International clinical harmonization of glycated hemoglobin in Japan: From Japan Diabetes Society to National Glycohemoglobin Standardization Program values

Ratio of low molecular weight serum adiponectin to the total adiponectin value is associated with type 2 diabetes through its relation to increasing insulin resistance

AIM

Among the three adiponectin isoforms, a lower ratio of high molecular weight (HMW) adiponectin to total adiponectin (TA) is well known to cause insulin resistance and type 2 diabetes (T2D). However, how the levels of other adiponectin isoforms, such as the middle molecular weight (MMW) and low molecular weight (LMW) isoforms, and their relative ratio to TA change in T2D subjects has not been determined. Therefore, we investigated the association of these adiponectin-related parameters with T2D.

METHODS

We examined the associations between adiponectin-related parameters and diabetes in a group of 394 T2D subjects and 374 controls (1st group) randomly selected from among the participants in our previous study. The associations between these parameters and the HOMA-IR in a 2nd group, consisting of the subjects remaining in the 1st group after the exclusion of subjects receiving diabetic medication, were also examined.

RESULT

In the 1st group, after adjusting for confounding factor, the levels of all the adiponectin isoforms and the HMW/TA ratio were significantly lower among the diabetic subjects than among the controls (all P values < 0.01). On the contrary, the LMW/TA ratio was significantly higher among the diabetic subjects (P < 0.01) and was positively associated with T2D (odds ratio = 8.64, P < 0.01). In the 2nd group, the HMW/TA ratio was inversely associated with the HOMA-IR; however, the LMW/TA ratio was positively associated with the HOMA-IR (β for LMW/TA ratio = 0.89, SE = 0.24, P < 0.001), similar to the association with T2D. The MMW/TA ratio was not associated with T2D or the HOMA-IR.

CONCLUSION

The current investigation demonstrated that, unlike the reduction in the levels of all the adiponectin isoforms and the HMW/TA ratio, an increased LMW/TA ratio was associated with T2D through its relation to insulin resistance.

Influence of Single-Nucleotide Polymorphisms in PPAR-δ, PPAR-γ, and PRKAA2 on the Changes in Anthropometric Indices and Blood Measurements through Exercise-Centered Lifestyle Intervention in Japanese Middle-Aged Men

The purpose of the current study was to examine the influence of single-nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor-δ (PPAR-δ), PPAR-γ, and α2 isoforms of the catalytic subunit of AMP-activated protein kinase (PRKAA2) on the extent of changes in anthropometric indices and blood measurements through exercise-centered lifestyle intervention in middle-aged men. A total of 109 Japanese middle-aged male subjects (47.0 ± 0.4 years) participated in the baseline health checkup, 6-month exercise-centered lifestyle intervention, and second checkup conducted several months after the subject completed the intervention. The body mass index (BMI), waist circumference, and clinical measurements, including hemoglobin A_lc (HbA_1c), triglyceride (TG), alanine aminotransferase (ALT), and γ-glutamyl-transpeptidase (γ-GTP), were measured at the baseline and second checkup. The three SNPs of PPAR-δ A/G (rs2267668), PPAR-γ C/G (rs1801282), and PRKAA2 A/G (rs1418442) were determined. Blunted responses in the reduction in the BMI and waist circumference were observed in A/A carriers of PPAR-δ SNP compared with G allele carriers (all p < 0.05). The A/A carriers also displayed less-marked improvements in HbA_1c, TG, ALT, and γ-GTP (all p < 0.05). The current results suggest that A/A carriers of PPAR-δ SNP (rs2267668) may enjoy fewer beneficial effects of exercise-centered lifestyle intervention on anthropometric indices and blood measurements.

Normal meal tolerance test is preferable to the glucagon stimulation test in patients with type 2 diabetes that are not in a hyperglycemic state: Comparison with the change of C-peptide immunoreactivity

AIMS/INTRODUCTION

The aim of the present study was to evaluate the properties of the glucagon stimulation test (GST) and the normal meal tolerance test (NMTT) in patients with type 2 diabetes.

MATERIALS AND METHODS

We enrolled 142 patients with type 2 diabetes, and carried out a GST and a NMTT. We carried out the NMTT using a calorie-controlled meal based on an intake of 30 kcal/kg ideal bodyweight/day. We calculated the change in C-peptide immunoreactivity (ΔCPR) by subtracting fasting CPR from the CPR 6 min after the 1-mg glucagon injection (GST) or 120 min after the meal (NMTT).

RESULTS

Mean ΔCPR for the GST was 2.0 ng/mL, and for the NMTT was 3.1 ng/mL. A total of 104 patients had greater ΔCPR in the NMTT than the GST, and the mean ΔCPR was significantly greater in the NMTT than the GST (P < 0.05). To exclude any influence of antidiabetic drugs, we examined 42 individuals not taking antidiabetic agents, and found the mean ΔCPR was significantly greater in the NMTT than the GST (GST 2.4 ng/mL, NMTT 4.3 ng/mL; P < 0.05). To consider the influence of glucose toxicity, we carried out receiver operating characteristic analyses with fasting plasma glucose and glycated hemoglobin. The optimal cut-off levels predicting GST ΔCPR to be larger than NMTT ΔCPR were fasting plasma glucose 147 mg/dL and glycated hemoglobin 9.0% (fasting plasma glucose: sensitivity 0.64, specificity 0.76, area under the curve 0.73; glycated hemoglobin: sensitivity 0.56, specificity 0.71, area under the curve 0.66).

CONCLUSIONS

The NMTT is a reliable insulin secretion test in patients with type 2 diabetes, except for those in a hyperglycemic state.

Influence of Iron Deficiency on HbA1c Levels in Pregnant Women: Comparison with Non-Pregnant Women

Although HbA1c is widely used as a glycemic control indicator, HbA1c is known to show falsely high levels in patients in an iron deficient state (IDS). We compared the influence of IDS on HbA1c levels between pregnant women, due to mainly an increase in demand for iron without bleeding, and non-pregnant women, due to mainly bleeding (menstruation). We studied 42 non-diabetic pregnant women (pregnant group) and 42 age-matched non-pregnant women with normal glucose tolerance (non-pregnant group). We compared HbA1c and glycated albumin (GA) levels between IDS and normal iron state (NIS) in both groups. Furthermore, we analyzed the correlation between indicators of glycemic control and iron-related parameters [mean corpuscular hemoglobin, serum transferrin saturation (%Tf), and serum ferritin] in both groups. Compared with non-pregnant women, pregnant women had significantly lower %Tf and serum ferritin levels and significantly higher morbidity of IDS. HbA1c, but not GA, had significantly higher levels in pregnant women with IDS compared with NIS; however, HbA1c in non-pregnant women showed no significant difference for both IDS and NIS. In pregnant women, significant negative correlations were observed between HbA1c and iron-related parameters. In non-pregnant women, negative correlations were observed between HbA1c and these parameters, but they were not significant. No significant correlations were observed between GA and iron-related parameters in both groups. HbA1c levels in pregnant women were found to be largely affected by iron deficiency compared with non-pregnant women. For this reason, GA, which is not affected by iron deficiency, is desirable for use in the assessment of glycemic control during pregnancy.

Reduced Lung Function and Cerebral Small Vessel Disease in Japanese Men: the Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA)

Aim: We aimed to investigate the association between reduced lung function and cerebral small vessel diseases via cranial magnetic resonance imaging (MRI) in the cross-sectional study of the general Japanese population.

Methods: We recruited participants aged ≥ 40 years from the general population of a single city in Japan. We clarified the comorbidities and treatments, smoking habits, second-hand smoke exposure, current alcohol consumption, education level, exercise habits, and occupation. The pulmonary function test was performed to assess the forced expiratory volume in 1 second (FEV₁) % predicted and forced vital capacity (FVC) % predicted values. Cranial MRI was performed to evaluate the white matter lesions (WMLs) and lacunar infarcts. We examined the association of the WMLs and lacunar infarcts with a 1-standard deviation (SD) lower in the FEV₁ % predicted and FVC % predicted, on the basis of the smoking status.

Results: A total of 473 men were examined. The association of WMLs and lacunar infarcts with the spirometry-based indices were significant only in never smokers. The association between lung function impairment and cerebral small vessel disease did not change after further adjusting for second-hand smoke exposure.

Conclusion: In a community-based sample of Japanese men, we found an association between reduced lung function and WMLs and lacunar infarcts in never smokers.

A new pathological scoring system by the Japanese classification to predict renal outcome in diabetic nephropathy

Background and objectives

The impact of the newly proposed pathological classification by the Japan Renal Pathology Society (JRPS) on renal outcome is unclear. So we evaluated that impact and created a new pathological scoring to predict outcome using this classification.

Design, setting, participants, & measurements

A multicenter cohort of 493 biopsy-proven Japanese patients with diabetic nephropathy (DN) were analyzed. The association between each pathological factor—Tervaert’ and JRPS classifications—and renal outcome (dialysis initiation or 50% eGFR decline) was estimated by adjusted Cox regression. The overall pathological risk score (J-score) was calculated, whereupon its predictive ability for 10-year risk of renal outcome was evaluated.

