Attenuated Dentin Matrix Protein 1 Enhances Fibroblast Growth Factor 23 in Calvaria in a Primary Hyperparathyroidism Model

Fibroblast growth factor 23 (FGF23) secretion is facilitated by the PTH, particularly in hyperparathyroidism. The PTH also attenuates dentin matrix protein 1 (DMP1), which is produced by osteocytes to contribute to bone mineralization and suppress FGF23 expression. Nevertheless, it remains unknown whether attenuated DMP1 affects FGF23 expression in hyperparathyroidism. We examined their expression in bone tissue using a mouse model of primary hyperparathyroidism (PHPT). PHPT mice increased serum FGF23 levels, along with a high level of serum PTH. Fgf23 expression increased, and Dmp1 decreased significantly in the calvaria of PHPT mice compared with wild-type mice and primary osteoblasts treated with PTH. In UMR106 mature osteoblasts, PTH increased Fgf23 expression and decreased Dmp1 expression, and stimulation of protein kinase A (PKA) signaling by forskolin also increased Fgf23 expression and decreased Dmp1 expression in a dose-dependent manner, whereas inhibition of PKA signaling with 10-5 M H89 reversed the changes in Fgf23 and Dmp1 expression when cells were stimulated with PTH. Silencing Dmp1 along with PTH treatment led to an additive increase in Fgf23 expression, accompanied by additive phosphorylation of the cAMP-response element-binding protein. These results indicate that persistent and high levels of PTH lead to the continuous activation of PKA signaling in osteoblasts/osteocytes, resulting in an increase in FGF23 and a decrease in DMP1 in bone. Moreover, suppression of DMP1 enhanced FGF23 expression in PHPT, besides having a direct effect on PTH. These mechanisms may describe one of the pathogeneses behind the increase in FGF23 transcription in bone tissue in patients with PHPT.

Aerobic Exercise Training with Brisk Walking Increases Intestinal Bacteroides in Healthy Elderly Women

This study examined the effect of an exercise intervention on the composition of the intestinal microbiota in healthy elderly women. Thirty-two sedentary women that were aged 65 years and older participated in a 12-week, non-randomized comparative trial. The subjects were allocated to two groups receiving different exercise interventions, trunk muscle training (TM), or aerobic exercise training (AE). AE included brisk walking, i.e., at an intensity of ≥ 3 metabolic equivalents (METs). The composition of the intestinal microbiota in fecal samples was determined before and after the training period. We also assessed the daily physical activity using an accelerometer, trunk muscle strength by the modified Kraus-Weber (K-W) test, and cardiorespiratory fitness by a 6-min. walk test (6MWT). K-W test scores and distance achieved during the 6MWT (6MWD) improved in both groups. The relative abundance of intestinal Bacteroides only significantly increased in the AE group, particularly in subjects showing increases in the time spent in brisk walking. Overall, the increases in intestinal Bacteroides following the exercise intervention were associated with increases in 6MWD. In conclusion, aerobic exercise training that targets an increase of the time spent in brisk walking may increase intestinal Bacteroides in association with improved cardiorespiratory fitness in healthy elderly women.

Impact of diabetes on sarcopenia and mortality in patients undergoing hemodialysis

Background

Sarcopenia has become a serious disorder in modern society. Chronic kidney disease requiring dialysis and diabetes are some of the disorders that accelerate the onset and progression of sarcopenia. We, therefore, investigated the prevalence of sarcopenia in patients undergoing hemodialysis (HD) and confirmed the impact of diabetes mellitus (DM) on this population.

Methods

This study included 308 patients whose muscle strength and mass had been evaluated using handgrip strength and dual-energy X-ray absorptiometry, respectively. Sarcopenia was defined according to the criteria established by the Asian Working Group on Sarcopenia. In addition, this cohort had been followed up for 9 years.

