Training effects of cross-country skiing and running on maximal aerobic cycle performance and on blood lipids

Summary Two experiments were carried out to compare the cardiorespiratory and metabolic effects of cross-country skiing and running training during two successive winters. Forty-year-old men were randomly assigned into skiing (n = 15 in study 1,n = 16 in study 2), running (n = 16 in study 1 andn = 16 in study 2) and control (n = 17 in study 1 andn = 16 in study 2) groups. Three subjects dropped out of the programme. The training lasted 9–10 weeks with 40-min exercise sessions three times each week. The training intensity was controlled at 75%–85% of the maximal oxygen consumption (VO_2max) using portable heart rate metres and the mean heart rate was 156–157 beats·min^–1 in the training groups. In the pooled data of the two studies the mean increase in theVO_2max (in ml·min^–1·kg^–1) on a cycle ergometer was 17% for the skiing group, 13% for the running group and 2% for the control group. The increase inVO_2max was highly significant in the combined exercise group compared to the control group but did not differ significantly between the skiing and running groups. The fasting serum concentrations of lipoproteins and insulin did not change significantly in any of the groups. These results suggested that training by cross-country skiing and running of the same duration and intensity at each session for 9–10 weeks improved equally the cardiorespiratory fitness of untrained middle-aged men.     

Relationship of angiotensin-converting enzyme gene polymorphism to carotid wall thickness in middle-aged men

The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele has been suggested to be a potent risk factor for coronary artery disease; however, the effect of the ACE gene on carotid atherosclerosis remains controversial. We therefore studied the relationship between the ACE gene I/D polymorphism and carotid artery intima-media thickness (IMT). A random sample of 300 men aged 50-59 years living in southern Finland were selected, and 233 agreed to participate (74%). Data were collected in 219 subjects. Quantitative B-mode ultrasonography was used to measure the maximum near and far wall IMT of right and left common, bifurcation, and internal carotid artery. The mean maximum IMT (overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard sites were assumed to have carotid atherosclerosis. The I/D polymorphism was determined by polymerase chain reaction. Overestimation of the frequency of the DD genotype was eliminated by insertion-specific primer and the inclusion of 5% dimethylsulfoxide. No significant differences were found in carotid wall thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30, 1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively. Similarly, the ACE genotypes and allele frequencies did not differ significantly between the subjects with and those without carotid atherosclerosis. There was no association in the subgroups among only nonsmoking subjects or subjects without chronic medication. The present data indicate that the I/D polymorphism of the ACE gene is not related to carotid IMT and is unlikely to play a major role in carotid atherosclerosis.     

Infant botulism acquired from household dust presenting as sudden infant death syndrome

Clostridium botulinum type B was detected by multiplex PCR in the intestinal contents of a suddenly deceased 11-week-old infant and in vacuum cleaner dust from the patient's household. C. botulinum was also isolated from the deceased infant's intestinal contents and from the household dust. The genetic similarity of the two isolates was demonstrated by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA analysis, thereby confirming that dust may act as a vehicle for infant botulism that results in sudden death.     

Public health burden of coronary heart disease risk factors among middle-aged and elderly men

BACKGROUND: An epidemiological evidence shows that smoking, high total cholesterol, hypertension, overweight, and a low level of physical activity are significant risk factors for coronary heart disease mortality. Therefore, by turning these risk factors in a healthier direction, presumably a substantial proportion of the deaths would be preventable. METHODS: The avoidable proportion of coronary heart disease deaths associated with smoking, a high level of total cholesterol, systolic hypertension, overweight, and a low level of leisure-time physical activity was assessed with the use of the population attributable risks for initially 30- to 63-year-old Finnish men (six studies with 1,340-7,928 subjects) who were followed up from 7 to 30 years. RESULTS: The theoretical estimates of population at tributable risks derived from published studies were as follows: smoking 10 to 33%; high total cholesterol 9 to 21%; hypertension 6 to 15%; overweight 3 to 6%; and low level of leisure-time physical activity 22 to 39%. CONCLUSIONS: These estimations, based on observed mortality rates and risk factor prevalences, suggest that, even if modest estimates are used, the burden from coronary heart disease deaths can be substantially reduced by converting the risk factors to more healthful levels. The results also suggest that efforts to increase physical activity deserve as much consideration as those aimed at influencing more traditional risk factors.     

