AGT and RH blood group polymorphisms affect blood pressure and lipids in Afro-Caribbeans.

Population blood pressure variation is most likely due to multiple genes. This is likely the reason why monogenic testing with the angiotensinogen (AGT) gene polymorphisms on chromosome 1 (1q42-43), especially M235T, has met with negative results, especially in those of African descent. The RH blood group system, also on chromosome 1 (1 p36.2-34), has likewise been associated with blood pressure variation in African-Americans and with the rise in blood pressure with age in whites. Using a random sample of the population, we investigated the combined effects of single and combined variation of the AGTN M235T and RH genotypes on blood pressure, lipids, and lipoprotein concentrations in Afro-Caribbeans aged 18-60 years from the island nation of Dominica. In monogenic analysis, AGT M235T was not associated with blood pressure. However, it was associated with HDL (MM 42+/-23, MT 44+/-12, TT 52+/-14 (P=0.002)). RH genotype was significantly associated with systolic blood pressure (P=0.006) and Apo-A (P=0.003). These effects remained after adjustment for age, gender, weight, and BMI. In the polygenetic analysis, AGT M235T and RH were significantly associated with systolic blood pressure (P=0.037; interaction effects, P=0.068). The association of the AGT M235T with blood pressure across RH blood group haplotypes was then tested. Of the five RH haplotypes available for analysis, the AGT M235T was significantly associated with blood pressure within the "D" haplotype (P=0.01). The RH blood group and gender were significantly associated with systolic blood pressure and Apo-A levels (P=0.005 and 0.012, respectively). All interactions were independent of age and weight. In conclusion, we demonstrate a significant association of AGT M235T with blood pressure and cholesterol metabolism in an Afro-Caribbean population in the "genetic context" of the RH blood group system. Further investigation of these interactions may help understand the effects of genetic factors on cardiovascular risk in African-derived and other populations.

Prevalence of cardiovascular risk factors in the Republic of Georgia.

BACKGROUND: Eastern Europe is experiencing an epidemic of deaths from cardiovascular diseases with an increase since the early 1990s approaching 50%. The ability to survey the risk factors associated with this striking rise is severely hampered by the current disarray of the area's public health system. We used a rapid survey method to describe the epidemiology of cardiovascular risk in the capital of the Republic of Georgia, Tbilisi. METHODS: A two-stage cluster design, 'rapid survey method' developed by the Chronic Disease Center was used to estimate the frequency of hypertension, a major cardiovascular risk factor. Local personnel were trained and certified in blood pressure measurement and rapid survey techniques. The training and survey were conducted over a period of 14 days at which time a preliminary report of the survey was presented to the Ministry of Health. RESULTS: A total of 321 subjects were surveyed. The frequency of high blood pressure (>140/>90 mm Hg) at the time of the examination was 58% in men and 56% in women. The major correlates for blood pressure were gender and age. In addition we found that 31% of the population had a total cholesterol > or =220 mg% and a similar number had a low high density lipoprotein < or =35 mg%. Smoking was present in 60% of men and none were taking aspirin daily to prevent premature coronary artery disease. CONCLUSIONS: The rapid survey method is feasible in the former Soviet Union and can quickly provide estimates of the risk factors associated with the epidemic of cardiovascular disease in this area.

A curriculum for the training and certification of blood pressure measurement for health care providers.

Blood pressure measurement in clinical practice is almost never performed according to accepted guidelines. This is likely to be a result of inadequate training. We describe a standardized training program for teaching blood pressure measurement to health care students, practitioners and clinical investigators as well as lay personnel. The goal is to have the student understand the rationale and be able to perform accurate blood pressure measurements. Students must master the knowledge of proper blood pressure measurement technique, document their accuracy on standardized video tests and demonstrate their performance of proper technique. In addition the program reviews key historical and physiological aspects of blood pressure measurement and the cardiovascular complications of high blood pressure. The operation and maintenance of sphygmomanometers and the stethoscope, and monitoring for biases in blood pressure measurements in clinical practice, are also covered. The curriculum time requires a minimum of 7 h and biannual recertification is recommended. With training of instructors, the program can be easily replicated and should be considered in any setting in which blood pressure measurement is taught.

Blood pressure in blacks. Twin studies in Barbados.

We have recently reported that there are significant genetic influences on the population variation in blood pressure in black twins in Los Angeles. The present cross-sectional study was undertaken to replicate these findings in a black twin population that lives in a different biosocial environment. We chose the Caribbean island nation of Barbados, where 96% of the population is black, the literacy rate is 99%, and the access to health care is guaranteed. The goals were 1) to test the feasibility of twin studies in blood pressure research in a developing country and 2) to estimate the relative contribution of genes and environment to blood pressure variability in blacks in the Caribbean. The names of 200 twin sets were obtained with the assistance of community resources including a twin club, by media advertisement, and by asking people at public blood pressure screenings if they knew any twins. By using these methods, we identified 200 sets of twins. Of these, 37.5% (75/200) met our criteria for study. Although 97% of the sets of twins (73/75) said they were willing to participate, only 69% (52/75) were able to be scheduled during the 1 week of the study when the full team of investigators was in Barbados. Of those scheduled, 83% (43/52) were examined. Examination included medical history, physical examination, recumbent blood pressure measurements by two observers, anthropometric measurements, 24-hour urine collections for sodium and potassium tests, and blood tests for zygosity.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure in blacks: twin studies in Barbados

