Structural changes in Schwann cells and nerve fibres in type 1 diabetes: relationship with diabetic polyneuropathy.

AIMS/HYPOTHESIS: Our aim was to investigate structural changes of cutaneous Schwann cells (SCs), including nociceptive Schwann cells (nSCs) and axons, in individuals with diabetic polyneuropathy. We also aimed to investigate the relationship between these changes and peripheral neuropathic symptoms in type 1 diabetes. METHODS: Skin biopsies (3 mm) taken from carefully phenotyped participants with type 1 diabetes without polyneuropathy (T1D, n=25), type 1 diabetes with painless diabetic polyneuropathy (T1DPN, n=30) and type 1 diabetes with painful diabetic polyneuropathy (P-T1DPN, n=27), and from healthy control individuals (n=25) were immunostained with relevant antibodies to visualise SCs and nerve fibres. Stereological methods were used to quantify the expression of cutaneous SCs and nerve fibres. RESULTS: There was a difference in the number density of nSCs not abutting to nerve fibres between the groups (p=0.004) but not in the number density of nSCs abutting to nerve fibres, nor in solitary or total subepidermal SC soma number density. The overall dermal SC expression (measured by dermal SC area fraction and subepidermal SC process density) and peripheral nerve fibre expression (measured by intraepidermal nerve fibre density, dermal nerve fibre area fraction and subepidermal nerve fibre density) differed between the groups (all p<0.05): significant differences were seen in participants with T1DPN and P-T1DPN compared with those without diabetic polyneuropathy (healthy control and T1D groups) (all p<0.05). No difference was found between participants in the T1DPN and P-T1DPN group, nor between participants in the T1D and healthy control group (all p>0.05). Correlational analysis showed that cutaneous SC processes and nerve fibres were highly associated, and they were weakly negatively correlated with different neuropathy measures. CONCLUSIONS/INTERPRETATION: Cutaneous SC processes and nerves, but not SC soma, are degenerated and interdependent in individuals with diabetic polyneuropathy. However, an increase in structurally damaged nSCs was seen in individuals with diabetic polyneuropathy. Furthermore, dermal SC processes and nerve fibres correlate weakly with clinical measures of neuropathy and may play a partial role in the pathophysiology of diabetic polyneuropathy in type 1 diabetes.

In vivo molecular imaging of cardiac angiogenesis in persons with and without type 2 diabetes: A cross-sectional 68 Ga-RGD-PET study.

AIMS: To assess cardiac angiogenesis in type 2 diabetes by positron emission tomography (PET) tracer [68 Ga]Ga-NODAGA-E[(cRGDyK)]2 (68 Ga-RGD) imaging. METHODS: Cross-sectional study including 20 persons with type 2 diabetes and 10 non-diabetic controls (CONs). Primary prespecified outcome was difference in cardiac angiogenesis (cardiac 68 Ga-RGD mean target-to-background ratio [TBRmean ]) between type 2 diabetes and CONs. Secondary outcome was to investigate associations between cardiac angiogenesis and kidney function and other risk factors. RESULTS: Participants with type 2 diabetes had a mean ± SD age of 61 ± 9 years, 30% were women, median (IQR) diabetes duration of 11 (6-19) years and 3 (15%) had a history of cardiovascular disease. The CONs had comparable age and sex distribution to the participants with type 2 diabetes, and none had a history of coronary artery disease. Myocardial flow reserve was lower in type 2 diabetes (2.7 ± 0.6) compared with CONs (3.4 ± 1.2) ( p  = 0.03) and coronary artery calcium score was higher (562 [142-905] vs. 1 [0-150] p  = 0.04). Cardiac 68 Ga-RGD TBRmean was similar in participants with type 2 diabetes (0.89 ± 0.09) and CONs (0.89 ± 0.10) ( p  = 0.92). Cardiac 68 Ga-RGD TBRmean was not associated with estimated glomerular filtration rate, urine albumin creatinine ratio, cardiovascular disease, coronary artery calcium score or baroreflex sensitivity, neither in pooled analyses nor in type 2 diabetes. CONCLUSIONS: Cardiac angiogenesis, evaluated with 68 Ga-RGD PET, was similar in type 2 diabetes and CONs. Cardiac angiogenesis was not associated with kidney function or other risk markers in pooled analyses or in analyses restricted to type 2 diabetes.