Results

The J-scores of diffuse lesion classes 2 or 3, GBM doubling class 3, presence of mesangiolysis, polar vasculosis, and arteriolar hyalinosis were, respectively, 1, 2, 4, 1, and 2. The scores of IFTA classes 1, 2, and 3 were, respectively, 3, 4, and 4, and those of interstitial inflammation classes 1, 2, and 3 were 5, 5, and 4 (J-score range, 0–19). Renal survival curves, when dividing into four J-score grades (0–5, 6–10, 11–15, and 16–19), were significantly different from each other (p<0.01, log-rank test). After adjusting clinical factors, the J-score was a significant predictor of renal outcome. Ability to predict 10-year renal outcome was improved when the J-score was added to the basic model: c-statistics from 0.661 to 0.685; category-free net reclassification improvement, 0.154 (-0.040, 0.349, p = 0.12); and integrated discrimination improvement, 0.015 (0.003, 0.028, p = 0.02).

Conclusions

Mesangiolysis, polar vasculosis, and doubling of GBM—features of the JRPS system—were significantly associated with renal outcome. Prediction of DN patients’ renal outcome was better with the J-score than without it.

Self-reported Sleep Duration and Subclinical Atherosclerosis in a General Population of Japanese Men

Aim: There are few data regarding associations between sleep duration and subclinical atherosclerosis in Japan. The aim of this study was to evaluate associations of self-reported sleep duration with calcification in the coronary arteries (CAC) and carotid intima media thickness (IMT) in Japanese men.

Methods: This was a cross-sectional survey of 1093 randomly selected men from Kusatsu City, Japan. Average sleep duration on weekdays was estimated through questionnaire; CAC by computed tomography; and carotid IMT by ultrasonography.

Results: The prevalence of CAC was 50.0% for participants with sleep duration < 5.5 h, 43.9% with 5.5–6.4 h, 50.0% with 6.5–7.4 h, 49.3% with 7.5–8.4 h, and 62.5% with ≥ 8.5 h. In univariate analysis, participants with sleep duration ≥ 8.5 h had significantly higher prevalence of CAC than those with 6.5–7.4 h (p = 0.043). After adjustment for age and other risk factors, however, the association was not significant (p = 0.776). The average IMT was 0.85 mm for participants with sleep duration < 5.5 h, 0.83 mm with 5.5–6.4 h, 0.85 mm with 6.5–7.4 h, 0.88 mm with 7.5–8.4 h, and 0.90 mm with ≥ 8.5 h. None of the differences in IMT observed in crude or multivariable-adjusted analyses was significant (all p > 0.1).

Conclusion: Self-reported sleep duration was not associated with increased CAC or carotid IMT in a general population of Japanese men.

Serum Bilirubin Concentration is Associated with Left Ventricular Remodeling in Patients with Type 2 Diabetes Mellitus: A Cohort Study

INTRODUCTION

Previous studies have shown that serum bilirubin concentration is inversely associated with the risk of cardiovascular disease. The relationship between serum bilirubin concentration and left ventricular geometry, however, has not been investigated in patients with diabetes mellitus.

METHODS

In this cohort study, 158 asymptomatic patients with type 2 diabetes mellitus without overt heart disease were enrolled. Left ventricular structure and function were assessed using echocardiography. Serum bilirubin concentration, glycemic control, lipid profile, and other clinical characteristics were evaluated, and their association with left ventricular geometry was determined. Patients with New York Heart Association Functional Classification greater than I, left ventricular ejection fraction less than 50%, history of coronary artery disease, severe valvulopathy, chronic atrial fibrillation, or creatinine clearance less than 30 ml/min, and those receiving insulin treatment, were excluded.

RESULTS

Univariate analyses showed that relative wall thickness (RWT) was significantly correlated with diastolic blood pressure (P = 0.003), HbA1c (P = 0.024), total cholesterol (P = 0.043), urinary albumin (P = 0.023), and serum bilirubin concentration (P = 0.009). There was no association between left ventricular mass index and serum bilirubin concentration. Multivariate linear regression analysis showed that log RWT was positively correlated with diastolic blood pressure (P = 0.010) and that log RWT was inversely correlated with log bilirubin (P = 0.003). In addition, the patients with bilirubin less than 0.8 mg/dl had a higher prevalence of concentric left ventricular remodeling compared with those with bilirubin 0.8 mg/dl or more.

CONCLUSION

Our study shows that the serum bilirubin concentration may be associated with the progression of concentric left ventricular remodeling in patients with type 2 diabetes mellitus.

Inverse association between excessive alcohol drinking and cardiometabolically healthy status in middle-aged men with and without overweight and obesity

AIMS

The aim of this study was to clarify the relationship between drinking and metabolically healthy status in men with normal weight, overweight and obesity.

METHODS

The subjects were Japanese men aged from 35 to 60 years (n=31781) and they were divided by daily amount of drinking (g ethanol) into light (< 22), moderate (≥22 and <44), heavy (≥44 and <66) and very heavy (≥66) drinkers. Metabolically healthy subjects were defined as those without hypertension, dyslipidemia and diabetes.

RESULTS

The percentage of metabolically healthy subjects was much lower in the overweight (BMI≥25 and <30) and obese (BMI≥30) groups than in the normal weight group (BMI≥18.5 and <25) and was much lower in the obese group than in the overweight group. In each of the normal weight and overweight groups, percentages of metabolically healthy subjects were significantly lower in heavy and very heavy drinkers than in nondrinkers and were marginally significantly higher in light drinkers than in nondrinkers. The above associations between drinking and metabolically healthy status were confirmed by logistic regression analysis. In the obese group, the percentage of metabolically healthy subjects was significantly lower in regular drinkers (including all drinker categories) than in nondrinkers, and metabolically healthy subjects were rare (0.56%) among regular drinkers.

CONCLUSIONS

Regardless of absence and presence of overweight or obesity, excessive alcohol drinking is inversely associated with metabolically healthy status and should be avoided for prevention of cardiovascular disease.

The impact of carbohydrate intake and its sources on hemoglobin A1c levels in Japanese patients with type 2 diabetes not taking anti-diabetic medication

BACKGROUND

Although postprandial glucose levels largely depend on carbohydrate intake, the impact of carbohydrate and its sources on hemoglobin A1c (HbA1c) levels has not been demonstrated in patients with type 2 diabetes (T2DM) probably because, in previous studies, more than 50% of patients were taking anti-diabetic medication, and the researchers used energy percent of carbohydrate as an indicator of carbohydrate intake.

PATIENTS AND METHODS

We recruited 125 Japanese men (mean age 58±12 years) and 104 women (mean age 62±10 years) with T2DM who were not taking anti-diabetic medication and dietary therapy. We used 3-day dietary records to assess total carbohydrate intake and its sources, computed Spearman's correlation coefficients, and conducted multiple regression analyses for associations of carbohydrate sources with HbA1c by sex.

RESULTS

Mean HbA1c and total carbohydrate intake were 8.2%±1.9% and 272.0±84.6 g/day in men and 7.6%±1.3% and 226.7±61.5 g/day in women, respectively. We observed positive correlation of total carbohydrate intake (g/day) with HbA1c in men (r_s=0.384) and women (r_s=0.251), but no correlation for % carbohydrate in either sex. Regarding carbohydrate sources, we found positive correlations of carbohydrate from noodles (r_s=0.231) and drinks (r_s=0.325), but not from rice, with HbA1c in men. In women, carbohydrate from rice had a positive correlation (r_s=0.317), but there were no correlations for carbohydrate from noodles and drinks. The association of total carbohydrate intake (g/day) and carbohydrate from soft drinks with HbA1c in men remained significant even after adjustment for total energy by multiple regression analyses.

CONCLUSION

Our findings warrant interventional studies for moderate low-carbohydrate diets that focus on carbohydrate sources and sex differences in order to efficiently decrease HbA1c in patients with T2DM.

Impact of Normoglycemia in Reducing Microvascular Complications in Patients with Type 2 Diabetes: A Follow-Up Study

AIMS

Hyperglycemia is associated with an increased risk of microvascular complications in patients with type 2 diabetes. The aim of the present study was to investigate whether the reduction of the levels of HbA1c by tight glycemic control (GC) decreases the rate of microvascular complications and improves the neurological measures in patients with type 2 diabetes.

METHODS

Detailed clinical and neurological examinations including corneal confocal microscopy (CCM) were performed in 141 Japanese patients with type 2 diabetes and 60 age-matched control subjects at baseline and follow-up with GC for 4 years. Patients were stratified according to the mean HbA1c level during follow-up into good (HbA1c < 53.0 mmol/mol, mean; 47.5 mmol/mol), fair (53.0 mmol/mol ≤HbA1c < 58.5 mmol/mol, mean; 55.6 mmol/mol), and poor (HbA1c ≥ 58.5 mmol/mol, mean; 68.9 mmol/mol) GC groups with similar HbA1c levels at baseline (84.5-88.2 mmol/mol).

