Lipoprotein (a) and apoprotein B in an apparently healthy population of fighter pilots and ground personnel: their significance as potential markers of atherosclerosis.

BACKGROUND

Individuals who carry cardiovascular risk factors (CVRF) have a higher incidence of cardiovascular pathology. Among the most commonly screened CVRF are apoprotein A and B and lipoprotein (a), which represent 'independent' risk factors for atherosclerosis. In the air force community, cardiovascular pathology has been reported as the primary reason for grounding pilots.

DESIGN

The aim of this study was to evaluate the frequency of CVRF in an apparently healthy population of military fighter pilots (group B, n = 50), and military ground personnel (group A, n = 50) who were matched for age, sex and body mass index but not involved in flight activity, and to evaluate whether any particular pattern of CVRF might be related to flight.

METHODS

Each subject fasted overnight, and underwent the following measurements: blood pressure and resting ECG recording; and determination of serum levels of total and high-density lipoprotein cholesterol, triglycerides, uric acid and plasma levels of glucose. In addition, serum levels of apolipoprotein A, B and lipoprotein (a) were detected.

RESULTS

An overall risk index for coronary artery disease was calculated using the Framingham equation. This risk index was slightly but not significantly increased in group A compared with group B. By contrast, a significant increase in both apoprotein B (P < 0.005) and lipoprotein (a) (P < 0.0005) was found in group B compared with group A. No significant differences between groups were detected for the other parameters evaluated.

CONCLUSIONS

We suggest the presence in group B of an underlying trend towards the development of atherosclerosis, which may not be identified by a routine approach. Moreover, on a purely theoretical basis with no experimental evidence, the issue of the possible pathophysiological mechanism of these findings and their relationship to flight environment is also addressed.