Structural Changes of Cutaneous Immune Cells in Patients With Type 1 Diabetes and Their Relationship With Diabetic Polyneuropathy

BACKGROUND AND OBJECTIVES

Diabetic polyneuropathy (DPN) is a complication of diabetes characterized by pain or lack of peripheral sensation, but the underlying mechanisms are not yet fully understood. Recent evidence showed increased cutaneous macrophage infiltration in patients with type 2 diabetes and painful DPN, and this study aimed to understand whether the same applies to type 1 diabetes.

METHODS

The study included 104 participants: 26 healthy controls and 78 participants with type 1 diabetes (participants without DPN [n = 24], participants with painless DPN [n = 29], and participants with painful DPN [n = 25]). Two immune cells, dermal IBA1⁺ macrophages and epidermal Langerhans cells (LCs, CD207⁺), were visualized and quantified using immunohistological labeling and stereological counting methods on skin biopsies from the participants. The IBA1⁺ macrophage infiltration, LC number density, LC soma cross-sectional area, and LC processes were measured in this study.

RESULTS

Significant difference in IBA1⁺ macrophage expression was seen between the groups (p = 0.003), with lower expression of IBA1 in participants with DPN. No differences in LC morphologies (LC number density, soma cross-sectional area, and process level) were found between the groups (all p > 0.05). In addition, IBA1⁺ macrophages, but not LCs, correlated with intraepidermal nerve fiber density, Michigan neuropathy symptom inventory, (questionnaire and total score), severity of neuropathy as assessed by the Toronto clinical neuropathy score, and vibration detection threshold in the whole study cohort.

DISCUSSION

This study showed expressional differences of cutaneous IBA1⁺ macrophages but not LC in participants with type 1 diabetes-induced DPN compared with those in controls. The study suggests that a reduction in macrophages may play a role in the development and progression of autoimmune-induced diabetic neuropathy.

Autonomic dysfunction is associated with the development of arterial stiffness: the Whitehall II cohort

This study aims to examine the association between baseline level and change of autonomic nervous function with subsequent development of arterial stiffness. Autonomic nervous function was assessed in 4901 participants of the Whitehall II occupational cohort by heart rate variability (HRV) indices and resting heart rate (rHR) three times between 1997 and 2009, while arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWV) measured twice between 2007 and 2013. First, individual HRV/rHR levels and annual changes were estimated. Then, we modelled the development of PWV by HRV/rHR using linear mixed effect models. First, we adjusted for sex and ethnicity (model 1), and then for socioeconomic and lifestyle factors, various clinical measurements, and medications (model 2). A decrease in HRV and unchanged rHR was associated with subsequent higher levels of PWV, but the effect of a change in HRV was less pronounced at higher ages. A typical individual aged 65 years with a SDNN level of 30 ms and a 2% annual decrease in SDNN had 1.32 (0.95; 1.69) higher PWV compared to one with the same age and SDNN level but with a 1% annual decrease in SDNN. Further adjustment had no major effect on the results. People who experience a steeper decline in autonomic nervous function have higher levels of arterial stiffness. The association was stronger in younger people.

Collagen turnover is associated with cardiovascular autonomic and peripheral neuropathy in type 1 diabetes: novel pathophysiological mechanism?

BACKGROUND

Diabetic cardiovascular autonomic neuropathy (CAN) and distal symmetrical polyneuropathy (DSPN) are severe diabetic complications. Collagen type VI (COL6) and III (COL3) have been associated with nerve function. We investigated if markers of COL6 formation (PRO-C6) and COL3 degradation (C3M) were associated with neuropathy in people with type 1 diabetes (T1D).

METHODS

In a cross-sectional study including 300 people with T1D, serum and urine PRO-C6 and C3M were obtained. CAN was assessed by cardiovascular reflex tests: heart rate response to deep breathing (E/I ratio), to standing (30/15 ratio) and to the Valsalva maneuver (VM). Two or three pathological CARTs constituted CAN. DSPN was assessed by biothesiometry. Symmetrical vibration sensation threshold above 25 V constituted DSPN.

RESULTS

Participants were (mean (SD)) 55.7 (9.3) years, 51% were males, diabetes duration was 40.0 (8.9) years, HbA1c was 63 (11 mmol/mol, (median (IQR)) serum PRO-C6 was 7.8 (6.2;11.0) ng/ml and C3M 8.3 (7.1;10.0) ng/ml. CAN and DSPN were diagnosed in 34% and 43% of participants, respectively. In models adjusted for relevant confounders a doubling of serum PRO-C6, was significantly associated with odds ratio > 2 for CAN and > 1 for DSPN, respectively. Significance was retained after additional adjustments for eGFR only for CAN. Higher serum C3M was associated with presence of CAN, but not after adjustment for eGFR. C3M was not associated with DSPN. Urine PRO-C6 analyses indicated similar associations.

CONCLUSIONS

Results show previously undescribed associations between markers of collagen turnover and risk of CAN and to a lesser degree DSPN in T1D.

Cardiovascular Autonomic Neuropathy Is Associated With Increased Glucose Variability in People With Type 1 Diabetes

OBJECTIVE

We investigated the association between the cardiovascular autonomic neuropathy (CAN) diagnosis and glucose variability (GV) in type 1 diabetes (T1D), as autonomic dysfunction previously has been associated with increased GV.

RESEARCH DESIGN AND METHODS

CAN was assessed by three recommended cardiovascular reflex tests (CARTs). Glucose metrics were obtained from 10-day blinded continuous glucose monitoring (CGM). Between-group differences in GV indices were assessed by regression analyses in 24 participants with T1D with CAN and 24 matched control subjects without CAN.

