Control of OPC proliferation and repopulation by the intellectual disability gene PAK1 under homeostatic and demyelinating conditions.

Appropriate proliferation and repopulation of oligodendrocyte progenitor cells (OPCs) determine successful (re)myelination in homeostatic and demyelinating brains. Activating mutations in p21-activated kinase 1 (PAK1) cause intellectual disability, neurodevelopmental abnormality, and white matter anomaly in children. It remains unclear if and how PAK1 regulates oligodendroglial development. Here, we report that PAK1 controls proliferation and regeneration of OPCs. Unlike differentiating oligodendrocytes, OPCs display high PAK1 activity which maintains them in a proliferative state by modulating PDGFRa-mediated mitogenic signaling. PAK1-deficient or kinase-inhibited OPCs reduce their proliferation capacity and population expansion. Mice carrying OPC-specific PAK1 deletion or kinase inhibition are populated with fewer OPCs in the homeostatic and demyelinated CNS than control mice. Together, our findings suggest that kinase-activating PAK1 mutations stall OPCs in a progenitor state, impacting timely oligodendroglial differentiation in the CNS of affected children and that PAK1 is a potential molecular target for replenishing OPCs in demyelinating lesions.

Quality Indicators for the Diagnosis and Management of Primary Hyperparathyroidism.

IMPORTANCE: Primary hyperparathyroidism (pHPT) is a common endocrine disorder with many diagnostic and treatment challenges. Despite high-quality guidelines, care is variable, and there is low adherence to evidence-based treatment pathways. OBJECTIVE: To develop quality indicators (QIs) to evaluate the diagnosis and treatment of pHPT that could measure, improve, and optimize quality of care and outcomes for patients with this disease. DESIGN, SETTING, AND PARTICIPANTS: This quality improvement study used a guideline-based approach to develop QIs that were ranked by a Canadian 9-member expert panel of 3 endocrinologists, 3 otolaryngologists, and 3 endocrine surgeons. Data were analyzed between September 2020 and May 2021. MAIN OUTCOMES AND MEASURES: Candidate indicators (CIs) were extracted from published primary hyperparathyroidism guidelines and summarized with supporting evidence. The 9-member expert panel rated each CI on the validity, reliability, and feasibility of measurement. Final QIs were selected from CIs using the modified RAND-University of California, Los Angeles appropriateness methodology. All panelists were then asked to rank the top 5 QIs for primary, endocrine, and surgical care. RESULTS: Forty QIs were identified and evaluated by the expert panel. After 2 rounds of evaluations and discussion, a total of 18 QIs were selected as appropriate measures of high-quality care. The top 5 QIs for primary, endocrine, and surgical care were selected following panelist rankings. CONCLUSIONS AND RELEVANCE: This quality improvement study proposes 18 QIs for the diagnosis and management of pHPT. Furthermore, the top 5 QIs applicable to physicians commonly treating pHPT, including general physicians, internists, endocrinologists, otolaryngologists, and surgeons, are included. These QIs not only assess the quality of care to guide the process of improvement, but also can assess the implementation of evidence-based guideline recommendations. Using these indicators in clinical practice and health system registries can improve quality and cost-effectiveness of care for patients with pHPT.

Women's Mid-Life Night Sweats and 2-Year Bone Mineral Density Changes: A Prospective, Observational Population-Based Investigation from the Canadian Multicentre Osteoporosis Study (CaMos).

Women's hot flushes and night sweats, collectively called vasomotor symptoms (VMS), are maximal (79%) in late perimenopause. The evidence describing whether VMS are associated with loss of areal bone mineral density (BMD) is mixed. We examined baseline and 2-year data for 1570 randomly selected women aged 43⁻63 in the Canadian Multicentre Osteoporosis Study (CaMos), a prospective Canada-wide study; we used linear regression to assess the relationship of night sweats (VMSn) with BMD and its changes. Clinically important VMSn occurred for 12.2%. Women with VMSn were slightly younger (54.5 vs. 55.3 years, p = 0.02) and less likely to use sex steroid therapies (39.8% vs. 51.4%, p < 0.05). BMD at the lumbar spine (L1-4), femoral neck (FN) and total hip (TH) were similar between those with/without VMSn. In adjusted models, we did not find a significant association between VMSn and 2-year change in L1-4, FN and TH BMD. Age, reproductive status, weight, sex steroid therapy and smoking status were associated with 2-year change in BMD. Incident fractures over 2 years also did not differ by VMSn. Our analyses were restricted to VMSn and may not truly capture the relationship between VMS and BMD. Additional research involving VMS, bone loss and fracture incidence is needed.

