title: Circulating surfactant protein A (SP-A), a marker of lung injury, is associated with insulin resistance.
abstract: OBJECTIVE
  Impaired lung function and inflammation have both attracted interest as potentially novel risk factors for glucose intolerance, insulin resistance, and type 2 diabetes. We hypothesized that circulating levels of surfactant protein (SP)-A, which reflects interstitial lung injury, could be associated with altered glucose tolerance and insulin resistance.
  
  
  METHODS
  Circulating SP-A concentration and metabolic variables (including insulin sensitivity by minimal model method, n = 89) were measured in 164 nonsmoking men.
  
  
  RESULTS
  Circulating SP-A concentration was significantly higher among patients with glucose intolerance and type 2 diabetes than in subjects with normal glucose tolerance, even after adjustment for BMI, age, and smoking status (ex/never). The most significant differences were found in overweight and obese subjects with altered glucose tolerance (n = 59) who showed significantly increased serum SP-A concentrations (by a mean of 24%) compared with obese subjects with normal glucose tolerance (n = 58) (log SP-A 1.54 +/- 0.13 vs. 1.44 +/- 0.13; P < 0.0001). Insulin sensitivity (P = 0.003) contributed independently to 22% of SP-A variance among all subjects. In subjects with altered glucose tolerance, insulin sensitivity (P = 0.01) and fasting triglycerides (P = 0.02) contributed to 37% of SP-A variance. Controlling for serum creatinine or C-reactive protein in these models did not significantly change the results.
  
  
  CONCLUSIONS
  Lung-derived SP-A protein was associated with altered glucose tolerance and insulin resistance in 164 nonsmoking men.
authors.affiliation: Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona and CIBER Fisiopatología de la Obesidad y Nutrición, Girona, Spain. uden.jmfernandezreal@htrueta.scs.es
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Fernández-Real
authors.forename: Berta
authors.initials: B
authors.lastname: Chico
authors.forename: Masanori
authors.initials: M
authors.lastname: Shiratori
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nara
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Wifredo
authors.initials: W
authors.lastname: Ricart
mesh_terms: D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D018149:Glucose Intolerance / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance; D008168:Lung / Q000503:physiopathology*; D008297:Male; D037662:Pulmonary Surfactant-Associated Protein A / Q000097:blood*; D012016:Reference Values; D012128:Respiratory Distress Syndrome / Q000097:blood*; D044465:White People
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D037662:Pulmonary Surfactant-Associated Protein A; D002784:Cholesterol