RESULTS

The CAN diagnosis was associated with 4.9% (95% CI 1.0, 8.7) higher coefficient of variation (CV) (P = 0.014), 0.7 mmol/L (0.3, 1.1) higher SD (P = 0.002) of glucose, and 1.4 mmol/mol (0.0, 2.7) higher mean amplitude of glycemic excursions (P = 0.047). Lower measures of CARTs were associated with higher CV, SD, and time above range values.

CONCLUSIONS

The CAN diagnosis associates with a significantly higher GV in T1D, despite a high prevalence of routine CGM use.

Advanced glycation end-products are associated with diabetic neuropathy in young adults with type 1 diabetes

AIMS/HYPOTHESIS

Advanced glycation end-products (AGEs) may contribute to the development of diabetic neuropathy. In young adults with type 1 diabetes, we aimed to investigate the association between AGEs and cardiovascular autonomic neuropathy (CAN) and distal symmetric polyneuropathy (DSPN).

METHODS

This cross-sectional study comprised 151 young adults. CAN was assessed by cardiovascular autonomic reflex tests; lying-to-standing test, deep breathing test (E/I), Valsalva manoeuvre, and heart rate variability indices; and the mean square of the sum of the squares of differences between consecutive R-R intervals and standard deviation of normal-to-normal intervals (SDNN), high- (HF) and low-frequency (LF) power, total frequency power, and the LF/HF ratio. DSPN was assessed by light touch, pain and vibration perception threshold (VPT), neuropathy questionnaires, and objective measures. AGEs were analysed in four groups using z-scores adjusted for relevant confounders and multiple testing: i) "glycolytic dysfunction", ii) "lipid peroxidation", iii) "oxidative stress", and iv) "glucotoxicity".

RESULTS

A higher z-score of "glycolytic dysfunction" was associated with higher VPT (4.14% (95% CI 1.31; 7.04), p = 0.004) and E/I (0.03% (95% CI 0.01; 0.05), p = 0.005), "lipid peroxidation" was associated with higher LF/HF ratio (37.72% (95% CI 1.12; 87.57), p = 0.044), and "glucotoxicity" was associated with lower SDNN (-4.20% (95% CI -8.1416; -0.0896), p = 0.047). No significance remained after adjustment for multiple testing.

CONCLUSIONS/INTERPRETATIONS

In young adults with type 1 diabetes, increased levels of AGEs involving different metabolic pathways were associated with several measures of CAN and DSPN, suggesting that AGEs may play a diverse role in the pathogeneses of diabetic neuropathy.

Cardiovascular Autonomic Neuropathy in Type 1 Diabetes Is Associated With Disturbances in TCA, Lipid, and Glucose Metabolism

INTRODUCTION

Diabetic cardiovascular autonomic neuropathy (CAN) is associated with increased mortality and morbidity. To explore metabolic mechanisms associated with CAN we investigated associations between serum metabolites and CAN in persons with type 1 diabetes (T1D).

MATERIALS AND METHODS

Cardiovascular reflex tests (CARTs) (heart rate response to: deep breathing; lying-to-standing test; and the Valsalva maneuver) were used to diagnose CAN in 302 persons with T1D. More than one pathological CARTs defined the CAN diagnosis. Serum metabolomics and lipidomic profiles were analyzed with two complementary non-targeted mass-spectrometry methods. Cross-sectional associations between metabolites and CAN were assessed by linear regression models adjusted for relevant confounders.

RESULTS

Participants were median (IQR) aged 55(49, 63) years, 48% males with diabetes duration 39(32, 47) years, HbA_1c 63(55,69) mmol/mol and 34% had CAN. A total of 75 metabolites and 106 lipids were analyzed. In crude models, the CAN diagnosis was associated with higher levels of hydroxy fatty acids (2,4- and 3,4-dihydroxybutanoic acids, 4-deoxytetronic acid), creatinine, sugar derivates (ribitol, ribonic acid, myo-inositol), citric acid, glycerol, phenols, phosphatidylcholines and lower levels of free fatty acids and the amino acid methionine (p<0.05). Upon adjustment, positive associations with the CAN diagnoses were retained for hydroxy fatty acids, tricarboxylic acid (TCA) cycle-based sugar derivates, citric acid, and phenols (P<0.05).

CONCLUSION

Metabolic pathways, including the TCA cycle, hydroxy fatty acids, phosphatidylcholines and sugar derivatives are associated with the CAN diagnosis in T1D. These pathway may be part of the pathogeneses leading to CAN and may be modifiable risk factors for the complication.

Heart Rate and Heart Rate Variability Changes Are Not Related to Future Cardiovascular Disease and Death in People With and Without Dysglycemia: A Downfall of Risk Markers? The Whitehall II Cohort Study

OBJECTIVE

Higher resting heart rate (rHR) and lower heart rate variability (HRV) are associated with increased risk of cardiovascular disease (CVD) and all-cause mortality in people with and without diabetes. It is unknown whether temporal changes in rHR and HRV may contribute to this risk. We investigated associations between 5-year changes in rHR and HRV and risk of future CVD and death, taking into account participants' baseline glycemic state.

RESEARCH DESIGN AND METHODS

In this prospective, population-based cohort study we investigated 4,611 CVD-free civil servants (mean [SD] age, 60 [5.9] years; 70% men). We measured rHR and/or six indices of HRV. Associations of 5-year change in 5-min rHR and HRV with fatal and nonfatal CVD and all-cause mortality or the composite of the two were assessed, with adjustments made for relevant confounders. Effect modification by glycemic state was tested.

RESULTS

At baseline, 63% of participants were normoglycemic, 29% had prediabetes, and 8% had diabetes. During a median (interquartile range) follow-up of 11.9 (11.4; 12.3) years, 298 participants (6.5%) experienced a CVD event and 279 (6.1%) died of non-CVD-related causes. We found no association between 5-year changes in rHR and HRV and future events. Only baseline rHR was associated with all-cause mortality. A 10 bpm-higher baseline HR level was associated with an 11.4% higher rate of all-cause mortality (95% CI 1.0-22.9%; P = 0.032). Glycemic state did not modify associations.

