Etiologic factors of breast cancer elucidated by a study of unselected twins.

The Danish Twin Register consists of the total population of twin pairs born in Denmark during a certain period. Within this population were found 50 monozygotic (MZ) female twins belonging to 45 MZ pairs and 81 dizygotic (DZ) twins belonging to 77 DZ female pairs, of which at least 1 twin had breast cancer (BC) and both twins were alive at the time of the first BC diagnosis. In 5 MZ and 4 DZ pairs, both partners had BC. Pairwise concordance rates were not significantly different between the 2 groups of twins but were of the same magnitude as in a previous study. The heritability, evaluated by genetic determination, was estimated to be 0.30-0.40. The observed number of BC cases developing in the co-twins after the first BC diagnosis in the twin pairs was increased by a factor of nearly 6 in MZ co-twins and by a factor of about 2 in DZ co-twins. For cancer of other sites, the observed and expected numbers were nearly identical in both MZ and DZ co-twins. In 8 of 9 pairs concordant for BC, the lesion was found on the same side. The mean age at diagnosis showed no significant difference between the concordant and discordant pairs. In the 40 MZ pairs with only 1 twin affected, she was more often unmarried and/or nulliparous than her unaffected, genetically identical co-twin, but this finding was not significant. A general tendency for the twin with BC to have the first child at a later age than her unaffected twin sister could not be demonstrated.

Survival of diabetic hypertensive patients.

Seventy-nine of 673 patients attending a hypertensive outpatient clinic were classified as diabetics at the first examination. These patients were age- and sex-matched to two control groups: nondiabetic hypertensives and the background population. Nondiabetic hypertensive patients had a significantly poorer survival than expected during a 10-year observation period; the survival of diabetic hypertensives was even poorer, although not significantly. No sex difference was observed in the survival rates of hypertensive diabetics, neither was a difference seen between insulin-dependent and non-insulin-dependent patients. Acute myocardial infarction was the most frequent cause of death in both diabetic (40%) and nondiabetic (42%) hypertensive persons.

Sympathetic hyperreactivity in offspring of essential hypertensive patients.

A multistage exercise test was carried out in normotensive subjects with normotensive parents (controls; n = 12), and 32 offspring of essential hypertensive patients that were normotensive (NTO; n = 20) or borderline hypertensive (BHO; n = 12) The groups were comparable as to age, weight and working capacity. Changes in sympathetic nervous activity were determined by measurements of plasma noradrenaline. The initial rise in noradrenaline levels during the exercise test was proportional to the increase in work load until the noradrenaline concentration rose sharply to levels more than 1000 pg/ml above baseline levels. The work load immediately prior to the steep rise in plasma noradrenaline (sympathetic threshold level: STL) is considered to represent the point from which anaerobic energy-yielding processes play an increasingly greater role as the work load increases. The initial increase in plasma noradrenaline until STL was significantly higher in both the NTO (p less than 0.02) and BHO (p less than 0.005) compared to the control group. The absolute noradrenaline level at STL and the increase in noradrenaline from baseline to STL were significantly higher in the BHO group (p less than 0.02, p less than 0.005). No significant differences between the groups were found when comparing noradrenaline levels at rest or at absolute or relative work loads. The systolic blood pressure response during the exercise test was significantly more pronounced in the BHO group (p less than 0.05) compared to the controls and the NTO group.

An investigation of the effect of regional variation in the treatment of hypertension.

Over a period both a monetary and physical measure of antihypertensive drug consumption has increased in Denmark, but the consumption has varied considerably between counties in any given year. Concurrently, SMR for myocardial infarctions and cerebrovascular diseases due to hypertension has declined. The relation between intensity of treatment and outcome in terms of reduced loss of life time or healthy time is analyzed at an aggregate level within a health economic framework. The relation is analyzed by using a pooled time series cross section regression analysis. Two models, a covariance and an error component model are used. Within the range of observed drug consumption, loss of life years and loss of good health show a tendency towards negative regression on consumption of drugs when controlled for relevant variables such as occupational structure, degree of urbanization, and hardness of the drinking water.

[Long-term survival of patients with hypertension treated in general practice or at a specialized hypertension clinic. A 21-year observation study of 831 patients with hypertension]. / Langtidsoverlevelse ved hypertension behandlet i almen praksis eller i specialiseret hypertensionsambulatorium. Et 21-års observationsstudie af 831 hypertensionspatienter.

This article is based on a study first published in Blood Pressure. After an initial diagnostic and therapeutic assessment at a specialized hypertension clinic, 831 patients with primary hypertension were during a 15-year period allocated to continuing managing care either by their general practitioner or by the hypertension clinic. Survival was assessed in the two groups: general practice (n = 437, 223 males, 214 females) and specialized hypertension clinic (n = 394, 208 males, 186 females). Median observation times for both groups were 11 years. There were no significant differences between the groups concerning age at entry, pretreatment clinical status, pretreatment blood pressure or treated blood pressure level before allocation. Judged by a Cox' regression model, no difference in survival between the two groups could be registered. The leading cause of death in both groups was ischemic heart disease. Our results indicate that after the initial diagnostic assessment and adjustment of treatment, managing care in a specialized hypertension clinic offers no advantage concerning survival compared to managing care in general practice.

[Influence of basic health service on mortality in the first 5 years of living in northeast Nigeria]. / Den basale helsetjenestes indflydelse på dødeligheden i de første 5 leveår i Nordøst-Nigeria.

In the area of the Gongola State, North-East Nigeria, where the Danish Sudan Mission has offered health service since 1913, survival until the 5th birthday has been actuarially calculated based on interviews with pregnant mothers in four areas with different health service intensities: 1. health clinic with medical doctor plus referral hospital, 2. nurse- and midwife health clinic, 3. "medical aide" clinic, and 4. no organized health service. Survivals to 1st birthday were 96, 97, 95, and 87 percent, respectively and to 5th birthday 90, 86, 89, and 68 percent. Differences between the first three groups are small and insignificant, whereas the difference between the area without organized health service and the other areas is highly significant. It is concluded that cost/effectiveness of even the most scanty health service is very favourable, whereas the effect of further health service development is less easily demonstrated. Reservations must be taken because of the limited size of the material and the need for data concerning basic morbidity and mortality in the different areas.