PubMed Health⌕ Search

Biomedical subjects

W D Hall

Publications and source records attributed to W D Hall.

At least 19 recordsLinked to original sources
PubMed2001

Allowing the medical use of cannabis.

Cannabis has been advocated as a treatment for nausea, vomiting, wasting, pain and muscle spasm in cancer, HIV/AIDS, and neurological disorders. Such uses are prohibited by law; cannabinoid drugs are not registered for medical use in Australia and a smoked plant product is unlikely to be registered. A New South Wales Working Party has recommended granting exemption from prosecution to patients who are medically certified to have specified medical conditions. This proposal deserves to be considered by other State and Territory governments.

Australia↗
PubMed2001

Risk factors for kidney stones in older women in the southern United States.

BACKGROUND: The occurrence of kidney stones is disproportionate in the southern region of the United States. Risk factors for the occurrence of kidney stones in this geographic area have not been reported previously. METHODS: The Women's Health Initiative (WHI) is an ongoing multicenter clinical investigation of strategies for the prevention of common causes of morbidity and mortality among postmenopausal women. A case-control ancillary study was conducted on 27,410 (white or black) women enrolled in the 9 southern WHI clinical centers. There were 1,179 cases (4.3%) of kidney stones at the baseline evaluation. Risk factors for stone formation were assessed in cases versus age- and race-matched control subjects. RESULTS: Risk factors (univariate) included low dietary potassium (2,404 versus 2,500 mg/day, P = 0.006), magnesium (243 versus 253 mg/day, P = 0.003) and oxalate (330 versus 345 mg/day, P = 0.02) intake, as well as increased body mass index (28.5 versus 27.7 kg/m2, P = 0.001) and a history of hypertension (42% versus 34%, P = 0.001). A slightly lower dietary calcium intake (683 versus 711 mg/day, P = 0.04) was noted in case subjects versus control subjects, but interpretation was confounded by the study of prevalent rather than incident cases. Supplemental calcium intake >500 mg/day was inversely associated with stone occurrence. CONCLUSION: Multivariate risk factors for the occurrence of kidney stones in postmenopausal women include a history of hypertension, a low dietary intake of magnesium, and low use of calcium supplements.

Age Factors↗
PubMed2001

Antihypertensive pharmacogenetics: getting the right drug into the right patient.

Pharmacogenetic investigation seeks to identify genetic factors that contribute to interpatient and interdrug variation in responses to antihypertensive drug therapy. Classical studies have characterized single gene polymorphisms of drug metabolizing enzymes that are responsible for large interindividual differences in pharmacokinetic responses to several antihypertensive drugs. Progress is being made using candidate gene and genome scanning approaches to identify and characterize many additional genes influencing pharmacodynamic mechanisms that contribute to interindividual differences in responses to antihypertensive drug therapy. Knowledge of polymorphic variation in these genes will help to predict individual patients' blood pressure responses to antihypertensive drug therapy and may also provide new insights into molecular mechanisms responsible for elevation of blood pressure.

Antihypertensive Agents↗
PubMed2000

How many dependent heroin users are there in Australia?

OBJECTIVE: To estimate the prevalence of dependent or daily heroin users in Australia, and to compare the prevalence in Australia with that in other developed countries. DESIGN: We applied three different methods of estimation (back-projection, capture-recapture, and multiplier) to data on national opioid overdose deaths in Australia, first-time entrants to methadone maintenance treatment, and heroin-related arrests in New South Wales. We compared our estimates with estimates derived by similar methods in countries of the European Union. DATA SOURCES: Data on national opioid overdose deaths were obtained from the Australian Bureau of Statistics. Data on methadone entrants in NSW were extracted from a database maintained by the NSW Department of Health. Data on arrests for heroin-related offences were supplied by the NSW Police Service. RESULTS: The best estimates of the number of dependent heroin users in Australia in 1997-1998 from the three methods of estimation were between 67 000 and 92 000 and the median estimate was 74 000. The population prevalence was 6.9 per 1000 adults aged 15-54 years. The prevalence of heroin dependence in Australia is the same as that in Britain (7 per 1000) and within the range of recently derived estimates in the European Union (3-8 per 1000 adults aged 15-54 years). CONCLUSIONS: Although the exact figures need to be interpreted with caution, our estimates suggest that Australia has a substantial public health problem with dependent heroin use that is of a magnitude similar to that in comparable European societies.

