In order to assess the relationship between impaired reaction times and other clinical parameters a study was conducted on a population of public transport drivers, 26 impaired reaction times subjects and 114 controls, matched for age, sex and type of job-task, compared for years of employment, blood pressure, audiometric test, mood disorders, sleepiness and body mass index (BMI). Statistical analysis indicates a close trend to relationship of reaction times impairment with BMI and hypertension; these two variables are also correlated. Our results agree with previous literature: despite the fact that mechanisms underlying the relationship between BMI and cognitive impairments remains unknown, subclinical levels of pathophysiologic changes associated with elevated BMI, could account for the observed differences in our samples. Assessing eligibility in occupational medicine, it could be suitable to evaluate some preventive measures evaluating the efficacy of weight loss on cognitive function and on the ability to work safely.