Efficacy and Safety of Low-dose Spironolactone for Chronic Kidney Disease in Type 2 Diabetes.

CONTEXT: Although adding spironolactone to renin-angiotensin system blockers reduces albuminuria in adults with chronic kidney disease and type 2 diabetes, it increases the risk of hyperkalemia. OBJECTIVE: To assess whether a lower dose of spironolactone (12.5 mg/d) reduces the risk of hyperkalemia while maintaining its effect on reducing albuminemia. DESIGN: Multicenter, open-label, randomized controlled trial. SETTING: This study was conducted from July 2016 to November 2020 in ambulatory care at 3 diabetes medical institutions in Japan. PATIENTS: We enrolled 130 Japanese adults with type 2 diabetes and albuminuria (≥30 mg/gCre), estimated glomerular filtration rate ≥30 mL/min/1.73 m2, and serum potassium level <5.0 mEq/L. INTERVENTIONS: The participants were randomly assigned to the spironolactone-administered and control groups. MAIN OUTCOME MEASURES: Changes in urine albumin-to-creatinine ratio (UACR) from baseline over the 24-week interventional period. RESULTS: The spironolactone group showed a significant reduction in UACR from baseline (mean decrease, 103.47 ± 340.80 mg/gCre) compared with the control group, which showed an increased UACR (mean increase, 63.93 ± 310.14 mg/gCre; P = .0007, Wilcoxon rank-sum test and t test). Although the spironolactone group had a statistically significant increase in serum potassium levels, none of the participants had a potassium level ≥5.5 mEq/L at 24 weeks. Further, participants with a higher initial serum potassium level tended to have a smaller increase (estimate, -0.37, analysis of covariance). CONCLUSIONS: Low-dose spironolactone administration reduced albuminuria without causing hyperkalemia. Spironolactone administration, the oldest known and most cost-effective mineralocorticoid receptor antagonist, at lower doses should be reconsidered.

Autonomic and sensory ganglionopathy occurring in a patient with fulminant type 1 diabetes mellitus.

A 63-year-old male with a previous infection was admitted to our hospital because of acute pancreatitis. Although he had no history of diabetes mellitus, laboratory examinations revealed marked hyperglycemia on admission, and intensive insulin treatment was required. After 2 weeks, he developed severe pandysautonomia and sensory impairment, and eventually died from colonic perforation caused by paralytic ileus at 1 year after onset. Autopsy findings showed a complete loss of pancreatic islet beta cells with mild fibrosis of the exocrine pancreas. Neuropathological examination showed myelin loss of the dorsal fasciculus at all levels of the spinal cord and ganglionopathy of the dorsal root and sympathetic truncus, revealing degeneration of ganglion cells and a decrease in their number with the formation of Nageotte nodules. On the basis of this clinicopathological evidence, fulminant type 1 diabetes mellitus (T1DM) and idiopathic immune-mediated autonomic neuropathy were suspected. Here, we suggest a close etiological relationship between both diseases.

Cytosolic T3-binding protein modulates dynamic alteration of T3-mediated gene expression in cells.

µ-Crystallin (CRYM) is also known as NADPH-dependent cytosolic T3-binding protein. A study using CRYM-null mice suggested that CRYM stores triiodothyronine (T3) in tissues. We previously established CRYM-expressing cells derived from parental GH3 cells. To examine the precise regulation of T3-responsive genes in the presence of CRYM, we evaluated serial alterations of T3-responsive gene expression by changing pericellular T3 concentrations in the media. We estimated the constitutive expression of three T3-responsive genes, growth hormone (GH), deiodinase 1 (Dio1), and deiodinase 2 (Dio2), in two cell lines. Subsequently, we measured the responsiveness of these three genes at 4, 8, 16, and 24 h after adding various concentrations of T3. We also estimated the levels of these mRNAs 24 and 48 h after removing T3. The levels of constitutive expression of GH and Dio1 were low and high in C8 cells, respectively, while Dio2 expression was not significantly different between GH3 and C8 cells. When treated with T3, Dio2 expression was significantly enhanced in C8 cells, while there were no differences in GH or Dio1 expression between GH3 and C8 cell lines. In contrast, removal of T3 retained the mRNA expression of GH and Dio2 in C8 cells. These results suggest that CRYM expression increases and sustains the T3 responsiveness of genes in cells, especially with alteration of the pericellular T3 concentration. The heterogeneity of T3-related gene expression is dependent on cellular CRYM expression in cases of dynamic changes in pericellular T3 concentration.