Experimental pharmacological approaches to reverse impaired awareness of hypoglycemia-a review.

The colossal global burden of diabetes management is compounded by the serious complication of hypoglycemia. Protective physiologic hormonal and neurogenic counterregulatory responses to hypoglycemia are essential to preserve glucose homeostasis and avert serious morbidity. With recurrent exposure to hypoglycemic episodes over time, these counterregulatory responses to hypoglycemia can diminish, resulting in an impaired awareness of hypoglycemia (IAH). IAH is characterized by sudden neuroglycopenia rather than preceding cautionary autonomic symptoms. IAH increases the risk of subsequent sudden and severe hypoglycemic episodes in patients with diabetes. The postulated causative mechanisms behind IAH are complex and varied. It is therefore challenging to identify a single effective therapeutic strategy. In this review, we closely examine the efficacy and feasibility of a myriad of pharmaceutical interventions in preventing and treating IAH as described in clinical and preclinical studies. Pharmaceutical agents outlined include N-acetyl cysteine, GABA A receptor blockers, opioid receptor antagonists, AMP activated protein kinase agonists, potassium channel openers, dehydroepiandrosterone, metoclopramide, antiadrenergic agents, antidiabetic agents and glucagon.

Population Pharmacokinetic Model of N-Acetylcysteine During Periods of Recurrent Hypoglycemia in Healthy Volunteers.

Recurrent hypoglycemia leads to impaired awareness of hypoglycemia where the blood glucose threshold that elicits the counterregulatory response is lowered. Hypoglycemia-induced oxidative stress is hypothesized to contribute to impaired awareness of hypoglycemia development and hypoglycemia-associated autonomic failure. Our group conducted a randomized, double-blinded, placebo-controlled, crossover study in healthy individuals undergoing experimentally induced recurrent hypoglycemia to evaluate the impact of intravenous N-acetylcysteine (NAC) during experimental hypoglycemia to preserve the counterregulatory response to subsequent hypoglycemia. The work presented herein aimed to characterize the NAC pharmacokinetics and its effects on oxidative stress. Whole blood and plasma samples were collected at specified time points during separate NAC and placebo infusions from 10 healthy volunteers. Samples were analyzed for NAC, cysteine, and glutathione (GSH) concentrations. A 2-compartment population NAC pharmacokinetic model was developed. Estimates for central compartment clearance and volume of distribution were 19.8 L/h, and 12.2 L, respectively, for a 70-kg person. Peripheral compartment clearance and volume of distribution estimates were 34.9 L/h and 13.1 L, respectively, for a 70-kg person. The PK parameters estimated here were different from those reported in the literature, suggesting a higher NAC clearance during hypoglycemic episodes. NAC leads to a significant increase in circulating cysteine concentration in a NAC concentration-dependent manner, suggesting rapid biotransformation. A transient decrease in plasma GSH was observed, supporting the hypothesis that NAC can act as a reducing agent displacing glutathione from the disulfide bond allowing for increased clearance and/or distribution of GSH.

A rare case of isolated IgG4-related hypophysitis with Rathke's cleft cyst presenting as panhypopituitarism.

Summary: We report a rare case of biopsy-proven isolated immunoglobulin G4 (IgG4)-related hypophysitis and Rathke's cleft cyst (RCC) presenting as panhypopituitarism. A 54-year-old Caucasian female presented with symptoms of slurred speech, altered mental status, polyuria and polydipsia and was found to have panhypopituitarism. Brain MRI showed a suprasellar mass with suspected intralesional hemorrhage. She underwent trans-sphenoidal resection due to MRI evidence of compression of the optic chiasm and left optic nerve. Preoperatively, she was started on hydrocortisone, levothyroxine and desmopressin. Histopathology demonstrated a RCC with adjacent lymphoplasmacytic hypophysitis with numerous IgG4-immunoreactive plasma cells. Hydrocortisone was stopped at 10 months after confirming hypothalamic-pituitary-adrenal (HPA)-axis recovery and desmopressin was stopped at 1 year. There was recurrence of a cystic mass at 1 year follow-up. Over 4 years of follow-up, she continued to require levothyroxine, and the mass remained stable in size. In order to begin to understand how this case's unique histopathological presentation influences clinical presentation, pituitary imaging and prognosis, we present an accompanying literature review. Learning points: Isolated IgG4 hypophysitis and coexisting Rathke's cleft cyst is a rare condition, which presents a diagnostic challenge. Recognizing its characteristic features can assist with early recognition and initiation of therapy to promote optimal outcomes. Further studies investigating the mechanisms promoting co-occurrence of these entities and their effect on prognosis are needed.

