The Keewatin Health Assessment Study, NWT, Canada.
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
T K Young
Publications and source records attributed to T K Young.
Obesity and its relation to cardiovascular disease risk factors in Canadian adults. Canadian Heart Health Surveys Research Group.
OBJECTIVE: To describe the distribution of weight and abdominal obesity among Canadian adults and to determine the association of obesity with other risk factors for cardiovascular disease. DESIGN: Population-based cross-sectional surveys. Survey nurses administered a standard questionnaire and recorded two blood pressure measurements during a home visit. At a subsequent visit to a survey clinic two further blood pressure readings were made, anthropometric measurements recorded and a blood specimen taken for plasma lipid determination. SETTING: Nine Canadian provinces, from 1986 to 1990. PARTICIPANTS: A probability sample of 26,293 men and women aged 18 to 74 years was selected from the health insurance registration files of each province. Anthropometry was performed on 17,858 subjects. OUTCOME MEASURES: Body mass index (BMI), ratio of waist to hip circumference (WHR), mean plasma lipid levels, prevalence of high blood pressure (diastolic greater than or equal to 90 mm Hg or patient on treatment) and self-reported diabetes mellitus. MAIN RESULTS: The prevalence of obesity (BMI greater than or equal to 27) increased with age and was greater in men (35%) than in women (27%). Abdominal obesity was likewise higher in men and increased with both age and BMI. The prevalence of high blood pressure was greater in those with higher BMI, especially in those with a high WHR. Although total plasma cholesterol levels increased only modestly with BMI, levels of low density lipoprotein (LDL) cholesterol and triglycerides and the ratio of total cholesterol to high density lipoprotein (HDL) cholesterol increased steadily, while HDL-cholesterol decreased consistently with increasing BMI. High total cholesterol levels (greater than or equal to 5.2 mmol/L) were more prevalent among people with high BMI, especially those with a high WHR. The prevalence of diabetes increased with BMI among those 35 years or older, especially those with abdominal obesity. About half of men and two-thirds of women who were obese were trying to lose weight. CONCLUSION: Obesity remains common among Canadian adults. There is a need for broad-based programs that facilitate healthy eating and activity patterns for all age groups. Health professionals should incorporate measurement of BMI and WHR into their routine examinations of patients to enhance their evaluation of health risk.
Adult↗
Effect of traditional Chinese herbal medicines on the pharmacokinetics of western drugs in Sprague-Dawley rats of different ages (II): Aminophylline-huan shao tan and aminophylline-pu chung yi chi tang.
The effect of Chinese herbal medicines (Huan Shao Tan and Pu Chung Yi Chi Tang) and western drugs (sodium phenobarbital and cimetidine) on the serum concentration and pharmacokinetic parameters of theophylline and cytochrome P-450 of Sprague-Dawley (SD) rats of three different ages were examined. The older rats without pretreatment with Chinese herbal medicines and western drugs exhibited higher serum theophylline concentration and lower pharmacokinetic parameters of theophylline than middle-aged and younger rats (P < 0.05), but there was no difference in cytochrome P-450 activity among the three different ages of rats. All rats when pretreated with sodium phenobarbital showed lower serum theophylline concentration and higher pharmacokinetics parameters of theophylline. Also, the activity of cytochrome P-450 was higher (P < 0.05). When cimetidine was pre-administered in SD rats of three age groups, all rats exhibited lower serum theophylline concentration and higher pharmacokinetics parameters (P < 0.05), but the activity of cytochrome P-450 remained unchanged (P > 0.05). The results were opposite to other studies, probably because the dose and dosing intervals were different. No single effect occurred on the younger and middle-aged rats after pretreatment with Huan Shao Tan and Pu Chung Yi Chi Tang: their serum theophylline concentration, pharmacokinetics parameters and cytochrome P-450 activity were the same as the control group. However, the older rats after pretreatment with Huan Shao Tan or Pu Chung Yi Chi Tang showed lower serum theophylline concentration and higher pharmacokinetics parameters than the younger and middle-aged rats pretreated with similar Chinese herbal medicines. This indicates that Huan Shao Tan and Pu Chung Yi Chi Tang may perhaps improve the elimination of theophylline in older rats. This might be attributed to the increase in hepatic blood flow or in liver volume, since the activity of cytochrome P-450 was not affected by the administration of Chinese herbal medicines.