CONCLUSIONS

Changes in rHR and HRV and possibly also baseline values of these measures are not associated with future CVD or death in people with or without dysglycemia.

The Association Between Cardiovascular Autonomic Function and Changes in Kidney and Myocardial Function in Type 2 Diabetes and Healthy Controls

BACKGROUND

The mechanisms linking cardiovascular autonomic neuropathy, diabetic kidney disease and cardiovascular mortality in type 2 diabetes are widely unknown. We investigated the relationship between baseline cardiovascular autonomic function and changes in kidney and myocardial function over six years in patients with type 2 diabetes and healthy controls.

METHODS

Post-hoc analysis of a cohort study in 24 patients with type 2 diabetes and 18 healthy controls. Baseline determinants were cardiovascular autonomic reflex tests (heart rate response to: standing (30:15); deep breathing (E:I); and the Valsalva test) and time- and frequency-domain heart rate variability indices. Outcomes were changes in estimated glomerular filtration rate (eGFR), albuminuria, myocardial flow reserve (MFR) measured by cardiac ⁸²Rb Positron emission tomography computed tomography (PET/CT), and coronary artery calcium score (CACS).

RESULTS

Mean age at inclusion was 61 ± 10 years and 36% were female. Mean follow up time was 6 ± 0 years. A lower response in heart rate to the Valsalva test (corresponding to weaker autonomic function) was associated with a larger decline in eGFR (p=0.04), but not significantly after adjustment for sex, baseline age, smoking status, systolic blood pressure, heart rate, HbA_1c, body mass index and baseline eGFR (p=0.12). A higher baseline response in heart rate to standing (30:15) was associated with a larger decline in myocardial flow reserve in the unadjusted analysis (p=0.02) and after adjustment (p=0.02). A higher response in heart rate to the Valsalva maneuver was associated with a larger increase in CACS (p = 0.02), but the association became insignificant after adjustment (p = 0.16).

CONCLUSION

A lower response in heart rate to the Valsalva test was associated with a larger decline in kidney function, indicating that autonomic dysfunction may predict future loss of kidney function. However, we did not find any association between lower values in cardiovascular autonomic function at baseline and a worsening in albuminuria, myocardial function, or atherosclerotic burden.

Hyperoxia improves autonomic function in individuals with long-duration type 1 diabetes and macroalbuminuria

AIM

Acute oxygen inhalation and slow deep breathing improve measures of autonomic function transiently in individuals with short-duration type 1 diabetes. Our aims were to examine these interventions and changes in autonomic function in individuals with long-duration type 1 diabetes and to explore interactions with the presence of macroalbuminuria or existing cardiovascular autonomic neuropathy.

METHODS

Individuals with type 1 diabetes (n = 54) were exposed to acute oxygen inhalation, slow deep breathing and a combination of both (hereafter 'the combination'). Primary outcomes were change in baroreflex sensitivity and heart rate variability. Associations between changes in outcomes were evaluated using mixed effects models.

RESULTS

Mean age ± sd was 60 ± 10 years and diabetes duration was 38 ± 14 years. Changes are presented as per cent difference from baseline with 95% confidence intervals. Acute oxygen inhalation, slow deep breathing and the combination increased baroreflex sensitivity by 21 (10, 34)%, 32 (13, 53)% and 30 (10, 54)%, respectively. Acute oxygen inhalation trended towards increasing heart rate variability 8 (-1, 17)% (P = 0.056), and slow deep breathing and the combination increased heart rate variability by 33 (18, 49)% and 44 (27, 64)% respectively. Macroalbuminuria or cardiovascular autonomic neuropathy did not modify results.

CONCLUSION

Autonomic function is improved transiently in individuals with long-duration type 1 diabetes and normoalbuminuria or macroalbuminuria by acute oxygen inhalation and slow deep breathing. There is a risk of survival bias. Autonomic dysfunction might be a reversible condition, and hypoxia might represent a target of intervention.

Epicardial adipose tissue predicts incident cardiovascular disease and mortality in patients with type 2 diabetes

Background

Cardiac fat is a cardiovascular biomarker but its importance in patients with type 2 diabetes is not clear. The aim was to evaluate the predictive potential of epicardial (EAT), pericardial (PAT) and total cardiac (CAT) fat in type 2 diabetes and elucidate sex differences.

Methods

EAT and PAT were measured by echocardiography in 1030 patients with type 2 diabetes. Follow-up was performed through national registries. The end-point was the composite of incident cardiovascular disease (CVD) and all-cause mortality. Analyses were unadjusted (model 1), adjusted for age and sex (model 2), plus systolic blood pressure, body mass index (BMI), low-density lipoprotein (LDL), smoking, diabetes duration and glycated hemoglobin (HbA_1c) (model 3).

Results

Median follow-up was 4.7 years and 248 patients (191 men vs. 57 women) experienced the composite end-point. Patients with high EAT (> median level) had increased risk of the composite end-point in model 1 [Hazard ratio (HR): 1.46 (1.13; 1.88), p = 0.004], model 2 [HR: 1.31 (1.01; 1.69), p = 0.038], and borderline in model 3 [HR: 1.32 (0.99; 1.77), p = 0.058]. For men, but not women, high EAT was associated with a 41% increased risk of CVD and mortality in model 3 (p = 0.041). Net reclassification index improved when high EAT was added to model 3 (19.6%, p = 0.035). PAT or CAT were not associated with the end-point.

