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N Poulter

Publications and source records attributed to N Poulter.

34 records · Page 2Linked to original sources
PubMed1994

Lipid profiles after the daily consumption of an oat-based cereal: a controlled crossover trial.

Water-soluble fiber has been reported to reduce serum cholesterol and consequently, oat bran, which has a high soluble-fiber content, has been recommended as part of a lipid-lowering diet. However, a recent small study of 20 volunteers with low mean serum cholesterol concentrations (4.8 mmol/L) demonstrated no lipid-lowering effect of oat bran. The present study investigated 64 volunteers with cholesterol concentrations much more typical of the UK population (6 mmol/L). Subjects were randomly allocated to receive either a normal-sized helping of an oat-based cereal or a cereal containing no oats for 4 wk and then crossed over to the alternative regimen for a further 4 wk. Small (2.23% and 4.55%) but significant (P < 0.04 and P < 0.05) reductions in total and low-density-lipoprotein cholesterol, respectively, were observed in association with the consumption of oat-based cereal. These data support the view that consumption of oat-based cereals may well contribute usefully to a lipid-lowering diet.

Cholesterol, HDL↗
PubMed1992

Hypertension and the probability of an incapacitating event over a defined period: impact of treatment.

(1) The risks of coronary heart disease, cerebrovascular disease and all-cause mortality associated with increasing levels of pressure are graded and continuous from the lowest to the highest levels. (2) Data from several large prospective studies allow evaluation of individual risk based on blood pressure level but may require modification in the context of aircrew. (3) Because cardiovascular risk factors appear to interact and 'cluster' in hypertensives, a broadened approach to the evaluation of risk for the individual and the management of hypertension is necessary and appropriate. (4) Anti-hypertensive treatment has been shown in trials to reduce the incidence of stroke but appears much less effective at reducing coronary events. It may be that a management policy which involves an assessment of and intervention on all risk factors together, incorporating the use of anti-hypertensive drugs which do not have adverse metabolic effects will be more effective in this context. Evaluation of such a policy in a long-term morbidity and mortality trial is however urgently required.

Adult↗
PubMed1991

Management of multiple risk factors for coronary heart disease in patients with hypertension.

Hypertension intervention trials, which have involved mainly the use of diuretics and beta-blockers, have demonstrated a disappointing benefit in terms of reduction of coronary heart disease (CHD). Rather than suggesting that elevated blood pressure and CHD are not causally related, these data suggest that the antihypertensive agents used were not optimal for the management of hypertension and a review of the currently recommended therapies is needed. Major risk factors for CHD, which include increased blood pressure, elevated serum cholesterol levels, and smoking, are highly prevalent in the general population and appear to cluster in patients with hypertension. Therefore the treatment of hypertension demands a multifactorial approach, one that takes into consideration all the risk factors for CHD. Diuretics and beta-blockers adversely affect the serum lipid profile, and this could negate some of the CHD benefit afforded by blood pressure reduction.

Adrenergic beta-Antagonists↗
PubMed1991

The effects of blood pressure reduction on abnormal left ventricular diastolic function in hypertensive patients.

To investigate whether reduction in blood pressure has a beneficial effect on left ventricular diastolic function, we investigated 20 hypertensive patients with evidence of diastolic dysfunction at baseline and at 3 and 6 months after initiation of captopril therapy. Two-dimensional echocardiography was used to determine left ventricular mass index and Doppler ultrasound to assess diastolic function. Fifteen of the 20 patients had a significant reduction in blood pressure at 3 and 6 months and left ventricular mass index remained unchanged during the study period. Despite reduction in blood pressure, no difference in isovolumic relaxation time, early and atrial filling velocities or their ratio was observed. Our results suggest that a direct relationship between blood pressure and left ventricular diastolic function does not exist and that other factors such as alterations in muscle or collagen composition of the left ventricle may be more important in determining abnormal diastolic function in hypertension.

Adult↗
PubMed1991

Determinants of left ventricular filling in hypertension.

The relationship of left ventricular (LV) filling to the clinical and echocardiographic characteristics of 51 patients with untreated hypertension (borderline hypertension n = 17, essential hypertension n = 34) was investigated using two-dimensional echocardiography and Doppler ultrasound. Twenty-five patients had evidence of abnormal LV filling. Linear regression analysis revealed weak but significant correlations of LV filling with age (r = -0.53; P less than 0.0001), systolic blood pressure (r = -0.38; P less than 0.006), LV septal wall thickness (r = -0.44; P less than 0.0001) and LV mass index (r = -0.33; P less than 0.02). There was no association between LV filling and sex, race, heart rate or LV posterior wall thickness or cavity dimension. After stepwise regression analysis, age was found to be the only independent variable associated with LV filling, indicating that the other variables were dependent on age. This study suggests that a) abnormal LV filling is a frequent observation in hypertension b) LV filling is more dependent on age than blood pressure or LV size and c) other pathophysiological factors, so far undetermined, must contribute to the development of these abnormalities.