Aging↗
Determinants of tuberculin sensitivity in a child population covered by mass BCG vaccination.
A cross-sectional survey of 701 Indian children aged 1-15 in five northern Canadian communities showed that 82% had a documented history of BCG vaccination while only 78% had a visible scar. The prevalence of 5 mm or more induration on Mantoux testing varied from 6 to 26%. Multiple logistic regression indicated that community, age, past use of isoniazid and time since the last Mantoux test were positive predictors of sensitivity. The presence of a BCG scar and the number of past vaccinations were not significantly associated but the elapsed time since the last BCG was negatively associated with a positive reaction. Overcrowding, nutritional status and past history of household and community contact with an active case of tuberculosis were also investigated but their independent effect could not be demonstrated. Despite the presence of mass BCG vaccination in this population, tuberculin testing is still a useful tool in assessing the risk of infection.
Adolescent↗
Prevalence of diagnosed diabetes in circumpolar indigenous populations.
The prevalence of diagnosed diabetes in several genetically closely related indigenous populations in the circumpolar arctic and subarctic regions of Russia, Alaska and Canada is compared. The age-standardized (to the IARC's hypothetical world population) prevalence ranged from 1.8/1000 among the Chukchi and Eskimo of Chukotka, 3.6 and 7.9/1000 among the Eskimos/Inuit of the Canadian Northwest Territories (NWT) and Alaska respectively, 7.1, 9.3 and 18.6/1000 among Athapaskan Indians in the NWT, Yukon and Alaska respectively, to a high of 22.7/1000 among the Aleuts in Alaska. All are below the US all-race prevalence of 23.5/1000 and far below the extreme high prevalence reported from many North American Indian tribes. As a group, such arctic and subarctic peoples have a much shorter and less intense history of European contact and acculturation. Environmental factors are also likely to be responsible for the current differences between these indigenous populations in the circumpolar region, assuming that they share susceptibility genes for diabetes inferred from their close genetic relationships based on markers in other loci. Formal surveys of glucose tolerance and potential risk factors such as diet, physical activity, obesity, insulin resistance and genetic admixture in the circumpolar region would improve knowledge of the aetiology of diabetes in genetically and culturally diverse human populations.
Adult↗
Platelet levels of reduced glutathione, superoxide dismutase, zinc and malondialdehyde in uremic patients.
Platelet-reduced glutathione (GSH), superoxide dismutase (SOD) and zinc content as well as malondialdehyde (MDA) formation were studied in 24 healthy volunteers as controls and 25 patients with chronic renal failure. Uremic patients had a significantly lower GSH and SOD content as well as an abnormal MDA formation in platelets. Their plasma zinc levels were sharply below the normal value, but the platelet zinc content was similar to normal controls. The decrease in the platelet GSH level was closely related to plasma zinc in uremic patients. We also found that the platelet zinc levels were positively correlated to the platelet GSH content in normal controls and uremic patients, but not to the platelet SOD level. The results suggest that uremic toxins may influence the content of platelet GSH and SOD, as well as inhibit prostaglandin synthesis. The decreases in platelet GSH may partially be related to the low plasma zinc level.
Adult↗
An epidemiological perspective of injuries in the Northwest Territories.
This paper reviews the epidemiology of injuries in the multiethnic population of the Northwest Territories (NWT), Canada, based on mortality, hospital morbidity, and health survey data. Overall, injury mortality in the NWT has remained consistently higher than the Canadian national rate. In the NWT, an increasing trend was observed for motor vehicle accidents and homicide in both sexes, and suicide among males, while other accidents (including fires and drowning) have declined substantially among males. The age group which reported the highest suicide rate was shifted downward between the periods 1961-70 and 1981-86. Of the three major groups in the NWT, the overall injury mortality rate was comparable between Indians and Inuit, and their rates were twice as high as that of non-Natives. The age-standardized hospitalization rate for all injuries for the Keewatin Region was similar to that of Canada as a whole whereas the rate for the entire NWT was about twice as high. In the NWT, age-specific hospitalization rate was highest in both sexes among the elderly (age 65+), followed by those in age group 15-24. A survey of a random sample of Keewatin Region residents indicated a low usage rate for seatbelts and helmets while a significant minority of drivers (18%) admitted to drinking and driving sometimes. Such data contribute to a more comprehensive assessment of the burden of injury mortality and morbidity, an important prerequisite for the investigation of risk factors and design of intervention programs.