Conclusion

High levels of EAT were associated with the composite of incident CVD and mortality in patients with type 2 diabetes, particularly in men, after adjusting for CVD risk factors. EAT modestly improved risk prediction over CVD risk factors.

Epicardial and pericardial adipose tissues are associated with reduced diastolic and systolic function in type 2 diabetes

The aim of this study was to investigate the association of epicardial (EAT) and pericardial (PAT) adipose tissues with myocardial function in type 2 diabetes (T2D). EAT and PAT were measured by ultrasound in 770 patients with T2D and 234 age- and sex-matched non-diabetic controls. Echocardiography was performed, including tissue Doppler imaging and 2D speckle tracking. Patients with T2D versus controls had increased EAT (4.6 ± 1.8 mm vs. 3.4 ± 1.2 mm, P < 0.0001) and PAT (6.3 ± 2.8 mm vs. 5.3 ± 2.4 mm, P < 0.0001). EAT and PAT were associated with structural cardiac measures both in T2D patients and controls (all P < 0.043), but only in T2D patients with functional measures: PAT was associated with impaired global longitudinal strain [beta coefficient (SE)] [0.11% (0.04), P = 0.002], while EAT was associated with reduced diastolic function by lateral early diastolic myocardial velocity (e'_lat ) [-0.31 (0.05) cm/s, P = 0.001], mitral inflow velocities: peak early (E)/peak atrial (A) ratio [-0.02 (0.01), P = 0.001] and lateral E/e'_lat [0.36 (0.10), P < 0.001]. However, no interaction was found between diabetes status and PAT (P = 0.75) or EAT (P = 0.45). Adipose tissue in intimate relation to the myocardium is higher in patients with T2D versus controls and is associated with functional myocardial measures in T2D.

Efficacy of Long-Term Remote Ischemic Conditioning on Vascular and Neuronal Function in Type 2 Diabetes Patients With Peripheral Arterial Disease

Background

Peripheral artery disease is a major socioeconomic challenge in the diabetes mellitus community and non‐surgical treatment options are limited. As remote ischemic conditioning (RIC) improves vascular function and attenuates ischemia‐induced tissue damage, we investigated the efficacy of RIC on vascular and neuronal function in type 2 diabetes mellitus patients with peripheral artery disease.

Methods and Results

We enrolled 36 type 2 diabetes mellitus patients with moderately reduced toe pressure (40–70 mm Hg) in a randomized sham‐controlled double‐masked trial. Patients were allocated to 12 weeks once daily upper arm cuff‐based treatment of either RIC treatment (4 cycles of 5‐minute ischemia followed by 5‐minute reperfusion) or similar sham‐device treatment. Primary outcome was transcutaneous tissue oxygen tension of the instep of the feet. Secondary outcomes were aortic pulse wave velocity, toe pressure and toe‐brachial index. Tertiary outcomes were markers of peripheral and autonomic nerve function. We enrolled 36 patients (83% men). Patients had a mean (SD) age of 70.7 years (6.8), diabetes mellitus duration of 18.4 years (8.3), HbA1c (gycated hemoglobin) of 59.7 mmol/mol (11.2). Eighty percent had peripheral symmetrical neuropathy. The mean difference in change of transcutaneous tissue oxygen tension from baseline between the RIC and sham‐treated groups was −0.03 mm Hg ([95% CI −0.1; 0.04], P=0.438). RIC did not elicit any change in additional outcomes. Three patients experienced transient skin petechiae in the treated arm.

Conclusions

Long‐term repeated remote ischemic conditioning treatment have no effect on tissue oxygenation, vascular or neuronal function in patients with type 2 diabetes mellitus and moderate peripheral artery disease.

Clinical Trial Registration

URL: http://www.ClinicalTrials.gov. Unique identifier: NCT02749942.

Cardiovascular autonomic neuropathy and bone metabolism in Type 1 diabetes

AIM

To investigate the association between cardiovascular autonomic neuropathy and bone metabolism in people with Type 1 diabetes.

METHODS

We assessed cardiovascular autonomic neuropathy in 329 people with Type 1 diabetes according to heart rate response to deep breathing, to standing and to the Valsalva manoeuvre, and 2-min resting heart rate. More than one pathological non-resting test was defined as cardiovascular autonomic neuropathy. Bone mineral density of the femoral neck (BMDfn) was assessed by dual energy X-ray absorptiometry. Serum parathyroid hormone levels and other bone markers were measured.

RESULTS

The mean (sd) age of the participants was 55.6 (9.4) years, 52% were men, and the mean (sd) diabetes duration was 40 (8.9) years, HbA_1c 62 (9) mmol/mol and estimated GFR 78 (26) ml/min/1.73m² . In all, 36% had cardiovascular autonomic neuropathy. Participants with cardiovascular autonomic neuropathy had 4.2% (95% CI -8.0 to -0.2; P=0.038) lower BMDfn and 33.6% (95% CI 14.3 to 53.8; P=0.0002) higher parathyroid hormone levels compared with participants without cardiovascular autonomic neuropathy in adjusted models. Higher resting heart rate remained associated with higher parathyroid hormone level and lower BMDfn after additional adjustment for eGFR (P<0.0001 and P = 0.042, respectively).

CONCLUSIONS

The presence of cardiovascular autonomic neuropathy was associated with reduced BMDfn and increased levels of parathyroid hormone. Kidney function may either confound or mediate these findings. Cardiovascular autonomic neuropathy could be associated with increased risk of osteoporosis in Type 1 diabetes. Whether cardiovascular autonomic neuropathy directly affects bone metabolism detrimentally or if this association is mediated via decreased kidney function should be investigated further.

