Neuropathic phenotypes of type 1 diabetes are related to different signatures of magnetic resonance spectroscopy-assessed brain metabolites.

OBJECTIVES: The study aimed to investigate brain metabolites in type 1 diabetes and the associations with disease characteristics. We explored the metabolic profiles predicting different neuropathic phenotypes using multiple linear regression analyses. METHODS: We compared brain metabolites in 55 adults with type 1 diabetes (including painful diabetic peripheral neuropathy (DPN), painless DPN, without DPN) with 20 healthy controls. Proton magnetic resonance spectroscopy measurements (N-acetylaspartate (NAA), glutamate (glu), myo-inositol (mI), and glycerophosphocholine (GPC) were obtained in ratios to creatine (cre)) from the parietal region, anterior cingulate cortex and thalamus. RESULTS: The overall diabetes group revealed decreased parietal NAA/cre compared to healthy controls (1.41 ± 0.12 vs. 1.55 ± 0.13,p < 0.001) and increased mI/cre (parietal: 0.62 ± 0.08 vs. 0.57 ± 0.07,p = 0.025, cingulate: 0.65 ± 0.08 vs. 0.60 ± 0.08,p = 0.033). Reduced NAA/cre was associated with more severe DPN (all p ≤ 0.04) whereas increased mI/cre was associated with higher hemoglobin A1c (HbA1c) (p = 0.02). Diabetes was predicted from decreased parietal NAA/cre, increased parietal ml/cre, and decreased thalamic glu/cre. DPN was predicted from decreased parietal NAA/cre and increased GPC/cre. Painful DPN was predicted from increased parietal GPC/cre and thalamic glu/cre. CONCLUSIONS: Specific metabolic brain profiles were linked to the different phenotypes of diabetes, DPN and painful DPN. SIGNIFICANCE: Assessment of metabolic profiles could be relevant for detailed understanding of central neuropathy in diabetes.

Transcutaneous vagal nerve stimulation for treating gastrointestinal symptoms in individuals with diabetes: a randomised, double-blind, sham-controlled, multicentre trial.

AIMS/HYPOTHESIS: Diabetic gastroenteropathy frequently causes debilitating gastrointestinal symptoms. Previous uncontrolled studies have shown that transcutaneous vagal nerve stimulation (tVNS) may improve gastrointestinal symptoms. To investigate the effect of cervical tVNS in individuals with diabetes suffering from autonomic neuropathy and gastrointestinal symptoms, we conducted a randomised, sham-controlled, double-blind (participants and investigators were blinded to the allocated treatment) study. METHODS: This study included adults (aged 20-86) with type 1 or 2 diabetes, gastrointestinal symptoms and autonomic neuropathy recruited from three Steno Diabetes Centres in Denmark. Participants were randomly allocated 1:1 to receive active or sham stimulation. Active cervical tVNS or sham stimulation was self-administered over two successive study periods: 1 week of four daily stimulations and 8 weeks of two daily stimulations. The primary outcome measures were gastrointestinal symptom changes as measured using the gastroparesis cardinal symptom index (GCSI) and the gastrointestinal symptom rating scale (GSRS). Secondary outcomes included gastrointestinal transit times and cardiovascular autonomic function. RESULTS: Sixty-eight participants were randomised to the active group, while 77 were randomised to the sham group. Sixty-three in the active and 68 in the sham group remained for analysis in study period 1, while 62 in each group were analysed in study period 2. In study period 1, active and sham tVNS resulted in similar symptom reductions (GCSI: -0.26 ± 0.64 vs -0.17 ± 0.62, p=0.44; GSRS: -0.35 ± 0.62 vs -0.32 ± 0.59, p=0.77; mean ± SD). In study period 2, active stimulation also caused a mean symptom decrease that was comparable to that observed after sham stimulation (GCSI: -0.47 ± 0.78 vs -0.33 ± 0.75, p=0.34; GSRS: -0.46 ± 0.90 vs -0.35 ± 0.79, p=0.50). Gastric emptying time was increased in the active group compared with sham (23 min vs -19 min, p=0.04). Segmental intestinal transit times and cardiovascular autonomic measurements did not differ between treatment groups (all p>0.05). The tVNS was well-tolerated. CONCLUSIONS/INTERPRETATION: Cervical tVNS, compared with sham stimulation, does not improve gastrointestinal symptoms among individuals with diabetes and autonomic neuropathy. TRIAL REGISTRATION: ClinicalTrials.gov NCT04143269 FUNDING: The study was funded by the Novo Nordisk Foundation (grant number NNF180C0052045).

Bisphosphonate Use and Risk of Atypical Femoral Fractures: A Danish Case Cohort Study with Blinded Radiographic Review.

