Arctic medical research最新文献

For epidemiologic studies of spondyloarthropathy in circumpolar peoples of Chukotka, Russia and Alaska, we gathered demographic, physical and laboratory data to provide a background for evaluating and comparing factors that may influence susceptibility and clinical expression of disease. The study groups included the Chukchi and Siberian Eskimo of Russia and the Inupiat and Yupik Eskimo of Alaska. The 4 groups were remarkably similar in population structure, educational attainment, mean hemoglobin concentrations and frequency of the Class I histocompatibility antigen HLAB27. The Alaskan and Chukotkan groups were similar in mean height, but the Alaskans had higher body weights and significantly greater body mass indexes, probably a reflection of a shift away from traditional lifestyle and diet. Differences in the frequencies of ABO and MN blood group antigens were also apparent, with higher frequencies of blood group M in the Alaskan populations, particularly the Inupiat.

Background: Hospital admissions in general are characterised by a marked seasonal variation. We studied the periodicity in hospital treatment for chronic obstructive pulmonary disease (COPD) in Finland where the unfavourable climate with great climatic differences between summer and winter may play an important role in causing the seasonality in COPD hospitalisation.

Methods: Data by month were obtained for the years 1972-92 from the National Discharge Register, which contains information on patients treated in all hospitals in Finland. The search was concentrated on principal diagnoses conforming to International Classification of Diseases codes 491, 492 and 496. There were 182, 723 admissions of COPD patients aged 55 years or over during the period in question. Time series analysis was carried out on retrospective data over a 21 year period and analysed by two age groups (55-74 years or > 74 years) and gender. The autoregressive integrated moving average (ARIMA) model was used to analyse seasonality.

Results: The seasonality pattern showed a peak in winter (13.4% excess mean monthly admissions in January) and a trough in summer (10.0% deficit in below mean monthly admissions in July). This pattern was more prominent in women and in those aged 75 years or over.

Conclusion: The cold winter together with an increased incidence of respiratory infections may be the most probable cause of the periodicity noted here. Due to the unfavourable northern climate even a greater seasonal variation was expected.

Coronary heart disease and diabetes, once rare in Eskimos, is on the increase in some Alaskan communities. As part of a detailed assessment of the prevalence of these diseases and associated risk factors in several villages, we report here on the plasma concentrations of lipoprotein and apoprotein in a sample of Siberian Yupik Eskimos aged 40-87 years living in the village of Gambell on St. Lawrence Island. Mean cholesterol levels for females were 242 mg/dl and 223 for males. LDL levels were 161 for females and 149 for males, while HDL levels were 67 for females and 58 for males. The mean ApoB and Apo-A1 values were 112 mg/dl and 167 mg/dl for males and females. Triglycerides were 73 for females and 77 for males. The allele frequency of APOE*3 and APOE*4 were .900 and .100 respectively. There was a total absence of the APOE*2 allele in this sample. Mean total cholesterol concentrations in this sample were markedly higher than those reported in 1958 from this village and from those recently reported for closely related Yupik Eskimos living in Siberia. The cholesterol levels were higher and the triglyceride levels were lower than in U.S. Indian populations. The data suggest the possibility of recent increased risk of cardiovascular disease for this Eskimo population. The new information indicates a need for comprehensive epidemiological studies to identify and characterize cardiovascular disease risk factors in all Alaska Native populations in order to provide a database for meaningful interventions. The lipoprotein profiles reported here are significantly different from Amerind groups, a finding that may reflect both dietary and genetic differences.

Parallel epidemiologic studies of spondyloarthropathy in aboriginal circumpolar populations were carried out by U.S. and Russian investigators. These complementary studies used the same data collection instrument and disease criteria to facilitate comparisons. During three expeditions to Siberia, Russian investigators collected cross-sectional data from four settlements of Eskimos and Chukchi Indians on the Chukotka peninsula for a study of disease prevalence. U.S. researchers collected cross-sectional data from Eskimos in four Alaskan regions for studies of prevalence and longitudinal data for studies of clinical manifestations, natural history, disease impact, and health care utilization. The aims of these studies were to describe the spectrum of spondyloarthropathy in these populations, and to lay the groundwork for investigations of the role of specific genetic and environmental factors in the pathogenesis and expression of disease. These studies were carried out with a minimum disruption to the native people.

All episodes of restraint in a Norwegian university psychiatric hospital during a five and a half-year period have been studied retrospectively. An examination of the protocols in which the use of restraint is noted reveals that patients' aggression and the subsequent use of restraint follows daily and seasonal rhythms. There is a daily peak with most use of restraint in the afternoon and early evening and a seasonal peak- with the most use of restraint in autumn. Patients' age and sex also influence the daily and seasonal patterns of restraint. It is suggested that the 24-hour patterns as well as the seasonal patterns of aggression and restraint result from the combined influence, in susceptible patients, of light-dark cycles and variations in life-events and the ward environment.

The associations of maternal smoking and blood mercury concentration on birthweight were studied in 1106 liveborn singletons from Greenland with a gestational period of 37+ weeks. After control for population group, smoking was significantly associated with low birthweight while consumption of marine mammals, maternal or cord blood mercury concentration were not. Only in West Greenlanders a week association was found between mercury and low birthweight. The Greenlandic diet of marine mammals has high concentrations of mercury and organochlorines which may reduce birthweight, and it is rich in n-3 fatty acids which have been shown to prolong pregnancy and thereby increase birthweight. In the present study neither previous reports of a negative influence of marine diet on birthweight due to methylmercury or previous reports of a positive influence of marine diet on birthweight due to n-3 fatty acids were supported.

Meta-analysis of blood pressure (BP) studies in children was performed in order to evaluate whether BP readings obtained in various studies may be pooled. In total 30 original reports on BP in children were analyzed and the age and sex-specific BP values reported for 12 and 15-year-old subjects in 11 of these were tested for homogeneity. The differences in sample size-weighted means between the devices used (with 95% confidence intervals) were evaluated. The BP values reported in different studies for systolic Korotkoffs first phase BP (K1) and diastolic Korotkoffs fourth (K4) and fifth (K5) phase BP were shown to be too heterogeneous (p < 0.001) to be pooled. Heterogeneity and measurement biases in the BP results were caused by differences between the devices and the diastolic BP indicator (K4 vs K5) and by observer biases such as uncontrolled terminal digit preference. The device-specific weighted means for K1, K4 and K5 BP in 12 and 15-year-old subjects showed statistically significant differences between random zero (RZS) and ordinary mercury (OMS) sphygmomanometer (p < 0.001) the difference (OMS-RZS) being from 0.7 to 6.6 mmHg for K1 (p < 0.001, except in 12-year-old girls), from 1.1 to 7.1 mmHg for K4 (p < 0.001, except in 12-year-old girls) and from 4.5 to 7.9 mmHg for K5 (p < 0.001). Such a discrepancy was also apparent between ordinary and automated mercury sphygmomanometer (AMS) in the case of diastolic K4 and K5 BP (p < 0.001), but not in K1. BP results obtained in different investigations using different BP devices and Korotkoffs phases as indicator of diastolic BP should not be pooled. More widely accepted recommendations are needed to standardize the measurement of BP in children.