The iPSYCH2012 case-cohort sample: new directions for unravelling genetic and environmental architectures of severe mental disorders

The Integrative Psychiatric Research (iPSYCH) consortium has established a large Danish population-based Case-Cohort sample (iPSYCH2012) aimed at unravelling the genetic and environmental architecture of severe mental disorders. The iPSYCH2012 sample is nested within the entire Danish population born between 1981 and 2005, including 1 472 762 persons. This paper introduces the iPSYCH2012 sample and outlines key future research directions. Cases were identified as persons with schizophrenia (N=3540), autism (N=16 146), attention-deficit/hyperactivity disorder (N=18 726) and affective disorder (N=26 380), of which 1928 had bipolar affective disorder. Controls were randomly sampled individuals (N=30 000). Within the sample of 86 189 individuals, a total of 57 377 individuals had at least one major mental disorder. DNA was extracted from the neonatal dried blood spot samples obtained from the Danish Neonatal Screening Biobank and genotyped using the Illumina PsychChip. Genotyping was successful for 90% of the sample. The assessments of exome sequencing, methylation profiling, metabolome profiling, vitamin-D, inflammatory and neurotrophic factors are in progress. For each individual, the iPSYCH2012 sample also includes longitudinal information on health, prescribed medicine, social and socioeconomic information, and analogous information among relatives. To the best of our knowledge, the iPSYCH2012 sample is the largest and most comprehensive data source for the combined study of genetic and environmental aetiologies of severe mental disorders.

Differential DNA methylation at birth associated with mental disorder in individuals with 22q11.2 deletion syndrome

Individuals with 22q11.2 deletion syndrome (DS) have an increased risk of comorbid mental disorders including schizophrenia, attention deficit hyperactivity disorder, depression, as well as intellectual disability. Although most 22q11.2 deletion carriers have the long 3-Mb form of the hemizygous deletion, there remains a large variation in the development and progression of psychiatric disorders, which suggests that alternative factors contribute to the pathogenesis. In this study we investigated whether neonatal DNA methylation signatures in individuals with the 22q11.2 deletion associate with mental disorder later in life. DNA methylation was measured genome-wide from neonatal dried blood spots in a cohort of 164 individuals with 22q11.2DS, including 48 individuals diagnosed with a psychiatric disorder. Among several CpG sites with P-value<10-6, we identified cg23546855 (P-value=2.15 × 10-7) mapping to STK32C to be associated with a later psychiatric diagnosis. Pathway analysis of the top findings resulted in the identification of several Gene Ontology pathways to be significantly enriched (P-value<0.05 after Benjamini-Hochberg correction); among them are the following: neurogenesis, neuron development, neuron projection development, astrocyte development, axonogenesis and axon guidance. In addition, we identified differentially methylated CpG sites in LRP2BP (P-value=5.37 × 10-8) to be associated with intellectual disability (F70-79), in TOP1 (P-value=1.86 × 10-7) with behavioral disorders (F90-98), in NOSIP (P-value=5.12 × 10-8) with disorders of psychological development (F80-89) and in SEMA4B (P-value=4.02 × 10-7) with schizophrenia spectrum disorders (F20-29). In conclusion, our study suggests an association of DNA methylation differences at birth with development of mental disorder later in life in 22q11.2DS individuals.

Epicardial, pericardial and total cardiac fat and cardiovascular disease in type 2 diabetic patients with elevated urinary albumin excretion rate

Background We evaluated the association of cardiac adipose tissue including epicardial adipose tissue and pericardial adipose tissue with incident cardiovascular disease and mortality, coronary artery calcium, carotid intima media thickness and inflammatory markers. Design A prospective study of 200 patients with type 2 diabetes and elevated urinary albumin excretion rate (UAER). Methods Cardiac adipose tissue was measured from baseline echocardiography. The composite endpoint comprised incident cardiovascular disease and all-cause mortality. Coronary artery calcium, carotid intima media thickness and inflammatory markers were measured at baseline. Cardiac adipose tissue was investigated as continuous and binary variable. Analyses were performed unadjusted (model 1), and adjusted for age, sex (model 2), body mass index, low-density lipoprotein cholesterol, smoking, glycated haemoglobin, and systolic blood pressure (model 3). Results Patients were followed-up after 6.1 years for non-fatal cardiovascular disease ( n = 29) or mortality ( n = 23). Cardiac adipose tissue ( p = 0.049) and epicardial adipose tissue ( p = 0.029) were associated with cardiovascular disease and mortality in model 1. When split by the median, patients with high cardiac adipose tissue had a higher risk of cardiovascular disease and mortality than patients with low cardiac adipose tissue in unadjusted (hazard ratio 1.9, confidence interval: 1.1; 3.4, p = 0.027) and adjusted (hazard ratio 2.0, confidence interval: 1.1; 3.7, p = 0.017) models. Cardiac adipose tissue ( p =  0.033) was associated with baseline coronary artery calcium (model 1) and interleukin-8 (models 1-3, all p < 0.039). Conclusions In type 2 diabetes patients without coronary artery disease, high cardiac adipose tissue levels were associated with increased risk of incident cardiovascular disease or all-cause mortality even after accounting for traditional cardiovascular disease risk factors. High cardiac adipose tissue amounts were associated with subclinical atherosclerosis (coronary artery calcium) and with the pro-atherogenic inflammatory marker interleukin-8.

High and low vitamin D level is associated with cardiovascular autonomic neuropathy in people with Type 1 and Type 2 diabetes

AIM

To investigate the possible association between vitamin D deficiency and cardiovascular autonomic neuropathy in people with diabetes.

METHODS

A total of 113 people with Type 1 or Type 2 diabetes [mean (interquartile range) diabetes duration 22.0 (12-31) years, mean (sd) age 56.2 (13.0) years, 58% men] underwent vitamin D (D2 and D3) assessment, and were screened for cardiovascular autonomic neuropathy using three cardiovascular reflex tests [heart rate response to deep breathing (E/I ratio), to standing (30/15 ratio) and to the Valsalva manoeuvre] and assessment of 5-min resting heart rate and heart rate variability indices.