The impact of elexacaftor/tezacaftor/ivacaftor on body composition in a small cohort of youth with cystic fibrosis.

BACKGROUND: The effects of elexacaftor-tezacaftor-ivacaftor (ETI) on body composition in people with CF (pwCF) are unknown. METHODS: Dual-energy X-ray absorptiometry fat-free mass and fat mass adjusted for height (FMI) as well as oral glucose tolerance test derived measures of insulin secretion and sensitivity were compared before and after ETI initiation in eight pwCF. RESULTS: Patients median age: 22 years interquartile range (IQR: 16-28), 87.5% male, median time on ETI:11 months. Weight z-score increased from -0.52 to 0.18 (p = 0.014); FMI increased from 4.12 to 6.29 (p = 0.014). Insulin secretion (C pep iAUC/Gluc iAUC) increased from 8.71 to 14.21 (p = 0.021), insulin resistance (HOMA2 IR) increased from 0.73 to 1.25 (p = 0.014) and insulin sensitivity decreased (Matsuda) 8.88 to 5.58 (p = 0.036). CONCLUSIONS: ETI resulted in increased weight and fat mass. BMI and muscle mass did not change. Both insulin secretion and insulin resistance increased. Longer-term metabolic consequences of ETI need further investigation.

Clinical Presentation and Diagnostic Approach to Hypoglycemia in Adults Without Diabetes Mellitus.

OBJECTIVE: To review the clinical presentation, causes, and diagnostic approach to spontaneous hypoglycemia in adults without diabetes mellitus. METHODS: A literature review was performed using the PubMed and Google Scholar databases. RESULTS: Hypoglycemia is uncommon in people who are not on glucose-lowering medications. Under normal physiologic conditions, multiple neural and hormonal counterregulatory mechanisms prevent the development of abnormally low levels of plasma glucose. If spontaneous hypoglycemia is suspected, the Whipple triad should be used to confirm hypoglycemia before pursuing further diagnostic workup. The Whipple criteria include the following: (1) low levels of plasma glucose, (2) signs or symptoms that would be expected with low levels of plasma glucose, and (3) improvement in those signs or symptoms when the level of plasma glucose increases. Spontaneous hypoglycemia can be caused by conditions that cause endogenous hyperinsulinism, including insulinoma, postbariatric hypoglycemia, and noninsulinoma pancreatogenous hypoglycemia. Spontaneous hypoglycemia can also be seen with critical illness, hepatic or renal dysfunction, hormonal deficiency, non-diabetes-related medications, and non-islet cell tumors. The initial diagnostic approach should begin by obtaining a detailed history of the nature and timing of the patient's symptoms, medications, underlying comorbid conditions, and any acute illness. A laboratory evaluation should be conducted at the time of the spontaneous symptomatic episode. Supervised tests such as a 72-hour fast or mixed-meal test may be needed to recreate the situation under which the patient is likely to experience symptoms. CONCLUSION: We provide an overview of the physiology of counterregulatory response to hypoglycemia, its causes, and diagnostic approaches to spontaneous hypoglycemia in adults.

Coronary artery disease in patients with cystic fibrosis - A case series and review of the literature.

