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Biomedical subjects

J G Fodor

Publications and source records attributed to J G Fodor.

At least 37 records · Page 2Linked to original sources
PubMed1991

The geography of the community sex ratios for young children in Newfoundland.

Abnormalities of the sex ratio of births may be linked with environmental factors, including diet and pollutants in the general or occupational environments, which in turn can cause ill-health. To examine this relationship in the Province of Newfoundland and Labrador, where a geographical imbalance of mortality has already been identified, we examined the geographical distribution of sex ratios (boys/girls x 100) of young children (0-4 years) in the communities of the Province during recent years. The individual communities of the 1976 and 1981 censuses were assigned to contiguous regions and their component districts. The numbers in the appropriate age-groups in the communities in these two census years were used to calculate a mean sex ratio for each community; each community was allocated, according to the value of its ratio, to one of four predefined categories of ratio. From the numbers of communities belonging to these various categories of sex ratio in the regions and districts, the community sex ratios of these areas (i.e. regions and districts) were derived. As a preliminary assessment of the relationship between sex ratios and mortality, a small group of communities with the highest sex ratios was selected, and the mean standardized mortality ratios (SMRs) for all deaths in those communities were calculated. The community sex ratios of regions and districts declined from east to west. The difference in the ratios between the Avalon region (in the most easterly part of the Province) and the southwest region was statistically significant. Districts with high ratios were frequent, particularly those on the Avalon peninsula in the south-east of the island, whereas low ratios were more frequent on the south-west coast of the island, and a low ratio was also found for the only inland district. Of the communities with statistically reliable numbers, the township of Makkovik in Labrador had the highest sex ratio (100 x 50/25 = 200). The SMR of that community during 1976-82 was statistically elevated at 218. In the small group of communities studied, however, high sex ratios from census data for individual communities were not reliable predictors of high SMRs. Further work is required to clarify the inter-relationships between the sex ratios of the census data, the sex ratios of births, the mortality rates and environmental factors.

Child, Preschool↗
PubMed1991

Treatment of mild hypertension.

The mortality of males and females increases two-fold with increasing diastolic blood pressure (DBP) from 83 to 102 mm Hg. There is a corresponding significant increase in cardiovascular morbidity. While there is a general consensus about the need for drug treatment for those patients with DBP of 100 mm Hg or more, there is a controversy as to the justification of pharmacotherapy in the DBP range of 90-100 mm Hg. The arguments against drug treatment of patients with sustained mild hypertension with DBP less than 100 mm Hg rest on results of the large scale clinical trials, which have shown only modest benefit, not commensurate with the risks and inconveniences of pharmacotherapy. Critical appraisal of trials conducted in the past decade suggest a good efficacy of treatment of mild hypertension. Furthermore, recent studies indicate that hypertension is not a symptomless well-being. The inconveniences and side effects of treatment could be greatly reduced with lower doses and selective application of the most appropriate drugs. In a randomized, double-blind, parallel-group study of 80 patients with mild hypertension, 10-20 mg of nitrendipine once a day was an efficacious blood pressure lowering treatment with no significant difference in the incidence of side effects compared to a placebo-treated control group.

Adult↗
PubMed1991

Treatment of mild-to-moderate hypertension: comparison between a calcium-channel blocker and a potassium-sparing diuretic.