CONTEXT: Prolonged bisphosphonate (BP) treatment for osteoporosis prevents hip and other fractures but causes atypical femoral fractures (AFF). OBJECTIVE: To establish the relationship between patterns of BP use and the risk of AFF and hip fractures. Other potential risk factors for AFF were also examined. DESIGN: Population-based case-cohort study. SETTING: The Danish National Healthcare system maintains longitudinal records of medication use, healthcare utilization, and x-ray images. PARTICIPANTS: Among all 1.9 million Danish adults ≥50, those with subtrochanteric or femoral shaft fractures between 2010-2015 (n = 4,973) were identified and compared to a random sample (n = 37,021). PREDICTORS: Bisphosphonate use was collected from 1995-2015. MAIN OUTCOME MEASURES: Fracture radiographs (n = 4,769) were reviewed by blinded study radiologists to identify AFFs (n = 181) using established criteria. Traditional hip fractures in the random sample (n = 691) were identified by ICD-10. RESULTS: Compared to <1 year of BP use, 5-7 years of use was associated with a 7-fold increase in AFF [adjusted HR = 7.29 (CI: 3.07,17.30)]; the risk of AFF fell quickly after discontinuation. The 5-year number-needed-to-harm for one AFF was 1,424, while the 5-year number-needed-to-treat to prevent one hip fracture was 56. Glucocorticoid and proton pump inhibitor use were independently associated with increased AFF risk. Thirty-one percent of those with AFF had no BP exposure. CONCLUSIONS: The risk of AFF increases with duration of BP use but the beneficial effects of BP therapy in adults ≥50 dramatically exceed this increased risk. Nearly one-third of those with AFF have no BP exposure.

Monocyte recruitment in venous pulmonary embolism at time of cancer diagnosis in upper gastrointestinal cancer patients.

Upper gastrointestinal cancer is frequently complicated by venous thromboembolisms (VTE), especially pulmonary embolisms (PE) increase the mortality rate. Monocytes are a part of the innate immune system and up-regulation may indicate an ongoing inflammatory response or infectious disease and has lately been associated with a moderate risk of suffering from VTE. This prospectively study aims to compare the incidence of pulmonary embolism with markers of coagulation and compare it to the absolute monocyte count. A consecutive cohort of 250 patients with biopsy proven upper gastrointestinal cancer (i.e. pancreas, biliary tract, esophagus and gastric cancer) where included at the time of cancer diagnosis and before treatment. All patients underwent bilateral compression ultrasonography for detection of deep vein thrombosis (DVT). Of these 143 had an additionally pulmonary angiografi (CTPA) with the staging computer tomography. 13 of 250 patients (5.2%) had a DVT and 11 of 143 (7.7%) had CTPA proven PE. PE was significantly more common among patients with elevated D-dimer (OR 11.62, 95%CI: 1.13-119, P = 0.039) and elevated absolute monocyte count (OR 7.59, 95%CI: 1.37-41.98, P = 0.020). Only patients with pancreatic cancer had a significantly higher risk of DVT (OR 11.03, 95%CI: 1.25-97.43, P = 0.031). The sensitivity of absolute monocyte count was 63.6 (95%CI: 30.8-89.1) and specificity 80.3 (95%CI: 72.5-86.7), with a negative predictive value of 96.4 (95%CI: 91-99) in PE. An increased absolute monocyte count was detected in patients suffering from PE but not DVT, suggesting a possible interaction with the innate immune system.

Pan-alimentary assessment of motility, luminal content, and structures: an MRI-based framework.

BACKGROUND: Gastrointestinal symptoms originating from different segments overlap and complicate diagnosis and treatment. In this study, we aimed to develop and test a pan-alimentary framework for the evaluation of gastrointestinal (GI) motility and different static endpoints based on magnetic resonance imaging (MRI) without contrast agents or bowel preparation. METHODS: Twenty healthy volunteers (55.6 ± 10.9 years, BMI 30.8 ± 9.2 kg/m2) underwent baseline and post-meal MRI scans at multiple time points. From the scans, the following were obtained: Gastric segmental volumes and motility, emptying half time (T50), small bowel volume and motility, colonic segmental volumes, and fecal water content. Questionnaires to assess GI symptoms were collected between and after MRI scans. KEY RESULTS: We observed an increase in stomach and small bowel volume immediately after meal intake from baseline values (p<.001 for the stomach and p=.05 for the small bowel). The volume increase of the stomach primarily involved the fundus (p<.001) in the earliest phase of digestion with a T50 of 92.1 ± 35.3 min. The intake of the meal immediately elicited a motility increase in the small bowel (p<.001). No differences in colonic fecal water content between baseline and 105 min were observed. CONCLUSION & INFERENCES: We developed a framework for a pan-alimentary assessment of GI endpoints and observed how different dynamic and static physiological endpoints responded to meal intake. All endpoints aligned with the current literature for individual gut segments, showing that a comprehensive model may unravel complex and incoherent gastrointestinal symptoms in patients.