We have recently reported that there are significant genetic influences on the population variation in blood pressure in black twins in Los Angeles. The present cross-sectional study was undertaken to replicate these findings in a black twin population that lives in a different biosocial environment. We chose the Caribbean island nation of Barbados, where 96 percent of the population is black, the literacy rate is 99 percent, and the access to health care is guaranteed. The goals were 1) to test the feasibility of twin studies in blood pressure research in a developing country and 2) to estimate the relative contribution of genes and environment to blood pressure variability in blacks in the Caribbean. The names of 200 twin sets were obtained with the assistance of community resources including a twin club, by media advertisement, and by asking people at public blood pressure screenings if they knew any twins. By using these methods, we identified 200 sets of twins. Of these, 37.5 percent (75/200) met our criteria for study. Although 97 percent of the sets of twins (73/75) said they were willing to participate, only 69 percent (52/75) were able to be scheduled during the 1 week of the study when the full team of investigators was in Barbados. Of those scheduled, 83 percent (43/52) were examined. Examination included medical history, physical examination, recumbent blood pressure measurements by two observers, anthropometric measurements, 24-hour urine collections for sodium and potassium tests, and blood tests for zygosity. (ABSTRACT TRUNCATED AT 250 WORDS) (AU)

Nursing assessment of the patient with high blood pressure.

Whether or not the nurse is responsible for the complete assessment of a patient with high blood pressure, he or she should be capable of completing the subjective data base according to the guidelines provided. The extent to which nurses participate in the collection of objective data will depend upon their level of comfort with the process, their prior training, and the setting. A knowledge base should be developed that is sufficient to collaborate with the health team (which includes the patient) in order to identify problems, formulate interventions, and evaluate outcomes. The problem-oriented approach is presented as a rational approach to the assessment process. The problem-oriented health record provides documentation of care and account-ability, both of which are important to nursing as a profession. The results of the total assessment provide the information necessary to begin the extended process of patient education and contracting that is necessary in the treatment of high blood pressure. Armed with knowledge, concern, enthusiasm, an inquiring mind, and a rational approach, the nurse can have a significant impact on the quality of care available to those at risk from hypertension.

Sensitivity and specificity of screening tests for renal vascular hypertension.

To facilitate the identification of patients with renal vascular hypertension, we evaluated four potential screening tests: rapid-sequence urography, systolic-diastolic abdominal bruit, upright plasma renin activity (PRA), and response to saralasin infusion. Our study included 379 normal subjects, 199 essential hypertensive patients with normal renal angiograms, and 64 patients with surgically responsive renal vascular hypertension. Thirty-nine percent of patients with renal vascular hypertension had systolic-diastolic bruits, 76% abnormal urograms, and 27% a PRA greater than 30 ng of angiotensin 1/mL.3 h. Only one half of the 23 patients with renal vascular hypertension tested had a depressor response to saralasin, as did two of 13 essential hypertensive patients. In essential hypertensive subjects, 1% had systolic-diastolic bruits, 2% abnormal urograms, and 5% upright renin values greater than 30 ng of angiotensin 1/mL.3 h. The screening combination of urogram, bruit, or upright renin value offered a test sensitivity of 93%, with a specificity of 92%. The results of saralasin infusion failed to increase the diagnostic yield.

Rapid blood pressure control with minoxidil: acute and chronic effects on blood pressure, sodium excretion, and the renin-aldosterone system.

Changes in blood pressure, heart rate, electrolyte excretion, and the renin-angiotensin-aldosterone system were monitored before and after minoxidil was added to a regimen of a diuretic and propranolol hydrochloride in 12 severely hypertensive patients. None required more than 40 mg of minoxidil daily for control. On a constant intake, urinary sodium excretion decreased, while urinary potassium excretion remained stable. Heart rate, body weight, and plasma volume increased, while creatinine clearance did not change. Although plasma renin activity increased fourfold, the plasma aldosterone concentration did not increase. Six subjects were restudied after two months of minoxidil treatment. Although blood pressure control continued to be excellent in these subjects, plasma renin values and plasma volume had returned to pretreatment levels. These studies suggest that minoxidil rapidly and effectively lowers blood pressure. Although sodium retention accompanies minoxidil administration acutely, the effect is independent of aldosterone and may be transient.

Minoxidil treatment of malignant hypertension. Recovery of renal function.

We treated eight severely hypertensive, long-term hemodialysis patients who failed to respond to ultrafiltration or conventional medication with minoxidil rather than with bilateral nephrectomy. Control of blood pressure and relief of symptoms was achieved in all eight. In addition, three of the patients, who were all severely oliguric, recovered sufficient renal function to allow the discontinuation of dialysis. Two are presently doing well, while one died of causes unrelated to uremia or minoxidil therapy. We presently reserve bilateral nephrectomy for those hypertensive dialysis patients who are awaiting transplantation.