Risk factors for the development of stroke was studied in a prospective long-term investigation of 855 male in a random population sampled of the same age. After 13 years of follow-up 25 participants had suffered from stroke, which gives an incidence of 19/10,000 annually. At the 1963 year investigation several parametras were studied. The stroke-prone person had higher values of systolic and diastolic blood pressure and had a significant greater total heart volume. Blood parametras as the fasting of serum cholesterole, triglyceride and erytrocyte sedimentation rate were significantly elevated in those who developed stroke. They also tended to consume more coffee and showed a higher tobacco consumption. By applying the multiple regression model it was disclosed that the most predective risk-variables were diastolic blood pressure, erytrocyte sedimentation rate and smoking habits.
The genetics of primary angle-closure glaucome (a.c.g.) was studied: a) through the prevalence in sibs and children of a.c.g. probands, and b) through the family distribution of the closely correlated axial anterior chamber depth (ACD). The material emerged from an epidemiologic study in Greeland Eskimos. a) Compared with the general population, the observed prevalence of a.c.g. was increased in sibs of a.c.g. probands and the estimated, future prevalence was found to be the same in sibs and children. Age influence prevented a proper Mendelian analysis, but no simple monogenic inheritance seems probable. b) The biometric study showed a relatively shallow chamber in sibs, children, nephews, nieces and grandchildren of a.c.g. probands. Regression analyses revealed a corresponding pattern, also in control families of probands with shallow chambers and in general population families. A heritability of 70% was found, indicating that about two thirds of the age and sex independent variation in ACD seems to be genetic.
The purpose of this study was to compare the predicted maximal oxygen concumption derived from the Canadian Home Fitness Test (CHFT) and the Astrand ergometer test to the observed VO2 max determined from a progressive multi-stage treadmill test. Sixty-four sedentary subjects (35 males and 29 females) ranging in age from 20 to 54 years participated in the study. The mean VO2 max measured on the treadmill for males and females was 34.6 +/- 6.0 ml/kg/min while the Astrand procedure predicted a mean VO2max of 29.6 +/- 6.5 ml/kg/min and the CHFT predicted a mean VO2 max of 34.8 +/- 5.0 ml/kg/min. Statistical analysis revealed a significant under-prediction (P less than 0.001) of the VO2 predicted by the Astrand test to the VO2 max derived from the treadmill test while there were no differences between the treadmill VO2max and that predicted by the CHFT. When the male and female values were analyzed separately, the same results were seen in the males. For the females, however, there were no significant differences among predicted and observed values. It concluded that the CHFT provided an adequate prediction of cardio-respiratory fitness as well as, if not superior to, the Astrand procedure.
Studies have been made of age- and sex-adjusted 1968 provincial rates for individual surgical procedures. For elective and discretionary operations, such as tonsillectomy and adenoidectomy, hysterectomy, vein stripping and lens extraction, provincial rates varied by approximately 100 percent. Newfoundland, with few surgeons and hospital beds, had the lowest discretionary rates, and Alberta, which ranked hgih both for surgeons and hospital beds, the highest. Interprovincial differences were of smaller magnitude for non-discretionary surgery (radical mastectomy, cesarean section, colectomy., lobectomy, etc.). Ther were statistically significant correlations between numbers of surgeons and elective and discretionary surgical rates and between numbers of hospital beds and bed use in the provinces. The effect of disease prevalence on discretionary surgical rates was minimized because the rates were age- and sex-adjusted. Provincial organization of, and payment for, medical services has been similar. Hence, the ratio of surgical personnel to population in each province is postulated as a major determinant of the differing interprovincial rates.
We compared respiratory variables in 441 grain elevator workers with 180 civic outside laborers in Thunder Bay. The grain handlers had a lower frequency of both positive skin reactions to pollens and molds and a family history of asthma, which suggests that they may have been self-selected for a decreased tendency to develop allergic respiratory disease. There was a higher frequency of cough and rales and a small decrease in forced vital capacity and forced expiratory volume in one sec among the grain handlers, as compared to the civic workers matched for smoking. However, these differences between grain and nongrain workers were small in comparison to those between smokers and nonsmokers. There was no clear indication of a worsening of respiratory functions that could be attributed specifically to duration of employment as a grain elevator worker.