Adult↗
PubMed1990

Regression of hypertensive left ventricular hypertrophy and left ventricular diastolic function.

The effect of antihypertensive therapy on regression of left ventricular hypertrophy and left ventricular diastolic function was investigated in 25 hypertensive patients for up to 18 months after initiation of treatment. Left ventricular mass index was calculated by two-dimensional echocardiography and left ventricular diastolic function assessed by transmitral pulsed doppler ultrasound. Significant reduction in left ventricular mass index was observed after 9 months of treatment. Only 13 patients had a reduction in mass greater than the intraobserver variability of the technique. There was no change in doppler indices of left ventricular diastolic function. In 7 patients who were studied for a further 9 months after regression had occurred there was still no appreciable difference in left ventricular diastolic function. These findings indicate that there is no direct relation between left ventricular mass and abnormal left ventricular diastolic function.

Adult↗
PubMed1989

Multiple risk factor evaluation in a hypertension clinic.

Hypertension is associated with abnormal lipoprotein metabolism, which may be exacerbated by some groups of antihypertensive drugs and represents an additional powerful coronary heart disease risk factor. Of our Hypertension Clinic population, 75% had a total fasting serum cholesterol greater than 5.2 mmol/l. Dietary advice and adjustment of antihypertensive therapy has achieved significant reductions in total cholesterol, serum triglycerides and body weight (14%, 18% and 4.3%, respectively) in a cohort of 65 patients reassessed over a period of 3-21 months. The reduction in cholesterol is likely to represent at least a 28% reduction in the risk of a major coronary heart disease event, even before taking account of any improvement in other coronary heart disease risk factors.

Cholesterol↗
PubMed1989

Blood pressure in four remote populations in the INTERSALT Study.

Four remote population samples (Yanomamo and Xingu Indians of Brazil and rural populations in Kenya and Papua New Guinea) had the lowest average blood pressures among all 52 populations studied in INTERSALT, an international cooperative investigation of electrolytes and blood pressure. Average systolic blood pressure was 103 versus 120 mm Hg in the remaining INTERSALT centers; diastolic blood pressure in these four population samples averaged 63 versus 74 mm Hg in the 48 other centers. There was little or no upward slope of blood pressure with age; hypertension was present in only 5% of the rural Kenyan sample and virtually absent in the other three centers. Also in marked contrast with the rest of the centers was level of daily salt intake, as estimated by 24-hour urinary sodium excretion. Median salt intake ranged from under 1 g to 3 g daily versus more than 9 g in the rest of INTERSALT populations. Average body weight was also low in these four centers, with no or low average alcohol intake, again unlike the other centers. The association within these four centers between the above variables and blood pressure was low, possibly reflecting their limited variability. While several other INTERSALT centers also had low average body weight or low prevalence of alcohol drinking, when this was accompanied by much higher salt intake (7-12 g salt or 120-210 mmol sodium daily), hypertension prevalence ranged from 8% to 19%. These findings confirm previous reports that in populations with a low salt intake, there is little or no hypertension or rise of blood pressure with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

A double-blind, placebo-controlled, crossover trial to investigate the additive hypotensive effect of a diuretic (mefruside) to that produced by nifedipine.

Several reports suggest that when diuretics are added to nifedipine (N), they do not exert any additional hypotensive effect to that produced by N alone. We present the first double-blind, crossover trial to investigate this interaction. Twenty-four black patients with moderate to severe essential hypertension entered the trial. After an initial "open" 4 weeks of therapy with N slow release (SR) 20 mg. b.i.d., those 17 patients whose blood pressures (BP) were not controlled (greater than 160 mm Hg systolic and/or greater than 90 mm Hg diastolic) were randomly allocated (double-blind) to 4 weeks treatment with N SR 20 mg. b.i.d., plus either mefruside 1 q.d. (a thiazide-like diuretic) or matching placebo. Patients then crossed over for a second 4 week treatment period. Blood pressures were measured at 2 weekly intervals under the same conditions using Hawksley random zero sphgymomanometers by one of two standardized observers after patients had been lying for 5 min and standing for 2 min. Analysis (taking account of period effect) of the mean results for the 16 patients completing the trial confirms that, contrary to what previous uncontrolled data suggest, lying and standing systolic and diastolic BPs are significantly lower (8.5/4.5 mm Hg: 2p less than 0.01 and 7.9/5.0 mm Hg: 2p less than 0.05, respectively) with nifedipine plus diuretic than with nifedipine plus placebo.