Adolescent↗
Reduced glutathione, superoxide dismutase contents and malondialdehyde formation in platelets from uremic patients: relation to plasma and platelet zinc.
Platelet-reduced glutathione (GSH), superoxide dismutase (SOD) and zinc content as well as malondialdehyde (MDA) formation were studied in 55 healthy volunteers as controls and 49 patients with chronic renal failure. Uremic patients had a significantly lower GSH and SOD content as well as an abnormal MDA formation in their platelets. Their plasma zinc level was sharply below the normal value, but their platelet zinc content was similar to that of normal controls. We also found that the plasma zinc and platelet zinc level was positively correlated to the platelet GSH content in normal controls and uremic patients. Therefore, the results suggest that in uremic patients the decrease in platelet antioxidant agents (GSH and SOD) may be partially related to their low plasma zinc level.
Adult↗
Antidiuresis and natriuresis induced by gastric distension in water-loaded rats.
Antidiuretic and natriuretic responses were observed following gastric distension in anesthetized, water-loaded rats. An increase of intragastric pressure to 25, 30, 35, and 40 cm H2O of 2-minute duration respectively elicited 11, 35, 45, and 55% inhibition of water diuresis with concomitant, graded increase of sodium excretion by the kidney. These antidiuretic and natriuretic responses to gastric distension persisted and sustained the same intensity after acute bilateral cervical vagotomy, indicating that the sensory input conveyed from the gastric mechanoreceptors to central nervous system during gastric distension should involve afferent fibers other than vagus nerve. Rats with diabetes insipidus (D1) produced by hypothalamic lesions were also tested, but neither antidiuresis nor natriuresis in response to gastric distension was observed in these D1 rats whose neurohypophysis contained little antidiuretic hormone (ADH). In conclusion, gastric distension may induce liberation of ADH and probably other neurohypophysial hormone which affects renal handling of sodium and water in anesthetized, water-loaded rats.
Animals↗
Estimated burden of diabetes mellitus in Manitoba according to health insurance claims: a pilot study.
OBJECTIVE: To estimate the burden of diabetes mellitus in Manitoba from 1980 to 1984. DESIGN: Review of the Manitoba Health Services Commission (MHSC) database. The validity of the MHSC data was established through two substudies: one involved self-reports from a survey of elderly Manitobans, and the other involved people with confirmed diabetes enrolled in the provincial diabetes education program. SUBJECTS: Sample of 100,000 people stratified by age, sex and MHSC health region: 50,000 were aged 25 to 64 years, and 50,000 were aged 65 or more. All MHSC claims containing the ICD-9-CM code for diabetes mellitus or gestational diabetes were identified. MAIN RESULTS: Of the sample 7627 people were found to have a diagnosis of diabetes, the annual prevalence being 0.8% among those 25 to 44 years of age, 3.5% among those 45 to 64 and 7.6% among those 65 or older. The annual incidence rate among those over 25 years of age was 7.8 per 1000. Of the 4556 pregnant women 25 to 44 years old 85 (1.9%) had diabetes; 23 were believed to have gestational diabetes. CONCLUSIONS: The incidence and prevalence rates were similar to those determined on the basis of self-reports in Canadian and US national surveys. The use of an administrative database such as that of the MHSC will provide key information for planning health services for diabetic patients and will permit the monitoring of long-term trends in the incidence and prevalence of the disease.
Adult↗
Prevalence and correlates of hypertension in a subarctic Indian population.