RESULTS

We found an inverse U-shaped association between serum vitamin D level and E/I ratio, 30/15 ratio and three heart rate variability indices (P < 0.05). Vitamin D level was non-linearly associated with cardiovascular autonomic neuropathy diagnosis (P < 0.05 adjusted for age and sex). Linear regression models showed that an increase in vitamin D level from 25 to 50 nmol/l was associated with an increase of 3.9% (95% CI 0.1;7.9) in E/I ratio and 4.8% (95% CI 4.7;9.3) in 30/15 ratio. Conversely, an increase from 125 to 150 nmol/l in vitamin D level was associated with a decrease of 2.6% (95% CI -5.8;0.1) and 4.1% (95% CI -5.8;-0.5) in the respective outcome measures.

CONCLUSIONS

High and low vitamin D levels were associated with cardiovascular autonomic neuropathy in people with diabetes. Future studies should explore this association and the efficacy of treating dysvitaminosis D to prevent cardiovascular autonomic neuropathy.

Vitamin B12 deficiency is associated with cardiovascular autonomic neuropathy in patients with type 2 diabetes

AIMS

Vitamin B12 deficiency could be associated with cardiovascular autonomic neuropathy (CAN) in diabetes patients. We aim to investigate the association between serum levels of vitamin B12 and CAN in type 2 diabetes patients.

METHODS

469 ambulatory type 2 diabetes patients (mean diabetes duration 10.0years (IQR 5.0;17.0), mean age 59.0years (SD 11.6), 63% men, mean B12 289.0pmol/l (IQR 217;390)) were screened for CAN using three cardiovascular reflex tests, five minute resting heart rate (5min RHR) and heart rate variability indices.

RESULTS

Serum levels of vitamin B12 were significantly lower in patients treated with metformin and/or proton pump inhibitors (PPIs) compared with patients not treated (p<0.001). A 25pmol/l higher level of vitamin B12 was associated with an odds ratio of the CAN diagnosis of 0.94 (95% CI 0.88; 1.00, p=0.034), an increase in E/I-ratio of 0.21% (95% CI 0.01; 0.43, p=0.038), and a decrease in 5min RHR of 0.25 beats per minute (95% CI -0.47; -0.03, p=0.025).

CONCLUSION

Vitamin B12 may be inversely associated with CAN in patients with type 2 diabetes. Confirmatory studies investigating a causal role of vitamin B12 for the development of diabetic CAN are warranted.

High-throughput immuno-profiling of mamba (Dendroaspis) venom toxin epitopes using high-density peptide microarrays

Snakebite envenoming is a serious condition requiring medical attention and administration of antivenom. Current antivenoms are antibody preparations obtained from the plasma of animals immunised with whole venom(s) and contain antibodies against snake venom toxins, but also against other antigens. In order to better understand the molecular interactions between antivenom antibodies and epitopes on snake venom toxins, a high-throughput immuno-profiling study on all manually curated toxins from Dendroaspis species and selected African Naja species was performed based on custom-made high-density peptide microarrays displaying linear toxin fragments. By detection of binding for three different antivenoms and performing an alanine scan, linear elements of epitopes and the positions important for binding were identified. A strong tendency of antivenom antibodies recognizing and binding to epitopes at the functional sites of toxins was observed. With these results, high-density peptide microarray technology is for the first time introduced in the field of toxinology and molecular details of the evolution of antibody-toxin interactions based on molecular recognition of distinctive toxic motifs are elucidated.

Making sense of a new technology in clinical practice: a qualitative study of patient and physician perspectives

BACKGROUND

The number of new technologies for risk assessment available in health care is increasing. These technologies are intended to contribute to both improved care practices and improved patient outcomes. To do so however, there is a need to study how new technologies are understood and interpreted by users in clinical practice. The objective of this study was to explore patient and physician perspectives on the usefulness of a new technology to detect Cardiovascular Autonomic Neuropathy (CAN) in a specialist diabetes clinic. The technology is a handheld device that measures resting heart rate and conducts three cardiac autonomic reflex tests to evaluate heart rate variability.

METHODS

The study relied on three sources of data: observations of medical consultations where results of the CAN test were reported (n = 8); interviews with patients who had received the CAN test (n = 19); and interviews with physicians who reported results of the CAN test (n = 9). Data were collected at the specialist diabetes clinic between November 2013 and January 2014. Data were analysed using the concept of technological frames which is used to assess how physicians and patients understand and interpret the new technology.

RESULTS

Physicians generally found it difficult to communicate test results to patients in terms that patients could understand and to translate results into meaningful implications for the treatment of patients. Results of the study indicate that patients did not recall having done the CAN test nor recall receiving the results. Furthermore, patients were generally unsure about the purpose of the CAN test and the implications of the results.

DISCUSSION

Involving patients and physicians is essential when a new technology is introduced in clinical practice. This particularly includes the interpretation and communication processes related to its use.

CONCLUSIONS

The integration of a new risk assessment technology into clinical practice can be accompanied by several challenges. It is suggested that more information about the CAN test be provided to patients and that a dialogue-based approach be used when communicating test results to patients in order to best support the use of the technology in clinical practice.