RESULTS

At baseline, CCM revealed significant nerve fiber damage in all patients compared to that in controls. The interval changes in most corneal nerve fiber (CNF) parameters and neurophysiological functions were significantly related with the mean HbA1c levels during follow-up. Interestingly, the baseline HbA1c level did not impact on neurological functions at follow-up. Interval changes in neuropathy outcomes were associated with mean clinical factors during follow-up and hypoglycemic strategies. Good GC improved all nerve functions, including CNF branch density and bead, but not the length and main fiber density. Fair GC deteriorated some nerve functions. Poor GC compromised all neuropathy outcomes. Irrespective of GC levels, retinopathy increased after follow-up period, while nephropathy decreased.

CONCLUSION

This study showed that tight GC was beneficial just for nephropathy among microvascular complications. Despite strict GC, the retinopathy progressed in patients with type 2 diabetes. Glucose control did not improve neurophysiological and corneal nerve measurements unless near-normoglycemia was reached.

Severity and multiplicity of microvascular complications are associated with QT interval prolongation in patients with type 2 diabetes

Aims/Introduction

A prolonged QT interval plays a causal role in life‐threatening arrhythmia, and becomes a risk factor for sudden cardiac death. Here, we assessed the association between microvascular complications and the QT interval in patients with type 2 diabetes.

Materials and Methods

Patients with type 2 diabetes (n = 219) admitted to Nippon Medical School Hospital (Tokyo, Japan) for glycemic control were enrolled. QT interval was measured manually in lead II on the electrocardiogram, and corrected for heart rate using Bazett's formula (QTc). Diabetic neuropathy, retinopathy and nephropathy were assessed by neuropathic symptoms or Achilles tendon reflex, ophthalmoscopy and urinary albumin excretion, respectively.

Results

In univariate analyses, female sex (P = 0.025), duration of type 2 diabetes (P = 0.041), body mass index (P = 0.0008), systolic blood pressure (P = 0.0011) and receiving insulin therapy (P < 0.0001) were positively associated with QTc. Patients with each of the three microvascular complications had longer QTc than those without: neuropathy (P = 0.0005), retinopathy (P = 0.0019) and nephropathy (P = 0.0001). As retinopathy or nephropathy progressed, QTc became longer (P < 0.001 and P < 0.001 for trend in retinopathy and nephropathy, respectively). Furthermore, QTc was prolonged with the multiplicity of the microvascular complications (P < 0.001 for trend). Multiple regression analyses showed that neuropathy, nephropathy and the multiplicity of the microvascular complications were independently associated with QTc.

Conclusions

Patients with type 2 diabetes with severe microvascular complications might be at high risk for life‐threatening arrhythmia associated with QT interval prolongation.

Ketonuria may be associated with low serum amylase independent of body weight and glucose metabolism

CONTEXT

Ketonuria, which reflects a preferential combustion of lipids relative to carbohydrates, is often observed in lean rather than obese people. Clinical studies have shown that individuals with diabetes and/or obesity predispose to have low serum amylase (LSA).

OBJECTIVE

To investigate the association between ketonuria and LSA.

METHODS

We examined ketonuria assessed by dipstick urinalysis and clinical parameters including serum amylase in 3638 Japanese people aged 25-79 years who underwent a health-screening checkup.

RESULTS

There was an inverse relationship between body mass index (BMI) and serum amylase. The lowest serum amylase was observed in obese subjects (BMI ≥ 25.0 kg/m2) with positive ketonuria. Logistic regression analysis showed that ketonuria was significantly associated with LSA (<50 IU/L), which was not altered by the adjustments for relevant confounders including age, sex, BMI, and HbA1c.

CONCLUSIONS

Current results suggest a relative unavailability of carbohydrates for energy production in individuals with LSA.

The joint impact of habitual exercise and glycemic control on the incidence of chronic kidney disease (CKD) in middle-aged and older males

Background

This retrospective study evaluated the influence of the joint impact of habitual exercise and glycemic control on the incidence of chronic kidney disease (CKD) during a 6-year follow-up period in middle-aged and older males.

Methods

The study population included 303 males without a history of cardiovascular disease, stroke, renal dysfunction, or dialysis treatment. Their lifestyle behaviors regarding exercise and physical activity were evaluated using a standardized self-administered questionnaire. The participants were divided into four categories according to the performance or non-performance of habitual exercise and the presence or absence of hyperglycemia.

Results

After 6 years, 32 subjects (10.6%) developed CKD (estimated glomerular filtration rate < 60 ml/min/1.73 m² and/or proteinuria). The cumulative incidence of CKD was significantly higher among subjects who did not perform habitual exercise and hyperglycemic subjects (log-rank test: p < 0.05, respectively). According to a Cox proportional hazards model, the hazard ratio (HR) for the incidence of CKD in subjects with a normal glucose tolerance (NGT) who did not perform habitual exercise (HR = 2.82, 95% confidence of interval (CI) = 1.07–7.36, p = 0.034) and that in hyperglycemic subjects who did not perform habitual exercise (HR = 5.89, 95% CI = 1.87–16.63, p = 0.003) were significantly higher in comparison to the subjects with a NGT who performed habitual exercise.

Conclusions

These results suggest that the habitual exercise and good glycemic control and their combination were associated with the incidence of CKD.

d-Ribose as a Contributor to Glycated Haemoglobin

Glycated haemoglobin (HbA1c) is the most important marker of hyperglycaemia in diabetes mellitus. We show that d-ribose reacts with haemoglobin, thus yielding HbA1c. Using mass spectrometry, we detected glycation of haemoglobin with d-ribose produces 10 carboxylmethyllysines (CMLs). The first-order rate constant of fructosamine formation for d-ribose was approximately 60 times higher than that for d-glucose at the initial stage. Zucker Diabetic Fatty (ZDF) rat, a common model for type 2 diabetes mellitus (T2DM), had high levels of d-ribose and HbA1c, accompanied by a decrease of transketolase (TK) in the liver. The administration of benfotiamine, an activator of TK, significantly decreased d-ribose followed by a decline in HbA1c. In clinical investigation, T2DM patients with high HbA1c had a high level of urine d-ribose, though the level of their urine d-glucose was low. That is, d-ribose contributes to HbA1c, which prompts future studies to further explore whether d-ribose plays a role in the pathophysiological mechanism of T2DM.

Comparison of the efficacy and safety of 10-mg empagliflozin every day versus every other day in Japanese patients with Type 2 Diabetes Mellitus: a pilot trial

The terminal elimination half-life (t1/2) of empagliflozin is 13.1 hours. Accordingly, we hypothesized that the administration of empagliflozin every other day might improve glycemic control in patients with type 2 diabetes mellitus, not being inferior to the therapy every day. We investigated the clinical effects and safety of the addition of empagliflozin every day or every other day to type 2 diabetic patients with a poor control in glycemia. Thirteen Japanese patients diagnosed as type 2 diabetes mellitus recruited to this study. Subjects were divided into two groups; one was treatment with 10 mg of empagliflozin every day (Group A), the other was 10 mg of empagliflozin every other day (Group B). The comparable study of multiple clinical indexes between the 2 groups was made before and 8, 16, and 24 weeks after the treatment. After the treatment for 24 weeks, the HbA1c level was decreased both in group A (from 7.5%±1.1% to 6.5%±0.8%) and in group B (from 7.6%±0.8% to 7.2%±0.5%). This pilot trial suggested the possibility of 10-mg every other day administration with empagliflozin for Japanese patients with type 2 diabetes mellitus. J. Med. Invest. 64: 50-57, February, 2017.

Hyperinsulinemia and Insulin Receptor Gene Mutation in Nonobese Healthy Subjects in Japan

Context:

Hyperinsulinemia is often observed in obese people, owing to their insulin resistance accompanied by visceral fat accumulation, but the frequency of hyperinsulinemia in nonobese people is not well known. Mutations in the insulin receptor gene are known to cause insulin resistance and hyperinsulinemia in type A insulin resistance syndrome, Rabson-Mendenhall syndrome, and Donohue syndrome. However, insulin receptor gene abnormalities have not been investigated in asymptomatic hyperinsulinemic subjects.

Purpose:

The aim of the current study was to investigate the prevalence of hyperinsulinemia in nonobese Japanese subjects and to examine the involvement of insulin receptor gene mutations.

Methods:

We enrolled 11,046 subjects who received health checkups. From these, we extracted nonobese subjects (body mass index <25 kg/m²) who exhibited hyperinsulinemia (serum fasting immunoreactive insulin ≥15 µU/mL). Genetic analysis was performed for the insulin receptor gene in 11 nonobese subjects with hyperinsulinemia.

Results:

The prevalence of hyperinsulinemia without apparent diabetes in nonobese subjects was 0.4% (33/8630). In the 11 analyzed subjects, two novel heterozygous nonsense mutations were detected [c.2106 T>G (p.Y702X) and c.2779-2780 GC>A]. The prevalence of insulin receptor gene mutations was 18.2% (2/11).

Conclusions:

To our knowledge, this is the first report of the prevalence of hyperinsulinemia in nonobese healthy subjects. We identified two novel mutations in the insulin receptor gene. These findings indicate that mutations in the insulin receptor gene may be related to fasting hyperinsulinemia, and insulin receptor gene screening may be useful for determining the cause of unexplained hyperinsulinemia.