Progressive obstructive pulmonary disease is the primary life-shortening complication in people with Cystic Fibrosis (CF); improvement in life expectancy has led to increased prevalence of non-pulmonary complications. Patients with CF are considered to be at low risk for coronary artery disease (CAD). We report here a case series of six patients with CF with and without known cystic fibrosis related diabetes (CFRD) who had acute myocardial infarction (AMI) requiring coronary stent placement. This was a heterogeneous group of patients, without a clear pattern of consistent risk factors. Interestingly, most patients in this cohort had low LDL. In this review, we discuss risk factors of cardiovascular disease (CVD) that may apply to the CF population. While CAD is rare in people with CF, it does occur. We postulate that the risk will grow with increased longevity and the increased prevalence of co-morbidities such as obesity and dyslipidemia.

Hospital-Care Utilization and Medical Cost Patterns Among Patients With Insulin-Dependent Diabetes.

OBJECTIVE: Using claims data from an integrated payer-provider, we compared costs incurred by patients with insulin-dependent diabetes mellitus (IDDM) who received Hospital Inpatient/Observation/EmeRgency Department care (HIghER care) for diabetes-related events with those who did not receive such care to identify a target population for interventions in future studies. METHODS: A retrospective study pooled real-world claims data for IDDM (type 1 or type 2) between July 1, 2018, and June 30, 2019. Medical claims were used to calculate the total and diabetes-related allowed medical costs to the enterprise and per member per month costs. RESULTS: Medical and prescription drug coverage from 19 378 members was analyzed. Only 8.4% of the IDDM population received HIghER care but incurred 20% of medical expenses and nearly 40% of diabetes-related medical costs. For HIghER care patients, medical spending was higher in every inpatient and outpatient category (Wilcoxon 2-sample tests, all P < .0001). Non-diabetes-related prescription drug costs were greater in this group (Wilcoxon test, Z = 2.2879, P = .0221), whereas diabetes-related prescription drug costs were higher for non-HIghER care (Wilcoxon test, Z = -9.5918, P < .0001). In a longitudinal study of 29 602 patients over 24 months, previous-year receipt of HIghER care was a significant predictor of HIghER care the subsequent year (odds ratio, 3.28). CONCLUSION: Medical spending for patients receiving HIghER care was disproportionately high and greater in every inpatient and outpatient category. HIghER care receipt the previous year was highly predictive of HIghER care episodes the following year.

Relationship Between Hypoglycemia Awareness Status on Clarke/Gold Methods and Counterregulatory Response to Hypoglycemia.

Context: Impaired awareness of hypoglycemia (IAH) is characterized by the diminished ability to perceive symptoms of hypoglycemia. Gold and Clark questionnaires are commonly used to identify patients with IAH. The relationship between IAH status on questionnaires and a person's symptom and epinephrine responses to hypoglycemia are not well understood. Objective: We aimed to examine the relationship between hypoglycemia awareness status on Clarke and Gold questionnaires with both hormonal and symptomatic responses to experimental hypoglycemia. Methods: In this university medical center study, we examined data from 78 subjects with type 1 diabetes (T1D) who completed both questionnaires and underwent a hyperinsulinemic hypoglycemic clamp (target glucose 50 mg/dL). Results: Clarke and Gold scores were highly correlated with one another (r = 0.82) and each had a moderate negative relationship with epinephrine (Clarke: r = -0.51, Gold: r = -0.50) and total symptom response (Clarke: r = -0.59, Gold: r = -0.57). However, 32% of the subjects were classified inconsistently by Clark vs Gold. A clustering analysis was done to examine how disagreement between the 2 questionnaires on IAH classification relates to epinephrine and symptoms responses during hypoglycemia. Subjects who had partial loss of symptoms or of epinephrine response were more likely to be classified inconsistently. Conclusion: Our results show that IAH classification may be discordant between Clark and Gold questionnaires and that hypoglycemia awareness status on Clarke and Gold questionnaires poorly predicts hormonal and symptomatic responses to hypoglycemia in subjects with T1D and moderate blunting of symptoms or epinephrine.