Results

The prevalence of sarcopenia was 40% (37% in males and 45% in females) with gender differences being insignificant (p = 0.237). The DM morbidity rate was significantly higher in those with sarcopenia than in those without sarcopenia (41% vs. 27%, p = 0.015). Multivariate regression analyses showed that the presence of DM was an independent contributor to sarcopenia in patients undergoing HD (odds ratio 3.11; 95% confidence interval 1.63–5.93; p <  0.001). During the follow-up of 76 ± 35 months, 100 patients died. Patients with sarcopenia demonstrated significantly higher rates of all-cause mortality than those without sarcopenia (p <  0.001 using the log-rank test). Multivariate Cox proportional hazards analyses revealed that the presence of DM was significantly associated with higher all-cause mortality (adjusted hazard ratio: 2.39; 95% confidence interval 1.51–3.81; p <  0.001).

Conclusions

The prevalence of sarcopenia among this cohort of patients undergoing HD was determined to be 40%. Moreover, the presence of DM was an independent contributor to sarcopenia and an independent predictor of all-cause mortality in this population.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1271-8) contains supplementary material, which is available to authorized users.

Association of cystatin C- and creatinine-based eGFR with osteoporotic fracture in Japanese postmenopausal women with osteoporosis: sarcopenia as risk for fracture

Coexistence of chronic kidney disease (CKD) is regarded as a risk for osteoporotic fracture particularly in postmenopausal women, not only because of increased parathyroid hormone level but also uremic sarcopenia. We examined the relationships of cystatin C-based glomerular filtration rate (eGFRcys) and creatinine-based GFR (eGFRcr), as well as their ratio with occurrence of osteoporotic fracture in postmenopausal osteoporotic women. This cross-sectional study included 555 postmenopausal women with osteoporosis. eGFRcr and eGFRcys were simultaneously measured, while occurrence of osteoporotic fracture was obtained by a medical chart review. Patients with osteoporotic fractures (n = 211) exhibited significantly lower levels of physical activity, eGFRcr, eGFRcys, and eGFRcys/eGFRcr ratios, while a higher percentage was CKD stage 3 or more, estimated by eGFRcr or eGFRcys (CKDcys), than those without (n = 344). Lower eGFRcys, but not lower eGFRcr, was independently associated with osteoporotic fracture in the entire cohort and that association was retained in CKDcys patients. Of great interest, higher eGFRcr was associated with osteoporotic fracture independent of eGFRcys in CKDcys patients. Furthermore, lower eGFRcys/eGFRcr ratio was independently associated with osteoporotic fracture in both CKDcys patients and the entire cohort. eGFRcys reduction might be associated with osteoporotic fracture in postmenopausal osteoporotic women, indicating the involvement of renal osteopathy in its occurrence. Furthermore, the association of higher, but not lower, eGFRcr with osteoporotic fracture in CKDcys cases might be explained by underestimation of renal dysfunction by eGFRcr resulting from decreased muscle mass and quality in those patients.

Plasma omentin levels are associated with vascular endothelial function in patients with type 2 diabetes at elevated cardiovascular risk

AIMS

Omentin is an adipokine that has protective effects against cardiovascular damage. Previous studies showed an inverse relationship between omentin and obesity, diabetes, and cardiovascular disease. This study aimed to investigate the association between omentin and vascular endothelial function in patients with type 2 diabetes (T2D).

METHODS

The subjects were 425 patients with T2D and 223 non-diabetic controls. Fasting plasma omentin levels were measured by enzyme-linked immunosorbent assay, and the endothelium-dependent, flow-mediated dilatation (FMD) was measured by ultrasonography.

RESULTS

Plasma omentin levels were higher, while FMD was lower in participants with T2D than in non-diabetic controls. No significant correlation was found between plasma omentin levels and FMD in either non-diabetic controls or participants with T2D on multivariate analysis. However, stratified analysis in T2D patients revealed that plasma omentin levels were independently and positively associated with FMD in high cardiovascular risk subgroups according to age (≥65 years), estimated glomerular filtration rate (<60 mL/min/1.73 m²), or preexisting cardiovascular diseases but not in low-risk subgroups.

CONCLUSIONS

Plasma omentin levels are independently associated with endothelial function in subgroups of patients with T2D at elevated cardiovascular risk. This study suggests a protective role of omentin against endothelial dysfunction, particularly in high-risk patients.