Adult↗
PubMed1984

Salt and blood pressure in various populations.

A relationship between salt intake and blood pressure has been described in cross-sectional studies of several populations. However, serious methodological problems in many studies could have resulted in erroneous results. In the present studies, the blood pressure profiles of a Kenyan tribe have been shown to differ according to environment, being lower in rural and higher in urban communities. Although several factors could explain the observed blood pressure differences, dietary factors, including sodium and potassium intake, could be important determinants of the observed differences. A within-population study of 1,737 rural male subjects was carried out in which it was found that systolic and diastolic pressures correlated positively with urinary sodium/potassium ratios. In this rural group, within subject day-to-day variations in dietary electrolytes are small, as indicated from multiple urinary collections, and are less than those observed in Western societies. We have demonstrated in this rural population that causal samples of urine correlated well with average sodium and potassium excretion over a 7-day period. Preliminary results are reported of a longitudinal study of migrants from a low to a high blood pressure environment and a nonmigrant population. The blood pressure rise consequent to migration was related independently to changes in body weight and urinary electrolytes. The implications of these observations for active intervention studies are discussed.

Adolescent↗
PubMed1984

Blood pressure and its correlates in an African tribe in urban and rural environments.

As part of a longitudinal study of migrants who move from a subsistence farming rural society to Nairobi, blood pressures and associated factors were measured in cross sectional studies of members of the Luo tribe in their traditional rural environment and in the urban environment of Nairobi. Blood pressures in Nairobi correlated with duration of urban residence. In the rural area men showed a negligible rise in blood pressure with age, and both sexes showed a significantly smaller rise than in the urban area. Although mean weights of the rural group were smaller, this did not account for all the urban/rural differences in blood pressures. Nevertheless, mean urinary sodium concentration and sodium ratios (sodium/potassium and sodium/creatinine) were significantly higher in the urban group whereas mean urinary potassium concentration and potassium/creatinine ratio were significantly lower. Perhaps the ratio of sodium to potassium in the diet contributes to the different blood pressure profiles of these two populations.

Adult↗
PubMed1981

Acute interstitial nephritis complicating Legionnaires' Disease.

An acute interstitial nephritis was found in a patient with sudden renal failure and lung infection caused by Legionella pneumophilia. Our patient regained and maintained normal renal function after a short period of dialysis support. The diagnosis should be considered in any patient with a chest infection complicated by acute renal failure especially if confusion is disproportionate to the degree of uremia.

Acute Disease↗
PubMed1976

The measurement of muscle mass in children using [15N]creatine.

In eight infants and children who had recovered from protein-energy malnutrition (PEM), muscle mass was estimated by measuring creatine turnover by an isotope dilution technique using [15N]creatine, creatine concentration, and urinary creatinine output. Creatine turnover varied from 1.5 to 2.6% of the muscle creatine pool per day and muscle creatine concentration ranged from 1.7 to 3.9 mug/mug muscle mass was between 15% and 37% of total body weight. The results indicate that daily creatinine output is not a reliable indicator of muscle mass in children who have recently recovered from severe PEM.

Body Composition↗
PubMedDate not supplied

Blood pressure and associated factors in a rural Kenyan community.

Blood pressure (BP) and associated factors were determined in 1737 men in a remote Kenyan agricultural community. Systolic BP showed no significant rise with age until after 54 years; diastolic BP showed a small rise with age. Both systolic and diastolic BP correlated with weight independent of age. Systolic and diastolic BP correlated positively with casual urinary sodium/potassium and negatively with potassium/creatinine ratios. Both systolic and diastolic BP correlated significantly with the number of years of education, as did urinary sodium/potassium and sodium/creatinine ratios. Potassium/creatinine ratios were negatively correlated with the number of years of education. Blood pressure and urinary sodium/creatinine ratios were significantly lower in subsistence farmers compared with those in other occupations, and potassium/creatinine ratios were significantly higher. Two pilot studies of Luo tribesmen showed a strong correlation between casual urinary electrolyte ratios and those derived from 24-hour urine samples and a greater variance of sodium excretion between these people than that found within individuals. These results suggest that a relationship between BP and casual urine electrolyte estimations may be identifiable in communities where there is less day-to-day dietary variation. They also suggest that some of the changes in BP associated with urbanization could be mediated by changes in dietary electrolytes.

Adolescent↗