Heterogeneity in Epinephrine Response to Experimental Hypoglycemia in Type 1 Diabetes and Controls.

Context: The epinephrine response (Epi) to a first episode of hypoglycemia (HG) has been proposed to be predictive of Epi in subsequent HG and to provide insight into the risk for developing HG-associated autonomic failure (HAAF) in healthy controls (HCs). Objective: To determine if Epi and symptom response (SR) to the first episode of HG predicts who will develop HAAF after exposure to recurrent HG in volunteers with type 1 diabetes (T1D) and in HCs. Design: Review of data collected between 2013 and 2019. Setting: Academic clinical research unit. Patients or Participants: Volunteers with T1D and HCs. Interventions: Subjects participated in a preinduction protocol where they were exposed to three 2-hour episodes of clamped HG over 2 days. Data collected during clamp 1 were compared with data collected during clamp 3. Main outcome measure: Difference in Epi and SR. Results: Using the standard definition of HAAF in which HG-induced Epi during clamp 3 is at least 20% lower than during clamp 1, 21/28 HCs and 13/19 volunteers with T1D developed HAAF. Epi during clamp 1 was significantly higher in those subjects who developed HAAF than in those who did not in both groups (P = 0.02). If HAAF is defined as achieving a 20% reduction in HG-induced SR measured during clamp 3 compared with clamp 1, 10/27 HCs and 10/19 volunteers with T1D developed SR-based HAAF. Conclusion: There was heterogeneity in the response to the preinduction protocol. Epi during clamp 1 was higher than in clamp 3 in HCs and in those with T1D who developed HAAF.

New Concepts in the Pathogenesis of Cystic Fibrosis-Related Diabetes.

CONTEXT: Cystic fibrosis-related diabetes (CFRD) is the most common extrapulmonary complication of cystic fibrosis (CF). Approximately 40% of people with CF who are older than 20 years have CFRD. Presence of CFRD is associated with poor health outcomes in people with CF. OBJECTIVE: This review summarizes current knowledge on pathophysiology of CFRD. METHODS: A PubMed review of the literature was conducted, with search terms that included CFRD, cystic fibrosis, cystic fibrosis related diabetes, and cystic fibrosis transmembrane conductance regulator (CFTR). Additional sources were identified through manual searches of reference lists. Pathophysiology of CFRD: The pathophysiology underlying development of glucose tolerance abnormalities in CF is complex and not fully understood. ß-cell loss and functional impairment of the remaining ß-cell function results in progressive insulin insufficiency. Factors that may contribute to development of CFRD include local islet and systemic inflammation, alterations in the incretion hormone axis, varying degrees of insulin resistance and genetic factors related to type 2 diabetes. CONCLUSION: The prevalence of CFRD is expected to further increase with improving life expectancy of people with CF. Further research is needed to better understand the mechanisms underlying the development of CFRD and the impact of diabetes on clinical outcomes in CF.

Different FreeSurfer versions might generate different statistical outcomes in case-control comparison studies.

