Serum lipids and haematological factors associated with resting heart rate: the CORDIS Study. Cardiovascular Occupational Risk Factors Detection in Israeli Industries.

Objective: We set out to examine the association between resting heart rate and haematological factors and blood lipids, all believed to be associated with coronary heart disease.

Methods: In a cross-sectional study, 6016 industrial employees in Israel were screened between 1985 and 1987 for cardiovascular disease risk factors [the CORDIS Study (Cardiovascular Occupational Risk Factors Detection in Israeli Industries)]. Repeated measures of resting heart rates were obtained. Complete data were available for 5393 participants. The lowest mean measure was used to examine the association with individual factors.

Results: For men, of the blood lipids, only triglycerides were independently positively associated with resting heart rate after controlling for all the possible confounding factors (P<0.002). Mean heart rate was higher at elevated triglyceride levels (70 beats/min at < or = 93 mg/dl and 73.3 beats/min at > 150 mg/dl). Platelet count and haemoglobin were independently positively associated with heart rate (P < 0.0001 in both groups). For women, low-density lipoprotein cholesterol and leucocyte count were independently positively associated with resting heart rate (P < 0.05 and P = 0.006, respectively).

Conclusion: These associations suggest that the role of resting heart rate as a predictor of coronary heart disease may be partly explained by its association with triglycerides, haemoglobin, platelet count and leucocyte count, which may be confounding factors or intervening variables.