Relation of cardiac adipose tissue to coronary calcification and myocardial microvascular function in type 1 and type 2 diabetes.

BACKGROUND: Cardiac adipose tissue may have local paracrine effects on epicardial arteries and the underlying myocardium, promoting calcification and affecting myocardial microcirculation. We explored whether the total amount of cardiac adipose tissue was associated with coronary artery calcium score (CAC) and myocardial flow reserve in persons with type 1 or type 2 diabetes and healthy controls. METHODS: We studied three groups: (1) 30 controls, (2) 60 persons with type 1 diabetes and (3) 60 persons with type 2 diabetes. The three groups were matched for sex and age. The three groups derived from retrospective analysis of two clinical studies. All underwent cardiac 82Rb positron emission tomography/computed tomography (PET/CT) scanning. Cardiac adipose tissue volume (the sum of epicardial and pericardial fat), CAC, and myocardial flow reserve (ratio of pharmacological stress flow and rest flow) were evaluated using semiautomatic software. We applied linear regression to assess the association between cardiac adipose tissue, CAC and myocardial flow reserve. RESULTS: Mean (SD) cardiac adipose tissue volume was 99 (61) mL in the control group, 106 (78) mL in the type 1 diabetes group and 228 (97) mL in the type 2 diabetes group. Cardiac adipose tissue was positively associated with body mass index in all three groups (p ≤ 0.02). In the controls, cardiac adipose tissue was positively associated with CAC score (p = 0.008) and negatively associated with myocardial flow reserve (p = 0.005). However, cardiac adipose tissue was not associated with CAC or myocardial flow reserve in the groups including persons with type 1 or type 2 diabetes (p ≥ 0.50). CONCLUSIONS: In contrast to what was found in healthy controls, we could not establish a relation between cardiac adipose tissue and coronary calcification or myocardial microvascular function in person with type 1 or type 2 diabetes. The role of cardiac adipose tissue in cardiovascular disease in diabetes remains unclear.

Metformin may adversely affect orthostatic blood pressure recovery in patients with type 2 diabetes: substudy from the placebo-controlled Copenhagen Insulin and Metformin Therapy (CIMT) trial.

BACKGROUND: Metformin has been shown to have both neuroprotective and neurodegenerative effects. The aim of this study was to investigate the effect of metformin in combination with insulin on cardiovascular autonomic neuropathy (CAN) and distal peripheral neuropathy (DPN) in individuals with type 2 diabetes (T2DM). METHODS: The study is a sub-study of the CIMT trial, a randomized placebo-controlled trial with a 2 × 3 factorial design, where 412 patients with T2DM were randomized to 18 months of metformin or placebo in addition to open-labelled insulin. Outcomes were measures of CAN: Changes in heart rate response to deep breathing (beat-to-beat), orthostatic blood pressure (OBP) and heart rate and vibration detection threshold (VDT) as a marker DPN. Serum levels of vitamin B12 and methyl malonic acid (MMA) were analysed. RESULTS: After 18 months early drop in OBP (30 s after standing) was increased in the metformin group compared to placebo: systolic blood pressure drop increased by 3.4 mmHg (95% CI 0.6; 6.2, p = 0.02) and diastolic blood pressure drop increased by 1.3 mmHg (95% CI 0.3; 2.6, p = 0.045) compared to placebo. Beat-to-beat variation decreased in the metformin group by 1.1 beats per minute (95% CI - 2.4; 0.2, p = 0.10). Metformin treatment did not affect VDT group difference - 0.33 V (95% CI - 1.99; 1.33, p = 0.39) or other outcomes. Changes in B12, MMA and HbA1c did not confound the associations. CONCLUSIONS: Eighteen months of metformin treatment in combination with insulin compared with insulin alone increased early drop in OBP indicating an adverse effect of metformin on CAN independent of vitamin B12, MMA HbA1c. Trial registration The protocol was approved by the Regional Committee on Biomedical Research Ethics (H-D-2007-112), the Danish Medicines Agency and registered with ClinicalTrials.gov (NCT00657943).

Liraglutide treatment reduced interleukin-6 in adults with type 1 diabetes but did not improve established autonomic or polyneuropathy.