Diabetes Distress, Depression and Glycemic Control in a Canadian-Based Specialty Care Setting.

OBJECTIVES: The objectives of this study were to determine rates of diabetes distress and depression in patients with type 2 diabetes in a tertiary care setting, to examine the relationship among glycemic control, diabetes distress and depression, and to identify predictors of diabetes distress and depression on the basis of demographic and clinical characteristics. METHODS: We recruited 148 adults with type 2 diabetes who were presenting to a specialty diabetes clinic in Vancouver, British Columbia, Canada. Participants completed a questionnaire measuring diabetes distress, depressive symptoms and demographic backgrounds. The Diabetes Distress Scale was used to assess overall distress as well as 4 distinct distress dimensions, including emotional burden, physician-related, regimen-related and interpersonal distress. The Personal Health Questionnaire-9 was used to assess depressive symptoms. Glycated hemoglobin (A1C) data were also collected. RESULTS: The prevalence of diabetes distress and depression was 39% and 12% in our population, respectively. A1C levels emerged as a significant predictor of emotional burden (p=0.03) and regimen-related distress (p=0.01); higher A1C levels were associated with increased distress regarding emotional functioning and regimen adherence. A1C levels (p=0.02) and education levels (p=0.03) emerged as predictors of physician-related distress, with higher A1C levels associated with decreased distress regarding confidence in physicians. CONCLUSIONS: Our findings reveal that the rate of diabetes distress for patients in a tertiary care setting is high. Furthermore, diabetes distress, particularly emotion- and self-care-related distress, plays a significant role in glycemic control, whereas depression does not. Routine screening for diabetes distress as part of an initial specialty clinic evaluation should be explored.

Hypogonadotropic Hypogonadism in Males with Glycogen Storage Disease Type 1.

BACKGROUND: Glycogen storage disease type 1 is an autosomal recessive disorder with an incidence of 1 in 100,000. Long-term complications include chronic blood glucose lability, lactic academia, short stature, osteoporosis, delayed puberty, gout, progressive renal insufficiency, systemic or pulmonary hypertension, hepatic adenomas at risk for malignant transformation, anemia, vitamin D deficiency, hyperuricemic nephrocalcinosis, inflammatory bowel syndrome (type 1b), hypertriglyceridemia, and irregular menstrual cycles. We describe hypogonadotropic hypogonadism as a novel complication in glycogen storage disease (GSD) type 1. Case Studies and Methods: Four unrelated patients with GSD 1a (N = 1) and 1b (N = 3) were found to have hypogonadotropic hypogonadism diagnosed at different ages. Institutional Research Ethics Board approval was obtained as appropriate. Participant consent was obtained. A retrospective chart review was performed and clinical symptoms and results of investigations summarized as a case series. RESULTS: All patients were confirmed biochemically to have low luteinizing hormone (LH) and follicular stimulating hormone (FSH), and correspondingly low total testosterone. Clinical symptoms of hypogonadism varied widely. Investigations for other causes of hypogonadotropic hypogonadism were unremarkable. In addition, all patients were found to have disproportionately low bone mineral density at the lumbar spine compared to the hip. Common to all patients was erratic metabolic control, including recurrent hypoglycemia and elevated lactate levels. DISCUSSION: Recurrent elevations in cortisol in response to hypoglycemia may be the underlying pathology leading to suppression of gonadotropin-releasing hormone (GnRH) release. Incorporating clinical and/or biochemical screening of the hypothalamic-pituitary-gonadal axis may be important in the management of this disease. Testosterone therapy however needs to be carefully considered because of the risk of hepatic adenomas.