Effects of a peripherally acting µ-opioid receptor antagonist for the prevention of recurrent acute pancreatitis: study protocol for an investigator-initiated, randomized, placebo-controlled, double-blind clinical trial (PAMORA-RAP trial).

BACKGROUND: Acute and chronic pancreatitis constitute a continuum of inflammatory disease of the pancreas with an increasing incidence in most high-income countries. A subset of patients with a history of pancreatitis suffer from recurrence of acute pancreatitis attacks, which accelerate disease progression towards end-stage chronic pancreatitis with loss of exocrine and endocrine function. There is currently no available prophylactic treatment for recurrent acute pancreatitis apart from removing risk factors, which is not always possible. Pain is the primary symptom of acute pancreatitis, which induces the endogenous release of opioids. This may further be potentiated by opioid administration for pain management. Increased exposure to opioids leads to potentially harmful effects on the gastrointestinal tract, including, e.g. increased sphincter tones and decreased fluid secretion, which may impair pancreatic ductal clearance and elevate the risk for new pancreatitis attacks and accelerate disease progression. Peripherally acting µ-opioid receptor antagonists (PAMORAs) have been developed to counteract the adverse effects of opioids on the gastrointestinal tract. We hypothesize that the PAMORA naldemedine will reduce the risk of new pancreatitis attacks in patients with recurrent acute pancreatitis and hence decelerate disease progression. METHODS: The study is a double-blind, randomized controlled trial with allocation of patients to either 0.2 mg naldemedine daily or matching placebo for 12 months. A total of 120 outpatients will be enrolled from five specialist centres in Denmark and Sweden. The main inclusion criteria is a history of recurrent acute pancreatitis (minimum of two confirmed pancreatitis attacks). The primary endpoint is time to acute pancreatitis recurrence after randomization. Secondary outcomes include changes in quality of life, gastrointestinal symptom scores, new-onset diabetes, exocrine pancreatic insufficiency, disease severity, health care utilization, adherence to treatment, and frequency of adverse events. Exploratory outcomes are included for mechanistic linkage and include the progression of chronic pancreatitis-related findings on magnetic resonance imaging (MRI) and changes in circulating blood markers of inflammation and fibrosis. DISCUSSION: This study investigates if naldemedine can change the natural course of pancreatitis in patients with recurrent acute pancreatitis and improve patient outcomes. TRIAL REGISTRATION: EudraCT no. 2021-000069-34. CLINICALTRIALS: gov NCT04966559. Registered on July 8, 2021.

Cognitive function in individuals with and without painful and painless diabetic polyneuropathy-A cross-sectional study in type 1 diabetes.

INTRODUCTION: Previous studies suggest that cognitive impairment is more prevalent in individuals with painful and painless diabetic peripheral neuropathy (DPN). However, the current evidence is not well described. This study investigated cognitive function in adults with type 1 diabetes mellitus (T1DM) and the association to painful/painless DPN and clinical parameters. METHODS: This cross-sectional, observational, case-control study included 58 participants with T1DM, sub-grouped into 20 participants with T1DM and painful DPN, 19 participants with T1DM and painless DPN, 19 participants with T1DM without DPN, and 20 healthy controls were included. The groups were matched for sex and age. The participants performed Addenbrooke's examination III (ACE-III), which assesses attention, memory, verbal fluency, language and visuospatial skills. Working memory was evaluated using an N-back task. Cognitive scores were compared between the groups and correlated to age, diabetes duration, HbA1c and nerve conduction measurements. RESULTS: Compared to healthy controls, T1DM participants showed lower total ACE-III (p = .028), memory (p = .013) and language scores (p = .028), together with longer reaction times in the N-back task (p = .041). Subgroup analyses demonstrated lower memory scores in those with painless DPN compared with healthy controls (p = .013). No differences were observed between the three T1DM subgroups. Cognitive scores and clinical parameters were not associated. CONCLUSIONS: This study supports the notion of cognitive alterations in T1DM and indicates that cognitive function is altered in T1DM regardless of underlying neuropathic complications. The memory domain appears altered in T1DM, particularly in those with painless DPN. Further studies are needed to verify the findings.

T2* weighted fetal MRI and the correlation with placental dysfunction.