Adolescent↗
PubMed2000

Functional impairment, depression, and life satisfaction among older hemodialysis patients and age-matched controls: a prospective study.

OBJECTIVE: To compare change over time in functional impairment, depression, and life satisfaction among older dialysis patients and age-matched controls. DESIGN: Prospective cohort study over 3 years. SETTING: Urban and rural communities throughout Georgia. SUBJECTS: One hundred thirteen prevalent renal failure patients on in-center hemodialysis and 286 controls. MAIN OUTCOME MEASURES: Ordinal functional impairment index and life satisfaction rating, and Center for Epidemiologic Studies Depression Scale. RESULTS: Dialysis patients, compared with controls, reported significantly more functional impairment at baseline, and also at follow-up after adjusting for baseline impairment and covariates. Dialysis patients had higher depression scores at baseline, and also at follow-up after adjusting for baseline depression and covariates. In contrast, dialysis patients reported lower life satisfaction at baseline than did controls, but the two cohorts were not significantly different on reported life satisfaction at follow-up, after adjusting for baseline life satisfaction and race. In both cohorts, functional impairment and depression were significantly related. CONCLUSION: Older dialysis patients' life satisfaction at a 3-year follow-up, which was similar to life satisfaction among age-matched controls, indicates the value of delivered dialysis care; the value of this care would be increased by reducing excess functional impairment in these patients.

Aged↗
PubMed2000

Pitfalls in the diagnosis and management of systolic hypertension.

BACKGROUND: Systolic blood pressure (SBP) is even more important than diastolic blood pressure (DBP) with regard to the risk of cardiovascular complications. METHODS AND RESULTS: Pitfalls in the diagnosis of systolic hypertension include the auscultatory gap, use of the proper size cuff (obese adult size for mid-arm circumference >33 cm and child's cuff for mid-arm circumference <23 cm), a "white coat" effect of about 17 mm Hg, regression toward the mean, and a tendency to focus only on hypertension rather than all of the cardiovascular risk factors. Pitfalls in the pharmacologic management of systolic hypertension include being too aggressive with "acute" therapy, too fast in up-titration, too complacent about adverse effects, too unaware of important drug or food interactions, and too content with the achieved level of SBP. CONCLUSION: In treated hypertensives, SBP is typically less well controlled than DBP. Clinicians must not generally be content with partial control of SBP.

Adult↗
PubMed2000

Black/white differences in symptoms and health satisfaction reported by older hemodialysis patients.

Although Black end-stage renal disease (ESRD) patients on dialysis report better functioning and well-being than do White patients, little is known about the association of race with disease symptoms and treatment side effects. Interviews were conducted with 183 older Black and 125 older White in-center hemodialysis (HD) patients in Georgia. Patients were identified in a stratified (by race and sex) random sample of patients aged 60+ years selected from the ESRD Network census of all patients in that age category. Self-assessed disease symptoms and/or side effects of treatment, disability days, and health satisfaction were measured. Data were analyzed via logistic or linear regression, controlling for the effects of patients' gender, age, months on dialysis, primary diagnosis of diabetes, cardiovascular co-morbidity, HD treatment time, and usual interdialytic weight gain. Older Whites, compared to older Blacks, were at increased risk for reporting nausea, sexual dysfunction, recent bed disability days, fatigue, greater HD recovery time, and health dissatisfaction. The relation of these complaints to dialysis adequacy and patients' nutritional status merits continued study.

Black or African American↗
PubMed1999

Opioid overdose mortality in Australia, 1964-1997: birth-cohort trends.