PURPOSE: Neuroimaging pipelines have long been known to generate mildly differing results depending on various factors, including software version. While considered generally acceptable and within the margin of reasonable error, little is known about their effect in common research scenarios such as inter-group comparisons between healthy controls and various pathological conditions. The aim of the presented study was to explore the differences in the inferences and statistical significances in a model situation comparing volumetric parameters between healthy controls and type 1 diabetes patients using various FreeSurfer versions. METHODS: T1- and T2-weighted structural scans of healthy controls and type 1 diabetes patients were processed with FreeSurfer 5.3, FreeSurfer 5.3 HCP, FreeSurfer 6.0 and FreeSurfer 7.1, followed by inter-group statistical comparison using outputs of individual FreeSurfer versions. RESULTS: Worryingly, FreeSurfer 5.3 detected both cortical and subcortical volume differences out of the preselected regions of interest, but newer versions such as FreeSurfer 5.3 HCP and FreeSurfer 6.0 reported only subcortical differences of lower magnitude and FreeSurfer 7.1 failed to find any statistically significant inter-group differences. CONCLUSION: Since group averages of individual FreeSurfer versions closely matched, in keeping with previous literature, the main origin of this disparity seemed to lie in substantially higher within-group variability in the model pathological condition. Ergo, until validation in common research scenarios as case-control comparison studies is included into the development process of new software suites, confirmatory analyses utilising a similar software based on analogous, but not fully equivalent principles, might be considered as supplement to careful quality control.

The Effect of Control IQ Hybrid Closed Loop Technology on Glycemic Control in Adolescents and Adults with Cystic Fibrosis-Related Diabetes.

Background: Cystic fibrosis-related diabetes (CFRD) is associated with pulmonary decline, compromised nutritional status, and earlier mortality. Although diabetes technology is increasingly being used in individuals with CFRD, there is a paucity of data investigating the impact of hybrid closed loop (HCL) technology on glycemia in this patient population. Materials and Methods: In this multicenter retrospective study of 13 adults and adolescents with CFRD, 14 days of continuous glucose monitor data were analyzed at baseline, 1 and 3 months after transition to the Tandem t:slim X2 pump with Control IQ™ technology, a HCL system. Results: Control IQ initiation was associated with a significant increase in % time in target range (70-180 mg/dL), as well as decreases in average glucose, % time in hyperglycemic ranges (% time >180 mg/dL, % time >250 mg/dL), and glycemic variability (standard deviation, coefficient of variation). There was no significant change in % time in hypoglycemia ranges (% time <54 mg/dL, % time <70 mg/dL). Conclusions: To our knowledge, this is the first study to report a beneficial effect of Food and Drug Administration (FDA)-approved HCL technology on glycemia in adults and adolescents with CFRD to date. Future studies are needed to understand the potential long-term glycemic benefits of HCL devices and to explore the impact of this technology on heath-related quality of life, pulmonary function, nutritional status, and mortality.

Glycemia and ß-cell function before and after elexacaftor/tezacaftor/ivacaftor in youth and adults with cystic fibrosis.

Background: Diabetes is prevalent among people with CF (PwCF) and associated with worse clinical outcomes. CFTR modulators are highly effective in improving the disease course of CF. However, the effects of elexacaftor/tezacaftor/ivacaftor (ETI) on glucose metabolism in PwCF are unclear. Methods: Twenty youth and adults with CF underwent frequently sampled oral glucose tolerance tests (fsOGTT) before and after ETI initiation. Glucose, insulin, and C-peptide were collected at 0, 10, 30, 60, 90, and 120 min after 1.75 g/kg (max 75 g) of dextrose. HbA1c and continuous glucose monitoring (CGM) were collected in a subset. Estimates of insulin secretion (C-peptide index), insulin resistance (HOMA2 IR and IS(OGTT Cpep)), and ß-cell function (C-peptide oral disposition index, oDIcoeo), were compared before and after ETI. Results: Participants were a median (IQR) of 20.4 (14.1, 28.6) years old, 75 % male. Follow-up occurred 10.5 (10.0, 12.3) months after ETI initiation. BMI z-score increased from 0.3 (-0.3, 0.8) to 0.8 (0.4, 1.5), p = 0.013 between visits. No significant differences were observed in glucose tolerance, glucose area under the curve, nor fsOGTT glucose concentrations before and after ETI. Median (IQR) C-peptide index increased from 5.7 (4.1, 8.3) to 8.8 (5.5, 10.8) p = 0.013 and HOMA2 IR increased (p < 0.001), while oDIcoeo was unchanged (p = 0.67). HbA1c decreased from 5.5 % (5.5, 5.8) to 5.4 % (5.2, 5.6) (p = 0.003) while CGM variables did not change. Conclusions: BMI z-score and measures of both insulin resistance and insulin secretion increased within the first year of ETI initiation. ß-cell function adjusted for insulin sensitivity (oDIcoeo) did not change.