INTRODUCTION: Transverse relaxation time (T2*) is related to tissue oxygenation and morphology. We aimed to describe T2* weighted MRI in selected fetal organs in normal pregnancies, and to investigate the correlation between fetal organ T2* and placental T2*, birthweight (BW) deviation, and redistribution of fetal blood flow. METHODS: T2*-weighted MRI was performed in 126 singleton pregnancies between 23+6- and 41+3-weeks' gestation. The T2* value was obtained from the placenta and fetal organs (brain, lungs, heart, liver, kidneys, and spleen). In normal BW pregnancies (BW > 10th centile), the correlation between the T2* value and gestational age (GA) at MRI was estimated by linear regression. The correlation between fetal organ Z-score and BW group was demonstrated by boxplots and investigated by analysis of variance (ANOVA) for each organ. RESULTS: In normal BW pregnancies fetal organ T2* was negatively correlated with GA. We found a significant correlation between BW group and fetal organ T2* z-score in the fetal heart, kidney, lung and spleen. A positive linear correlation was demonstrated between fetal organ T2* and outcomes related to placental function such as BW deviation and placenta T2* in all investigated fetal organs except for the fetal liver. In the fetal heart, kidneys, and spleen the T2* value showed a significant correlation with fetal redistribution of blood flow (Middle cerebral artery Pulsatility Index) before delivery. DISCUSSION: Fetal T2* is correlated with BW, placental function, and redistribution of fetal blood flow, suggesting that fetal organ T2* reflects fetal oxygenation and morphological changes related to placental dysfunction.

Vitamin K supplementation and bone mineral density in dialysis: results of the double-blind, randomized, placebo-controlled RenaKvit trial.

BACKGROUND: Vitamin K deficiency is highly prevalent in patients on dialysis and may contribute to their low bone mineral density (BMD) and increased risk of fracture. This study investigated the effect of menaquinone-7 (MK-7) supplementation on BMD in patients on chronic dialysis. METHODS: In a multicentre, double-blind, placebo-controlled intervention trial, 123 patients on chronic dialysis were randomised to a daily oral supplement of either MK-7 360 µg or placebo for 2 years. BMD of the distal radius (1/3, mid, ultradistal and total), femoral neck, lumbar spine (L1-L4) and whole body was assessed by dual-energy X-ray absorptiometry. Serum levels of vitamin K1 and MK-7 and plasma levels of total osteocalcin, dephosphorylated-uncarboxylated matrix Gla protein and protein induced by vitamin K absence II were measured to assess vitamin K status. RESULTS: After 2 years, an accelerated BMD loss of the 1/3 distal radius was found with MK-7 supplementation {mean difference of changes relative to placebo -0.023 g/cm2 [95% confidence interval (CI) -0.039 to -0.008]}, whereas the decrease in lumbar spine BMD seen in the placebo group was prevented [mean difference of changes between groups 0.050 g/cm2 (95% CI 0.015-0.085)]. No significant effects were observed at the remaining skeletal sites. Vitamin K status strongly improved in MK-7-supplemented participants. CONCLUSION: Compared with placebo, an accelerated BMD loss of the 1/3 distal radius was found after 2 years of MK-7 supplementation, whereas a decline in lumbar spine BMD was prevented. As such, MK-7 supplementation might modify BMD site-specifically in patients on dialysis. In aggregate, our findings do not support MK-7 supplementation to preserve bone in patients on dialysis.

Alterations in Functional Connectivity of Thalamus and Primary Somatosensory Cortex in Painful and Painless Diabetic Peripheral Neuropathy.

OBJECTIVE: In this study we aimed to investigate the functional connectivity of brain regions involved in sensory processing in diabetes with and without painful and painless diabetic peripheral neuropathy (DPN) and the association with peripheral nerve function and pain intensity. RESEARCH DESIGN AND METHODS: In this cross-sectional study we used resting-state functional MRI (fMRI) to investigate functional brain connectivity of 19 individuals with type 1 diabetes and painful DPN, 19 with type 1 diabetes and painless DPN, 18 with type 1 diabetes without DPN, and 20 healthy control subjects. Seed-based connectivity analyses were performed for thalamus, postcentral gyrus, and insula, and the connectivity z scores were correlated with peripheral nerve function measurements and pain scores. RESULTS: Overall, compared with those with painful DPN and healthy control subjects, subjects with type 1 diabetes without DPN showed hyperconnectivity between thalamus and motor areas and between postcentral gyrus and motor areas (all P ≤ 0.029). Poorer peripheral nerve functions and higher pain scores were associated with lower connectivity of the thalamus and postcentral gyrus (all P ≤ 0.043). No connectivity differences were found in insula (all P ≥ 0.071). CONCLUSIONS: Higher functional connectivity of thalamus and postcentral gyrus appeared only in diabetes without neuropathic complications. Thalamic/postcentral gyral connectivity measures demonstrated an association with peripheral nerve functions. Based on thalamic connectivity, it was possible to group the phenotypes of type 1 diabetes with painful/painless DPN and type 1 diabetes without DPN. The results of the current study support that fMRI can be used for phenotyping, and with validation, it may contribute to early detection and prevention of neuropathic complications.

Inter- and intra-observer variability of computed tomography-based parenchymal- and ductal diameters in chronic pancreatitis: a multi-observer international study.