OBJECTIVE: To examine trends in rates of opioid overdose deaths from 1964 to 1997 in different birth cohorts. DESIGN: Age-period-cohort analysis of national data from the Australian Bureau of Statistics. MAIN OUTCOME MEASURES: Annual population rates of death attributed to opioid dependence or accidental opioid poisoning in people aged 15-44 years, by sex and birth cohort (in five-year intervals, 1940-1944 to 1975-1979). RESULTS: The rate of opioid overdose deaths increased 55-fold between 1964 and 1997, from 1.3 to 71.5 per million population aged 15-44 years. The rate of opioid overdose deaths also increased substantially over the eight birth cohorts, with an incidence rate ratio of 20.70 (95% confidence interval, 13.60-31.46) in the 1975-1979 cohort compared with the 1940-1944 cohort. The age at which the cumulative rate of opioid overdose deaths reached 300 per million fell in successive cohorts (for men, from 28 years among those born 1955-1959 to 22 years among those born 1965-1974; for women, from 33 years among those born 1955-1959 to 27 years among those born 1965-1969). CONCLUSIONS: Heroin use in Australia largely began in the early 1970s and rates of heroin use have markedly increased in birth cohorts born since 1950.

Adolescent↗
PubMed1999

The Women's Health Trial Feasibility Study in Minority Populations: changes in dietary intakes.

This randomized clinical trial examined the feasibility of low-fat dietary interventions among postmenopausal women of diverse backgrounds. During 1992-1994, 2,208 women aged 50-79 years, 28% of whom were black and 16% Hispanic, enrolled at clinics in Atlanta, Georgia, Birmingham, Alabama, and Miami, Florida. Intervention/support groups met periodically with a nutritionist to reduce fat intake to 20% of energy and to make other diet modifications. At 6 months postrandomization, the intervention group reduced fat intake from 39.7% of energy at baseline to 26.4%, a reduction of 13.3% of energy, compared with 2.3% among controls. Saturated fatty acid and cholesterol intakes were reduced, but intakes of fruits and vegetables, but not grain products, increased. Similar effects were observed at 12 and 18 months. Black and non-Hispanic white women had similar levels of reduction in fat, but the decrease in Hispanic women was less. Changes did not vary significantly by education. While bias in self-reported intakes may have resulted in somewhat overestimated changes in fat intake, the reported reduction was similar to the approximately 10% of energy decrease found in most trials and suggests that large changes in fat consumption can be attained in diverse study populations and in many subgroups.

Aged↗
PubMed1999

Risk reduction associated with lowering systolic blood pressure: review of clinical trial data.

Hypertension is very common in adults >/=60 years of age. Isolated systolic hypertension (ISH) in particular is a good predictor of events associated with elevated blood pressure such as stroke, coronary heart disease, and congestive heart failure. Two large studies, the Systolic Hypertension in the Elderly Program (SHEP) and the Systolic Hypertension in Europe study (Syst-Eur), have demonstrated that antihypertensive drug therapy for elderly patients with ISH reduces the risk of stroke and other major cardiovascular events. SHEP demonstrated that antihypertensive drug treatment with a diuretic-based regimen in patients >/=60 years of age with ISH reduced the incidence of total stroke by 36%. SHEP also demonstrated a 32% reduction in the incidence of cardiovascular events for patients receiving active treatment. The 5-year average systolic blood pressure (SBP) was 155 mm Hg in the placebo group (n = 2371) compared with 143 mm Hg for the active treatment group (n = 2365). Results from the recently completed Syst-Eur study also support the benefits of antihypertensive treatment in patients >/=60 years of age with ISH. Active treatment in Syst-Eur consisted of the calcium channel blocker nitrendipine, with the addition of enalapril and hydrochlorothiazide as needed to reduce SBP to <150 mm Hg. In the active treatment group, total stroke decreased by 42%, and all cardiovascular events decreased by 31%. At 2 years, sitting SBP had decreased by 13 mm Hg in the placebo group (n = 2297) compared with 23 mm Hg in the active treatment group (n = 2398).

Adult↗
PubMed1999

Effects of ephedrine enantiomers on conditioned taste aversion and kaolin intake in rats.