Insulin Resistance Associated with Plasma Xanthine Oxidoreductase Activity Independent of Visceral Adiposity and Adiponectin Level: MedCity21 Health Examination Registry

BACKGROUND

Higher levels of uric acid production have been reported in individuals with visceral fat obesity, and obesity is known to enhance xanthine oxidoreductase (XOR) activity, although the precise mechanism remains unclear. We investigated the associations of visceral fat area (VFA), serum adiponectin level, and insulin resistance with plasma XOR activity using our novel highly sensitive assay based on [¹³C₂,¹⁵N₂] xanthine and liquid chromatography/triple quadrupole mass spectrometry.

METHODS

This cross-sectional study included 193 subjects (92 males and 101 females) registered in the MedCity21 health examination registry. Plasma XOR activity, serum adiponectin level, and VFA obtained by computed tomography were measured, and insulin resistance was determined based on the homeostasis model assessment (HOMA-IR) index.

RESULTS

The mean values for VFA, log HOMA-IR, and log plasma XOR activity were 76.8 ± 45.8 cm², 0.14 ± 0.30, and 1.50 ± 0.44 pmol/h/mL, respectively. Multiple regression analysis showed that HOMA-IR was significantly (p=0.020) associated with plasma XOR activity independent of other factors, including VFA and adiponectin level, as well as age, sex, alcohol drinking habit, smoking habit, alanine transaminase, HbA1c, and eGFR. The "sex∗HOMA - IR" interaction was not significant (p=0.020) associated with plasma XOR activity independent of other factors, including VFA and adiponectin level, as well as age, sex, alcohol drinking habit, smoking habit, alanine transaminase, HbA1c, and eGFR. The ".

CONCLUSIONS

Our results indicate that insulin resistance is associated with plasma XOR activity and that relationship is independent of visceral adiposity and adiponectin level, suggesting that the development of insulin resistance resulting from increased visceral adiposity and/or reduced serum adiponectin contributes to increased uric acid production by stimulating XOR activity.

Impaired residual renal function predicts denosumab-induced serum calcium decrement as well as increment of bone mineral density in non-severe renal insufficiency

Denosumab treatment of osteoporotic patients, except those with severe renal insufficiency, reduced cCa levels. Low baseline cCa, low estimated glomerular filtration rate, and high bone turnover increased the risk of lower cCa, while increasing bone mineral density. Pretreatment with antiresorptive agents was beneficial in reducing the risk of hypocalcemia.

INTRODUCTION

Although denosumab-induced hypocalcemia has been frequently observed in patients with chronic kidney disease (CKD) stages 4-5D being treated with denosumab for osteoporosis, few studies have assessed the risk factors for serum-corrected calcium (cCa) reductions in patients with non-severe renal insufficiency. This study assessed the risk factors for reduced cCa concentration following denosumab administration and analyzed factors predictive of changes in bone mineral density (BMD).

METHODS

Seventy-seven osteoporotic patients, not including those with CKD stages 4-5D, were treated with 60 mg denosumab once every 6 months. Biochemical parameters and BMD were analyzed from prior to the initial dose until 1 month after the second dose.

RESULTS

Following the first administration of denosumab, cCa levels decreased, reaching a minimum on day 7. Multiple linear regression analyses showed that baseline cCa, estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m², tartrate-resistant acid phosphatase-5b (TRACP-5b), and bone alkaline phosphatase (BAP) or pretreatment with antiresorptive agents were significant factors independently associated with the absolute reduction in cCa from baseline to day 7 (ΔcCa_0-7 days). ΔcCa_0-7 days after the second dose of denosumab was significantly lower than that after the first dose. After 6 months of denosumab treatment, both LS-BMD and FN-BMD significantly increased from baseline. LS-BMD and FN-BMD correlated significantly with baseline TRACP-5b or BAP and eGFR, respectively.

CONCLUSIONS

Both low eGFR and high bone turnover were independent risk factors for denosumab-induced cCa decrement, and for increases in BMD. Pretreatment with antiresorptive agents may reduce the risk of hypocalcemia.

Improvement of glycemic control by treatment for insomnia with suvorexant in type 2 diabetes mellitus

Introduction

Acute and chronic insomnia can exacerbate type 2 diabetes mellitus (T2DM). We investigated suvorexant (an anti-insomnia drug that targets the orexin system) effects on sleep architecture and glucose metabolism in T2DM patients with insomnia.