Body weight-dependent relationships between alcohol consumption and pulse pressure in middle-aged Japanese women

High pulse pressure is a risk factor for cardiovascular disease, and excessive alcohol drinking increases the risk of hypertension. The purpose of this study was to elucidate the relationship between alcohol intake and pulse pressure in women and to determine whether body weight influences their relationship. The subjects were 18,791 Japanese middle-aged women, and they were divided into tertile groups for body weight or three different body mass index (BMI, kg/m²) groups (low BMI <22; middle BMI ≥22 and <25; high BMI ≥25). The subjects in each group were further divided into four groups of nondrinkers, occasional drinkers, regular light drinkers, and regular heavy drinkers by habitual alcohol consumption. Pulse pressure levels were compared between nondrinkers and drinkers in each group for body weight or BMI. Pulse pressure was significantly higher in regular heavy drinkers than in nondrinkers in the first tertile group for body weight and in the low BMI group but not in the second and third tertile groups for body weight and in the middle and high BMI groups. In all tertile groups and all BMI groups, pulse pressure was not significantly different in occasional drinkers and regular light drinkers than in nondrinkers. In women with lower body weight, heavy drinking was positively associated with pulse pressure, while this association was not found in women with middle or higher body weight. Thus, body weight potently confounds the relationship between alcohol consumption and pulse pressure.

Effective waist circumference reduction rate necessary to avoid the development of type 2 diabetes in Japanese men with abdominal obesity

The aim of this study was to determine the effective waist circumference (WC) reduction rate in avoiding the development of type 2 diabetes mellitus (T2DM) in <55 years and ≥55 years Japanese men with abdominal obesity. The study subjects were 795 men with WC ≥85 cm, fasting plasma glucose <126 mg/dL, 2-hr plasma glucose on 75 g of oral glucose tolerance test <200 mg/dL, and HbA1c 5.6-6.4 % (38-40 mmol/mol) at baseline who underwent general health checkups more than twice between April 2007 and May 2015. They were divided into 5 groups based on the change in WC during the observation period (WC gain group, and four groups stratified according the rate of WC loss). The subjects were also divided into the <55 years and ≥55 years (at baseline) subgroups. The cumulative incidence rate of T2DM was analyzed and compared among the groups. The cumulative incidence rates of the largest WC loss quartile (≥5.45 %) in all age, of the largest WC loss quartile (≥5.60 %) and second largest WC loss quartile (3.44-5.59 %) in the <55 years subgroup, and of the largest WC loss quartile (≥5.37 %) in the ≥55 years subgroup were significantly lower than that of the gain group (p<0.001, p=0.009, 0.012, and 0.012, respectively). WC reduction rate of at least about 3 % in the younger (<55 years) and at least about 5 % in the older (≥55 years) non-diabetic Japanese men with abdominal obesity can effectively reduce the chance of development of T2DM.

Association between serum uric acid level and renal arteriolar hyalinization in individuals without chronic kidney disease

BACKGROUND AND AIMS

Recent studies have reported an association between serum uric acid (SUA) and renal arteriolar changes in patients with chronic kidney disease (CKD). However, the association in individuals without CKD remains unclear. In this study, we investigated the relationship between SUA and renal arteriolar lesions in individuals without CKD from our living kidney donor cohort.

METHODS

Between January 2006 and May 2016, 393 living kidney donors underwent "time-zero" biopsy at Kyushu University Hospital. Patients were divided into sex-specific quartiles of SUA before donation: Q1, Q2, Q3, and Q4 (male: <5.2,5.2-5.8,5.9-6.4, and ≥6.5 mg/dL, female: <3.8,3.8-4.3,4.4-5.0, and ≥5.1 mg/dL). Renal arteriolar hyalinization and wall thickening were assessed using a semiquantitative grading system. Predictive performance was compared between models with and without SUA by calculating the net reclassification improvement (NRI).

RESULTS

In total, 158 (40.2%) patients had arteriolar hyalinization, and 148 (37.6%) had wall thickening. High SUA was significantly associated with arteriolar hyalinization in multivariable logistic analysis (odds ratio [OR] per 1-mg/dL increase in SUA, 1.24; 95% confidence interval [CI], 1.00-1.53; p = 0.048. OR for Q4 vs. Q2, 2.22; 95% CI, 1.17-4.21; p = 0.01). We found no association between SUA and wall thickening. When SUA was incorporated into a predictive model with conventional atherosclerotic factors, the NRI was 0.21 (p = 0.04).

CONCLUSIONS

High SUA was an independent risk factor for arteriolar hyalinization in individuals without CKD. SUA provided additional predictive value beyond conventional atherosclerotic factors in predicting arteriolar hyalinization.

Improvement in glycemic control through changes in insulin regimens: findings from a Japanese cohort of children and adolescents with type 1 diabetes

OBJECTIVE

Although insulin analogs have dramatically changed diabetes treatment, scarce evidence is available on those effects. We aimed to explore whether glycemic control had improved, the use of insulin analogs had been increased, and hypoglycemic events had decreased over time in Japanese pediatric patients with type 1 diabetes (T1D).

METHODS

Glycated hemoglobin A1c (HbA1c) values, proportion of insulin regimens, incidence of severe hypoglycemic events, and pubertal increase in HbA1c were compared in three cohorts of childhood-onset Japanese T1D patients (567 subjects in the 1995 cohort, 754 subjects in the 2000 cohort, and 806 subjects in the 2008 cohort).

RESULTS

Mean HbA1c values tended to decrease [78.5 mmol/mol (9.33%) in the 1995 cohort, 68.2 mmol/mol (8.39%) in the 2000 cohort, and 61.2 mmol/mol (7.75%) in the 2008 cohort; P < .0001]. The proportion of patients who received basal-bolus treatment tended to increase with statistical significance, as did the proportion on insulin analogs. The incidence of severe hypoglycemic events (events/100 patients/y) had decreased (19.1 in the 2000 cohort and 8.7 in the 2008 cohort; P = .02). The pubertal increase in HbA1c tended to decrease [males, 12.0 mmol/mol (1.10%) in 1995, 9.4 mmol/mol (0.85%) in 2008, and 9.4 mmol/mol (0.86%) in 2008; P = .55; females, 14.0 mmol/mol (1.28%) in 1995, 10.3 mmol/mol (0.94%) in 2000, and 4.2 mmol/mol (0.38%) in 2008; P = .0003].

CONCLUSIONS

Glycemic control and incidence of severe hypoglycemic events were chronologically improved, especially in female adolescents.

Effects of Cardiac Rehabilitation on High-Density Lipoprotein-mediated Cholesterol Efflux Capacity and Paraoxonase-1 Activity in Patients with Acute Coronary Syndrome

AIMS

We evaluated whether exercised-based cardiac rehabilitation (CR) can ameliorate the HDL function, i.e., cholesterol efflux capacity (CEC) and paraoxonase-1 activity in patients with acute coronary syndrome (ACS).

METHODS

This study is a retrospective analysis of stored serum from patients with ACS following successful percutaneous coronary intervention. The CEC, measured by a cell-based ex vivo assay using apolipoprotein B-depleted serum and ³H-cholesterol labeled macrophages and arylesterase activity (AREA) at the onset or early phase of ACS, and the follow-up periods were compared between 69 patients who completed the five-month outpatient CR program (CR group) and 15 patients who did not participate and/or dropped out from CR program (non-CR group).

RESULTS

Apolipoprotein A-I (apoA-I) and CEC significantly increased by 4.0% and 9.4%, respectively, in the CR group, whereas HDL-cholesterol and AREA were not changed during the follow-up periods in both groups. Among CR patients, the CEC significantly increased, irrespective of the different statin treatment, while HDL-cholesterol and apoA-I significantly increased in patients treated with rosuvastatin or pitavastatin. Although CEC and AREA were significantly correlated each other, there is a discordance between CEC and AREA for their correlations with other biomarkers. Both CEC and AREA were significantly correlated with apoA-I rather than HDL-cholesterol. Changes in CEC and those in AREA were significantly correlated with those in apoA-I (rho=0.328, p=0.002, and rho=0.428, p＜0.0001, respectively) greater than those in HDL-cholesterol (rho=0.312, p= 0.0042,and rho=0.343, p=0.003, respectively).

CONCLUSIONS

CR can improve HDL function, and it is beneficial for secondary prevention.

Paratubular basement membrane insudative lesions predict renal prognosis in patients with type 2 diabetes and biopsy-proven diabetic nephropathy

AIMS

Glomerular insudative lesions are a pathological hallmark of diabetic nephropathy (DN). However, paratubular basement membrane insudative lesions (PTBMIL) have not attracted much attention, and the association between such lesions and the renal prognosis remains unclear.

METHODS

Among 142 patients with biopsy-proven DN and type 2 diabetes encountered from 1998 to 2011, 136 patients were enrolled in this study. Patients were classified into 3 groups (Group 1: mild, Group 2: moderate, Group 3: severe) according to the extent of cortical and medullary PTBMIL. The endpoint was a decline of the estimated glomerular filtration rate (eGFR) by ≥ 40% from baseline or commencement of dialysis for end-stage renal disease. The Cox proportional hazard model was employed to calculate hazard ratios (HRs) and 95% confidence interval (CIs) for the death-censored endpoint.