The ephedrine (EPH) enantiomers, (-)-EPH and (+)-EPH, have different biological activity in the rat, with the (-)-EPH enantiomer exerting a greater impact on suppression of feeding, induction of locomotion, and activation of brown adipose tissue thermogenesis. Recent studies document that (-)-EPH treatment produces an alteration of extracellular dopamine in the brain, an effect that is consistent with the locomotor-stimulating and reinforcing effects of this drug. Whether the EPH enantiomers exert aversive actions in the rat is unknown. Experiment 1 examined the impact of systemically administered (+)-EPH (0, 5, 10, or 20 mg/kg) or (-)-EPH (0, 5, 10, or 20 mg/kg) on conditioned taste aversion (CTA) in adult male rats relative to the effect of 32 mg/kg lithium chloride (LiCl). No dose of either enantiomer produced CTA, whereas strong CTA was evident for LiCl. In Experiment 2, consumption of kaolin (a nonnutritive clay) over a 24-h period was used to assess drug toxicity. Rats treated with either 0, 5, 10, 20, or 40 mg/kg (+)-EPH or 0, 5, 10, 20, or 40 mg/kg (-)-EPH did not exhibit alteration of kaolin intake. In contrast, systematic increases in kaolin intake were observed in rats after systemic administration of LiCl (0, 16, 32, 64, and 96 mg/kg). These findings suggest that the enantiomers of EPH do not exert aversive effects at behaviorally relevant doses.

Analysis of Variance↗
PubMed1999

Abnormalities of kidney function as a cause and a consequence of cardiovascular disease.

Hypertension, left ventricular hypertrophy (LVH), hypercreatininemia, and microalbuminuria (MA) are independent risk factors for cardiovascular disease (CVD). Hypertension increases the risk of CVD by two- to three-fold and LVH (especially concentric) is a risk factor for coronary heart disease, heart failure, stroke, and peripheral arterial disease. In people with hypertension, a serum creatinine level of 1.7 mg/dL or more may be an even stronger CVD risk factor than diabetes, smoking, LVH, or systolic blood pressure. Similarly, MA is a strong and independent predictor of CVD morbidity and mortality in people with and without diabetes and/or hypertension. Impaired renal sodium handling and sodium retention are physiological hallmarks of the very early stages of heart failure. Heart failure is a physiologically delicate condition that can decompensate with excess dietary salt intake or over diuresis, or compensate with cautious therapy designed to block the sodium retention and simultaneously interrupt excessively activated neurohumoral mechanisms.

Acute Disease↗
PubMed1999

Low-dose combination therapy as first-line hypertension treatment for blacks and nonblacks.

To assess the efficacy and safety of bisoprolol/6.25-mg hydrochlorothiazide (HCTZ), amlodipine, and enalapril in black and nonblack patients, data from two comparative studies were pooled and subgroup analyses performed. Both studies had similar designs and included all three active treatments. The second study also included a placebo group. Subjects (n = 541) with a sitting diastolic blood pressure of 95-114 mmHg were titrated to achieve a diastolic blood pressure < or = 90 mmHg. The studies included 114 blacks and 427 nonblacks. Results of an intention-to-treat analysis of mean change from baseline after 12 weeks of treatment showed the following: 1) blood pressure was significantly lowered by all three active drugs compared with baseline or placebo; 2) in blacks, bisoprolol/6.25-mg HCTZ resulted in significantly greater reductions of systolic and diastolic blood pressure than enalapril or placebo, but was not significantly different from amlodipine; 3) in nonblacks, bisoprolol/6.25-mg HCTZ resulted in significantly greater reduction of diastolic blood pressure than amlodipine, enalapril, or placebo. The placebo-corrected change in blood pressure was greater for blacks than whites on the bisoprolol/6.25-mg HCTZ combination, but this was not statistically significant. Bisoprolol/6.25-mg HCTZ controlled diastolic blood pressure to < or = 90 mmHg in significantly more patients than enalapril or placebo in blacks and nonblacks. The difference in control rates was not significant versus amlodipine. The incidence of drug-related adverse events was similar between treatments; however, bisoprolol/6.25-mg HCTZ had a lower discontinuation rate due to lack of blood pressure control or adverse experiences in both blacks and nonblacks.

Aged↗
PubMed1999

A rational approach to the treatment of hypertension in special populations.