High-throughput sequencing enhanced phage display enables the identification of patient-specific epitope motifs in serum

Phage display is a prominent screening technique with a multitude of applications including therapeutic antibody development and mapping of antigen epitopes. In this study, phages were selected based on their interaction with patient serum and exhaustively characterised by high-throughput sequencing. A bioinformatics approach was developed in order to identify peptide motifs of interest based on clustering and contrasting to control samples. Comparison of patient and control samples confirmed a major issue in phage display, namely the selection of unspecific peptides. The potential of the bioinformatic approach was demonstrated by identifying epitopes of a prominent peanut allergen, Ara h 1, in sera from patients with severe peanut allergy. The identified epitopes were confirmed by high-density peptide micro-arrays. The present study demonstrates that high-throughput sequencing can empower phage display by (i) enabling the analysis of complex biological samples, (ii) circumventing the traditional laborious picking and functional testing of individual phage clones and (iii) reducing the number of selection rounds.

The role of serum methylglyoxal on diabetic peripheral and cardiovascular autonomic neuropathy: the ADDITION Denmark study

AIMS

Cardiovascular autonomic neuropathy and diabetic peripheral neuropathy are common diabetic complications and independent predictors of cardiovascular disease. The glucose metabolite methylglyoxal has been suggested to play a causal role in the pathogeneses of diabetic peripheral neuropathy and possibly diabetic cardiovascular autonomic neuropathy. The aim of this study was to investigate the cross-sectional association between serum methylglyoxal and diabetic peripheral neuropathy and cardiovascular autonomic neuropathy in a subset of patients in the ADDITION-Denmark study with short-term screen-detected Type 2 diabetes (duration ~ 5.8 years).

METHODS

The patients were well controlled with regard to HbA(1c), lipids and blood pressure. Cardiovascular autonomic neuropathy was assessed by measures of resting heart rate variability and cardiovascular autonomic reflex tests. Diabetic peripheral neuropathy was assessed by vibration detection threshold (n = 319), 10 g monofilament (n = 543) and the Michigan Neuropathy Screening Instrument questionnaire (n = 966). Painful diabetic neuropathy was assessed using the Brief Pain Inventory short form (n = 882).

RESULTS

No associations between methylglyoxal and cardiovascular autonomic reflex tests or any measures of diabetic peripheral neuropathy or painful diabetic neuropathy were observed. However, a positive association between methylglyoxal and several heart rate variability indices was observed, although these associations were not statistically significant when corrected for multiple testing.

CONCLUSION

Serum methylglyoxal is not associated with cardiovascular autonomic neuropathy, diabetic peripheral neuropathy or painful diabetic neuropathy in this cohort of well-treated patients with short-term diabetes.

Immunomodulatory effects of helminths and protozoa in multiple sclerosis and experimental autoimmune encephalomyelitis

Multiple sclerosis is a chronic inflammatory CNS disease, which affects about 1 in 1000 individuals in the western world. During the last couple of decades, epidemiological data have accumulated, pointing towards increases in incidence. This has been suggested to be linked to the relatively high hygiene standards that exist in the western world, with reduced exposure to various pathogens, including parasites, as a consequence. Parasites are known to employ various immunomodulatory and anti-inflammatory strategies, which enable them to evade destruction by the immune system. This is most likely one of the reasons for the disease-dampening effects, reported in numerous studies investigating parasite infections and autoimmunity. This review will focus on recent advances in the field of parasites as beneficial immunomodulators, in multiple sclerosis and the animal model experimental autoimmune encephalomyelitis.

Diesel exhaust particles induce endothelial dysfunction in apoE−/− mice

BACKGROUND

Particulate air pollution can aggravate cardiovascular disease by mechanisms suggested to involve translocation of particles to the bloodstream and impairment of endothelial function, possibly dependent on present atherosclerosis.

AIM

We investigated the effects of exposure to diesel exhaust particles (DEP) in vivo and ex vivo on vasomotor functions in aorta from apoE(-/-) mice with slight atherosclerosis and from normal apoE(+/+) mice.

METHODS

DEP 0, 0.5 or 5 mg/kg bodyweight in saline was administered i.p. The mice were sacrificed 1 h later and aorta ring segments were mounted on wire myographs. Segments from unexposed mice were also incubated ex vivo with 0, 10 and 100 microg DEP/ml before measurement of vasomotor functions.

RESULTS

Exposure to 0.5 mg/kg DEP in vivo caused a decrease in the endothelium-dependent acetylcholine elicited vasorelaxation in apoE(-/-) mice, whereas the response was enhanced in apoE(+/+) mice. No significant change was observed after administration of 5 mg/kg DEP. In vivo DEP exposure did not affect constriction induced by K(+) or phenylephrine. In vitro exposure to 100 microg DEP/ml enhanced acetylcholine-induced relaxation and attenuated phenylephrine-induced constriction. Vasodilation induced by sodium nitroprusside was not affected by any DEP exposure.

CONCLUSION

Exposure to DEP has acute effect on vascular functions. Endothelial dysfunction possibly due to decreased NO production as suggested by decreased acetylcholine-induced vasorelaxation and unchanged sodium nitroprusside response can be induced by DEP in vivo only in vessels of mice with some atherosclerosis.

[Attitudes towards medical abortion among gynecologic patients]

This study describes and discusses the attitudes regarding use of medical abortion among patients at a department of gynaecology. The patients received a leaflet about medical abortion and subsequently answered a questionnaire. If given the choice, half of the patients would prefer medical abortion. The answer was independent of age, marital status and choice of contraceptive. The study provides information on women's priorities regarding abortion and justifies the introduction of medical abortion in Denmark.