In a multicenter study, 61 patients, 18-70 years of age, with mild-to-moderate hypertension [diastolic blood pressure (DBP) 95/114] completed a 28-week treatment. After initial placebo washout, patients were randomly allocated either to diltiazem or hydrochlorothiazide/triamterene. At the end of 12 weeks, the patients continued on the same medication if their goal blood pressure achieved (DBP less than 90; or 10 mm Hg below baseline). If not, the alternate agent was added (either diltiazem + hydrochlorothiazide/triamterene or hydrochlorothiazide/triamterene + diltiazem). At the end of 28 weeks, the intent-to-treat analysis showed that 90% on diltiazem alone, 73.7% on hydrochlorothiazide/triamterene alone, 71.4% on (diltiazem + hydrochlorothiazide/triamterene), and 57.1% on (hydrochlorothiazide/triamterene + diltiazem) achieved goal BP. End point mean values of BP and heart rate after adjusting for sex, baseline values, age, and weight showed no significant difference between groups. Forty-six percent on hydrochlorothiazide/triamterene alone and 24% on diltiazem alone reported one or more adverse events, possibly related to study medication. Patients with diltiazem as the first choice had better BP control than those on hydrochlorothiazide/triamterene alone (81.5% vs. 69.7%). Furthermore, among non-goal achievers at week 12, there was a greater response in the group when hydrochlorothiazide/triamterene was added to diltiazem than when diltiazem was added to hydrochlorothiazide/triamterene. This study suggests that in mild-to-moderate hypertension, diltiazem is better than hydrochlorothiazide/triamterene as first line therapy.

Adolescent↗
PubMed1991

Efficacy of once daily nitrendipine in mild hypertension: comparison with placebo.

A randomized, double-blind, parallel group study was carried out to compare the antihypertensive efficacy of nitrendipine with that of placebo in 80 mild hypertensives. The dose of nitrendipine was initially 10 mg once daily and was doubled to 20 mg once daily after four weeks in patients who responded poorly (33% of patients on nitrendipine and 49% of patients on placebo required doubling of dose). Blood pressure was assessed 20 to 24 h after dosing. Mean (+/- standard error) reductions in supine systolic and diastolic blood pressures for patients who completed 10 weeks of therapy were significantly greater for the nitrendipine group than for the placebo group (systolic blood pressure 18.1 +/- 2.7 mmHg versus 4.2 +/- 2.5, P less than 0.0001; and diastolic blood pressure 10.6 +/- 1.1 mmHg versus 6.6 +/- 1.3, P = 0.002). A comparison of mean reductions in standing systolic and diastolic blood pressures produced similar results. Goal of therapy (diastolic blood pressure no more than 90 mmHg or reduction of at least 10 mmHg) was achieved in 71% of nitrendipine-treated and 45% of placebo-treated patients (P less than 0.05). Nine of 80 patients randomized to therapy dropped out during treatment (nitrendipine: four adverse experiences and one moved from the area; placebo: two adverse experiences, and drug ineffective in two). Overall, the incidence of adverse experiences considered by the physician to be related to treatment was higher in the placebo group (32%) than in the nitrendipine group (23%). Only flushing had a higher incidence in the nitrendipine group; however, the overall incidence was low (9%).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1991

Modification of cardiovascular risk factors in rural population of Newfoundland through nutritional counselling.

Cardiovascular risk factor (CVRF) evaluation has been offered to the adult population of a rural area of Newfoundland. Out of 4,814 residents of the selected communities 522 persons volunteered for a screening examination. The assessed variables included medical history, blood pressure, total cholesterol, smoking and body mass index. The most frequent CVRF encountered had been hypercholesterolaemia, ascertained in 61% of all residents. Among the respondents 30% were smokers and 27% were hypertensives. A six-month intensive educational programme aimed at a cohort of 41 high risk individuals led to a significant decline of systolic blood pressure, body mass index and serum cholesterol. Although, after termination of the intervention programme six months later, the risk factor levels increased again, they have remained below the original values. The results of this pilot study led to a design of a major random clinical trial on non-pharmacological therapy to be implemented in the years 1990/1993.

Adult↗
PubMed1990

Accurate, reproducible measurement of blood pressure.

