Carotid body chemosensitivity: early biomarker of dysmetabolism in humans

OBJECTIVE: The carotid bodies (CB) are peripheral chemoreceptor organs classically described as being O2 sensors, which are increasingly emerging as core players in metabolic control. Herein we evaluated CB activity in prediabetes patients and determined its correlation with dysmetabolism clinical features.

DESIGN AND METHODS: Prediabetes patients were recruited at the Cardiology Service, Hospital Santa Marta, Centro Hospitalar Lisboa Central, EPE (CHLC-EPE). The study was approved by CHLC-EPE and NOVA Medical School Ethics Committee. Thirty-three prediabetic and 14 age-matched, non-prediabetic, volunteers had their peripheral chemosensitivity evaluated by the Dejours test. Serum biomarkers of metabolic disease, insulin sensitivity (HOMA-IR), blood pressure, carotid intima-media thickness (cIMT) and glucose tolerance were assessed.

RESULTS: CB chemosensitivity was significantly increased in prediabetic group (p<0.01). Fasting blood, glucose intolerance, fasting insulin and HOMA-IR were significantly higher in prediabetes patients. Insulin resistance correlated both with peripheral chemosensitivity, assessed by the Dejours test, (p<0.05) and with abdominal circumference (p<0.01). HbA1c correlated with HOMA-IR (p<0.05) and left cIMT (p<0.05) in prediabetes patients.

CONCLUSIONS: We conclude that CB is overactive in prediabetes subjects and that peripheral chemosensitivity correlates with fasting insulin and insulin resistance representing a novel non-invasive functional biomarker to forecast early metabolic disease.