It is known that residents at high altitude (HA) have a lower basal glycemia than residents at sea level (SL). However, whether such a difference is maintained throughout the full day remains unknown. We compared 12-h blood glucose profiles from 10 healthy males native residents at HA (3250 m) and 8 male residents at SL. Glucose profile at HA was lower throughout the glucose monitoring than that at SL (mean profile: 50.6 +/- 3.7 and 73.4 +/- 4.0 mg/dL, respectively; p < 0.001). Basal and postprandial insulin and triacylglycerol values were similar in both groups. In conclusion, HA natives resident have a lower blood glucose profile than SL residents throughout 12-h continuous monitoring.