The diagnosis of mild hypertension and the treatment of hypertension require accurate measurement of blood pressure. Blood pressure readings are altered by various factors that influence the patient, the techniques used and the accuracy of the sphygmomanometer. The variability of readings can be reduced if informed patients prepare in advance by emptying their bladder and bowel, by avoiding over-the-counter vasoactive drugs the day of measurement and by avoiding exposure to cold, caffeine consumption, smoking and physical exertion within half an hour before measurement. The use of standardized techniques to measure blood pressure will help to avoid large systematic errors. Poor technique can account for differences in readings of more than 15 mm Hg and ultimately misdiagnosis. Most of the recommended procedures are simple and, when routinely incorporated into clinical practice, require little additional time. The equipment must be appropriate and in good condition. Physicians should have a suitable selection of cuff sizes readily available; the use of the correct cuff size is essential to minimize systematic errors in blood pressure measurement. Semiannual calibration of aneroid sphygmomanometers and annual inspection of mercury sphygmomanometers and blood pressure cuffs are recommended. We review the methods recommended for measuring blood pressure and discuss the factors known to produce large differences in blood pressure readings.

Adult↗
PubMed1990

Intersalt in Newfoundland and Labrador.

In Intersalt, positive relations between 24-hour urinary sodium and potassium excretion and blood pressure were observed in over 10,000 men and women in 52 centers around the world. Body mass index (BMI), alcohol intake and smoking showed different associations with blood pressure in various population groups. We investigated these variables in the 2 Canadian centers and could not confirm the sodium-potassium relationship. In a multiple stepwise regression analysis, BMI and alcohol had the strongest relation with blood pressure in men. Among the female participants, BMI and sodium were the most influential factors on systolic blood pressure. For diastolic blood pressure, BMI and smoking showed the strongest significance. Neither in men nor in women could the influence of high sodium and low potassium excretion on blood pressure be discerned.

Adult↗
PubMed1990

The Canadian consensus report on non-pharmacological approaches to the management of high blood pressure.

The Canadian Consensus Conference on Non-Pharmacological Approaches to the Management of High Blood Pressure reviewed in March, 1989 on its meeting in Halifax, Nova Scotia, data concerning the efficacy of eight interventional strategies used for controlling hypertension. These strategies were as follows: alcohol restriction, weight reduction, physical exercise, reduction of salt intake, relaxation/stress management, increase of potassium and calcium intake and combination of pharmacological and non-pharmacological management. The Panel of the Consensus Conference recommended as efficacious the following interventions: alcohol restriction for less than two standard drinks per day, reduction of excessive body weight, and reduction of salt intake. There is sufficient scientific evidence for recommending potassium rich diet for normotensives and hypertensive persons. The Panel also concluded that a combination of pharmacological and non-pharmacological management is an efficacious measure. The Panel at this point of time could not issue recommendations as to the value of relaxation/stress management, physical exercise and calcium intake.

Alcohol Drinking↗
PubMed1990

Cardiovascular risk factors in Newfoundland population and modification of their level through nonpharmacological intervention.

In the rural area of Newfoundland, 522 residents volunteered for a cardiovascular risk factor evaluation. Medical history, blood pressure (BP), blood cholesterol, smoking, and body mass index were assessed. Seventy-five percent of the population had at least one of these risk factors. The most frequent condition had been hypercholesterolemia in 61% of respondents. An intensive 6-month educational program aimed at a group of 41 high-risk individuals led to a significant decline in systolic BP, diastolic BP, body mass index, and serum cholesterol. Although the risk factor levels increased again after termination of the intervention program 6 months later, they have remained below the original values. The results of this pilot study led to a design of a major random clinical trial on nonpharmacological therapy, to be implemented in the years 1990-1993.

Blood Pressure↗
PubMed1990

Clinical assessment of blood pressure.