PURPOSE: The need for incorporation of quantitative imaging biomarkers of pancreatic parenchymal and ductal structures has been highlighted in recent proposals for new scoring systems in chronic pancreatitis (CP). To quantify inter- and intra-observer variability in CT-based measurements of ductal- and gland diameters in CP patients. MATERIALS AND METHODS: Prospectively acquired pancreatic CT examinations from 50 CP patients were reviewed by 12 radiologists and four pancreatologists from 10 institutions. Assessment entailed measuring maximum diameter in the axial plane of four structures: (1) pancreatic head (PDhead), (2) pancreatic body (PDbody), (3) main pancreatic duct in the pancreatic head (MPDhead), and (4) body (MPDbody). Agreement was assessed by the 95% limits of agreement with the mean (LOAM), representing how much a single measurement for a specific subject may plausibly deviate from the mean of all measurements on the specific subject. Bland-Altman limits of agreement (LoA) were generated for intra-observer pairs. RESULTS: The 16 observers completed 6400 caliper placements comprising a first and second measurement session. The widest inter-observer LOAM was seen with PDhead (± 9.1 mm), followed by PDbody (± 5.1 mm), MPDhead (± 3.2 mm), and MPDbody (± 2.6 mm), whereas the mean intra-observer LoA width was ± 7.3, ± 5.1, ± 3.7, and ± 2.4 mm, respectively. CONCLUSION: Substantial intra- and inter-observer variability was observed in pancreatic two-point measurements. This was especially pronounced for parenchymal and duct diameters of the pancreatic head. These findings challenge the implementation of two-point measurements as the foundation for quantitative imaging scoring systems in CP.

Clinical Course of Medically Managed Patients With Large and Small Duct Chronic Pancreatitis.

INTRODUCTION: Pancreatic duct obstruction is the primary indication for endoscopic and/or surgical therapy in patients with chronic pancreatitis (CP). However, the clinical course of medically managed patients in relation to pancreatic duct obstruction is largely unknown. METHODS: This was a retrospective cohort study of medically managed patients with CP. We classified patients based on pancreatic duct obstruction from a stricture or stone using cross-sectional imaging (i.e., large vs small duct CP). We compared prevalence of diabetes and exocrine insufficiency (EPI) between subgroups at inclusion and investigated risk of new-onset diabetes, EPI, and all-cause mortality over a follow-up period of 5 years. Changes in pancreatic morphology were studied in patients who underwent follow-up imaging. RESULTS: A total of 198 patients (mean age 58 ± 12 years, 70% male, 60% alcoholic etiology, 38% large duct CP) were evaluated. At inclusion, patients with large vs small duct CP had a higher prevalence of both diabetes (43% vs 24%, P = 0.004) and EPI (47% vs 28%, P = 0.007). There was an increased risk of new-onset EPI in patients with large duct CP (hazard ratio 1.72; 95% confidence interval [1.05-2.80], P = 0.031) and higher rates of pancreatic atrophy ( P < 0.001). No differences between groups were observed for new-onset diabetes and all-cause mortality. Conversion from small to large duct CP or vice versa during follow-up was observed in 14% of patients. DISCUSSION: In a medically managed cohort of patients, large duct CP was associated with increased risk of EPI and pancreatic atrophy compared with small duct CP.

Ultra-low-dose non-contrast CT and CT angiography can be used interchangeably for assessing maximal abdominal aortic diameter.

Background: Routine CT scans may increasingly be used to document normal aortic size and to detect incidental abdominal aortic aneurysms. Purpose: To determine whether ultra-low-dose non-contrast CT (ULDNC-CT) can be used instead of the gold standard CT angiography (CTA) for assessment of maximal abdominal aortic diameter. Materials and Methods: This retrospective study included 50 patients who underwent CTA and a normal-dose non-contrast CT for suspected renal artery stenosis. ULDNC-CT datasets were generated from the normal-dose non-contrast CT datasets using a simulation technique. Using the centerline technique, radiology consultants (n = 4) and residents (n = 3) determined maximal abdominal aortic diameter. The limits of agreement with the mean (LOAM) was used to access observer agreement. LOAM represents how much a measurement by a single observer may plausibly deviate from the mean of all observers on the specific subject. Results: Observers completed 1400 measurements encompassing repeated CTA and ULDNC-CT measurements. The mean diameter was 24.0 and 25.0 mm for CTA and ULDNC-CT, respectively, yielding a significant but minor mean difference of 1.0 mm. The 95% LOAM reproducibility was similar for CTA and ULDNC-CT (2.3 vs 2.3 mm). In addition, the 95% LOAM and mean diameters were similar for CTA and ULDNC-CT when observers were grouped as consultants and residents. Conclusions: Ultra-low-dose non-contrast CT exhibited similar accuracy and reproducibility of measurements compared with CTA for assessing maximal abdominal aortic diameter supporting that ULDNC-CT can be used interchangeably with CTA in the lower range of aortic sizes.

