetS components (metabolically healthy: no components; metabolically unhealthy: one or more components) other than BMI. In multiple logistic regression analyses adjusted for sex, age, and other potential confounders, high coffee consumption (≥3 cups/day) was associated with a lower prevalence of MetS and metabolically unhealthy phenotypes both in normal weight (OR 0.83, 95% CI 0.76-0.90) and obese subjects (OR 0.83, 95% CI 0.69-0.99). Filtered/instant coffee consumption was inversely associated with the prevalence of MetS and metabolically unhealthy phenotypes, whereas canned/bottled/packed coffee consumption was not. CONCLUSION: The present results suggest that high coffee consumption, particularly filtered/instant coffee, is inversely associated with the prevalence of metabolically unhealthy phenotypes in both normal weight and obese Japanese adults.

Associations of metabolic syndrome and metabolically unhealthy obesity with cancer mortality: The Japan Multi-Institutional Collaborative Cohort (J-MICC) study.

PURPOSE: The association between metabolic syndrome (MetS) and the risk of death from cancer is still a controversial issue. The purpose of this study was to examine the associations of MetS and metabolically unhealthy obesity (MUHO) with cancer mortality in a Japanese population. METHODS: We used data from the Japan Multi-Institutional Collaborative Cohort Study. The study population consisted of 28,554 eligible subjects (14,103 men and 14,451 women) aged 35-69 years. MetS was diagnosed based on the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) and the Japan Society for the Study of Obesity (JASSO), using the body mass index instead of waist circumference. The Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for total cancer mortality in relation to MetS and its components. Additionally, the associations of obesity and the metabolic health status with cancer mortality were examined. RESULTS: During an average 6.9-year follow-up, there were 192 deaths from cancer. The presence of MetS was significantly correlated with increased total cancer mortality when the JASSO criteria were used (HR = 1.51, 95% CI 1.04-2.21), but not when the NCEP-ATP III criteria were used (HR = 1.09, 95% CI 0.78-1.53). Metabolic risk factors, elevated fasting blood glucose, and MUHO were positively associated with cancer mortality (P <0.05). CONCLUSION: MetS diagnosed using the JASSO criteria and MUHO were associated with an increased risk of total cancer mortality in the Japanese population.

Novel method utilizing bisulfite conversion with dual amplification-refractory mutation system polymerase chain reaction to detect circulating pancreatic ß-cell cfDNA.

AIMS/INTRODUCTION: Several research groups have reported methods for quantifying pancreatic beta cell (ß-cell) injury by measuring ß-cell-specific CpG unmethylation of the insulin gene in circulation using digital droplet PCR or next-generation sequencing. However, these methods have certain disadvantages, such as the need to consider the background signal owing to the small number of target CpG sites and the need for unique equipment. MATERIALS AND METHODS: We established a novel method for detecting four CpG unmethylations of the insulin gene using two-step amplification refractory mutation system PCR. We applied it to type 1 diabetes (T1D) patients with a wide range of disease durations and to healthy adults. RESULTS: The assay showed high linearity and could detect a single copy of unmethylated insulin DNA in experiments using methylated and unmethylated plasmid DNA. The unmethylated insulin DNA level in the type 1 diabetes group, whose ß-cell mass was considerably reduced, was similar to that of healthy adults. An inverse correlation was observed between copy number and disease duration in patients with unmethylated insulin DNA-positive type 1 diabetes. CONCLUSIONS: We developed a novel method for detecting unmethylated insulin DNA in circulation that can be performed using a conventional real-time PCR system. This method would be useful for analyzing dynamic profiles of ß-cells in human disease such as type 1 diabetes.

Basal insulin requirement in patients with type 1 diabetes depends on the age and body mass index.

AIMS/INTRODUCTION: To investigate the basal insulin requirement in patients with type 1 diabetes who are on multiple daily injections (MDI) and to assess the patient characteristics that affect the percent of total daily basal insulin dose to the total daily insulin dose (%TBD/TDD). MATERIALS AND METHODS: The subjects of this study were 67 inpatients with type 1 diabetes who were served diabetic meals of 25-30 kcal/kg standard body weight during several weeks of hospitalization. The basal insulin requirement was adjusted to keep the blood glucose level from bedtime to before breakfast within a 30 mg/dL difference. The bolus insulin dose before the meal was adjusted to keep the blood glucose level below 140 and 200 mg/dL before and 2 h after each meal, respectively. The total daily insulin dose (TDD), the percent of total daily basal insulin dose (TBD) to TDD (%TBD/TDD), and clinical characteristics were collected. RESULTS: The median (Q1, Q3) of TDD was 33.0 (26.0, 49.0) units, and the %TBD/TDD was 24.1 ± 9.8%. The %TBD/TDD was positively correlated with the body mass index (BMI) and negatively correlated with the age at the onset and at the examination according to a univariate analysis. However, the %TBD/TDD was dependent on the BMI (ß = 0.340, P = 0.004) and the age at examination (ß = -0.288, P = 0.012) according to the multiple regression analysis. CONCLUSIONS: The average %TBD/TDD in patients with type 1 diabetes on MDI was approximately 24% under inpatient conditions. The basal insulin requirement was dependent on the BMI and the age at examination.