Materials and methods

This 7 day open-label, single-arm, intervention trial included 18 subjects with T2DM and insomnia. After 1 day acclimatization, daily glucose levels, sleep architecture, and autonomic nervous function were evaluated by continuous glucose monitoring (CGM), single-channel electroencephalography, and accelerometry, respectively.

Results

Suvorexant treatment for 3 days significantly increased total sleep time and sleep efficiency, with partial suppression of sympathetic nerve activity. CGM-measured 24 h mean glucose level decreased significantly from 157.7 ± 22.9 to 152.3 ± 17.8 mg/dL, especially in the early glucose surge after the midnight nadir (from 28.3 ± 15.0 to 18.2 ± 9.9 mg/dL), and until supper with a significant improvement in homeostasis model assessment of insulin resistance from 4.0 ± 2.8 to 2.9 ± 1.6, respectively.

Conclusions

Suvorexant treatment for insomnia of subjects with T2DM significantly improved CGM-measured daily glycemic control, which was associated with changes in sympathomimetic tone and/or improved insulin sensitivity. The amelioration of insomnia may therefore be a target for improving glycemic control in T2DM patients with insomnia.

Effect of Oral Alfacalcidol on Clinical Outcomes in Patients Without Secondary Hyperparathyroidism Receiving Maintenance Hemodialysis: The J-DAVID Randomized Clinical Trial

IMPORTANCE

Patients with chronic kidney disease have impaired vitamin D activation and elevated cardiovascular risk. Observational studies in patients treated with hemodialysis showed that the use of active vitamin D sterols was associated with lower risk of all-cause mortality, regardless of parathyroid hormone levels.

OBJECTIVE

To determine whether vitamin D receptor activators reduce cardiovascular events and mortality in patients without secondary hyperparathyroidism undergoing hemodialysis.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, open-label, blinded end point multicenter study of 1289 patients in 207 dialysis centers in Japan. The study included 976 patients receiving maintenance hemodialysis with serum intact parathyroid hormone levels less than or equal to 180 pg/mL. The first and last participants were enrolled on August 18, 2008, and January 26, 2011, respectively. The final date of follow-up was April 4, 2015.

INTERVENTIONS

Treatment with 0.5 μg of oral alfacalcidol per day (intervention group; n = 495) vs treatment without vitamin D receptor activators (control group; n = 481).

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite measure of fatal and nonfatal cardiovascular events, including myocardial infarctions, hospitalizations for congestive heart failure, stroke, aortic dissection/rupture, amputation of lower limb due to ischemia, and cardiac sudden death; coronary revascularization; and leg artery revascularization during 48 months of follow-up. The secondary outcome was all-cause death.

RESULTS

Among 976 patients who were randomized from 108 dialysis centers, 964 patients were included in the intention-to-treat analysis (median age, 65 years; 386 women [40.0%]), and 944 (97.9%) completed the trial. During follow-up (median, 4.0 years), the primary composite outcome of cardiovascular events occurred in 103 of 488 patients (21.1%) in the intervention group and 85 of 476 patients (17.9%) in the control group (absolute difference, 3.25% [95% CI, -1.75% to 8.24%]; hazard ratio, 1.25 [95% CI, 0.94-1.67]; P = .13). There was no significant difference in the secondary outcome of all-cause mortality between the groups (18.2% vs 16.8%, respectively; hazard ratio, 1.12 [95% CI, 0.83-1.52]; P = .46). Of the 488 participants in the intervention group, 199 (40.8%) experienced serious adverse events that were classified as cardiovascular, 64 (13.1%) experienced adverse events classified as infection, and 22 (4.5%) experienced malignancy-related serious adverse events. Of 476 participants in the control group, 191 (40.1%) experienced cardiovascular-related serious adverse events, 63 (13.2%) experienced infection-related serious adverse events, and 21 (4.4%) experienced malignancy-related adverse events.