Gray Matter Brain Alterations in Type 1 Diabetes - Findings Based on Detailed Phenotyping of Neuropathy Status.

AIMS: This study investigated brain structure in patients of type 1 diabetes with diabetic peripheral neuropathy (DPN) and type 1 diabetes with neuropathic pain and the associations to clinical, peripheral, and cognitive measurements. METHODS: Sixty individuals with type 1 diabetes and 20 healthy controls were included in the study. Nineteen individuals with type 1 diabetes and neuropathic pain, 19 with type 1 diabetes and DPN, 18 with type 1 diabetes without DPN, and 20 healthy controls were included in the brain analyses. We utilized structural brain magnetic resonance imaging to investigate total and regional gray matter volume. RESULTS: Significant lower gray matter volume was found in type 1 diabetes with neuropathic pain and in type 1 diabetes without DPN compared to healthy controls (p=0.024 and p=0.019, respectively). Lower insula volume was observed in all three diabetes groups (all p≤0.050). Thalamus and hippocampus volume was lower in type 1 diabetes with neuropathic pain, cerebellum volume was lower in type 1 diabetes with DPN, and somatosensory cortex volume was lower in type 1 diabetes without DPN (all p≤0.018). Attenuated memory was associated with lower gray matter volume in type 1 diabetes with DPN. No associations were found between gray matter volume and clinical/peripheral measurements. CONCLUSION: We demonstrated lower gray matter volume in individuals with type 1 diabetes regardless of the presence of DPN and neuropathic pain. Hence, central gray matter alteration was not associated with peripheral alterations.

T2*-weighted placental magnetic resonance imaging: a biomarker of placental dysfunction in small-for-gestational-age pregnancies.

BACKGROUND: The antenatal identification of placental dysfunction in small-for-gestational-age fetuses with normal fetal Doppler flows remains an obstetrical challenge. In a significant fraction of such pregnancies, placental dysfunction is revealed by clinical manifestations such as preeclampsia, preterm delivery, or severe small-for-gestational-age at birth or by abnormal findings in the postnatal placental histologic examination. Therefore, new methods to identify placental function directly in pregnancy at the time of small-for-gestational-age diagnosis is highly needed. T2*-weighted placental magnetic resonance imaging is sensitive to changes in placental morphology and oxygenation and is thereby related to placental function. Previous studies have demonstrated that pregnancies complicated by low birthweight and preeclampsia are characterized by low placental T2* values. However, the specific performance of placental T2* in the prediction of placenta-related outcomes in small-for-gestational-age pregnancies with normal fetal Doppler flows remains to be explored. OBJECTIVE: In small-for-gestational-age pregnancies with normal fetal Doppler flows, we aimed to evaluate T2*-weighted placental magnetic resonance imaging as an antenatal biomarker of placental dysfunction. In addition, we aimed to investigate the correlation between placental T2* and Doppler flow measurements of fetal and uterine arteries at the time of magnetic resonance imaging. STUDY DESIGN: In this prospective cohort study, the inclusion criterion was suspected small-for-gestational-age (ultrasound estimated fetal weight Z-score ≤-2.0 [2.3rd centile]) with normal fetal Doppler flows (middle cerebral artery pulsatility index Z-score > -2.0 and umbilical artery pulsatility index Z-score <2.0). The T2*-weighted placental magnetic resonance imaging scan was performed at inclusion in a 1.5 T system. The outcomes was placental dysfunction at birth defined by low birthweight (Z-score ≤-2.0), preeclampsia, preterm delivery (gestational age<37 weeks), or abnormal placental histologic examination such as placental vascular malperfusion according to the Amsterdam Consensus Statement. RESULTS: We included 92 pregnancies at 26+5 to 39+6 weeks gestation. The median time interval between the magnetic resonance imaging scan and birth was 4.6 weeks (interquartile range, 2.7-7.8 weeks). At birth, 55% (51/92) of pregnancies revealed at least 1 sign of placental dysfunction; 49% (40/81) had abnormal placental histologic examination, 29% (27/92) were born with low birthweight, 13% (12/92) were delivered preterm, and 7% (6/92) had preeclampsia. When adjusted for gestational age at magnetic resonance imaging, the placental T2* Z-score was a significant predictor of abnormal placental histologic examination (area under the curve, 0.73; P=.001), small-for-gestational-age at birth (area under the curve, 0.63; P=.030), preeclampsia (area under the curve, 0.88; P=.005), and preterm delivery (area under the curve, 0.81; P=.001). The placental T2* was reduced in pregnancies with a combination of clinical manifestations and abnormal placental histologic examination (T2* Z-score=-1.52±1.35 [mean±standard deviation]; P=.0001) and in clinically uneventful pregnancies with abnormal placental histologic examination (T2* Z-score=-0.79±0.97; P=.045). At the time of magnetic resonance imaging, the placental T2* Z-score showed a significant linear correlation with the uterine artery pulsatility index Z-scores (r=-0.24; P=.016) and the middle cerebral artery pulsatility index Z-scores (r=0.29; P=.017) but not with the umbilical artery pulsatility index Z-scores (r=0.18; P=.17) and the cerebroplacental ratio (r=0.03; P=.77). CONCLUSION: This study indicates that placental dysfunction is frequent in small-for-gestational-age fetuses with normal fetal Doppler flows. In this cohort, T2*-weighted placental magnetic resonance imaging is a sensitive biomarker of placental dysfunction regardless of the clinical manifestations. This finding supports a paradigm shift in the conception of placental dysfunction that may cover a wide spectrum of clinical and subclinical manifestations.

Perfusion fraction derived from IVIM analysis of diffusion-weighted MRI in the assessment of placental vascular malperfusion antenatally.

INTRODUCTION: Specific placental pathologies that may impact fetal development, such as vascular malperfusion, are diagnosed postpartum. We aimed to evaluate if placental perfusion fraction (f) derived from intravoxel incoherent motion (IVIM) analysis of diffusion-weighted magnetic resonance imaging (DWI) can be used to identify specific types of placental vascular malperfusion antenatally. METHOD: 93 women who underwent placental DWI with multiple b-values at 23.9-41.3 week's gestation and postpartum histological examination were identified in the local placental MRI research database. Based on the placental examination, 44 were defined as normal controls and 49 cases had placental vascular malperfusion. Vascular malperfusion was subdivided into fetal vascular malperfusion (n = 13), maternal vascular malperfusion (n = 30) or both (n = 6). For each placenta, regions of interest were drawn on three placental slices and their mean f was estimated using intravoxel incoherence motion analysis. RESULTS: In normal placentas mean f was 26.0 ± 4.6% (mean ± SD) and no linear correlation between f and gestational age was found, r = -0.05, p = 0.72. Placentas with fetal vascular malperfusion showed a significantly lower f (22.7 ± 4.4%) compared to normal controls, p = 0.03. In cases of maternal vascular malperfusion (25.2 ± 6.4%), no significant difference in f was revealed, p = 0.55. CONCLUSIONS: These results indicate that placental DWI-derived f may identify fetal vascular malperfusion in vivo. This study confirms a previous pilot study and provides initial evidence that fetal and maternal vascular malperfusion have different MRI signatures. Future studies are needed to further explore the clinical significance of this interesting finding.

Overlap and cumulative effects of pancreatic duct obstruction, abnormal pain processing and psychological distress on patient-reported outcomes in chronic pancreatitis.

OBJECTIVE: Several factors have been suggested to mediate pain in patients with chronic pancreatitis. However, it is unknown whether these factors are overlapping and if they have cumulative effects on patient-reported outcomes (PROs). DESIGN: We performed a multicentre cross-sectional study of 201 prospectively enrolled subjects with definitive chronic pancreatitis. All subjects underwent evaluation for pancreatic duct obstruction, abnormalities in pain processing using quantitative sensory testing, and screening for psychological distress (anxiety, depression and pain catastrophising) based on validated questionnaires. Abnormality was defined by normal reference values. PROs included pain symptom severity (Brief Pain Inventory short form) and quality of life (EORTC-QLQ-C30 questionnaire). Associations between pain-related factors and PROs were investigated by linear trend analyses, multiple regression models and mediation analyses. RESULTS: Clinical evaluation suggestive of pancreatic duct obstruction was observed in 29%, abnormal pain processing in 23%, anxiety in 47%, depression in 39% and pain catastrophising in 28%; each of these factors was associated with severity of at least one PRO. Two or more factors were present in 51% of subjects. With an increasing number of factors, there was an increase in pain severity scores (p<0.001) and pain interference scores (p<0.001), and a reduction in quality of life (p<0.001). All factors had independent and direct effects on PROs, with the strongest effect size observed for psychological distress. CONCLUSION: Pain-related factors in chronic pancreatitis are often present in an overlapping manner and have a cumulative detrimental effect on PROs. These findings support a multidisciplinary strategy for pain management. TRIAL REGISTRATION NUMBER: The study was registered with ClinicalTrials.gov (NCT03434392).

Reduced Thalamic Volume and Metabolites in Type 1 Diabetes with Polyneuropathy.

