PubMed Health⌕ Search

Biomedical subjects

P A Richey

Publications and source records attributed to P A Richey.

4 recordsLinked to original sources

Racial differences in the influence of body size on ambulatory blood pressure in youths.

BACKGROUND: African Americans have higher night-time blood pressures than Caucasians do despite their having similar daytime blood pressures. It is well established that body size is related to casual blood pressure. OBJECTIVE: To examine the influence of body size on racial differences in patterns of ambulatory blood pressure. METHODS: Ambulatory blood pressure recordings were performed on 292 healthy children and adolescents (148 African Americans and 144 Caucasian) aged 10-18 years (mean 13+/-2 years). These blood pressures were related to height, weight, body surface area, and body mass index in separate regression models that also included race, sex, and age as factors. RESULTS: The race-by-height interaction was significant for night-time systolic blood pressure (P<0.02), with a significant relationship for African Americans (P<0. 0001), but not for Caucasians. The race-by-weight interaction was significant for night-time systolic blood pressure (P<0.04), also with a greater relationship for African Americans (P<0.0001) than for Caucasians (P<0.03). In addition, the race-by-weight interaction was significant for night-time diastolic blood pressure (P<0.04), with a significant relationship for African Americans (P<0.01), but not for Caucasians. Finally, the race-by-body-surface-area interaction was significant for night-time diastolic blood pressure (P<0.05), again with a significant relationship for African Americans (P<0.02) but not for Caucasians. CONCLUSION: Differences in the relationship between body size and blood pressure contribute to the racial differences in patterns of ambulatory blood pressure and should be considered when evaluating patterns of blood pressure in African American youths.

Adolescent↗

Pathological versus physiological left ventricular hypertrophy: a review.

Left ventricular hypertrophy is recognized as an independent risk factor for cardiovascular morbid events. The primary mechanisms responsible for stimulating it are unknown. Epidemiological theories suggest that left ventricular hypertrophy is a continuous variable with no threshold, while morphological studies argue that it is the structure, or quality, and function of the myocardium (and therefore non-continuous), not the quantity of the myocardial mass, that poses the cardiovascular risk. Although left ventricular hypertrophy has been classically viewed as an adaptive response of the cardiovascular system to an imposed load, it has been demonstrated that haemodynamic overloading in selected hypertensive patients is not the sole determinant of left ventricular structure and function. Pathological and physiological states of left ventricular hypertrophy have been described primarily using criteria focusing on normal chamber performance and oxygen delivery as well as the reversibility of the hypertrophy once the overload is removed. Both states are also defined by the nature of the imposed load and the resulting myocardial adaptations. This review addresses the pathological and physiological states of left ventricular hypertrophy, the hypertrophy patterns, and the corresponding structural and functional characteristics, together with some of the biochemical factors thought to influence remodelling.

Cardiomyopathy, Hypertrophic↗

Racial differences in the age-related increase in left ventricular mass in youths.

We determined the factors related to left ventricular mass adjusted for body size in 60 black (mean age, 13 +/- 2 years) and 40 white (mean age, 14 +/- 2 years) normotensive youths. The factors examined included age, sex, systolic blood pressure, diastolic blood pressure, plasma renin activity, plasma aldosterone concentration, and sodium and potassium intake as determined by 24-hour excretion. Sex (beta = 13.3, P < .003), age (beta = 2.88, P < .001), and systolic blood pressure (beta = 0.41, P < .02) were independent predictors in the sample as a whole, accounting for 37% of the variance of left ventricular mass adjusted for height. Separate analyses were performed for black and white subjects. In the black subjects, age (beta = 4.4, P < .004) followed by sex (beta = 11.85, P < .02) were independent factors, accounting for 43% of the variance of left ventricular mass adjusted for height. In contrast, in white subjects systolic blood pressure (beta = 0.4, P < .003) followed by sodium excretion (beta = 0.13, P < .05) were independent factors, with gender (beta = 8.89, P < .07) tending to account for 36% of the variance. Similar results were observed for left ventricular mass adjusted for body surface area. In conclusion, the age-related increase in adjusted left ventricular mass in black but not white youths may in part account for the early development of cardiovascular disease among the black population.

Adolescent↗