Transforming growth factor beta 1 as a biomarker of diabetic peripheral neuropathy: cross-sectional study.
BACKGROUND
Simple and efficient screening methods are lacking for diabetic peripheral neuropathy (DPN), the most common and most difficult to treat of the long-term diabetic complications. Increased levels of transforming growth factor beta 1 (TGFbeta1) in type 2 diabetic patients (T2DM) plays an immunomodulatory role in diabetic nephropathy and, possibly, in atherosclerotic evolution. Since preliminary interrelationships between experimental DPN and TGFbeta1 have been observed, we sought to assess whether TGFbeta1 could be a biomarker molecule for human DPN.


METHODS
Cross-sectional cohort study focused on the assessment of the interrelationships between TGFbeta1 levels, cardiovascular disease (CVD), diabetic nephropathy (DNF), and neuropathy (DPN) in a group of T2DM patients (N=180; male 117, female 63) randomly selected from the North Catalonia Diabetes Study. DPN was diagnosed using clinical and neurophysiology evaluation. Incipient DNF was assessed by microalbuminuria (MAU). Total TGFbeta1 (without acidification) was measured by immunoassay by ELISA (Promega).


RESULTS
DPN correlated with age, time of diabetes duration, MAU, CVD, and TGFbeta1 (P<.0001). Log-transformed TGFbeta1 (logTGbeta1) was significantly higher in patients with DPN than in those without (P<.0005). LogTGFbeta1 (OR=7.5; P=.006), age (OR=1.1; P<.0005), and logMAU (OR=2.0; P=.016) appear as significant estimators of the occurrence of DPN in our series. The integrated ROC curve evaluation with these three parameters expressed an important sensitivity (78.1%), specificity (76.0%), positive predictive value (79.2%), and negative predictive value (70.3%) in relation to DPN presence.


CONCLUSIONS
TGFbeta1 stands as an important biomarker molecule for DFN and DPN screening in our series. Further prospective studies are warranted.
Ybarra
Juan
J
Instituto de Cardiología Avanzada (ICAMED), Centro Medico Teknon, Barcelona, Spain. juanybarra@hotmail.com
Pou
Josep M
JM
Romeo
June Hart
JH
Merce
Javier
J
Jurado
Jeroni
J
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications*; D003928:Diabetic Nephropathies / Q000097:blood*; D003929:Diabetic Neuropathies / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D053773:Transforming Growth Factor beta1 / Q000097:blood*
D015415:Biomarkers; D053773:Transforming Growth Factor beta1