BACKGROUND: In a cross-sectional survey of 704 Cree and Ojibwa Indians ages 20-64 in six northern Canadian communities, blood pressure was measured along with various anthropometric, dietary, biochemical, sociodemographic, and lifestyle data. METHODS: Two readings of systolic (SBP) and diastolic (DBP) pressures were obtained using a mercury sphygmomanometer in accordance with WHO protocol. In analyses where blood pressure (BP) was a continuous variable, the means of the two readings were used. Where "hypertension" as a dichotomous variable was used, a "normal" subject was one with no past history of known physician-treated hypertension and who currently had SBP less than or equal to 140 and DBP less than or equal to 90 mm Hg. All others were classified as "hypertensives." RESULTS: Based on these criteria, the adjusted prevalence of hypertension in the sample was 27%, with an increased frequency among males and those in the older age group. Compared with data from the Canada Health Survey, the mean SBP among the Indians exceeded that of Canadians in the younger age groups but was lower beyond age 45. For DBP, Indians had higher mean levels than Canadians consistently across all age groups and in both sexes. On univariate comparisons, significantly higher BP levels were found among men, the old, those with little education, nondrinkers, the physically inactive, the obese, and the diabetic. Hypertensives also differed from nonhypertensives in terms of total cholesterol, triglycerides, high-density lipoprotein cholesterol/total cholesterol ratio, various indices of obesity and fat patterning, and fasting glucose levels. In a multiple logistic regression model, significant predictors of hypertensive status included male sex, age, body mass index, total cholesterol, unemployed and single marital status, and positive family history of hypertension.
Adult↗
Effect of traditional Chinese herbal medicines on the pharmacokinetics of western drugs in SD rats of different ages. I. Aminophylline-Tin chuan Tang and aminophylline-Hsiao Ching Long Tang.
The effect of the traditional Chinese herbal medicines (Tin Chuan Tang and Hsiao Ching Long Tang) on the serum concentrations and pharmacokinetics of aminophylline was examined in three different ages of SD rats. Each traditional Chinese herbal medicine was orally preadministered to SD rats for one week and then aminophylline was administered intravenously. The serum concentrations and pharmacokinetic parameters of theophylline were estimated by a two-compartment open model. The liver isolated after the last blood sampling was homogenized and the activity of hepatic cytochrome p-450 was determined. Significant difference was found in some pharmacokinetic parameters of theophylline such as K10, t 1/2, Cl and Vd for three different ages of SD rats without pretreatment with Chinese herbal drugs (p less than 0.05). However, pretreatment with Tin Chuan Tang or Hsiao Ching Long Tang did not affect the pharmacokinetic parameters of theophylline in three different ages of SD rats (p greater than 0.05). We also found that there was no correlation between age and activity of cytochrome p-450 of SD rats (p greater than 0.05). The decline in some pharmacokinetic parameters of theophylline in the elderly rats perhaps might be attributed to the decrease in hepatic blood flow and liver volume. It is concluded that there was no drug interaction between theophylline and Tin Chuan Tang or Hsiao Ching Long Tang in the different ages of SD rats.
Age Factors↗
Determinants of tuberculin sensitivity in a child population covered by mass BCG vaccination.
Explore the source record for details and available documents.
Adolescent↗
Prevalence and correlates of hypertension in a subarctic Indian population.
Explore the source record for details and available documents.
Adult↗
Renal excretion of citrate in patients with chronic renal failure or nephrolithiasis.
Using a specific citrate lyase method, renal excretion of citrate was studied in 32 normal Chinese males, 30 nondialysed uremic male patients and 35 male subjects who had a history of nephrolithiasis. Patients with uremia or nephrolithiasis were found to have a lower urinary citrate excretion. Tubular reabsorption of citrate was markedly decreased in uremic patients, but in stone patients, the increased renal tubular reabsorption of citrate was only found in patients with hypocitraturia, whose renal citrate excretion was below 650 mumol/day and whose urinary magnesium was also low. Hypocitraturia was found in 45% (16/35) of the patients with renal stones whether their filtered load of citrate was normal or subnormal. Urinary citrate excretion was correlated with renal creatinine clearance in both normal subjects and in patients with renal stones or chronic renal failure. However, urinary phosphate correlating with urinary citrate was only found in normal subjects and in patients with kidney stones. In normal subjects, we found a positive correlation between urinary citrate and phosphate, but in stone patients, we found a negative correlation. Hypercalciuria and hyperoxalaturia were noted in some stone formers, who had, moreover, a lower urinary citrate and ascorbate excretion level. Mean urinary ascorbate excretion in patients with renal stones was markedly below that in normal subjects. Thus, we suggest that low urinary citrate excretion may be prevalent in patients with renal stones or chronic renal failure, and that hypocitraturia can be found in some stone formers, whose tubular reabsorption of citrate may be increased.
