title: Reduced respiratory muscle strength and endurance in type 2 diabetes mellitus.
abstract: BACKGROUND
  A restrictive lung function pattern is frequently observed in patients with diabetes mellitus (DM) and has been related to respiratory muscle dysfunction in type 1 DM or in mixed population. We aimed to verify whether such a relationship applies also to type 2 DM patients.
  
  
  METHODS
  The respiratory muscle function was explored in 75 non-smoking patients with type 2 DM without pulmonary or cardiac diseases and compared with that of 40 healthy non-smoking control subjects matched by age and sex. Maximal inspiratory and expiratory pressures (MIP, MEP) and maximum voluntary ventilation (MVV), which reflect respiratory muscle strength and endurance, respectively, were measured, and a complete respiratory function assessment was recorded.
  
  
  RESULTS
  Patients were in stable metabolic conditions and had, on average, normal total lung capacity and diffusing lung capacity for carbon monoxide. However, MIP and MVV were significantly reduced in comparison with those of control subjects. Both MIP/MEP and MVV significantly correlated with lung volumes and diffusing lung capacity for carbon monoxide. The multiple regression analysis identified age (beta coefficient = -0.238, p = 0.046), glycated haemoglobin (beta coefficient = -0.245, p = 0.047) and total lung capacity (beta coefficient = 0.430, p = 0.016) as independent correlates of MIP, whereas male sex (beta coefficient = 0.423, p = 0.004) and diabetic complications (beta coefficient = -0.248, p = 0.044) were independent correlates of MVV.
  
  
  CONCLUSIONS
  In type 2 DM, respiratory muscle strength was reduced and significantly related to lung volumes and quality of metabolic control, whereas impaired endurance of respiratory muscles prevailed in patients with microvascular complications.
authors.affiliation: Respiratory Disease Unit, Catholic University, Rome, Italy. leofuso@rm.unicatt.it
authors.forename: Leonello
authors.initials: L
authors.lastname: Fuso
authors.forename: Dario
authors.initials: D
authors.lastname: Pitocco
authors.forename: Anna
authors.initials: A
authors.lastname: Longobardi
authors.forename: Francesco
authors.initials: F
authors.lastname: Zaccardi
authors.forename: Chiara
authors.initials: C
authors.lastname: Contu
authors.forename: Carmen
authors.initials: C
authors.lastname: Pozzuto
authors.forename: Salvatore
authors.initials: S
authors.lastname: Basso
authors.forename: Francesco
authors.initials: F
authors.lastname: Varone
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ghirlanda
authors.forename: Raffaele
authors.initials: R
authors.lastname: Antonelli Incalzi
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008451:Maximal Voluntary Ventilation; D008875:Middle Aged; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000502:physiology*; D011653:Pulmonary Diffusing Capacity; D012044:Regression Analysis; D012132:Respiratory Muscles / Q000503:physiopathology*; D014109:Total Lung Capacity
chemical_list: D006442:Glycated Hemoglobin