Insuficiencia suprarrenal secundaria: una causa subestimada de hiponatremia euvolemica

RESUMEN Introducción: La hiponatremia por insuficiencia suprarenal secundaria es subestimada tratamiento inapropiados. Objetivos: Describir las características clínicas y bioquímicas de pacientes con hiponatremia por insuficiencia suprarrenal secundaria y sus causas. Materiales y Metodos: Revisión retrospectiva de historias clínicas de pacientes consultantes a un hospital de tercer nivel entre Enero 2015 a Septiembre 2017 con hiponatremia y bioquímica de insuficiencia suprarenal secundaria. Los hallazgos fueron comparados con los reportados por estudios previamente publicados. Resultados: Todos los pacientes con insuficiencia suprarrenal secundaria se presentaron con hiponatremia euvolemica hipotónica. 54.5% eran mujeres, la edad promedio fue 57 años. Solo 1 paciente tuvo hiponatremia leve. La mediana de la concentración de cortisol fue 2.8 mcg/dL (RIQ 1.75-3.25 mcg/dL) y la de ACTH fue de 7.7 pg/nL (RIQ 4.5-9.5 pg/nL). Todos los pacientes tuvieron densidad urinaria alta indistinguible del SSIDH. El hipogonadismo hipogonadotrópico y el hipotiroidismo central fueron las alteraciones de ejes hipofisarios mas comúnmente asociados. La presencia de hipoglicemia, hipotensión e hipercaliemia fue baja. La causa más frecuente fue silla turca vacía. Conclusiones: La hiponatremia hipotonica euvolémica es una presentación común de insuficiencia suprarrenal secundaria y no suele acompañarse de otras manifestaciones de deficiencia de glucocorticoides. Es clínica y bioquímicamente indistinguible del SSIDH. Un bajo umbral de sospecha y la medición de cortisol serico matutino es esencial en estos pacientes para evitar un diagnostico y manejo inapropiados.

ABSTRACT Introduction: Hyponatremia due to secondary adrenal insufficiency is frequently underestimated and underdiagnosed. This paper underscores the importance of an adequate evaluation of euvolemic hyponatremia to avoid an inappropriate treatment and diagnosis. Objectives: To describe the clinical and biochemical characteristics of patients with hyponatremia due to secondary adrenal insufficiency and its causes. Materials and Methods: A retrospective review of the clinical records of patients presenting to a third level hospital between January 2015 to September 2017 with hyponatremia and a biochemical profile of secondary adrenal insufficiency. Findings were compared with previously published reports. Results: All patients with secondary adrenal insufficiency presented with hypotonic euvolemic hyponatremia. 54.5% of patients were females, median age was 57 years. Only 1 patient had mild hyponatremia. Cortisol median concentration was 2.8 mcg/dL (IQR 1.75-3.25 mcg/dL) and median ACTH concentration was 7.7 pg/nL (IQR 4.5-9.5 pg/nL). All the patients had high urinary density and features indistinguishable from SIADH. Hypogonadotropic hypogonadism and central hypothyroidism were the most commonly accompanying hypophyseal axis. Hypoglycemia, hypotension, and hyperkalemia were infrequent findings in these patients. The most frequent etiology identified was empty sella syndrome. Conclusions: Euvolemic hypotonic hyponatremia is a common presentation of secondary adrenal insufficiency and is often not accompanied with other manifestations of glucocorticoid deficiency. This disease is clinical and biochemical indistinguishable from SIADH. A low threshold for suspicion and a serum morning cortisol measurement in these patients is essential to avoid an inappropriate diagnosis and management.

Effect of Long-Term Periodontal Care on Hemoglobin A1c in Type 2 Diabetes.

This was a prospective cohort study evaluating 126,805 individuals with diabetes and periodontal disease receiving care at all Veterans Administration medical centers and clinics in the United States from 2005 through 2012. The exposures were periodontal treatment at baseline (PT0) and at follow-up (PT2). The outcomes were change in HbA1c following initial treatment (ΔHbA1c1) and follow-up treatment (ΔHbA1c2), and diabetes control was defined as HbA1c at <7% and <9% following initial and follow-up treatment, respectively. Marginal structural models were used to account for potential confounding and selection bias. The objective was to evaluate the impact of long-term treatment of periodontal disease on glycemic control among individuals with type 2 diabetes. Participants were 64 y old on average, 97% were men, and 71% were white. At baseline, the average diabetes duration was 4 y, 12% of participants were receiving insulin, and 60% had HbA1c <7%. After an average 1.7 y of follow-up, the mean HbA1c increased from 7.03% to 7.21%. About 29.4% of participants attended their periodontal maintenance visit following baseline. Periodontal treatment at baseline and follow-up reduced HbA1c by -0.02% and -0.074%, respectively. Treatment at follow-up increased the likelihood of individuals achieving diabetes control by 5% and 3% at the HbA1c <7% and HbA1c <9% thresholds, respectively, and was observed even among never smokers. HbA1c reduction after periodontal treatment at follow-up was greater (ΔHbA1c2 = -0.25%) among individuals with higher baseline HbA1c. Long-term periodontal care provided in a clinical setting improved long-term glycemic control among individuals with type 2 diabetes and periodontal disease.

Nanomolar levels of PAHs in extracts from urban air induce MAPK signaling in HepG2 cells.

Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants that occur naturally in complex mixtures. Many of the adverse health effects of PAHs including cancer are linked to the activation of intracellular stress response signaling. This study has investigated intracellular MAPK signaling in response to PAHs in extracts from urban air collected in Stockholm, Sweden and Limeira, Brazil, in comparison to BP in HepG2 cells. Nanomolar concentrations of PAHs in the extracts induced activation of MEK4 signaling with down-stream increased gene expression of several important stress response mediators. Involvement of the MEK4/JNK pathway was confirmed using siRNA and an inhibitor of JNK signaling resulting in significantly reduced MAPK signaling transactivated by the AP-1 transcription factors ATF2 and c-Jun. ATF2 was also identified as a sensitive stress responsive protein with activation observed at extract concentrations equivalent to 0.1 nM BP. We show that exposure to low levels of environmental PAH mixtures more strongly activates these signaling pathways compared to BP alone suggesting effects due to interactions. Taken together, this is the first study showing the involvement of MEK4/JNK/AP-1 pathway in regulating the intracellular stress response after exposure to nanomolar levels of PAHs in environmental mixtures.

Molecular characterization of the Enterococcus faecalis cytolysin activator.

The gene encoding component A (cylA), the activator protein of the Enterococcus faecalis cytolysin, has been localized on pAD1, and the nucleotide sequence was determined. cylA consists of a 1,236-bp open reading frame encoding a 412-amino-acid polypeptide. A search of the National Biomedical Research Foundation data base revealed significant homology between the inferred amino acid sequence of component A and subtilisin BPN'. Component A activation of the cytolysin precursor (component L) was observed to be inhibited by the serine protease inhibitor diisopropylfluorophosphate. Mature component A exhibits a molecular weight of approximately 30,000 and an isoelectric point of 4.5. Differences between the size of the primary translation product (45,625 daltons) and the mature enzyme suggest that, as for subtilisin, component A is secreted as a proenzyme. These results provide the basis for a model of component A activation of component L and a role for component A in protecting the cytolysin-producing cell from lysis.