Direct neural induction and selective inhibition of mesoderm and epidermis inducers by Xnr3

During gastrulation in amphibians, secreted factors from Spemann's organizer act on dorsal ectoderm to induce the central nervous system. A number of secreted factors produced by Spemann's organizer have recently been identified. The TGFbeta family member Xnr3 is similar in amino acid sequence to the mouse factor nodal and is expressed in a restricted group of cells in the superficial layer of Spemann's organizer. Xnr3, unlike the related factors nodal, Xnr1 and Xnr2, lacks mesoderm-inducing activity. We report here that Xnr3 can directly induce neural tissue in Xenopus ectoderm explants (animal caps). Injection of animal caps with either Xnr3 RNA or plasmids induces the expression of the pan-neural genes NCAM and nrp1, as well as the anterior neural marker Cpl1. A growing body of evidence suggests that neural induction in Xenopus proceeds as the default in the absence of epidermis inducers. The best candidates for the endogenous epidermis inducers are BMP-4 and BMP-7. The neural inducing activity of Xnr3 can be inhibited by overexpression of BMP-4, as has been observed with the neural inducers noggin, chordin and follistatin. Furthermore, Xnr3 can block mesoderm induction by BMP-4 and activin, but not by Xnr2. The structural basis underlying the divergent activities of Xnr2 and Xnr3 was analyzed using site-directed mutagenesis. Mutations introduced to the conserved cysteine residues characteristic of the TGFbeta family were found to inactivate Xnr2, but not Xnr3. The most unique feature of Xnr3 is the absence of a conserved cysteine at the C terminus of the protein. This feature distinguishes Xnr3 from other TGFbeta family members, including Xnr2. However, we observed that changing the C terminus of Xnr3 to more closely resemble other TGFbeta family members did not significantly alter its activity, suggesting that other structural features of Xnr3 distinguish its biological activity from Xnr2.

Disposition of radiolabeled flumequine in rat and dog

Single doses of 14C-flumequine (a urinary tract antibacterial) were given to rats and dogs. Unchanged drug accounted for more than 80% of the drug in plasma of rats but only 25-50% in plasma of dogs. Although only a small percentage of the dose was excreted in the urine of each species as unchanged drug, a wide differentiation in the urinary metabolite profiles was observed. No significant tissue retention was seen in rats or dogs.

Plasma and urine levels of flumequine and 7-hydroxyflumequine following single and multiple oral dosing

Plasma and urine concentrations of flumequine and its microbiologically active metabolite, 7-hydroxyflumequine, were determined in healthy subjects following single oral doses of 400, 800, and 1200 mg of flumequine, and following multiple oral doses of 800 mg given four-times daily. After administration of the single oral doses, antimicrobial levels in plasma and urine were rapidly attained, were proportional to the dose given, and were maintained for 12 to 24 h. The multiple dosage regimen yielded antimicrobial levels in both plasma and urine that were several-fold higher than the levels required to inhibit the growth of susceptible bacteria. Following both the single and multiple dose regimens, the plasma elimination half-life of flumequine was about 7h. The excretion of 7-hydroxyflumequine in the urine contributed significantly to the antimicrobial activity.

Determination of flumequine and a hydroxy metabolite in biological fluids by high-pressure liquid chromatographic, fluorometric, and microbiological methods

A sensitive and specific high-pressure liquid chromatographic method is described for the determination of the antibacterial drug flumequine and a major metabolite, 7-hydroxyflumequine, in human plasma and urine. The assay was linear over a concentration range of 1 to 120 micrograms/ml for both compounds. This method is compared with fluorometric and microbiological assays for flumequine. These latter methods did not differentiate between flumequine and any fluorescent or antimicrobiologically active metabolites. However, because essentially all drug in the plasma was found to be flumequine in radiolabeled studies, levels of unchanged drug in the plasma could be quantitated by either high-pressure liquid chromatography or fluorometry. Although only high-pressure liquid chromatography was able to specifically measure flumequine in the urine, the antimicrobial activity of the urine, which is more therapeutically relevant due to antimicrobially active metabolites, could be quantitated by either the fluorometric or the microbiological assay.

Quantitative determination of nefopam in human plasma, saliva and cerebrospinal fluid by gas-liquid chromatography using a nitrogen-selective detector

A sensitive and selective gas-liquid chromatographic method for the determination of nefopam in human plasma, saliva and cerebrospinal fluid has been developed. The method includes the selective extraction of nefopam and the internal standard, orphenadrine, from biological fluids by a double extraction procedure. The extracted nefopam and internal standard are analyzed by a gas chromatograph equipped with a 3% OV-17 glass column and a nitrogen-phosphorus flame ionization detector (NPFID) operated in the nitrogen mode. The detector provides the needed high sensitivity and also selectivity due to the inherent characteristics of NPFID to discriminate against non-nitrogen containing materials. Five nanograms nefopam per ml plasma or saliva are routinely quantitated with a 1-ml sample or as little as 2 ng per ml cerebrospinal fluid with a 3-ml sample. The intra-day reproducibilities, expressed as the relative standard deviation, are 5, 2 and 3% at 10, 35 and 75 ng/ml plasma levels, respectively. The accuracies expressed by relative error at these levels are 12, -4 and -2%, respectively. The inter-day reproducibility is demonstrated by the small relative standard, deviation, 2%, of the slopes from ten plasma standard curves run on ten different days. In various clinical studies in humans the method has been successfully applied to the study of single-dose pharmacokinetics of nefopam and the monitoring of nefopam concentrations in saliva and cerebrospinal fluids.

GLC determination of nanogram quantities of a new analgesic, nefopam, in human plasma

A sensitive and specific method was developed for the quantitative GLC determination of plasma nefopam levels. The method includes a multiple-step solvent extraction of the analgesic drug and the internal mass standard, orphenadrine. The accuracy, expressed as the relative error, was--4,6,6, and 4% at 20, 40, 70, and 130 ng/ml, respectively. The precision, expressed as relative standard deviation, was 17, 7, 3, and 5% at these same concentrations, respectively. Quantitation of nefopam in human plasma is possible down to 20 ng/ml with a 2-ml plasma sample; the sensitivity can be increased by using larger plasma samples. The methods was applied successfully to the determination of plasma nefopam levels in humans in pharmacokinetic studies at therapeutic doses.