Obesity in cystic fibrosis.

The prevalence of obesity in patients with cystic fibrosis (CF) is increasing and around one-third of adults with CF are now overweight or obese. The causes of excess weight gain in CF are likely multifactorial, including: adherence to the high-fat legacy diet, reduced exercise tolerance, therapeutic advances, and general population trends. Increased weight has generally been considered favorable in CF, correlating with improved pulmonary function and survival. While the optimal BMI for overall health in CF is unknown, most studies demonstrate minimal improvement in pulmonary function when BMI exceeds 30 kg/m2. Dyslipidemia and cardiovascular disease are important co-morbidities of obesity in the general population, but are uncommon in CF. In people with CF, obesity is associated with hypertension and higher cholesterol levels. With longer life expectancy and rising obesity rates, there may be an increase in cardiovascular disease among people with CF in coming years. Overweight CF patients are more likely to be insulin resistant, taking on features of type 2 diabetes. Treating obesity in people with CF requires carefully weighing the metabolic risks of overnutrition with the impact of low or falling BMI on lung function. This article describes current knowledge on the epidemiology, causes, consequence, and treatment of obesity in people with CF.

Spontaneous and iatrogenic hypoglycemia in cystic fibrosis.

Spontaneous episodes of hypoglycemia can occur in people with cystic fibrosis (CF) without diabetes, who are not on glucose lowering medications. Spontaneous hypoglycemia in CF could occur both in the fasting or postprandial state (reactive hypoglycemia). The pathophysiology of fasting hypoglycemia is thought to be related to malnutrition and increased energy expenditure in the setting of inflammation and acute infections. Reactive hypoglycemia is thought to be due to impaired first phase insulin release in response to a glucose load, followed by a delayed and extended second phase insulin secretion; ineffective counterregulatory response to dropping glucose levels may also play a role. The overall prevalence of spontaneous hypoglycemia varies from 7 to 69% as examined with oral glucose tolerance test (OGTT) or with continuous glucose monitoring (CGM) under free living conditions. Spontaneous hypoglycemia in CF is associated with worse lung function, higher hospitalization rates, and worse clinical status. In addition, patients with CF related diabetes on glucose-lowering therapies are at risk for iatrogenic hypoglycemia. In this article, we will review the pathophysiology, prevalence, risk factors, clinical implications, and management of spontaneous and iatrogenic hypoglycemia in patients with CF.

Monitoring the Neurotransmitter Response to Glycemic Changes Using an Advanced Magnetic Resonance Spectroscopy Protocol at 7T.