Adult↗
Determinants of plasma glucose level and diabetic status in a northern Canadian Indian population.
We conducted a cross-sectional survey of 704 Indians aged 20 to 64 years in six remote communities in northern Ontario and Manitoba to determine the factors associated with the fasting plasma glucose and glycosylated hemoglobin levels and diabetic status, defined by past history and current fasting plasma glucose level. Multivariate analyses for the 671 subjects with complete data showed that triglyceride level, age and body mass index (BMI) were significant predictors of the log fasting plasma glucose level and the log glycosylated hemoglobin level; for the latter, waist/hip ratio, history of diabetes mellitus among first-degree relatives and low level of education were additional predictors. Significant risk factors for diabetes as a dichotomous variable included triglyceride level, age, BMI and family history of diabetes. Although energy intake per unit of body weight was lower among subjects with diabetes than those without diabetes, possibly reflecting the lower physical activity level of diabetic subjects, the former consumed significantly more "calorie-adjusted" protein and less carbohydrate than the latter. The findings are consistent with studies in other populations. Further study is needed to determine the natural history of diabetes and its metabolic consequences and to assess the effect of dietary alteration and promotion of physical activity on the incidence of the disease.
Adult↗
Geographical distribution of diabetes among the native population of Canada: a national survey.
The prevalence of diagnosed diabetes was determined for 76% of the registered Indian and Inuit (Eskimo) population of Canada from case registers maintained by the federal agency responsible for Indian health services. A total of 5324 cases were ascertained. The age-sex adjusted rate varied among the Indians from a low of 0.8% in the Northwest Territories to a high of 8.7% in the Atlantic region. Among Inuit, the prevalence was 0.4%. Most cases occur in middle-aged or older individuals, with a higher prevalence among Indian (but not Inuit) females. An ecologic analysis was performed with the crude prevalence of individual communities regressed upon independent variables that included longitude, latitude, geographic isolation, culture area, and language family. Stepwise regressions were also carried out within the Algonkian, Athapaskan, and Eskimoan language families. For the national sample, composite language phylum-culture area predictors were used. The results in the national sample confirmed most findings in the individual language family analysis. Six predictors: latitude, Northeast-Algonkian, Northeast-Iroquoian, Subarctic-Algonkian, Plains-Siouan, and Plains-Algonkian, ranked here in decreasing order of importance, explained 48.4% of the variation in diabetes prevalence. All the named groups had rates significantly greater than found in the reference group of Arctic-Eskimoans. We conclude that the distribution of diabetes among Canadian natives is determined by both genetic and environmental factors.
Aged↗
Renal excretion of zinc in patients with chronic uremia.
Though uremic patients have been reported to have subnormal zinc levels in plasma and an abnormal zinc metabolism, data on their renal excretion of zinc are still unavailable. In our study, 55 nondialyzed uremic patients had a markedly lower concentration of zinc in plasma and a lower urinary zinc excretion. They had a higher excretory fraction of zinc in the renal tubules and a higher ratio of zinc to creatinine excretion than normal subjects. We found that the total daily excretion of zinc, calcium, phosphate and ammonia was reduced, and that the ratio of calcium or ammonia to creatinine excretion decreased in uremic patients. Urinary zinc excretion was correlated with renal creatinine clearance (r = 0.50, p less than 0.001) in both normal subjects and uremic patients, but ammonia excretion was correlated with zinc excretion in normal subjects only. In uremia, urinary zinc excretion was correlated with urinary calcium (r = 0.55, p less than 0.001) and urinary phosphate excretion (r = 0.30, p less than 0.05). We conclude that the increased ratio of zinc to creatinine excretion and the excretory fraction of zinc in the renal tubules of uremic patients may increase the urinary zinc excretion, but a severe diminution of the glomerular filtered load of zinc may be the major factor in decreasing the urinary zinc excretion in uremia.
Adult↗