Urinary adiponectin excretion is an early predictive marker of the decline of the renal function in patients with diabetes mellitus.

AIMS: Since diabetes-associated kidney complication changes from diabetic nephropathy to diabetic kidney disease (DKD), more suitable biomarkers than urinary albumin are required. It has been hypothesized that urinary adiponectin (u-ADPN) is associated with the progression of DKD. We therefore evaluated the effectiveness of u-ADPN in predicting the decline of the renal function in patients with diabetes prior to end-stage renal disease. METHODS: An ultrasensitive immune complex transfer enzyme immunoassay (ICT-EIA) was used to measure total and high molecular weight (HMW) adiponectin separately. We evaluated the relationships between the creatinine-adjusted urinary total-ADPN and HMW-ADPN, albumin (UACR) and liver-type fatty acid binding protein (L-FABP) at baseline and the 2-year change of the estimated glomerular filtration rate (ΔeGFR). RESULTS: This 2-year prospective observational study included 201 patients with diabetes. These patients were divided into three groups according to their ΔeGFR: ≤-10 mL/min/1.73m2, >-10 and ≤0 mL/min/1.73m2, and >0 mL/min/1.73m2. Jonckheere-Terpstra test showed that lower ΔeGFR was associated with higher u-HMW-ADPN (p = 0.045). In logistic regression analysis, u-HMW-ADPN was associated with ΔeGFR after adjusted age, sex, and basal eGFR. CONCLUSION: Urinary HMW-ADPN could predict a declining renal function in patients with diabetes.

Development of fully automated and ultrasensitive assays for urinary adiponectin and their application as novel biomarkers for diabetic kidney disease.

Glomerular filtration rate (GFR) and urinary albumin excretion rate (UAER) are used to diagnose and classify the severity of chronic kidney disease. Total adiponectin (T-AN) and high molecular weight adiponectin (H-AN) assays were developed using the fully automated immunoassay system, HI-1000 and their significance over conventional biomarkers were investigated. The T-AN and H-AN assays had high reproducibility, good linearity, and sufficient sensitivity to detect trace amounts of adiponectin in the urine. Urine samples after gel filtration were analyzed for the presence of different molecular isoforms. Low molecular weight (LMW) forms and monomers were the major components (93%) of adiponectin in the urine from a diabetic patient with normoalbuminuria. Urine from a microalbuminuria patient contained both high molecular weight (HMW) (11%) and middle molecular weight (MMW) (28%) adiponectin, although the LMW level was still high (52%). The amount of HMW (32%) and MMW (42%) were more abundant than that of LMW (24%) in a diabetic patient with macroalbuminuria. T-AN (r = - 0.43) and H-AN (r = - 0.38) levels showed higher correlation with estimated GFR (eGFR) than UAER (r = - 0.23). Urinary levels of both T-AN and H-AN negatively correlated with renal function in diabetic patients and they may serve as new biomarkers for diabetic kidney disease.

Circulating FGF23 is not associated with cardiac dysfunction, atherosclerosis, infection or inflammation in hemodialysis patients.

Fibroblast growth factor (FGF) 23 is a bone-derived hormone regulating serum inorganic phosphate (Pi) concentration. FGF23 is also involved in the development of chronic kidney disease (CKD)-mineral and bone disorder. Serum FGF23 concentration begins to increase early in the progression of CKD and can be remarkably high in hemodialysis patients with end-stage renal disease. It has been reported that high FGF23 concentration is a risk factor for cardiac dysfunction, atherosclerosis, infection or systemic inflammation in CKD patients. FGF23 was also shown to induce cardiac hypertrophy directly acting on cardiomyocytes. However, it is still controversial whether high FGF23 is causing cardiac dysfunction, atherosclerosis, infection or systemic inflammation in CKD patients. In the current study, we investigated whether FGF23 concentration is associated with cardiac dysfunction, atherosclerosis, infection or systemic inflammation in Japanese hemodialysis patients. We recruited 119 hemodialysis patients and examined the association between serum FGF23 concentration and several parameters concerning mineral metabolism, cardiac dysfunction, atherosclerosis, infection, and systemic inflammation. Serum FGF23 concentration was independently associated with serum calcium and Pi concentration (ß = 0.276, p < 0.001; ß = 0.689, p < 0.001). However, serum FGF23 concentration was not associated with parameters of cardiac dysfunction, atherosclerosis, infection, and systemic inflammation, either. Our results do not support the hypothesis that high FGF23 in dialysis patients is the cause of cardiac dysfunction, atherosclerosis, infection or systemic inflammation.