The primary excitatory and inhibitory neurotransmitters glutamate (Glu) and gamma-aminobutyric acid (GABA) are thought to be involved in the response of the brain to changes in glycemia. Therefore, their reliable measurement is critical for understanding the dynamics of these responses. The concentrations of Glu and GABA, as well as glucose (Glc) in brain tissue, can be measured in vivo using proton (1H) magnetic resonance spectroscopy (MRS). Advanced MRS methodology at ultrahigh field allows reliable monitoring of these metabolites under changing metabolic states. However, the long acquisition times needed for these experiments while maintaining blood Glc levels at predetermined targets present many challenges. We present an advanced MRS acquisition protocol that combines commercial 7T hardware (Siemens Scanner and Nova Medical head coil), BaTiO3 dielectric padding, optical motion tracking, and dynamic frequency and B0 shim updates to ensure the acquisition of reproducibly high-quality data. Data were acquired with a semi-LASER sequence [repetition time/echo time (TR/TE) = 5,000/26 ms] from volumes of interest (VOIs) in the prefrontal cortex (PFC) and hypothalamus (HTL). Five healthy volunteers were scanned to evaluate the effect of the BaTiO3 pads on B 1 + distribution. Use of BaTiO3 padding resulted in a 60% gain in signal-to-noise ratio in the PFC VOI over the acquisition without the pad. The protocol was tested in six patients with type 1 diabetes during a clamp study where euglycemic (~100 mg/dL) and hypoglycemic (~50 mg/dL) blood Glc levels were maintained in the scanner. The new protocol allowed retention of all HTL data compared with our prior experience of having to exclude approximately half of the HTL data in similar clamp experiments in the 7T scanner due to subject motion. The advanced MRS protocol showed excellent data quality (reliable quantification of 11-12 metabolites) and stability (p > 0.05 for both signal-to-noise ratio and water linewidths) between euglycemia and hypoglycemia. Decreased brain Glc levels under hypoglycemia were reliably detected in both VOIs. In addition, mean Glu level trended lower at hypoglycemia than euglycemia for both VOIs, consistent with prior observations in the occipital cortex. This protocol will allow robust mechanistic investigations of the primary neurotransmitters, Glu and GABA, under changing glycemic conditions.

Lumacaftor/ivacaftor therapy fails to increase insulin secretion in F508del/F508del CF patients.

BACKGROUND: Glucose tolerance abnormalities including cystic fibrosis related diabetes (CFRD) are common in patients with cystic fibrosis (CF). The underlying pathophysiology is not fully understood. Emerging evidence suggests that CFTR dysfunction may directly or indirectly impact ß-cell function, offering the potential for improvement with CFTR modulator therapy. In small pilot studies, treatment with ivacaftor improved insulin secretion in patients with the G551D CFTR mutation. In the current study, we examined the impact of lumacaftor/ivacaftor therapy on glucose tolerance and insulin secretion in patients with CF who were homozygous for the F508del mutation. METHODS: 39 subjects from the PROSPECT Part B study who had been prescribed lumacaftor/ivacaftor by their CF care team at a CF Foundation's Therapeutic Development Network center were recruited. Subjects underwent 2-hour oral glucose tolerance tests (OGTTs) at baseline prior to first dose of lumacaftor/ivacaftor, and at 3, 6 and 12 months on therapy. OGTT glucose, insulin and c-peptide parameters were compared. RESULTS: Compared to baseline, OGTT fasting and 2 hour glucose levels, glucose area under the curve, insulin area under the curve and time to peak insulin level were not significantly different at 3, 6 and 12 months on lumacaftor/ivacaftor therapy. Similarly, C-peptide levels were no different. CONCLUSIONS: Lumacaftor/ivacaftor therapy did not improve insulin secretion or glucose tolerance in patients with CF who were homozygous for the F508del mutation.

Structural Alterations in Deep Brain Structures in Type 1 Diabetes.

Even though well known in type 2 diabetes, the existence of brain changes in type 1 diabetes (T1D) and both their neuroanatomical and clinical features are less well characterized. To fill the void in the current understanding of this disease, we sought to determine the possible neural correlate in long-duration T1D at several levels, including macrostructural, microstructural cerebral damage, and blood flow alterations. In this cross-sectional study, we compared a cohort of 61 patients with T1D with an average disease duration of 21 years with 54 well-matched control subjects without diabetes in a multimodal MRI protocol providing macrostructural metrics (cortical thickness and structural volumes), microstructural measures (T1-weighted/T2-weighted [T1w/T2w] ratio as a marker of myelin content, inflammation, and edema), and cerebral blood flow. Patients with T1D had higher T1w/T2w ratios in the right parahippocampal gyrus, the executive part of both putamina, both thalami, and the cerebellum. These alterations were reflected in lower putaminal and thalamic volume bilaterally. No cerebral blood flow differences between groups were found in any of these structures, suggesting nonvascular etiologies of these changes. Our findings implicate a marked nonvascular disruption in T1D of several essential neural nodes engaged in both cognitive and motor processing.