CONCLUSIONS AND RELEVANCE

Among patients without secondary hyperparathyroidism undergoing maintenance hemodialysis, oral alfacalcidol compared with usual care did not reduce the risk of a composite measure of select cardiovascular events. These findings do not support the use of vitamin D receptor activators for patients such as these.

TRIAL REGISTRATION

UMIN-CTR Identifier: UMIN000001194.

Association of Albuminuria With Intraglomerular Hydrostatic Pressure and Insulin Resistance in Subjects With Impaired Fasting Glucose and/or Impaired Glucose Tolerance

OBJECTIVE

Little is known about the relationships between insulin resistance, intrarenal hemodynamics, and urinary albumin excretion (UAE) in humans with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). The aim of the current study was to examine intrarenal hemodynamic abnormalities, insulin resistance, and UAE in subjects with IFG or IGT. We hypothesized that intrarenal hemodynamic abnormalities would be associated with insulin resistance.

RESEARCH DESIGN AND METHODS

Fifty-four kidney donors underwent 75-g oral glucose tolerance and inulin and para-aminohippuric acid clearance testing. Insulin sensitivity index (ISI) was evaluated by the Matsuda index. Intrarenal hemodynamic parameters were calculated by the Gomez formulae.

RESULTS

Of the 54 subjects, 33 exhibited IFG or IGT and 31 exhibited normal glucose tolerance (NGT). Glomerular hydrostatic pressure (P_glo) and UAE were significantly higher in the IFG or IGT subjects with obesity (P = 0.015 and 0.0001, respectively). Log ISI correlated significantly and negatively with P_glo (r = -0.351, P = 0.009) in all subjects. In multiple regression analyses among all subjects, log ISI was associated significantly and independently with P_glo (β = -0.316, P = 0.015), after adjustment for age, sex, and systolic blood pressure. Further, BMI (β = 0.517, P = 0.0004), P_glo (β = 0.420, P = 0.004), and log ISI (β = -0.366, P = 0.008) were each associated significantly and independently with UAE after adjustment.

CONCLUSIONS

We demonstrated that increased insulin resistance is associated with increased P_glo and UAE in IFG or IGT subjects. These hemodynamic burdens and insulin resistance may cause injury to the glomeruli even in subjects with IFG or IGT.

Microwave frequency comb Doppler reflectometer applying fast digital data acquisition system in LHD

We succeeded in increasing the radial observation points of the microwave frequency comb Doppler reflectometer system from 8 to 20 (or especially up to 45) using the high sampling rate of 40 GS/s digital signal processing. For a new acquisition system, the estimation scheme of the Doppler shifted frequency is constructed and compared with the conventional technique. Also, the fine radial profile of perpendicular velocity is obtained, and it is found that the perpendicular velocity profile is consistent with the E × B drift velocity one.

Positive association of plasma leptin with sleep quality in obese type 2 diabetes patients

AIMS/INTRODUCTION

Poor sleep quality is associated with obesity and diabetes. The adipocyte-derived hormone, leptin, was recently shown to underlie the link between abnormal sleep and obesity. We aimed to investigate the association between leptin and sleep quality in type 2 diabetes patients.

MATERIALS AND METHODS

In the present cross-sectional study, we studied 182 type 2 diabetes patients, among whom 113 were diagnosed with obesity (body mass index ≥25 kg/m2 ). Fasting plasma leptin levels were measured, and sleep architecture was assessed using single-channel electroencephalography.

RESULTS

Using unadjusted analyses, the obese type 2 diabetes patients, but not their non-obese counterparts, showed a positive correlation between plasma leptin levels and a parameter for deep sleep assessed by delta power during the first sleep cycle. Multivariate analysis showed that plasma leptin levels were positively associated with delta power, but not with the total sleep time, after adjusting for potential confounders including age, body mass index and the apnea-hypopnea index, in the obesity group. However, neither delta power nor total sleep time was associated with leptin in the non-obesity group.

CONCLUSIONS

Plasma leptin levels are independently associated with sleep quality in obese, but not in non-obese, type 2 diabetes patients. The present study indicates a favorable relationship between leptin and sleep quality in obese type 2 diabetes patients.