Circulating osteocalcin as a bone-derived hormone is inversely correlated with body fat in patients with type 1 diabetes.

The objective of the present study was to investigate the correlations between serum undercarboxylated osteocalcin (ucOC) or osteocalcin (OC) concentrations and %body fat, serum adiponectin and free-testosterone concentration, muscle strength and dose of exogenous insulin in patients with type 1 diabetes. We recruited 73 Japanese young adult patients with childhood-onset type 1 diabetes. All participants were receiving insulin replacement therapy. The correlations between logarithmic serum ucOC or OC concentrations and each parameter were examined. Serum ucOC and OC concentrations were inversely correlated with %body fat (r = -0.319, P = 0.007; r = -0.321, P = 0.006, respectively). Furthermore, multiple linear regression analyses were performed to determine whether or not serum ucOC or OC concentrations were factors associated with %body fat. Serum ucOC and OC concentrations remained significant factors even after adjusting for gender, HbA1c, body weight-adjusted total daily dose of insulin and duration of diabetes (ß = -0.260, P = 0.027; ß = -0.254, P = 0.031, respectively). However, serum ucOC and OC concentrations were not correlated with serum adiponectin or free-testosterone concentrations, muscle strength or dose of exogenous insulin. In conclusion, our study demonstrates the inverse correlation between serum ucOC or OC concentrations and body fat in patients with type 1 diabetes.

Association of accumulated advanced glycation end-products with a high prevalence of sarcopenia and dynapenia in patients with type 2 diabetes.

AIMS/INTRODUCTION: Advanced glycation end-products (AGEs), which are a major cause of diabetic vascular complications, accumulate in various tissues under chronic hyperglycemic conditions, as well as with aging in patients with diabetes. The loss of muscle mass and strength, so-called sarcopenia and dynapenia, has recently been recognized as a diabetic complication. However, the influence of accumulated AGEs on muscle mass and strength remains unclear. The present study aimed to evaluate the association of sarcopenia and dynapenia with accumulated AGEs in patients with type 2 diabetes. MATERIALS AND METHODS: We recruited 166 patients with type 2 diabetes aged ≥30 years (mean age 63.2 ± 12.3 years; body mass index 26.3 ± 4.9 kg/m2 ; glycated hemoglobin 7.1 ± 1.1%). Skin autofluorescence as a marker of AGEs, limb skeletal muscle mass index, grip strength, knee extension strength and gait speed were assessed. RESULTS: Sarcopenia and dynapenia were observed in 7.2 and 13.9% of participants, respectively. Skin autofluorescence was significantly higher in patients with sarcopenia and dynapenia. Skin autofluorescence was the independent determinant for skeletal muscle mass index, grip strength, knee extension strength, sarcopenia and dynapenia. CONCLUSIONS: Accumulated AGEs could contribute to reduced muscle mass and strength, leading to sarcopenia and dynapenia in patients with type 2 diabetes.

Dietary calcium intake is associated with serum high-sensitivity C-reactive protein level in the general Japanese population.

The beneficial effects of dietary calcium intake on high-sensitivity C-reactive protein levels, a risk factor of cardiovascular disease, have not been fully elucidated. This study investigated the associations between dietary calcium intake and serum high-sensitivity C-reactive protein levels in the general Japanese population. We analyzed the data of 2,019 subjects (1,194 men and 825 women) aged 35 to 69 years in a cross-sectional study of the Japan Multi-Institutional Collaborative Cohort Study. Nutrients intake including calcium were estimated using a validated food-frequency questionnaire. Analysis using a general linear model revealed that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels (p for trend <0.001) after adjustment for age, sex, research group, leisure-time physical activity, smoking habit, drinking habit, dietary intakes (energy, dietary fiber, saturated fatty acids and vitamin D) and menopausal status. The association was slightly attenuated after additional adjustment for body mass index; however, remained significant (p for trend = 0.008). There were no significant interactions between dietary calcium intakes and sex, body mass index, or vitamin D intake for high-sensitivity C-reactive protein levels. This study have demonstrated that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels in the general population.

Nutrient-Derived Dietary Patterns and Their Association With Metabolic Syndrome in a Japanese Population.