RESULTS

During a median follow-up period of 1.8 years (IQR: 0.9-3.5), the endpoint occurred in 104 patients. Baseline mean eGFR was 43.9 ± 22.8 ml/min/1.73 m2, and 125 patients (92%) had overt proteinuria. After adjusting for known indicators of DN progression, the HR for the endpoint was 2.32 (95% CI: 1.20-4.51) in PTBMIL Group 2 and 3.12 (1.48-6.58) in PTBMIL Group 3 versus PTBMIL Group 1. Furthermore, adding the PTBMIL Group to a multivariate model including known promoters of DN progression improved prediction of the endpoint (c-index increased by 0.02 [95% CI: 0.00-0.04]).

CONCLUSIONS

PTBMIL may be useful for predicting the renal prognosis of patients with biopsy-proven DN, but further investigation of these lesions in various stages of DN is needed.

Age-dependent changes in the association between sleep duration and impaired glucose metabolism

AIM

To investigate whether the association between sleep duration and impaired glucose metabolism varies among younger and older populations.

METHODS

We reviewed data of self-reported habitual sleep duration per night, HbA1c levels, and clinically relevant factors in a cross-sectional checkup database of 75472 Japanese from the general population aged 20-79 years (51695 men and 23777 women). Associations of prediabetes (HbA1c ≥ 5.7% and/or diabetic pharmacotherapy) or diabetes (HbA1c ≥ 6.5% and/or diabetic pharmacotherapy) with short and long sleep durations compared with a reference sleep duration (7 h) were investigated by multivariate logistic regression analysis. We controlled for potential relevant confounders, including age, sex, and work duration per day according to younger and older subjects.

RESULTS

As age advanced, sleep duration became longer and this increase in the 40s and 50s was two times greater in men than in women. This finding was accompanied by a deterioration in HbA1c levels. In subjects aged younger than 40 years (n = 32929), HbA1c levels were inversely and linearly correlated with sleep duration in both sexes. However, in subjects aged 40 years or older (n = 42543), HbA1c levels showed a non-linear relationship against sleep duration with a nadir at 7 h. Multivariate logistic regression analysis showed that in younger subjects, short durations of sleep (≤ 5 h and 6 h) were positively associated with prediabetes (both P < 0.001), but a long duration of sleep (≥ 8 h) was inversely associated with prediabetes (P < 0.001). These associations remained significant after adjustment for relevant confounders, including age, sex, and work duration per day (ORs = 1.20, 95%CI: 1.05-1.37, P < 0.001; ORs = 1.12, 95%CI: 1.02-1.24, P < 0.05; and ORs = 0.84, 95%CI: 0.72-0.99, P < 0.05, respectively). In contrast, in older subjects, besides an association of prediabetes with a short duration of sleep (≤ 5 h) (ORs = 1.12, 95%CI: 1.03-1.21, P < 0.01), diabetes was significantly associated with a long duration of sleep (≥ 8 h) (ORs = 1.11, 95%CI: 1.02-1.25, P < 0.05).

CONCLUSION

A short sleep duration may be associated with prediabetes throughout life. However, the association between a long sleep duration and glucose metabolism can change with aging.

Effect of re-coaching on self-injection of insulin in older diabetic patients - Impact of cognitive impairment

AIMS

We investigated the effect of re-coaching on self-injection of insulin and impact of cognitive function in 100 older diabetic patients.

METHODS

We examined patients on a variety of skills and knowledge regarding self-injection of insulin and evaluated the effect of re-coaching the patients after 3months and 4years. We also investigated the influence of cognitive impairment (CI) on coaching.

RESULTS

Skills scores for self-injection of insulin and HbA1c improved significantly 3months after re-coaching. In 51 patients followed-up for 4years, skills scores were maintained during the 4years, while knowledge scores improved after 3months but then returned to the baseline level. In the group of patients with CI as determined by the Mini-Mental Status Examination, skills scores were similar to those in the group without CI, while knowledge scores were significantly lower as compared with those in the group without CI at any time point. Skills scores were maintained during the 4years regardless of CI.

CONCLUSION

The present study showed that re-coaching in skills for self-injection of insulin was effective in improving and maintaining insulin treatment in older diabetic patients, even if patients had CI.

Alternative Measures of Hyperglycemia and Risk of Alzheimer's Disease in the Community: The Hisayama Study

CONTEXT AND OBJECTIVE

We investigated the associations of hemoglobin A1c (HbA1c), glycated albumin (GA), GA/HbA1c ratio, and 1,5-anhydroglucitol (1,5-AG) with the development of Alzheimer's disease (AD).

DESIGN AND PARTICIPANTS

A total of 1187 community-dwelling Japanese subjects aged ≥65 years without dementia were followed up for an average of 4.8 years.

RESULTS

The age- and sex-adjusted incidence of AD increased significantly with higher quartiles of GA/HbA1c ratio, and a similar tendency was seen for GA, whereas no such association was observed for HbA1c and 1,5-AG. After adjusting for potential confounding factors, positive association of GA/HbA1c ratio with the risk of AD remained significant: the multivariable-adjusted hazard ratio (HR) was significantly higher in the third [HR = 2.11, 95% confidence interval (CI) = 1.16 to 3.82] and fourth (HR = 2.01, 95% CI = 1.09 to 3.68) quartile than in the first quartile. Among subjects with normal glucose tolerance, those with high GA/HbA1c ratio had a higher risk of AD than those with low GA/HbA1c ratio (HR = 1.82, 95% CI = 1.05 to 3.16), and a similar tendency was found in those with glucose intolerance (HR = 1.73, 95% CI = 0.96 to 3.13). No such associations were observed for HbA1c, GA, and 1,5-AG, regardless of glucose tolerance status.

CONCLUSIONS

Our findings suggest that elevated GA/HbA1c ratio-but not HbA1c, GA, or 1,5-AG level-is significantly associated with the risk of AD in subjects both with and without glucose intolerance. GA/HbA1c ratio may be a useful biomarker for predicting incident AD.

High Serum Phospholipid Dihomo-γ-Linoleic Acid Concentration and Low Δ5-Desaturase Activity Are Associated with Increased Risk of Type 2 Diabetes among Japanese Adults in the Hitachi Health Study

Background: The association between the circulating fatty acid (FA) composition and type 2 diabetes (T2D) has been reported in Western populations, but evidence is scarce among Asian populations, including Japanese, who consume large amounts of fish.Objective: The objective of the present study was to prospectively examine the association between circulating concentrations of individual FAs and T2D incidence among Japanese adults.Methods: We conducted a nested case-control study in a cohort of 4754 employees, aged 34-69 y, who attended a comprehensive health checkup in 2008-2009 and donated blood samples for the Hitachi Health Study. During 5 y of follow-up, diabetes was identified on the basis of plasma glucose, glycated hemoglobin, and self-report. Two controls matched to each case by sex, age, and date of checkup were randomly chosen by using density sampling, resulting in 336 cases and 678 controls with FA measurements. GC was used to measure the FA composition in serum phospholipids. Cox proportional hazards regression was used to estimate the HRs and 95% CIs after adjusting for potential confounders. We examined the association of T2D risk with 25 different individual and combinations of FAs.Results: T2D risk was positively associated with serum dihomo-γ-linoleic acid concentration (highest compared with the lowest quartile-HR: 1.49; 95% CI: 1.04, 2.11; P-trend = 0.02) and inversely associated with Δ5-desaturase activity (highest compared with the lowest quartile-HR: 0.72; 95% CI: 0.52, 0.99; P-trend = 0.02), independent of body mass index (BMI). There were also inverse associations between T2D risk with serum total n-6 (ω-6) polyunsaturated fatty acids (PUFAs), linoleic acid, and cis-vaccenic acid, but these were attenuated and became nonsignificant after adjustment for BMI. Serum n-3 (ω-3) PUFAs and saturated fatty acids (SFAs) were not associated with T2D risk.Conclusions: T2D risk was associated with circulating concentrations of the n-6 PUFA dihomo-γ-linoleic acid and Δ5-desaturase activity but not with n-3 PUFA or SFA concentrations in Japanese adults.

Combined effect of body mass index and waist-height ratio on incident diabetes; a population based cohort study

We investigated the impact of combined effect of body mass index and waist-to-height ratio on risk of diabetes. Overweight and abdominal obesity were defined as body mass index ≥23 kg/m² and waist-to-height ratio ≥0.5, respectively. We divided participants into four groups according to presence of overweight and/or abdominal obesity. About 20% individuals with overweight did not complicated with an abdominal obesity. Among 3,737 participants, 286 participants had diabetes at baseline-examination. Adjusted odds ratios for prevalence of diabetes compared with non-overweight participants without abdominal obesity were as follow: 1.87 (95% confidence interval 1.09-3.14, p = 0.024) in non-overweight participants with abdominal obesity, 1.51 (0.87-2.55, p = 0.141) in overweight participants without abdominal obesity and 3.25 (2.37-4.52, p<0.001) in overweight participants with abdominal obesity. In the follow-up examination, 86 participants were diagnosed as diabetes among 2,263 participants. Adjusted odds ratios for incident diabetes were as follow: 2.59 (0.98-6.44, p = 0.056) in non-overweight participants with abdominal obesity, 1.65 (0.64-4.00, p = 0.288) in overweight participants without abdominal obesity and 2.77 (1.55-5.15, p<0.001) in overweight participants with abdominal obesity. Non-overweight individuals with abdominal obesity as well as overweight individuals with abdominal obesity was associated with diabetes compared with non-overweight individuals without abdominal obesity.