AIMS: Type 1 diabetes can be complicated with neuropathy that involves immune-mediated and inflammatory pathways. Glucagon-like peptide-1 receptor agonists such as liraglutide, have shown anti-inflammatory properties, and thus we hypothesized that long-term treatment with liraglutide induced diminished inflammation and thus improved neuronal function. METHODS: The study was a randomized, double-blinded, placebo-controlled trial of adults with type 1 diabetes and confirmed symmetrical polyneuropathy. They were randomly assigned (1:1) to receive either liraglutide or placebo. Titration was 6 weeks to 1.2-1.8 mg/d, continuing for 26 weeks. The primary endpoint was change in latency of early brain evoked potentials. Secondary endpoints were changes in proinflammatory cytokines, cortical evoked potential, autonomic function and peripheral neurophysiological testing. RESULTS: Thirty-nine patients completed the study, of whom 19 received liraglutide. In comparison to placebo, liraglutide reduced interleukin-6 (-22.6%; 95% confidence interval [CI]: -38.1, -3.2; P = .025) with concomitant numerical reductions in other proinflammatory cytokines. However neuronal function was unaltered at the central, autonomic or peripheral level. Treatment was associated with -3.38 kg (95% CI: -5.29, -1.48; P < .001] weight loss and a decrease in urine albumin/creatinine ratio (-40.2%; 95% CI: -60.6, -9.5; P = .02). CONCLUSION: Hitherto, diabetic neuropathy has no cure. Speculations can be raised whether mechanism targeted treatment, e.g. lowering the systemic level of proinflammatory cytokines may lead to prevention or treatment of the neuroinflammatory component in early stages of diabetic neuropathy. If ever successful, this would serve as an example of how fundamental mechanistic principles are translated into clinical practice similar to those applied in the cardiovascular and nephrological clinic.

Prediction of First Cardiovascular Disease Event in Type 1 Diabetes Mellitus: The Steno Type 1 Risk Engine.

BACKGROUND: Patients with type 1 diabetes mellitus are at increased risk of developing cardiovascular disease (CVD), but they are currently undertreated. There are no risk scores used on a regular basis in clinical practice for assessing the risk of CVD in type 1 diabetes mellitus. METHODS AND RESULTS: From 4306 clinically diagnosed adult patients with type 1 diabetes mellitus, we developed a prediction model for estimating the risk of first fatal or nonfatal CVD event (ischemic heart disease, ischemic stroke, heart failure, and peripheral artery disease). Detailed clinical data including lifestyle factors were linked to event data from validated national registers. The risk prediction model was developed by using a 2-stage approach. First, a nonparametric, data-driven approach was used to identify potentially informative risk factors and interactions (random forest and survival tree analysis). Second, based on results from the first step, Poisson regression analysis was used to derive the final model. The final CVD prediction model was externally validated in a different population of 2119 patients with type 1 diabetes mellitus. During a median follow-up of 6.8 years (interquartile range, 2.9-10.9) a total of 793 (18.4%) patients developed CVD. The final prediction model included age, sex, diabetes duration, systolic blood pressure, low-density lipoprotein cholesterol, hemoglobin A1c, albuminuria, glomerular filtration rate, smoking, and exercise. Discrimination was excellent for a 5-year CVD event with a C-statistic of 0.826 (95% confidence interval, 0.807-0.845) in the derivation data and a C-statistic of 0.803 (95% confidence interval, 0.767-0.839) in the validation data. The Hosmer-Lemeshow test showed good calibration (P>0.05) in both cohorts. CONCLUSIONS: This high-performing CVD risk model allows for the implementation of decision rules in a clinical setting.

Adiponectin, biomarkers of inflammation and changes in cardiac autonomic function: Whitehall II study.