This study was performed to determine the blood pressure measuring techniques and accuracy of sphygmomanometers used by physicians in ambulatory care clinics on the Avalon Peninsula of Newfoundland. Of the 114 participating physicians, no physician completely followed all the recommended BP measuring techniques of the American Heart Association. Almost all physicians supported the patient's arm at heart level to measure BP. Fewer physicians used the following recommended techniques; palpation to initially assess systolic BP (38%), measurement of BP in both arms (23%), an appropriate rate of cuff deflation (18%), measurement of BP in recommended patient positions (10%), the appropriate length of rest (4%) or use of a cuff of appropriate size (3%). Approximately 8% of mercury sphygmomanometers were out of calibration by at least 4 mmHg but none were out by more than 6 mmHg. Forty percent of aneroid sphygmomanometers were out of calibration by at least 4 mmHg and of these 30% were out by 10 mmHg or more. Mercury and aneroid sphygmomanometers were used by 60% of physicians. Aneroid sphygmomanometers were used exclusively by 34% of physicians, while 5% of physicians relied solely on mercury devices. Standardized techniques for BP measurement are not used and inaccurate sphygmomanometers are common; these factors may lead to misclassification of blood pressure and inappropriate treatment of patients.

Blood Pressure↗
PubMed1988

Blood pressure profile in two adult male populations.

Causal blood pressure measurements were recorded in two groups of men aged 40 to 64 years; of the 7024 men in metropolitan Saint John, NB, and the 4044 men in seven suburbs of Quebec who were asked, 5840 (83.1%) and 3097 (76.6%) respectively agreed to participate. Of the Saint John group 9.0% were taking antihypertensive drugs, as compared with only 3.3% of the Quebec group (p less than 0.0001). Among the treated subjects 33% in Saint John and 53% in Quebec still had a diastolic pressure greater than 95 mm Hg (p less than 0.01). Among the participants not taking antihypertensive drugs the systolic blood pressure increased with age, but the diastolic blood pressure increased only slightly up to 55 years of age and then decreased. On average the subjects in Saint John who were not being treated had a systolic pressure 6.2 mm Hg lower and a diastolic blood pressure 3.6 mm Hg lower than their Quebec counterparts (p less than 0.0001). This difference was observed in all the age groups and was not the result of the treatment of a greater proportion of the Saint John cohort. Despite the higher blood pressures and the smaller number receiving adequate treatment in the Quebec group, the rate of death due to coronary artery disease was 10% lower than that in the Saint John group. A bias in the data from Quebec may have influenced the magnitude of the differences between the two samples, but if present it should have underestimated the blood pressures in the Quebec group and therefore not have changed the outcome.

Adult↗
PubMed1987

A comparison of the side effects of atenolol and propranolol in the treatment of patients with hypertension.

A single-blind study was conducted in 52 hypertensive patients, aged 25 to 68 years, to compare the side effects of an equally effective antihypertensive regimen of propranolol and atenolol. All patients had a history of side effects with beta-blocker therapy. Patients were treated with propranolol 40 to 160 mg bid for 8 weeks, followed by atenolol 50 to 100 mg given once daily for 8 weeks, and then rechallenged with the required dosage of propranolol for 8 weeks. Mean systolic and diastolic blood pressures were controlled during all three treatment phases. Side effects showed a definite trend toward improvement during the atenolol treatment phase. CNS side effects, in particular, showed significantly (P less than .05) reduced severity scores and overall incidence rates during the atenolol treatment phase. In conclusion, this study showed that at equally effective antihypertensive dosages the hydrophilic beta blocker atenolol produced significantly fewer CNS side effects than the lipophilic beta blocker propranolol.

Adrenergic beta-Antagonists↗
PubMed1987

Coffee and cholesterol in epidemiological and experimental studies.

Twenty-two cross-sectional studies involving 130,000 persons from 8 different countries have reported their findings on the association between coffee consumption and cholesterol levels. Results of these reports display a variety of trends in the association between coffee intake and serum cholesterol concentrations: 8 (36%) studies demonstrated a significant positive association in both sexes, and 5 (23%) studies showed no association in men or women. In 3 other reports where both sexes were included, significant positive association was observed only in women. The remaining 6 investigations examined only men with 4 (18%) reporting a significant correlation between coffee and cholesterol. This unexplained incongruity of cross-sectional data points to a relationship between coffee and cholesterol in some populations, which needs to be further explored. In addition, HDL cholesterol levels appeared unrelated to coffee intake in the 11 studies in which it was measured. The 7 available human experiments showed the same low level of agreement in the results among small numbers of volunteers. Experiments involving different brewing methods suggest that a major part of the cholesterol-increasing effect can be explained by different brewing methods. A critical assessment of the published reports leads to the conclusion that the data are insufficient to warrant public health admonitions against coffee drinking, but that it may be of clinical importance in some hypercholesterolemic individuals.

