Coronary Risk Factors and Ambulatory Blood Pressure and Heart Rate in Asian Indians

Abstract

Wang and co-workers reported on ethnic differences in ambulatory blood pressure (ABP) in African Americans compared to people of European origin (1). Data on ABP and heart rate (HR) on American Indians and Asian Indians could have made this study even more interesting (2). Details on diet and lifestyle factors also appear to be important for mapping circadian changes in blood pressure (BP) in populations studied by the BIOCOS group (3). Circadian changes in BP are synchronized by the daily routine via plasma concentrations of neurotransmitters, released by the pineal, pituitary and adrenal cortices, coordinated by clock genes situated in the brain's suprachiasmatic nucleus (2), and at the cellular level (4, 5). Many studies focusing on this issue have relied mostly on single measurements of BP and HR rather than on week-long profiles obtained with an ABPM, interpreted with a view of their time structures (chronomes) (3). It is now accepted that ABPM is superior to clinical spotchecks in terms of diagnosis and prognosis (6). Our study involved 209 subjects (142 men and 67 women) 42.4 ± 18.0 years of age living in Moradabad, India. Anticipated relationships were found. Namely, the MESOR of SBP, DBP and HR increased with age (SBP: r= 0.260, P<0.001; DBP: r=0.269, P<0.001; HR: r=0.242; P<0.005), as well as with BMI (SBP: r=0.232, P<0.005; DBP: r=0.257, P<0.001). The MESOR of HR also decreased with increased activity (F=5.558, P=0.001). The MESOR of SBP also decreased slightly with increased activity, yet the relationship is not statistically significant. Additional relations were uncovered. The SD of DBP increased as a function of BMI (r=0.248, P=0.002), whereas