BACKGROUND: Biomarkers of inflammation and adiponectin are associated with cardiovascular autonomic neuropathy (CAN) in cross-sectional studies, but prospective data are scarce. This study aimed to assess the associations of biomarkers of subclinical inflammation and adiponectin with subsequent changes in heart rate (HR) and heart rate variability (HRV) in non-diabetic and diabetic individuals. METHODS: Data are based on up to 25,050 person-examinations for 8469 study participants of the Whitehall II cohort study. Measures of CAN included HR and several HRV indices. Associations between baseline serum levels of high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1 receptor antagonist (IL-1Ra) and adiponectin and 5-year changes in HR and six HRV indices were estimated using mixed-effects models adjusting for age, sex, ethnicity, body mass index (BMI), metabolic covariates and medication. A modifying effect of diabetes was tested. RESULTS: Higher levels of IL-1Ra were associated with higher increases in HR. Additional associations with measures of HRV were observed for hsCRP, IL-6 and IL-1Ra, but these associations were explained by BMI and other confounders. Associations between adiponectin, HR and HRV differed depending on diabetes status. Higher adiponectin levels were associated with more pronounced decreases in HR and increases in three measures of HRV reflecting both sympathetic and vagal activity, but these findings were limited to individuals with type 2 diabetes. CONCLUSIONS: Higher IL-1Ra levels appeared as novel risk marker for increases in HR. Higher adiponectin levels were associated with a more favourable development of cardiovascular autonomic function in individuals with type 2 diabetes independently of multiple confounders.

Gastrointestinal symptom burden in diabetic autonomic and peripheral neuropathy - A Danes cohort study.

OBJECTIVE: We investigated associations between gastrointestinal symptoms - evaluated as a combined weighted symptom score (CWSS) - Diabetic autonomic neuropathy (DAN), and distal symmetrical polyneuropathy (DSPN) in type 1 and type 2 diabetes. RESEARCH DESIGN AND METHODS: Cross-sectional study in a tertiary outpatient clinic. CWSS was calculated based on questionnaires: gastroparesis composite symptom index (GCSI) and gastrointestinal symptom rating score (GSRS). DAN and DSPN were addressed using the composite autonomic symptom score 31 (COMPASS-31) questionnaire, cardiac autonomic reflex tests (CARTs), electrochemical skin conductance (ESC), vibration perception threshold (VPT), Michigan Neuropathy Screening Instrument (MNSI), pain- and thermal sensation. Analyses were adjusted for age, sex, diabetes duration, smoking, LDL-cholesterol, HbA1C and systolic blood pressure. Type 1 and type 2 diabetes were evaluated separately. RESULTS: We included 566 with type 1 diabetes and 377 with type 2 diabetes. Mean ± SD age was 58 ± 15 years and 565 (59.9 %) were women. A high CWSS was present in 143 (25 %) with type 1 and 142 (38 %) with type 2 diabetes. The odds of DAN by COMPASS-31 (p < 0.001) were higher in the high score group. For type 1 diabetes, odds of cardiac autonomic neuropathy were higher in the high CWSS group. The odds of DSPN by VPT and MNSI in type 1 diabetes, and by ESC, VPT and pain sensation in type 2 diabetes were higher in the high CWSS group. CONCLUSIONS: A high symptom score was associated with neuropathy by COMPASS-31 and vibration perception. Gastrointestinal symptom burden associated inconsistently with other neuropathy tests between diabetes types.

Presence of neuropathy in children and adolescents with type 1 diabetes evaluated with bedside modalities.

AIMS: To investigate the prevalence of diabetic polyneuropathy (DPN), cardiac autonomic neuropathy (CAN) and sudomotor dysfunction in children and adolescents with type 1 diabetes using bedside modalities. Secondly, to evaluate the co-existence of these types of diabetes neuropathies. METHODS: Cross-sectional study including 221 children and adolescents with type 1 diabetes. DPN was assessed by vibration sensation threshold and sural nerve conductance, CAN by cardiac reflex tests and sudomotor function by electrochemical skin conductance. RESULTS: Median (interquartile range) age was 14.2 (11.9, 16.5) years, diabetes duration 4.8 (2.7, 7.7) years and Hba1c 7.1 (6.6, 7.9) %, (54: 49, 63 mmol/mol). Three had retinopathy; all had normal albuminuria. DPN was present in 40 %, early CAN in 17 %, established CAN in 3 % and sudomotor dysfunction in the feet in 5 %. Of these, 60 % had one type of neuropathy, while 35 % had two types. Only 1 participant manifested all three types of neuropathies. CONCLUSIONS: Bedside modalities demonstrated a high prevalence of neuropathy in children and adolescents with type 1 diabetes, despite good glycemic outcome, short diabetes duration and absence of complications. A lack of co-existing neuropathies was shown, underscoring the need for multiple screening modalities.

Contemporary prevalence of diabetic neuropathies in individuals with type 1 and type 2 diabetes in a Danish tertiary outpatient clinic.

BACKGROUND: Population-based prevalence estimates of distal symmetric polyneuropathy (DPN) and diabetic autonomic neuropathy (DAN) are scares. Here we present neuropathy estimates and describe their overlap in a large cohort of people with type 1 and type 2 diabetes. METHODS: In a large population of outpatient participants, DPN was assessed using vibration perception threshold, sural nerve function, touch, pain and thermal sensation. Definite DPN was defined by the Toronto Consensus Criteria. Painful DPN was defined by Douleur Neuropathique 4 Questions. DAN measures were: cardiovascular reflex tests, electrochemical skin conductance, and gastroparesis cardinal symptom index. RESULTS: We included 822 individuals with type 1 (mean age (±SD) 54 ± 16 years, median [IQR] diabetes duration 26 [15-40] years) and 899 with type 2 diabetes (mean age 67 ± 11 years, median diabetes duration 16 [11-22] years). Definite DPN was prevalent in 54 % and 68 %, and painful DPN was in 5 % and 15 % of type 1 and type 2 participants, respectively. The prevalence of DAN varied between 6 and 39 % for type 1 and 9-49 % for type 2 diabetes. DPN without other neuropathy was present in 45 % with T1D and 50 % with T2D. CONCLUSION: The prevalence of DPN and DAN was high. DPN and DAN co-existed in only 50 % of cases.

Transcutaneous vagus nerve stimulation has no anti-inflammatory effect in diabetes.

Chronic inflammation is associated with diabetes and contributes to the development and progression of micro- and macrovascular complications. Transcutaneous vagus nerve stimulation (tVNS) has been proposed to reduce levels of circulating inflammatory cytokines in non-diabetics by activating the cholinergic anti-inflammatory pathway. We investigated the anti-inflammatory potential of tVNS as a secondary endpoint of a randomized controlled trial in people with diabetes (NCT04143269). 131 people with diabetes (type 1: n = 63; type 2: n = 68), gastrointestinal symptoms and various degrees of autonomic neuropathy were included and randomly assigned to self-administer active (n = 63) or sham (n = 68) tVNS over two successive study periods: (1) Seven days with four daily administrations and, (2) 56 days with two daily administrations. Levels of systemic inflammatory cytokines (IL-6, IL-8, IL-10, TNF-α, IFN-γ) were quantified from blood samples by multiplex technology. Information regarding age, sex, diabetes type, and the presence of cardiac autonomic neuropathy (CAN) was included in the analysis as possible confounders. No differences in either cytokine were seen after study period 1 and 2 between active and sham tVNS (all p-values > 0.08). Age, sex, diabetes type, presence of CAN, and baseline levels of inflammatory cytokines were not associated with changes after treatment (all p-values > 0.07). A tendency towards slight reductions in TNF-α levels after active treatment was observed in those with no CAN compared to those with early or manifest CAN (p = 0.052). In conclusion, tVNS did not influence the level of systemic inflammation in people with diabetes.

New Diabetic Treatment by Alleviation of Autonomic Nervous System Dysfunction Measured as Periosteal Pressure Sensitivity at Sternum Improves Empowerment, Treatment Satisfaction, and Self-Reported Health of People with Type 2 Diabetes: A Randomized Trial.

Purpose: Autonomic nervous system dysfunction (ANSD), for which presently no treatment exists, has a negative impact on prognosis in people with type 2 diabetes (T2D). Periosteal pressure sensitivity (PPS) on sternum may be a measure of autonomic nervous system dysfunction (ANSD). We tested if a non-pharmacological PPS-feedback-guided treatment program based on non-noxious sensory nerve stimulation, known to reduce PPS, changed empowerment, treatment satisfaction, and quality of life in people with T2D, compared to usual treatment. Patients and Methods: Analysis of secondary endpoints in a single center, two-armed, parallel-group, observer-blinded, randomized controlled trial of individuals with T2D. Participants were randomized to non-pharmacological intervention as an add-on to treatment as usual. Endpoints were evaluated by five validated questionnaires: Diabetes specific Empowerment (DES-SF), Diabetes Treatment Satisfaction (DTSQ), quality of life (QOL) (WHO-5), clinical stress signs (CSS), and self-reported health (SF-36). Sample size calculation was based on the primary endpoint HbA1c. Results: We included 144 participants, 71 allocated to active intervention and 73 to the control group. Active intervention compared to control revealed improved diabetes-specific empowerment (p = 0.004), DTSQ (p = 0.001), and SF-36 self-reported health (p=0.003) and tended to improve quality of life (WHO-5) (p = 0.056). The findings were clinically relevant with a Cohen's effect size of 0.5 to 0.7. Conclusion: This non-pharmacological intervention, aiming to reduce PPS, and thus ANSD, improved diabetes-specific empowerment, treatment satisfaction, and self-reported health when compared to usual treatment. The proposed intervention may be a supplement to conventional treatment for T2D.

