title: Neuroadrenergic denervation of the lung in type I diabetes mellitus complicated by autonomic neuropathy.
abstract: OBJECTIVE
  To verify whether autonomic neuropathy (AN) complicating type I, insulin-dependent diabetes mellitus affected neuroadrenergic bronchopulmonary innervation.
  
  
  METHODS
  Twenty nonsmoking diabetic patients without respiratory diseases were studied: 11 patients with AN (group AN) and 9 patients without AN (control; group C) diagnosed by standardized criteria.
  
  
  METHODS
  Patients underwent respiratory function tests and ventilatory scintigraphies with (123)I-metaiodobenzylguanidine (MIBG) and with (99m)Tc-diethylenetriaminepenta-acetic acid (DTPA) to assess both bronchopulmonary neuroadrenergic innervation and also permeability of the alveolar-capillary barrier to water-soluble tracers. Rates of pulmonary clearance of the two tracers were computed, and correlates were identified by nonparametric statistics.
  
  
  METHODS
  University hospital.
  
  
  RESULTS
  The AN and C groups had normal respiratory function test results and comparable duration of diabetes and quality of metabolic control. (99m)Tc-DTPA clearance did not distinguish the groups. (123)I-MIBG clearance was faster in the AN group than in the C group (mean +/- SD half-time of the radiotracer time-activity curve [T(1/2)], 116.1 +/- 22.8 min in the AN group vs 139.5 +/- 18.3 min in the C group, p = 0.022), which is consistent with neuroadrenergic denervation in the AN group. (123)I-MIBG clearance was independent from (99m)Tc-DTPA clearance. Faster (123)I-MIBG clearance was significantly associated with worse performance in three of the four autonomic tests.
  
  
  CONCLUSIONS
  Neuroadrenergic bronchopulmonary denervation may occur in diabetic patients with AN despite normal clinical and respiratory function findings. Further research is needed to identify clinical and prognostic implications of these findings.
authors.affiliation: Department of Internal Medicine, Catholic University, Rome, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Antonelli Incalzi
authors.forename: Leonello
authors.initials: L
authors.lastname: Fuso
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giordano
authors.forename: Dario
authors.initials: D
authors.lastname: Pitocco
authors.forename: Carmela
authors.initials: C
authors.lastname: Maiolo
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Calcagni
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ghirlanda
mesh_terms: D019797:3-Iodobenzylguanidine; D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000150:complications*; D001980:Bronchi / Q000294:innervation; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008168:Lung / Q000294:innervation*; D008297:Male; D008875:Middle Aged; D004369:Pentetic Acid; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D004369:Pentetic Acid