BACKGROUND: Nutrients have been proposed to be related to metabolic syndrome (MetS). The aims of this study were to identify dietary patterns that correlated with several nutrients using reduced rank regression (RRR) and to examine the association between extracted dietary patterns and prevalence of MetS in a Japanese population. METHODS: The study population comprised 1,092 Japanese men and women (35-69 years old) who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study in Tokushima Prefecture. Dietary patterns were derived with RRR using 46 food items as predictors and six established nutrients (potassium, calcium, vitamin D, vitamin C, insoluble dietary fiber, and carotene) as response variables. Associations between extracted dietary patterns and MetS were then examined with logistic regression models. RESULTS: Among the six dietary patterns, dietary pattern 1 (DP1) explained the largest proportion (60.1%) of variance in the six nutrients. Therefore, only DP1 was selected for further analysis. DP1 was characterized by high intake frequency of vegetables, fruits, fish and small fish, natto (fermented soybeans), and deep-fried tofu. After adjustment for potential confounders, significant inverse associations were found between DP1 score and MetS (odds ratio [OR] for each quartile: 1.00, 0.58, 0.60, 0.52; Ptrend = 0.02); DP1 and high blood pressure (Ptrend = 0.0002); and DP1 and high blood glucose (Ptrend = 0.02). CONCLUSION: A dietary pattern characterized by high intake of vegetables, fruits, fish and small fish, natto, and deep-fried tofu was associated with reduced prevalence of MetS in a Japanese population.

Relationships of serum high-sensitivity C-reactive protein and body size with insulin resistance in a Japanese cohort.

BACKGROUND: Impacts of chronic systemic inflammation and body size and their interaction effect on insulin resistance in Asian populations, in whom obesity is less common, are not fully understood. This study evaluated combined relationships of systemic inflammation and body size with insulin resistance in a Japanese cohort. METHODS: We analyzed cross-sectional data from 1,074 eligible subjects (536 men and 538 women) aged 35-69 years who participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan. Systemic inflammation level was assessed by serum high-sensitivity C-reactive protein (hs-CRP), and the degree of insulin resistance and beta-cell function were evaluated by the homeostasis model assessment insulin resistance (HOMA-IR) and beta-cell function (HOMA-ß), respectively. Overweight and obesity were defined as a body mass index (BMI) of 23.0-24.9 kg/m2 and ≥25.0 kg/m2, respectively. Associations between serum hs-CRP (assessed as quartiles and additionally continuous values after log-transformation) and indices of glucose homeostasis were analysed adjusting for probable covariates, including BMI (quartiles). Combined associations of serum hs-CRP (≤median, >median) and body size (normal, overweight, obese) with insulin resistance as well as their interaction effect on insulin resistance were also evaluated. RESULTS: Serum hs-CRP was dose-dependently associated with HOMA-IR, but not HOMA-ß, after adjustment for probable covariates, including BMI. Subjects with obesity and elevated serum hs-CRP (>median) showed a high multivariable-adjusted HOMA-IR value of 1.32 (95% confidence interval (CI) 1.23, 1.41) compared with subjects with normal BMI and low serum hs-CRP (≤median) whose multivariable-adjusted HOMA-IR value was 1.14 (95% CI 1.06, 1.21). The interaction effect between body size (normal, overweight, obese) and serum hs-CRP (≤median, >median) on HOMA-IR was significant (P for interaction <0.001). CONCLUSIONS: Our study suggests that elevated systemic inflammation is dose-dependently associated with increased insulin resistance, independent of the known risk factors, in a Japanese population. Concomitant obesity and elevated systemic inflammation may synergistically contribute to increased insulin resistance.

Systemic inflammation and family history in relation to the prevalence of type 2 diabetes based on an alternating decision tree.

To investigate unknown patterns associated with type 2 diabetes in the Japanese population, we first used an alternating decision tree (ADTree) algorithm, a powerful classification algorithm from data mining, for the data from 1,102 subjects aged 35-69 years. On the basis of the investigated patterns, we then evaluated the associations of serum high-sensitivity C-reactive protein (hs-CRP) as a biomarker of systemic inflammation and family history of diabetes (negative, positive or unknown) with the prevalence of type 2 diabetes because their detailed associations have been scarcely reported. Elevated serum hs-CRP levels were proportionally associated with the increased prevalence of type 2 diabetes after adjusting for probable covariates, including body mass index and family history of diabetes (P for trend = 0.016). Stratified analyses revealed that elevated serum hs-CRP levels were proportionally associated with increased prevalence of diabetes in subjects without a family history of diabetes (P for trend = 0.020) but not in those with a family history or with an unknown family history of diabetes. Our study demonstrates that systemic inflammation was proportionally associated with increased prevalence of type 2 diabetes even after adjusting for body mass index, especially in subjects without a family history of diabetes.