Which of the following lab values is abnormal and potentially disqualifying?

An HbA1c level of 11% is indeed abnormal and potentially disqualifying for a commercial driver. This value indicates poorly controlled diabetes over the preceding two to three months. Generally, an HbA1c level above 10% suggests a significant risk of complications such as neuropathy, retinopathy, or cardiovascular issues, which can impair a driver's ability to operate a commercial vehicle safely.

Hematocrit at 40% is considered within the normal range for healthy adults and does not typically raise concern for disqualifying health issues. An AST/SGOT level of 30 mg/ml also falls within normal limits for liver function, indicating no immediate risk for disqualification. The ESR value of 12 mm/hr is generally considered normal and is used to assess inflammation or other medical conditions, which do not disqualify a driver in the absence of significant clinical findings. Thus, the HbA1c level is the only marker here suggesting a serious health issue that could interfere with the safe operation of a vehicle.