Assessment of neuropathy subtypes in type 1 diabetes.

INTRODUCTION: Diabetic polyneuropathy (DPN), a common complication of diabetes, can manifest as small, large, or mixed fiber neuropathy (SFN, LFN, and MFN, respectively), depending on the type of fibers involved. Despite evidence indicating small fiber involvement prior to large fiber involvement in type 1 diabetes mellitus (T1DM)-associated DPN, no evidence has been produced to determine the more prevalent subtype. We aim to determine the more prevalent type of nerve fiber damage-SFN, LFN, and MFN-in T1DM-associated DPN, both with and without pain. RESEARCH DESIGN AND METHODS: In this cross-sectional study, participants (n=216) were divided into controls; T1DM; T1DM with non-painful DPN (NP-DPN); and T1DM with painful DPN (P-DPN). DPN was further subgrouped based on neuropathy severity. The more prevalent type of fiber damage was determined applying small and large fiber-specific tests and three diagnostic models: model 1 (≥1 abnormal test); model 2 (≥2 abnormal tests); and model 3 (≥3 abnormal tests). RESULTS: MFN showed the highest prevalence in T1DM-associated DPN. No differences in neuropathy subtype were found between NP-DPN and P-DPN. DPN, with prevalent SFN plateaus between models 2 and 3. All models showed increased prevalence of MFN according to DPN severity. Model 3 showed increased DPN with prevalent LFN in early neuropathy. DPN with prevalent SFN demonstrated a similar, but non-significant pattern. CONCLUSIONS: DPN primarily manifests as MFN in T1DM, with no differentiation between NP-DPN and P-DPN. Additionally, we propose model 2 as an initial criterion for diagnosing DPN with a more prevalent SFN subtype in T1DM. Lastly, the study suggests that in mild stages of DPN, one type of nerve fiber (either small or large) is more susceptible to damage.

Circulating metabolomic markers in association with overall burden of microvascular complications in type 1 diabetes.

INTRODUCTION: Diabetic retinopathy (DR), diabetic kidney disease (DKD) and distal symmetric polyneuropathy (DSPN) share common pathophysiology and pose an additive risk of early mortality. RESEARCH DESIGN AND METHODS: In adults with type 1 diabetes, 49 metabolites previously associated with either DR or DKD were assessed in relation to presence of DSPN. Metabolites overlapping in significance with presence of all three complications were assessed in relation to microvascular burden severity (additive number of complications-ie, presence of DKD±DR±DSPN) using linear regression models. Subsequently, the same metabolites were assessed with progression to endpoints: soft microvascular events (progression in albuminuria grade, ≥30% estimated glomerular filtration rate (eGFR) decline, or any progression in DR grade), hard microvascular events (progression to proliferative DR, chronic kidney failure, or ≥40% eGFR decline), and hard microvascular or macrovascular events (hard microvascular events, cardiovascular events (myocardial infarction, stroke, or arterial interventions), or cardiovascular mortality), using Cox models. All models were adjusted for sex, baseline age, diabetes duration, systolic blood pressure, HbA1c, body mass index, total cholesterol, smoking, and statin treatment. RESULTS: The full cohort investigated consisted of 487 participants. Mean (SD) follow-up was 4.8 (2.9, 5.7) years. Baseline biothesiometry was available in 202 participants, comprising the cross-sectional cohort. Eight metabolites were significantly associated with presence of DR, DKD, and DSPN, and six with additive microvascular burden severity. In the full cohort longitudinal analysis, higher levels of 3,4-dihydroxybutanoic acid (DHBA), 2,4-DHBA, ribonic acid, glycine, and ribitol were associated with development of events in both crude and adjusted models. Adding 3,4-DHBA, ribonic acid, and glycine to a traditional risk factor model improved the discrimination of hard microvascular events. CONCLUSIONS: While prospective studies directly assessing the predictive ability of these markers are needed, our results strengthen the role of clinical metabolomics in relation to risk assessment of diabetic complications in chronic type 1 diabetes.

