Factors influencing arterial pressure in the general population in Jamaica

ABSTRACT

Representative rural and urban populations in Jamaica were defined geographically, enumerated by private census, and visited at home by two physicians who carried out indirect arterial blood-pressure measurements. These readings have been related to a number of personal and environmental factors,and this analysis shows the following facts. 1. There was a considerable difference in the prevalence of hypertension, particularly among women, between neighbouring rural and urban negro populations, with relative higher prevalence in the women from the rural area. This was not attributable to differences in survey technique, weight, or pulse rate, nor to differnces in the prevalence of hypertension secondary to renal disease as detected by proteinuria. 2. Bacteriuria (the presence of Gram-negative rods in a concentration of 10E5 or more bacteria per ml. in repeated specimens of clean-voided urine), which was usually asymptomatic, was a common finding among women (4.4 percent of women investigated), was significantly more common in the rural area, was related to hypertension, and was found in 15 percent of females with diastolic pressures exceeding 110 mm Hg in these surveys. Bacteriuria was found in only 0.5 percent of males. 3. The relationship between bacteriuria, as detected in one prevalence study, and hypertension was not sufficient to account for the differences in the prevalence of hypertension between these two female populations. 4. Mean arterial pressures as found in these Jamaican populations were lower than those reported in other surveys of Western Negro populations. 5. Pregnant women in Jamaica had significantly lower systolic and diastolic pressures than those who were not pregnant. The prevalence of diastolic hypertension (100 mm Hg or more) was higher in nulliparous than in parous women, and was least in those with moderate sized families of two to five children. The prevalence of hypertension increased again in those with very large families, as did the presence of bacteriuria. 6. Body build, as measured by the ponderal index, had a small but consistent influence on arterial pressure as measured indirectly, in Jamaican subjects under age 55. The absence of this relationship in the elderly may be due to increased mortality among obese hypertensives. 7. The use of a qualitative method for determining the genetic factor in arterial pressure suggests that its inheritance is graded, the resemblance in pressure between close relatives being independent of the range of pressure considered, and closely similar to the genetic factor in blood-pressure found in the Welsh. 8. The pressures of middle-aged siblings of middle-age hypertensives showed no bimodality in their distribution (Summary)