Infusion of N-acetyl cysteine during hypoglycaemia in humans does not preserve the counterregulatory response to subsequent hypoglycaemia.

AIM: Administration of N-acetyl cysteine (NAC) during hypoglycaemia will preserve the counterregulatory response to subsequent hypoglycaemia in healthy humans. METHODS: This was a randomized double-blind cross over study where humans were given either a 60-minute infusion of NAC (150 mg/kg) followed by a 4-hour infusion of NAC (50 mg/kg) or saline starting 30 minutes before the initiation of a 2-hour hypoglycaemic (HG) clamp at 8 am. After rest at euglycaemia for ~2 hours, subjects were exposed to a 2nd HG clamp at 2 pm and discharged home in euglycaemia. They returned the following day for a 3rd HG clamp at 8 am. RESULTS: Twenty-two subjects were enrolled. Eighteen subjects completed the entire protocol. The epinephrine response during clamp 3 (171 ± 247 pg/mL) following clamp 1 NAC infusion was lower than the response during the clamp 1 NAC infusion (538 ± 392 pg/mL) (clamp 3 to clamp 1 NAC: P = .0013). The symptom response during clamp 3 (7 ± 5) following clamp 1 NAC infusion was lower than the response during the clamp 1 NAC infusion (16 ± 10) (clamp 3 to clamp 1 NAC: P = .0003). Nine subjects experienced rash, pruritus or nausea during NAC infusion. CONCLUSION: We found no difference in the hormone and symptom response to experimental hypoglycaemia measured in subjects who were administered NAC as opposed to saline the day before. This observation suggests that further development of NAC as a therapy for impaired awareness of hypoglycaemia in patients with diabetes may be unwarranted.

Prevalence and factors associated with overweight and obesity in adults with cystic fibrosis: A single-center analysis.

BACKGROUND: The relation between malnutrition and pulmonary death in patients with cystic fibrosis (CF) has resulted in intensive nutritional intervention over the last few decades, leading to a significant decline in underweight and the emergence of overweight/obesity as a potential new problem. METHODS: We performed a cross-sectional database analysis of 484 adults with CF seen at the University of Minnesota CF Center between January 2015-January 2017, to determine the prevalence and pulmonary/cardiovascular risk factors associated with overweight and obesity in this population. RESULTS: Mean age was 35.2 ±â€¯11.6 years. 5.2% were underweight (BMI<18.5 kg/m2), 62.6% normal weight (BMI ≥ 18.5-24.9 kg/m2), 25.6% overweight (BMI ≥ 25-29.9 kg/m2) and 6.6% obese (BMI ≥ 30 kg/m2). In the subgroup with severe genotypes, 25% had BMI ≥ 25 kg/m2. In the entire cohort, overweight/obese were likely to be older (OR = 1.04, p < 0.0001) and to have a mild CFTR genotype (OR = 3.33, p = 0.0003) and modestly elevated triglyceride levels (OR = 1.008, p < 0.0001). The prevalence of hypertension was higher in overweight (25%) and obese (31%) than normal (17%) or underweight (16%), p = 0.01. Total cholesterol levels were higher in overweight/obese versus normal/underweight (144-147 vs 123-131 mg/dL, p = 0.04) as were LDL levels (70-71 vs 53-60 mg/dL, p = 0.02), but all were within the normal range. Percent predicted FEV1 was higher in overweight/obese (78-81%) versus underweight (59%) and normal (70%), p < 0.0001, and overweight/obese experienced significantly fewer acute pulmonary exacerbations. CONCLUSIONS: Overweight/obesity is common in adults with CF including those with severe genotypes. Lung function is better in the overweight/obese and lipid levels are within the normal range, albeit higher than in normal/underweight.