Risk perception, self-efficacy, trust for physician, depression, and behavior modification in diabetic patients

We evaluated the associations of risk perception, self-efficacy, and trust with two health promotion behaviors (food habits and exercise) and depressive mood. Diabetic patients aged between 40 and 64 (n = 1195) were included in the analyses. Risk perception worsened behavioral changes in terms of food habits and depression, whereas self-efficacy and trust improved food habits, exercise, and depression; trust improved exercise and depression. In conclusion, self-efficacy and trust appear to be more beneficial than risk perception for positive behavioral changes and for improving depression in diabetic patients. However, their influence on behavioral changes may be different according to the types of behaviors.

Impact of postprandial hyperglycemia at clinic visits on the incidence of cardiovascular events and all-cause mortality in patients with type 2 diabetes

AIMS/INTRODUCTION

We evaluated the impact of postprandial hyperglycemia at clinic visits on the incidence of cardiovascular diseases (CVD) and all-cause mortality independently of mean glycosylated hemoglobin in type 2 diabetes patients in a real-world setting.

MATERIALS AND METHODS

The present retrospective observational cohort study included 646 type 2 diabetes patients. All of the participants had their initial consultations at the Institute for Diabetes Care and Research, Asahi Life Foundation affiliated Marunouchi Hospital, Tokyo, Japan, during the period from 1995 to 1996, visited the clinic ≥4 times, had their 2-h post-breakfast blood glucose (2h-PBBG) levels measured and were followed up for ≥1 year. The 646 patients were followed up for survival. Of the 646 patients, 618 had no history of CVD at the first visit and had measured 2h-PBBG until the first CVD onset or censorings. These two cohorts were followed up through June 2012, and subsequently questionnaires were mailed. Multivariate Cox proportional hazard models were used to evaluate the risk of CVD incidence and death.

RESULTS

CVD occurred in 78 patients, and 56 patients died. The median follow-up periods of the CVD cohort and the mortality cohort were 15.6 and 15.9 years, respectively. The mean 2h-PBBG is a significant predictor of the CVD incidence and all-cause mortality after adjusting for the mean glycosylated hemoglobin, the number of 2h-PBBG measurements, age, sex and classical risk factors.

CONCLUSIONS

Postprandial hyperglycemia represented by the mean level of 2h-PBBG at clinic visits is associated with CVD incidence and all-cause mortality independently of the mean glycosylated hemoglobin level in type 2 diabetes patients. Prospective interventional trials are warranted to confirm the present findings.

Leisure-time physical activity and risk of disability incidence: A 12-year prospective cohort study among young elderly of the same age at baseline

Background

To clarify the role of physical activity in preventing disability in Japan, we investigated the association between amount of leisure-time physical activity and incidence of disability among the young elderly.

Methods

In the New Integrated Suburban Seniority Investigation (NISSIN) project conducted from 1996 to 2013, we followed 2888 community-dwelling adults aged 64–65 years with no history of cerebrovascular disease for a median follow-up of 11.6 years. Disabilities were defined as follows based on the classifications of the Japanese long-term care insurance system: 1) support or care levels (support levels 1–2 or care levels 1–5); 2) care levels 2–5; 3) support or care levels with dementia; and 4) care levels 2–5 or death. In addition, we also assessed 5) all-cause mortality.

Results

After controlling for sociodemographic, lifestyle, and medical factors, male participants reporting an activity level of 18.1 metabolic equivalent (MET)-hours/week (the median among those with activities) or more had 52% less risk of being classified as support or care levels with dementia compared with the no activity group (hazard ratio 0.48; 95% confidence interval, 0.25–0.94). No significant association was found among women between amount of leisure-time physical activity and incidence of disability.

Conclusion

We identified an inverse dose–response relationship between the amount of leisure-time physical activity and the risk of disability with dementia in men. Therefore, a higher level of physical activity should be recommended to young elderly men to prevent disability with dementia.

•

We examined associations between physical activity and disability incidence.

•

We quantified amount of leisure-time physical activity.

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A dose–response relationship was found for the risk of disability with dementia.

Association of sarcopenia with both latent autoimmune diabetes in adults and type 2 diabetes: a cross-sectional study

BACKGROUND

To investigate the association of both latent autoimmune diabetes in adults (LADA) and type 2 diabetes (T2DM) with muscle mass and function (sarcopenia).

METHODS

Japanese patients with LADA (N=20), T2DM (N=208), and control subjects (N=41) were included in this cross-sectional study. The definition of LADA was based on age of onset (≥30), positive glutamic acid decarboxylase autoantibodies, and insulin requirement within the first 6months after diagnosis. Sarcopenia was diagnosed by the criteria for Asians, using skeletal muscle index (male <7.0 and female <5.4) and grip strength (male <26.0kg and female <18.0kg). The odds ratio (OR) with a 95% confidence interval (CI) was estimated using logistic regression.

RESULTS

The prevalence of sarcopenia was higher in LADA (35.0%) than in either T2DM (13.3%) or control subjects (9.8%). LADA was significantly associated with an increased risk for sarcopenia in a multivariate model in which age and body mass index were incorporated (OR: 9.57, 95% CI: 1.86-49.27). In contrast, T2DM tended to be associated with an increased risk for sarcopenia (OR: 2.99, 95% CI: 0.83-10.80).

CONCLUSIONS

This study provides evidence that patients with LADA are at a high risk for sarcopenia compared to those with T2DM or to control subjects.

Predictive ability of visit-to-visit variability in HbA1c and systolic blood pressure for the development of microalbuminuria and retinopathy in people with type 2 diabetes

AIMS

We explored whether visit-to-visit variability in both glycated hemoglobin (HbA1c) and systolic blood pressure (SBP) simultaneously predicted the development of microalbuminuria and retinopathy, and whether the predictive ability of these measurements changed according to mean HbA1c and SBP levels in people with type 2 diabetes.

METHODS

A retrospective observational cohort study was conducted on 243 type 2 diabetes patients with normoalbuminuria and 486 without retinopathy at the first visit and within 1year thereafter. The two cohorts were followed up from 1995 until 2012. Multivariate and stratified analyses were performed using Cox proportional hazard models.

RESULTS

Microalbuminuria developed in 84 patients and retinopathy in 108. Hazard ratios (HRs) for the development of microalbuminuria associated with the coefficient of variation (CV) and variation independent of mean (VIM) of both HbA1c and SBP significantly increased. In participants with a mean SBP <130mmHg, the HRs for the development of retinopathy associated with CV and VIM of HbA1c were abruptly elevated and significant compared with those with a mean SBP ≥130mmHg.

CONCLUSIONS

Visit-to-visit variability in both HbA1c and SBP simultaneously predict the development of microalbuminuria. HbA1c variability may predict the development of retinopathy when the mean SBP is normal (<130mmHg).

Ethnic Difference in the Pharmacodynamics-efficacy Relationship of Dipeptidyl Peptidase-4 Inhibitors Between Japanese and non-Japanese Patients: A Systematic Review

A systematic review of the differences in the efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors between Japanese and non-Japanese subjects was conducted. We searched for randomized controlled trials in patients with type 2 diabetes mellitus (T2DM) that studied the intervention of a DPP-4 inhibitor once-daily vs. placebo, as monotherapy or as add-on therapy. Data regarding placebo-corrected HbA1c reduction and trough DPP-4 inhibition rate after ≥12 weeks' treatment were extracted. In the 12 eligible studies, linear regression analysis revealed that the hemoglobin A1c (HbA1c) reduction at each DPP-4 inhibition level was larger in studies involving Japanese patients than in studies involving non-Japanese patients, with statistical significance between the two groups (P < 0.0001). Sensitivity analysis excluding studies of add-on therapies supported the robustness of the result. Our study indicated that DPP-4 inhibitors show greater efficacy in Japanese patients than in non-Japanese patients, which may be an important consideration in the global development strategy of new diabetic medications.

Influence of a home-based exercise program on the urine pH in elderly female subjects: a secondary analysis of a randomized controlled trial

Background

A low urine pH is a characteristic metabolic feature of metabolic syndrome and type 2 diabetes. The purpose of the current study was to investigate the effects of a 12-week home-based bench step exercise on the urine pH status of elderly female subjects.

Methods

The current study is a secondary analysis of a randomized controlled trial (RCT) in which 59 postmenopausal female subjects were randomized to either the exercise group (n = 29) or the control group (n = 30). The subjects in the exercise group were instructed to perform home-based exercises using a bench step at the anaerobic threshold (AT), with a goal of performing ≥140 min/week at home for 12 weeks. The subjects in the control group were instructed to not change their normal lifestyle. Urine was collected after overnight fasting, and the urine pH was measured using a urinary test strip. The inter-group-differences at baseline and the pre-post changes within groups were assessed using the Mann-Whitney U test and Wilcoxon’s signed-rank test, respectively. Additionally, the difference in the post-intervention urine pH levels of the two groups, adjusted for the pre-intervention values (the estimated effect size) and the precision (95% confidence intervals) were investigated using an analysis of covariance.