Fulminant onset of insulin-dependent diabetes with positive anti-GAD antibody titers during treatment with nivolumab in a patient with NSCLC

Programmed cell death-1 (PD-1) and programmed cell death-ligand-1 (PD-L1) inhibitors have been highlighted in the field of cancer treatment. The interaction between PD-1 and PD-L1 is thought to play an important role in the regulation of the self-immune tolerance mechanism, so blocking these molecules may cause serious immune-related adverse events (IrAE), including fulminant insulin-dependent (type 1) diabetes. Here, we describe a patient with fulminant type 1 diabetes induced by nivolumab, an anti-PD-1 antibody. The patient, a 78-year-old man, was being treated with nivolumab as a third-line treatment for squamous cell carcinoma of the lung. After three cycles, he experienced an abrupt flare-up of the blood glucose within half a day. His blood glucose further increased without clinical symptoms until his hospital visit. Laboratory data showed the complete exhaustion of intrinsic insulin and the elevation of serum antibody titer to glutamic acid decarboxylase (GAD). Although the patient was previously diagnosed with non-insulin-dependent (type 2) diabetes, his disease activity had been well controlled with oral medication and low-dose insulin therapy until just before the flare-up. Because of the laboratory findings and the extremely rapid onset of hyperglycemia, a diagnosis of fulminant, rather than the rapid onset, type 1 diabetes related to nivolumab therapy was strongly suspected. Our case study indicates that fulminant hyperglycemia can occur extremely rapidly. The blood glucose of patients receiving PD-1 antibody therapy should be closely monitored.

Association of Decreased Handgrip Strength with Reduced Cortical Thickness in Japanese Female Patients with Type 2 Diabetes Mellitus

LD-100, a quantitative ultrasonic device, allows us to measure cortical thickness (CoTh). Patients with type 2 diabetes mellitus (T2DM) show high prevalence of sarcopenia. This study aimed to clarify the association of handgrip strength (HGS) with cortical porosis, a major risk for fracture of DM. CoTh and trabecular bone mineral density (TrBMD) at the 5.5% distal radius were assessed in T2DM female patients (n = 122) and non-DM female controls (n = 704) by LD-100. T2DM patients aged older 40 years showed significantly lower HGS and CoTh, but not TrBMD, than non-DM counterparts. Although HGS was significantly and positively correlated with CoTh and TrBMD in T2DM patients, multivariate analysis revealed HGS as an independent factor positively associated with CoTh, but not TrBMD, in T2DM patients, suggesting the preferential association of HGS with cortical, but not trabecular, bone component in T2DM female patients. In conclusion, the present study demonstrated an early decline of HGS in T2DM female patients as compared with non-DM healthy controls after the age of 40 years, which is independently associated with thinner CoTh, but not TrBMD in T2DM patients, and thus suggested that reduced muscle strength associated with DM might be a major factor for cortical porosis development in DM patients.

Plasma polyunsaturated fatty acid profile is associated with vascular endothelial function in patients with type 2 diabetes

Decreased plasma n-3 polyunsaturated fatty acid levels or the n-3/n-6 polyunsaturated fatty acid ratios are associated with a risk of cardiovascular events. In this cross-sectional study, we measured plasma levels of eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid and investigated the association between the plasma polyunsaturated fatty acid profile and vascular endothelial function in 396 patients with type 2 diabetes. Endothelium-dependent, flow-mediated dilatation of the brachial artery was measured using ultrasonography. Multiple regression analyses, including age, sex, body mass index, and other cardiovascular risk factors, revealed that plasma eicosapentaenoic acid levels ( β = 0.140, p = 0.008) and the eicosapentaenoic acid/arachidonic acid ratio ( β = 0.127, p = 0.019), but not plasma docosahexaenoic acid levels ( β = 0.067, p = 0.220) or the docosahexaenoic acid/arachidonic acid ratio ( β = 0.034, p = 0.559), were independently and positively associated with flow-mediated dilatation. In conclusion, plasma eicosapentaenoic acid levels and the eicosapentaenoic acid/arachidonic acid ratio are independently associated with endothelial function in patients with type 2 diabetes. This study indicates a positive association between eicosapentaenoic acid, rather than docosahexaenoic acid, and endothelial function in type 2 diabetes.