Effect of Anterior Cruciate Ligament Injury of the Knee on Bone Mineral Density of the Spine and Affected Lower Extremity: A Prospective One-Year Follow-Up Study

The objective of this 1-year prospective follow-up study was to assess, with dual-energy X-ray absorptiometry (DXA), the effect of an anterior cruciate ligament (ACL) injury of the knee on areal bone mineral density (BMD) of the injured extremity and lumbar spine in two separate patient groups: 21 surgically treated patients (group A) and 12 conservatively treated patients (group B). Clinical and functional status of the patients and BMD of the spine (L2–L4), dominant distal radius, femoral neck, trochanter area of the femur, distal femur, patella, proximal tibia, and calcaneus of both lower extremities were determined at the time of the injury and after 4, 8, and 12 months. A surgically treated, complete ACL rupture (group A) resulted in considerable and statistically significant bone loss to the affected knee (distal femur 21%, patella 17%, proximal tibia 14%; P < 0.001 in each), whereas the other sites were clearly less affected. Patients with a conservatively treated, complete or partial ACL injury (group B) had only a small but statistically significant bone loss at the patella (−3%; P= 0.005) and proximal tibia (−2%; P= 0.022) of the injured knee, and the other sites remained unchanged. The obvious differences between the groups A and B in the severity of the injury itself (complete or partial tear), its treatment (surgical or conservative), and subsequent rehabilitation (longer nonweight-bearing times in group A) explain these different BMD results, and the forthcoming years will show whether the considerable posttraumatic osteoporosis in the affected knee of group A patients will finally recover, and if so, to what extent. Received: 16 June 1998 / Accepted: 6 October 1998     

Epidemiology and health for all

Summary World Health Organization's goal Health for All is the starting point for a most ambitious health policy ever. The paper analyzes the role of epidemiology in the Organization's work, particularly in the Health for All development. During WHO's early years, epidemiology helped to design and carry out major public health campaigns against such scourges of the humanity as yaws, tuberculosis, malaria and small pox. When the Organization during the 1960s began to emphasize the need to develop the infrastructure of health care, health services research partly replaced epidemiology as WHO's main scientific allay. After the Health for All policy was launched in 1987, epidemiology has again played a major role in establishing the scientific background of the policy. The European experiences show how the epidemiologists can help WHO to identify the most important health problems and set achievable and measurable targets for them. The paper concludes that epidemiology serves to identify problems, show ways to solve them, monitor the changes in the situation and evaluate the achievements.

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Zusammenfassung Das Ziel der Weltgesundheitsorganisation Gesundheit für alle ist Ausgangspunkt für die ehrgeizigste Gesundheitspolitik, die je definiert wurde. Der vorliegende Artikel analysiert die Rolle der Epidemiologie in der Arbeit der Organisation, insbesondere bei der Entwicklung von Gesundheit für alle. Während der frühen Jahre der WHO half die Epidemiologie bei der Planung und Ausführung der grossen Gesundheitskampagnen gegen Geisseln der Menschheit wie Frambösie, Tuberkulose, Malaria und Pocken. In den 60er Jahren begann die WHO, die Wichtigkeit der Entwicklung von Infrastrukturen für die Gesundheitsversorgung zu betonen, Gesundheitswesensforschung ersetzte in der Folge teilweise Epidemiologie als wichtigsten wissenschaftlichen Bereich der WHO. Seit 1987 aber Gesundheit für alle in Angriff genommen wurde, spielt die Epidemiologie wieder eine wichtige Rolle in der Erarbeitung des wissenschaftlichen Hintergrundes dieser Politik. Die europäische Erfahrung zeigt, wie Epidemiologen der WHO helfen können, die wichtigsten Gesundheitsprobleme zu erkennen und erreichbare und messbare Ziele für sie zu setzen. Der vorliegende Artikel schliesst, dass die Epidemiologie dazu dient, Gesundheitsprobleme zu identifizieren, Wege aufzuzeigen, wie sie zu lösen sind, Änderungen der Situation zu überwachen und die Erfolge zu evaluieren.

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Résumé Pour l'OMS (Organisation mondiale de la santé), le programme «Santé pour tous» doit être le point de départ d'une action de santé sans précédent. Cet article analyse le rôle de l'épidémiologie à l'OMS, en particulier dans le cadre de ce programme. Au début de l'existence de l'OMS l'épidémiologie a permis de planifier et de conduire les grandes campagnes contre des maladies telles que la tuberculose, la malaria et la variole. Dans les années 60, l'OMS a insisté sur le développement de l'infrastructure des soins, la recherche sur les services de santé remplaçant en partie le rôle conducteur de l'épidémiologie. Avec le lancement du programme «Santé pour tous» en 1987, l'épidémiologie joue à nouveau un rôle central pour fonder le programme scientifique de l'OMS. L'expérience européenne montre de quelle façon les épidémiologistes peuvent aider l'OMS pour identifier les problèmes les plus importants et établir des buts raisonnables et mesurables. L'article montre comment l'épidémiologie sert à identifier les problèmes, établir des façons de les résoudre et évaluer l'impact de ces programmes.