Results

The pre-post comparison of the urine pH data using Wilcoxon’s signed-rank test showed a significant increase in the urine pH levels of the exercise group (p < 0.05); there was no significant change in the urine pH levels of the control group. However, the estimated effect size (0.15) was small and the confidence interval straddled 0 (−0.25–0.55).

Conclusions

Based on the results of the current secondary analysis of an RCT, we could not clearly conclude that exercise has a beneficial effect on the urine pH. Further well-designed RCTs should be conducted to determine whether aerobic exercise is truly able to ameliorate urine acidification.

Trial registration

The study was retrospectively registered in the University Hospital Medical Information Network (UMIN) as “Effect of step exercise on aerobic fitness and progression of atherosclerosis in the elderly” under the registration number UMIN 000026743 (the date of registration: March 28, 2017).

Trends in prevalence and management of diabetes and related vascular risks in Japanese adults: Japan National Health and Nutrition Surveys 2003-2012

AIMS

To examine temporal changes in health system performance for the control of diabetes and related risks for vascular complications in Japan over a decade.

METHODS

Data of 51,128 individuals aged ≥20years were obtained from the National Health and Nutrition Surveys in 2003-2012. Diabetes was defined as currently being treated by insulin or oral hypoglycaemic agents or having a glycated haemoglobin (HbA1c) level ≥6.5% (≥48mmol/mol). We estimated the prevalence and proportions of people with diabetes being treated and achieving target goals of HbA1c <7.0% (<53mmol/mol), blood pressure <130/80mmHg, and non-high-density lipoprotein cholesterol <130mg/dL. All estimates were age-standardized using the Japanese population in 2010.

RESULTS

The age-standardized prevalence of diabetes remained constant at approximately 8% and was significantly higher in men (P<0.001) and in individuals age ≥65years (P<0.001) throughout the study period. The proportion of people with diabetes being treated significantly increased from 41.8% (95% confidence interval, 37.2-46.5%) in 2003 to 54.9% (51.9-57.8%) in 2012, and the proportion of those having controlled HbA1c significantly increased from 13.4% (10.3-17.3%) in 2003 to 28.8% (26.3-31.5%) in 2012. These two rates were significantly higher in age ≥65years compared with younger adults in most of the survey years (P<0.05). The control rates of blood pressure and non-high-density lipoprotein cholesterol remained around 20% and 30-40%, respectively.

CONCLUSIONS

Diabetes management in Japan has improved over the past decade but is still inadequate for prevention of vascular complications.

Effects of periodontal treatment on the medical status of patients with type 2 diabetes mellitus: a pilot study

Background

Studies have demonstrated that periodontal disease is associated with the development of systemic complications in patients with type 2 diabetes mellitus (T2DM). The purpose of this pilot study was to investigate which markers among various systemic disease parameters are affected by periodontal treatment in patients with T2DM.

Methods

Twelve patients with T2DM were given oral hygiene instructions and subsequent subgingival scaling and root planing. The periodontal status was recorded, and blood and urine samples were taken to measure various parameters of glucose control and systemic status at baseline and 1 month following the periodontal treatment. Serum concentrations of tumor necrosis factor-α and high-sensitivity C-reactive protein were measured by enzyme-linked immunosorbent assay.

Results

After the periodontal treatment, the glycated hemoglobin value was significantly improved. The levels of urinary N-acetyl-β-D-glucosaminidase and albumin, which are markers of renal dysfunction, also decreased significantly after treatment. Among the parameters measured in serum, the γ-glutamyl transpeptidase level, which is usually interpreted as a marker of liver dysfunction, was significantly reduced. The serum concentrations of tumor necrosis factor-α and high-sensitivity C-reactive protein were also significantly reduced by periodontal treatment.

Conclusion

Within the limitations of this pilot study, periodontal treatment may be effective not only in improving metabolic control, but also in reducing the risk of diabetic kidney and liver disease in patients with T2DM.

Cysteinylated transthyretin as a discriminator of cardiovascular risk in patients with diabetes mellitus

BACKGROUND

The cysteine residue on transthyretin (TTR) is susceptible to be oxidized, and serum cysteinylated TTR (Cys-TTR) level is thought to reflect oxidative stress. The purpose of this study was to elucidate the relationship between Cys-TTR and arterial stiffness, a known predictor of cardiovascular disease, in patients with type 2 diabetes.

METHODS

The subjects were 105 male outpatients with type 2 diabetes. Arterial stiffness was evaluated by measuring cardio-ankle vascular index (CAVI). The relationship between CAVI and ratio of Cys-TTR to total TTR (Cys-TTR ratio) was analyzed.

RESULTS

Cys-TTR ratio was significantly correlated with CAVI (Pearson's correlation coefficient: 0.316, p<0.01), and CAVI was significantly higher in the 3rd tertile group for Cys-TTR ratio than in its 1st tertile group. These relationships were also significant after adjusting for age, smoking, alcohol drinking, body mass index, mean arterial pressure, hemoglobin A1c, LDL cholesterol-to-HDL cholesterol ratio and eGFR. Prevalence of high CAVI (≥10.0) was significantly higher in the 3rd tertile for Cys-TTR ratio than in its 1st tertile and tended to be higher with an increase in tertile (28.6% in the 1st tertile, 42.9% in the 2nd tertile and 60.0% in the 3rd tertile). Odds ratio (OR) for high CAVI of the 3rd vs. 1st tertile groups for Cys-TTR ratio was significantly higher than the reference level of 1.00 both before and after adjustment for the above cardiovascular risk factors (crude OR, 3.75 [1.38-10.17]; adjusted OR, 5.09 [1.39-18.64]).

CONCLUSIONS

Cys-TTR ratio is associated with arterial stiffness in patients with diabetes and is proposed as a new discriminator of cardiovascular risk.

Postprandial Increase in Energy Expenditure Correlates with Body Weight Reduction in Patients with Type 2 Diabetes Receiving Diet Therapy

AIM

The clinical significance of energy expenditure (EE) in the treatment of type 2 diabetes has not been fully elucidated. Here we analyzed the relationships between EE and clinical measurements in patients with type 2 diabetes receiving diet therapy.

METHODS

A total of 100 patients (34 women and 66 men) with type 2 diabetes admitted to our hospital for glycemic control were enrolled. The participants received an energy-restricted diet during their hospitalization (median, 15 days). EE was measured in the fasted (FEE) and postprandial (PPEE) states using indirect calorimetry. The postprandial increment of EE (ΔEE) was calculated from the FEE and PPEE (ΔEE=PPEE-FEE).

RESULTS

FEE, PPEE, and ΔEE were 0.997±0.203, 1.104±0.213, and 0.107±0.134 kcal/min, respectively. Body weight decreased from 68.7±16.6 to 66.8±16.0 kg (p＜0.0001) during hospitalization. FEE and PPEE showed positive correlations with height, body weight, body mass index, and abdominal circumference at admission, but ΔEE was not correlated with these anthropometric measurements. On the other hand, ΔEE was inversely correlated with the body weight change. The association between ΔEE and the body weight change was independent of age, sex, and HbA1c.

CONCLUSIONS

Postprandial increase in energy expenditure may be a determinant of individual differences in weight reduction in patients with type 2 diabetes on diet therapy. As a simple surrogate for diet-induced thermogenesis, ΔEE may serve as a useful predictive marker for the efficacy of diet therapy.

The association between changes in lifestyle behaviors and the incidence of chronic kidney disease (CKD) in middle-aged and older men

Background

This study was designed to evaluate whether changes in lifestyle behaviors are correlated with the incidence of chronic kidney disease (CKD).

Methods

The subjects consisted of 316 men without a history of cardiovascular disease, stroke, or renal dysfunction or dialysis treatment. The following lifestyle behaviors were evaluated using a standardized self-administered questionnaire: habitual moderate exercise, daily physical activity, walking speed, eating speed, late-night dinner, bedtime snacking, skipping breakfast, and drinking and smoking habits. The subjects were divided into four categories according to the change in each lifestyle behavior from baseline to the end of follow-up (healthy–healthy, unhealthy–healthy, healthy–unhealthy and unhealthy–unhealthy).

Results

A multivariate analysis showed that, with respect to habitual moderate exercise and late-night dinner, maintaining an unhealthy lifestyle resulted in a significantly higher odds ratio (OR) for the incidence of CKD than maintaining a lifestyle (OR 8.94; 95% confidence interval [CI], 1.10–15.40 for habitual moderate exercise and OR 4.00; 95% CI, 1.38–11.57 for late-night dinner). In addition, with respect to bedtime snacking, the change from a healthy to an unhealthy lifestyle and maintaining an unhealthy lifestyle resulted in significantly higher OR for incidence of CKD than maintaining a healthy lifestyle (OR 4.44; 95% CI, 1.05–13.93 for healthy–unhealthy group and OR 11.02; 95% CI, 2.83–26.69 for unhealthy–unhealthy group).

Conclusions

The results of the present study suggest that the lack of habitual moderate exercise, late-night dinner, and bedtime snacking may increase the risk of CKD.