Protocol for the combined cardiometabolic deep phenotyping and registry-based 20-year follow-up study of the Inter99 cohort.

INTRODUCTION: The population-based Inter99 cohort has contributed extensively to our understanding of effects of a systematic screening and lifestyle intervention, as well as the multifactorial aetiology of type 2 diabetes (T2D) and cardiovascular disease. To understand causes, trajectories and patterns of early and overt cardiometabolic disease manifestations, we will perform a combined clinical deep phenotyping and registry follow-up study of the now 50-80 years old Inter99 participants. METHODS AND ANALYSIS: The Inter99 cohort comprises individuals aged 30-60 years, who lived in a representative geographical area of greater Copenhagen, Denmark, in 1999. Age-stratified and sex-stratified random subgroups were invited to participate in either a lifestyle intervention (N=13 016) or questionnaires (N=5264), while the rest served as a reference population (N=43 021). Of the 13 016 individuals assigned to the lifestyle intervention group, 6784 (52%) accepted participation in a baseline health examination in 1999, including screening for cardiovascular risk factors and prediabetic conditions. In total, 6004 eligible participants, who participated in the baseline examination, will be invited to participate in the deep phenotyping 20-year follow-up clinical examination including measurements of anthropometry, blood pressure, arterial stiffness, cardiometabolic biomarkers, coronary artery calcification, heart rate variability, heart rhythm, liver stiffness, fundus characteristics, muscle strength and mass, as well as health and lifestyle questionnaires. In a subsample, 10-day monitoring of diet, physical activity and continuous glucose measurements will be performed. Fasting blood, urine and faecal samples to be stored in a biobank. The established database will form the basis of multiple analyses. A main purpose is to investigate whether low birth weight independent of genetics, lifestyle and glucose tolerance predicts later common T2D cardiometabolic comorbidities. ETHICS AND DISSEMINATION: The study was approved by the Medical Ethics Committee, Capital Region, Denmark (H-20076231) and by the Danish Data Protection Agency through the Capital Region of Denmark's registration system (P-2020-1074). Informed consent will be obtained before examinations. Findings will be disseminated in peer-reviewed journals, at conferences and via presentations to stakeholders, including patients and public health policymakers. TRIAL REGISTRATION NUMBER: NCT05166447.

The association between blood oxygen saturation and baroreflex sensitivity in adults with type 1 diabetes with and without albuminuria.

BACKGROUND: Low baroreflex sensitivity is an indicator of early cardiovascular autonomic neuropathy. We explored the association between baroreflex sensivity and blood oxygen saturation (SpO2) in type 1 diabetes and various degrees of microvascular disease. METHODS: In this Danish-Finnish cross-sectional multicentre study, baroreflex sensivity and SpO2 (pulse oximetry) were examined in persons with type 1 diabetes and normoalbuminuria (n = 98), microalbuminuria (n = 28), or macroalbuminuria (n = 43), and in non-diabetic controls (n = 54). Associations and differences between groups were analysed using regression models and adjustment included age, sex, smoking, HbA1c, blood haemoglobin, urine albumin creatinine ratio, body mass index, and estimated glomerular filtration rate. RESULTS: In type 1 diabetes, higher baroreflex sensitivity was associated with higher SpO2 before adjustment (% increase per one % increase in SpO2 = 20 % (95%CI: 11-30); p < 0.001) and the association remained significant after adjustment (p = 0.02). Baroreflex sensitivity was not different between non-diabetic controls and persons with type 1 diabetes and normoalbuminuria (p = 0.052). Compared with type 1 diabetes and normoalbuminuria, baroreflex sensitivity was lower in micro- (p < 0.001) and macroalbuminuria (p < 0.001). SpO2 was lower in persons with type 1 diabetes and normoalbuminuria compared with non-diabetic controls (p < 0.01). Within the participants with type 1 diabetes, SpO2 was not different in micro- or macroalbuminuria compared with normoalbuminuria (p-values > 0.05), but lower in macro-compared with microalbuminuria (p < 0.01). CONCLUSIONS: Lower baroreflex sensitivity was associated with lower SpO2 in type 1 diabetes. The present study support the hypothesis that hypoxia could be a therapeutic target in persons with type 1 diabetes.