OBJECTIVE: Thalamus is essential in processing of sensory information. This study explored the associations between thalamic volume and intra-thalamic metabolites and associations to clinical and experimental characteristics of sensory function in adults with diabetic polyneuropathy. METHODS: 48 adults with type 1 diabetes and confirmed distal symmetric peripheral neuropathy (DPSN) and 28 healthy controls participated in a cross-sectional study and underwent a brain magnetic resonance imaging scan. Estimates for thalamic volume were extracted using voxel-based morphometry and intra-thalamic N-acetylaspartate/creatine (NAA/cre) levels were assessed by magnetic resonance spectroscopy. Associations between thalamic volume and clinical measures, quantitative sensory testing and neuropathic phenotype were explored. RESULTS: In diabetes, reduced gray matter volume was identified including bilateral thalamus (all p≤0.001) in comparison to healthy participants. Thalamic volume estimates were positively associated to intra-thalamic NAA/cre (r=0.4; p=0.006), however not to diabetes duration (p=0.5), severity of DSPN (p=0.7), or presence of pain (p=0.3). Individuals with the lowest thalamic volume had greatest loss of protective sensation (light touch using von Frey-like filaments, p=0.037) and highest pain tolerance to electric stimulation (tetanic stimulation, p=0.008) compared to individuals with the highest thalamic volume. CONCLUSIONS: In this cohort with type 1 diabetes and severe DSPN, thalamic atrophy was present and associated with reduced NAA/cre, indicating thalamic structural loss and dysfunction. Thalamic atrophy was associated to reduced sensory function involving large fiber neuropathy and sensation to tetanic stimulation that may reflect synaptic transmission. This may ultimately contribute to the current understanding of the pathophysiology behind the perception changes evident in DSPN.

Placental MRI: Longitudinal relaxation time (T1) in appropriate and small for gestational age pregnancies.

OBJECTIVE: The antenatal detection of small for gestational age (SGA) pregnancies is a challenge, which may be improved by placental MRI. The longitudinal relaxation time (T1) is a tissue constant related to tissue morphology and tissue oxygenation, thereby placental T1 may be related to placental function. The aim of this study is to investigate placental T1 in appropriate for gestational age (AGA) and SGA pregnancies. METHODS: A total of 132 singleton pregnancies were retrieved from our MRI research database. MRI and ultrasound estimated fetal weight (EFW) was performed at gestational week 20.6-41.7 in a 1.5 T system. SGA was defined as BW ≤ -15% of the expected for gestational age (≤10th centile). A subgroup of SGA pregnancies underwent postnatal placental histological examination (PHE) and abnormal PHE was defined as vascular malperfusion. The placental T1 values were converted into Z-scores adjusted for gestational age at MRI. The predictive performance of placental T1 and EFW was compared by receiver operating curves (ROC). RESULTS: In AGA pregnancies, placental T1 showed a negative linear correlation with gestational age (r = -0.36, p = 0.004) Placental T1 was significantly reduced in SGA pregnancies (mean Z-score = -0.34) when compared to AGA pregnancies, p = 0.03. Among SGA pregnancies placental T1 was not reduced in cases with abnormal PHE, p = 0.84. The predictive performance of EFW (AUC = 0.84, 95% CI, 0.77-0.91) was significantly stronger than placental T1 (AUC = 0.62, 95% CI, 0.52-0.72) (p = 0.002). DISCUSSION: A low placental T1 relaxation time is associated with SGA at birth. However, the predictive performance of placental T1 is not as strong as EFW.

T2* weighted placental MRI in relation to placental histology and birth weight.

INTRODUCTION: Placental dysfunction may be found among normal birth weight (BW) pregnancies, as indicated by abnormal histological findings in postnatal placental examination in some of these pregnancies. T2* weighted placental MRI provides non-invasive information on placental oxygenation and thereby placental function. The aim of this study was to investigate the correlation between placental T2*, BW and placental histology. METHODS: A total of 63 pregnant women underwent T2* weighted placental MRI at 15-40 week's gestation and a standardized placental histological examination (PHE). Abnormal PHE was defined by vascular malperfusion according to the Amsterdam workshop consensus. The correlation between PHE, BW z-score and T2* z-score was analyzed by logistic regression. RESULTS: Abnormal PHE was revealed in 28 pregnancies. Multiple logistic regression revealed a significant correlation between abnormal PHE and T2* z-score (OR = 0.34, p = 0.008), whereas BW z-score did not add significantly to the correlation of placental histology (OR = 0.52, p = 0.115). In BW z-score≥0, PHE was normal in 100% of pregnancies. In BW z-score ≤ -2, PHE was abnormal in 89% of pregnancies. In intermediate BW (z-score between -2 and 0), PPE was abnormal in 35% of pregnancies. In this intermediate group, placental T2* z-score was reduced (-1.52 ± 1.22 (mean SD)) when compared to normal PHE pregnancies (-0.28 ± 1.17), p = 0.006. DISCUSSION: This study demonstrates a correlation between abnormal placental histology and low placental T2* value regardless of fetal size. This indicates that T2* provides information of placental function in vivo even when fetal size is normal. This finding highlights that fetal size alone is not a valid marker of placental dysfunction.