•

The lack of exercise habit is associated with the incidence of CKD.

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Late-night dinner and bedtime snacking increase the risk of CKD.

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Early lifestyle intervention is necessary to prevent CKD incidence.

Factors affecting consultation length in a Japanese diabetes practice

AIMS

Sufficient consultation time is important for establishing good doctor-patient relationship. We examined the factors that affect consultation length in Japanese diabetes practice.

METHODS

This was a cross-sectional study performed at a diabetes clinic in central Tokyo, Japan. Regular diabetes consultations of 1197 patients with 22 physicians were analyzed. Consultation time and clinical characteristics were obtained from the electronic records. A negative binomial model, which included patient and physician characteristics, was constructed to examine the association of the variables with consultation length.

RESULTS

Of the 1197 patients (mean age, 66; women, 25%; type 1 diabetes, 10%), the mean consultation time was 10.1min. In the multivariate model, longer consultation time was recorded in patients with type 1 diabetes, higher glycated hemoglobin (HbA1c), use of insulin injections, and use of hypnotics/anxiolytics. The consultation time was longer in patients with HbA1c of ⩾7.0 to <8.0% (⩾53 to <64mmol/mol), ⩾8.0 to <9.0% (⩾64 to <75mmol/mol) and ⩾9.0% (⩾75mmol/mol), compared to those with HbA1c of <7.0% (<53mmol/mol) with the ratios of 1.03 (95% confidence interval (CI)=0.96-1.10), 1.16 (95% CI=1.07-1.26) and 1.17 (95% CI=1.06-1.29), respectively. Body mass index was also associated with long consultation. Older and female physicians provided longer consultation.

CONCLUSIONS

Clinical consultation length in diabetes practice was associated with certain patient and physician characteristics. The findings can be used for making diabetes consultation more efficacious, which could eventually lead to the provision of the most appropriate consultation time for individual patients.

Association between elevated blood glucose level on admission and long-term mortality in patients with acute decompensated heart failure

BACKGROUND

The effect of elevated blood glucose (BG) levels on the long-term prognosis of acute decompensated heart failure (ADHF) patients has not been well defined. The purpose of this study is to evaluate the long-term prognosis of ADHF with elevated BG.

METHODS

A cohort of patients consecutively admitted to the cardiac intensive care unit from 2007 to 2011 was studied. Among these, 495 patients who met the criteria were divided into 4 groups based on their BG level and diabetes mellitus (DM) status. The risks for all-cause mortality in each group were assessed using the multivariate Cox proportional hazards model.

RESULTS

At a median follow-up of 1.8 years, 148 patients had died. There were 168 patients without either BG elevation or DM, 67 without BG elevation but with DM, 105 with BG elevation but not DM, and 155 with both BG elevation and DM. In a multivariate model, those with BG elevation, regardless of DM status, showed a greater risk of increased mortality when compared with patients without either BG elevation or DM [hazard ratio (HR), 1.79; p=0.042 for BG elevation without DM and HR, 1.73; p=0.048 for BG elevation with DM].

CONCLUSION

Elevated BG levels, irrespective of the DM status, at the time of admission in patients with ADHF, appear to be a prognostic marker for ADHF.

Sarcopenia is associated with incident albuminuria in patients with type 2 diabetes: A retrospective observational study

Sarcopenia, defined as age‐related loss of skeletal muscle mass and function, increases the risk of albuminuria. However, it has still unknown whether sarcopenia could increase the risk for the progression of albuminuria. A total 238 patients with type 2 diabetes (mean age 64 ± 12 years; 39.2% women) were studied in the present retrospective observational study. The prevalence of sarcopenia was 17.6%. During the median follow‐up period of 2.6 years, albuminuria was measured 5.8 ± 1.8 times, and progression of albuminuria was observed in 14.9% of patients with normoalbuminuria, as was 11.5% in those with microalbuminuria. Sarcopenia was significantly associated with both progression (hazard ratio 2.61, 95% confidence interval 1.08–6.31, P = 0.034) and regression (hazard ratio 0.23, 95% confidence interval 0.05–0.98, P = 0.048) of albuminuria by multivariate Cox regression analysis. The present data suggest that sarcopenia is an important determinant of both progression and regression of albuminuria in patients with type 2 diabetes.

Circulating ferritin concentrations and risk of type 2 diabetes in Japanese individuals

AIMS/INTRODUCTION

Higher iron storage has been linked to an increased risk of type 2 diabetes, but little is known about the mediator of this association. Here, we prospectively investigated the association between circulating ferritin, a marker of iron storage, and the incidence of type 2 diabetes among Japanese individuals.

MATERIALS AND METHODS

The participants were 4,754 employees who attended a comprehensive health check-up in 2008-2009 and donated blood for the study. During 5 years of follow up, diabetes was identified based on plasma glucose, glycated hemoglobin and self-report. Two controls matched to each case on sex, age and date of check-up were randomly chosen using density sampling, giving 327 cases and 641 controls with ferritin measurement. Cox proportional hazards regression was used to estimate the hazard ratio while adjusting for a series of potential confounders or mediators.

RESULTS

Elevated serum ferritin levels were associated with a significantly increased risk of type 2 diabetes, with the hazard ratio adjusted for known risk factors in the highest vs lowest quartile of 1.42 (95% confidence interval: 1.03-1.96). This association was unchanged after adjustment for C-reactive protein and adiponectin, but attenuated after adjustment for liver enzyme and insulin resistance (hazard ratio 1.04). The ferritin-diabetes association was confined to non-obese participants.

CONCLUSIONS

These results suggest that elevated iron storage is associated with increased risk of type 2 diabetes in normal weight individuals, and that this association is partly mediated through liver dysfunction and resulting insulin resistance.

No causal impact of serum vascular endothelial growth factor level on temporal changes in body mass index in Japanese male workers: a five-year longitudinal study

PURPOSE

It has been reported that adipocytes secrete vascular endothelial growth factor. Therefore, we conducted a 5-year longitudinal epidemiological study to further elucidate the association between vascular endothelial growth factor levels and temporal changes in body mass index.

METHODS

Our study subjects were Japanese male workers, who had regular health check-ups. Vascular endothelial growth factor levels were measured at baseline. To examine the association between vascular endothelial growth factor levels and overweight, we calculated the odds ratio using a multivariate logistic regression model. Moreover, linear mixed effect models were used to assess the association between vascular endothelial growth factor level and temporal changes in body mass index during the 5-year follow-up period.

RESULTS

Vascular endothelial growth factor levels were marginally higher in subjects with a body mass index greater than 25 kg/m² compared with in those with a body mass index less than 25 kg/m² (505.4 vs. 465.5 pg/mL, P = 0.1) and were weakly correlated with leptin levels (β: 0.05, P = 0.07). In multivariate logistic regression, subjects in the highest vascular endothelial growth factor quantile were significantly associated with an increased risk for overweight compared with those in the lowest quantile (odds ratio 1.65, 95 % confidential interval: 1.10-2.50). Moreover P for trend was significant (P for trend = 0.003). However, the linear mixed effect model revealed that vascular endothelial growth factor levels were not associated with changes in body mass index over a 5-year period (quantile 2, β: 0.06, P = 0.46; quantile 3, β: -0.06, P = 0.45; quantile 4, β: -0.10, P = 0.22; quantile 1 as reference).

CONCLUSIONS

Our results suggested that high vascular endothelial growth factor levels were significantly associated with overweight in Japanese males but high vascular endothelial growth factor levels did not necessarily cause obesity.

Association between high cystatin C levels and carotid atherosclerosis

AIM

To investigate the association between carotid atherosclerosis and cystatin C (CysC) and to determine the optimal CysC cut-off value.

METHODS

One hundred twenty-eight subjects were included in this study. Atherosclerosis was defined as a maximum carotid plaque thickness (MCPT) of greater than 2 mm. A receiver operating characteristic curve analysis was used to determine the diagnostic value of serum CysC for atherosclerosis. The subjects were divided into two groups according to the CysC cut-off value. We screened for diabetes, hypertension, dyslipidemia, smoking status, alcohol consumption, and exercise behavior. The association between atherosclerosis and CysC levels was assessed using multivariate analysis.

RESULTS

The subjects were then divided into two groups according to the CysC cut-off value (0.73 mg/L). The median age of the high CysC group was 72 years (85% males), whereas that of the low CysC group was 61 years (63% males). The CysC levels were significantly correlated with Cr and estimated glomerular filtration rate (eGFR) values. Body-mass index, visceral fat area, hypertension, diabetes mellitus, and MCPT were significantly higher in the high CysC group than in the low CysC group. Furthermore, the eGFR was significantly lower in the high CysC group. Regarding lifestyle habits, only the exercise level was lower in the high CysC group than in the low CysC group. Multivariate analysis, adjusted for age and sex, revealed that high CysC levels were significantly associated with an MCPT of ≥ 2 mm (odds ratio: 2.92; 95%CI: 1.13-7.99).

CONCLUSION

Higher CysC levels were associated with an MCPT of ≥ 2 mm. The CysC cut-off value of 0.73 mg/L appears to aid in the diagnosis of atherosclerosis.