Cholesterol↗
PubMed1987

Lipid and lipoprotein levels of Newfoundland school children.

Serum concentrations of total cholesterol, HDL, LDL, and VLDL cholesterol were measured in 1,033 boys and girls age 8-10 years and 14-16 years who were living in two geographically distinct areas on the East and West coast of Newfoundland. The respondents enrolled to this study were school children attending four schools selected at random from all schools in the area. Ninety percent of the invited students participated in the study. The Newfoundland children had higher total cholesterol levels than those reported for children matched for age, sex and race living in the United States. However, their LDL cholesterol levels were found to be similar to those observed in US samples. It was concluded, therefore, that the higher total cholesterol levels of the Newfoundland children were due to their higher HDL cholesterol levels.

Adolescent↗
PubMed1987

Smoking habits and antihypertensive treatment.

Five hypertension intervention trials (HDFP, MRFIT, Australian National BP Study, IPPPSH, MRC) were analyzed for the effect of smoking on antihypertensive therapy and final outcome in coronary and all-cause mortality. In addition, an observational study of primary screenees for MRFIT was reviewed. Thus, the hypertensive population evaluated in this paper amounts to 135,851 patients. HDFP revealed that smokers had about twice the mortality rates compared to nonsmokers regardless of the treatment group to which they were randomized. The annual incidence of events in the Australian Study among nonsmokers in the placebo group was even lightly lower than in smokers under active therapy. The results of the MRFIT showed that smoking had a particularly deleterious impact on those hypertensives whose cholesterol levels were elevated. In this group, the coronary death rates were 10 times higher than in nonsmokers with lower cholesterol levels. Although the treatment with beta-blockers reduced the coronary event rates in the MRC and in IPPPSH, this beneficial effect was absent in smokers. However, in trials in which diuretic treatment is effective in nonsmokers, it is equally effective in smokers.

Adrenergic beta-Antagonists↗
PubMed1987

Electrolyte profiles in a hypertensive population: The Newfoundland Study.

Analysis of the electrolyte composition of the diets of 4 population samples in Newfoundland demonstrated: high sodium and low potassium, calcium, magnesium, and zinc contents. It is suggested that these nutritional factors could contribute to the high prevalence of hypertension in this Province.

Blood Pressure↗
PubMed1987

Consumption of precursors of N-nitroso compounds and human gastric cancer.

It has been hypothesized that dietary nitrate and nitrite are converted in the stomach to nitrous acid, which reacts with secondary amines and amides to form nitrosamines and nitrosamides, compounds frequently demonstrated to be carcinogenic in animals, and that vitamins C and E inhibit N-nitroso product formation by chemically reducing nitrous acid. This hypothesis and others were tested in a case-control study (controls were individually matched by age, sex and area of residence), utilizing a standardized, quantitative, dietary history questionnaire interview. Daily nutrient consumption values were calculated from interview responses, and continuous conditional logistic regression was used for the data analysis. Significant findings are as follows: (1) Average daily consumption of nitrite, chocolate and carbohydrate was associated with increasing trends in risk. (2) While citrus fruit intake appeared to be somewhat protective, any protective effect of vitamin C intake was less apparent, and of vitamin E, not at all apparent. (3) Consumption of dietary fibre was negatively associated with gastric cancer risk. These findings appear to implicate a number of dietary components, including nitrite consumption, in the genesis of gastric cancer in humans.

Adult↗