Declining Incidence Rates of Distal Symmetric Polyneuropathy in People With Type 1 and Type 2 Diabetes in Denmark, With Indications of Distinct Patterns in Type 1 Diabetes.

OBJECTIVE: It is not known if incidence rates for diabetic distal symmetric polyneuropathy (DSPN) are decreasing, as they are for other diabetic complications. Here, we investigated incidence rates of DSPN in type 1 and type 2 diabetes in a large population-based study. RESEARCH DESIGN AND METHODS: In the period 1996 to 2018, 19,342 individuals were identified at a Danish tertiary diabetes center. Vibration perception threshold was assessed by biothesiometry and repeated throughout the study. Exclusion of prevalent DSPN cases or missing data left data on 9,473 individuals for analysis of DSPN using a cutoff of >25 V and on 2,783 individuals for analysis using an age-, sex-, and height-specific cutoff. Poisson regression analysis was used to model incidence rates of DSPN for both cutoff types and separately for diabetes types. Covariates were sex, age, diabetes duration, and calendar time. RESULTS: Incidence rates (95% CI) of DSPN decreased from 1996 to 2018 (e.g., from 4.78 [3.60-6.33]/100 person-years [PY] to 1.15 [0.91-1.47]/100 PY for 40-year-old men with type 1 diabetes and from 16.54 [11.80-23.18]/100 PY to 8.02 [6.63-9.69]/100 PY for 60-year-old men with type 2 diabetes, when using >25 V as the cutoff value). Analyses using age-, sex-, and height-specific cutoff values demonstrated similar incidence patterns by calendar time without sex differences. For type 1 diabetes, decreasing incidence rates were seen with older age. CONCLUSIONS: Incidence rates for DSPN are declining in type 1 and type 2 diabetes, possibly due to improved diabetes treatment. This causality remains to be explored. Distinct age-related patterns indicate that the pathophysiology of DSPN may differ between diabetes types.

Oral capsules of tetra-hydro-cannabinol (THC), cannabidiol (CBD) and their combination in peripheral neuropathic pain treatment.

BACKGROUND: Cannabinoids are often prescribed for neuropathic pain, but the evidence-based recommendation is 'weak against'. OBJECTIVES: The aim was to examine the effect of two cannabinoids and their combination in peripheral neuropathic pain. METHODS: This was a randomized, double-blind, trial with treatment arms for cannabidiol (CBD), tetra-hydro-cannabinol (THC), CBD and THC combination (CBD/THC), and placebo in a 1:1:1:1 ratio and flexible drug doses (CBD 5-50 mg, THC 2.5-25 mg, and CBD/THC 5 mg/2.5 mg-50 mg/25 mg). Treatment periods of 8-week duration were proceeded by 1 week for baseline observations. Patients with painful polyneuropathy, post-herpetic neuralgia and peripheral nerve injury (traumatic or surgical) failing at least one previous evidence-based pharmacological treatment were eligible for inclusion. The primary outcome was the change in weekly average of daily pain measured with a numeric rating scale (NRS). Trail Making Test (TMT) was used as one of the tests of mental functioning. RESULTS: In all, 145 patients were included in the study of which 118 were randomized and 115 included in the intention-to-treat analysis. None of the treatments reduced pain compared to placebo (p = 0.04-0.60). Effect sizes as estimated in week 8 (positive values worse and negative better than placebo) were CBD mean 1.14 NRS points (95% CI 0.11-2.19), THC 0.38 (CI -0.65 to 1.4) and CBD/THC -0.12 (-1.13 to 0.89). CONCLUSIONS: CBD, THC and their combination did not relieve peripheral neuropathic pain in patients failing at least one previous evidence-based treatment for neuropathic pain.

Distal symmetrical polyneuropathy is present in all individuals with diabetes and foot ulcers - and does not associate with healing time.

We estimated the occurrence of diabetic neuropathy using six different diagnostic modalities in individuals with newly diagnosed diabetic foot ulcers (DFUs) and assessed the association with DFU healing time. All individuals with DFU had distal symmetrical polyneuropathy. Presence of neuropathy did not associate with ulcer healing time (p ≥ 0.12).