Hypertension in blacks is usually characterized by low renin, expanded volume and sensitivity to salt. Diuretics are the preferred initial therapy, but response to calcium channel antagonists is also good. The blood pressure response to monotherapy with beta blockers or angiotensin-converting enzyme (ACE) inhibitors is blunted, but this effect is abolished with concomitant use of diuretics. The two major types of hypertension in older persons are isolated systolic hypertension and combined systolic and diastolic hypertension. Strong data support the treatment of combined hypertension in patients 60 to 79 years of age and isolated systolic hypertension in patients 60 to 96 years of age. Diuretics and long-acting dihydropyridine calcium channel antagonists are the recommended initial therapies for isolated systolic hypertension. More studies are necessary before recommendations can be made about the treatment of combined hypertension in patients 80 years of age and older.

Black or African American↗
PubMed1999

Representation of blacks, women, and the very elderly (aged > or = 80) in 28 major randomized clinical trials.

OBJECTIVE: The purpose of this manuscript is to precisely quantify the representation of women, blacks, and very old (aged 80 or more) participants in 28 past or ongoing randomized clinical trials on hypertension, cardiovascular disease, renal disease, and diabetes mellitus. METHODS: Selection of the 28 studies was arbitrary, based primarily on the reference being often quoted or cited as relevant data for women, blacks, the elderly, or persons with diabetes mellitus. RESULTS: Twenty-three of the 28 studies enrolled a majority of men. Many of the completed trials had an under-representation of blacks (0% to 8%). An adequate number (1,091) of very old (aged 80 or more) persons have been studied for isolated systolic hypertension, but the number of such patients thus far studied for diastolic hypertension is too small to allow evidence-based recommendations for therapy. Reported studies in diabetes have included a majority of men (average, 58%) and four of the five trials reviewed enrolled relatively few blacks (average, 4.6%). CONCLUSIONS: Women, blacks, and the very old (aged 80 or more) have been under-represented in many past randomized clinical trials, but ongoing studies will resolve this discrepancy in most instances. The Women's Health Initiative (WHI) will provide data on 161,861 multi-ethnic postmenopausal women. ALLHAT results will include 15,133 hypertensive blacks, and AASK will have 1,094 hypertensive blacks with nephrosclerosis. ALLHAT, STOP-2, and HYVET will include more than 5,000 persons aged 80 or more. Future trials on diabetes mellitus must be designed to improve the representation of women and blacks.

Black or African American↗
PubMed1998

Comparison of the efficacy of dihydropyridine calcium channel blockers in African American patients with hypertension. ISHIB Investigators Group. International Society on Hypertension in Blacks.

BACKGROUND: Hypertension is a prevalent disease among African Americans, and successful treatment rates are low. Since calcium channel blockers are well-tolerated and efficacious in African Americans, we undertook this study to compare the efficacy, safety, and tolerability of 3 commonly prescribed calcium channel blockers: amlodipine besylate (Norvasc), nifedipine coat core (CC) (Adalat CC), and nifedipine gastrointestinal therapeutic system (GITS) (Procardia XL). METHODS: One hundred ninety-two hypertensive patients across 10 study centers were randomly assigned to double-blind monotherapy with amlodipine besylate (5 mg/d), nifedipine CC (30 mg/d), or nifedipine GITS (30 mg/d) for 8 weeks. Patients not achieving therapeutic response after 4 weeks had their dose doubled for the next 4 weeks. The primary end point was a comparison of the average reduction (week 8 minus baseline) in 24-hour ambulatory diastolic blood pressure (DBP). Secondary end points included a comparison of average 24-hour ambulatory systolic blood pressure (SBP), office SBP or DBP reduction, responder rates, safety, and tolerability. RESULTS: One hundred sixty-three patients were evaluable for efficacy after 8 weeks. There was no significant difference in the average 24-hour ambulatory DBP (-8.5, -9.0, and -6.1 mm Hg, respectively) or SBP (-14.3, -15.7, and -11.8 mm Hg, respectively) reduction. Average office SBP and DBP were reduced to a comparable degree (19-22 mm Hg [P =.50] and 12-14 mm Hg [P =.51], respectively). Responder rates (DBP <90 or reduced by > or = 10 mm Hg) were similar (P = .38). Discontinuation rates and adverse event frequency were distributed similarly across the 3 treatment groups. CONCLUSION: The efficacy, safety, and tolerability of the 3 dihydropyridine calcium channel blockers are equivalent in African Americans with stages 1 and 2 hypertension.

Adult↗