Does autonomic function link social position to coronary risk? The Whitehall II study.
BACKGROUND
Laboratory and clinical studies suggest that the autonomic nervous system responds to chronic behavioral and psychosocial stressors with adverse metabolic consequences and that this may explain the relation between low social position and high coronary risk. We sought to test this hypothesis in a healthy occupational cohort.


RESULTS
This study comprised 2197 male civil servants 45 to 68 years of age in the Whitehall II study who were undergoing standardized assessments of social position (employment grade) and the psychosocial, behavioral, and metabolic risk factors for coronary disease previously found to be associated with low social position. Five-minute recordings of heart rate variability (HRV) were used to assess cardiac parasympathetic function (SD of N-N intervals and high-frequency power [0.15 to 0.40 Hz]) and the influence of sympathetic and parasympathetic function (low-frequency power [0.04 to 0.15 Hz]). Low employment grade was associated with low HRV (age-adjusted trend for each modality, P< or =0.02). Adverse behavioral factors (smoking, exercise, alcohol, and diet) and psychosocial factors (job control) showed age-adjusted associations with low HRV (P<0.03). The age-adjusted mean low-frequency power was 319 ms2 among those participants in the bottom tertile of job control compared with 379 ms2 in the other participants (P=0.004). HRV showed strong (P<0.001) linear associations with components of the metabolic syndrome (waist circumference, systolic blood pressure, HDL cholesterol, triglycerides, and fasting and 2-hour postload glucose). The social gradient in prevalence of metabolic syndrome was explained statistically by adjustment for low-frequency power, behavioral factors, and job control.


CONCLUSIONS
Chronically impaired autonomic function may link social position to different components of coronary risk in the general population.
Hemingway
Harry
H
International Centre for Health and Society, Department of Epidemiology and Public Health, University College London Medical School, 1-19 Torrington Place, London WC1E 6BT UK. h.hemingway@ucl.ac.uk
Shipley
Martin
M
Brunner
Eric
E
Britton
Annie
A
Malik
Marek
M
Marmot
Michael
M
D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D003327:Coronary Disease / Q000453:epidemiology / Q000209:etiology* / Q000523:psychology; D004651:Employment; D015438:Health Behavior; D006339:Heart Rate; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome; D008875:Middle Aged; D011209:Power, Psychological; D012307:Risk Factors; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires