No abstract

Nine thousand and ninety seven male members of the construction building workers trade union in Stockholm, aged between 41 and 61 years, were asked to complete a postal questionnaire between September and November 1972. The questionnaire was comprised of several psychosocial questions including life-change items for the preceding year. All subjects were followed up for a 12 to 15-month period with regard to death from all causes and hospitalization for myocardial infarction (MI). The urban section of the sample was also followed up for other serious illnesses. The main results were as follows: (a) The life-change measurement technique did not predict near-future MI; (b) A pre-formed discord index predominantly composed of self-rated type A behaviour and dissatisfaction variables predicted a significant number of near-future MIs; (c) One individual life-change, increased responsibility at work, predicted significantly about 10 per cent of near-future MIs; (d) Elevated life-change measures for the last year indicated increased risk of near-future neurosis onset; (e) Several questions about irritability and dissatisfaction, for example hostility in queuesor with slow persons and dissatisfaction with home life, predicted several kinds of illnesses; (f) Other variables, for example, having grown up as a late child in a large family, perception of financial state, mode of living, marital status and tobacco smoking, were important in illness prediction.

No abstract

Twelve subjects were kept awake for 64 h under conditions of isolation from external time cues. Activity was sedentary and kept as constant as possible over time, as was intake of food and drink. Cardiovascular variables--blood pressure, heart rate, contractility (IJ-amplitude from ballistocardiogram), T-wave amplitude, QRS, PQ and QT intervals--were assessed every 3 h. At the same intervals, urine samples for catecholamine analysis were obtained. Data were analyzed by analysis of variance and cosinor techniques. Adrenaline excretion showed a pronounced circadian rhythm. Noradrenaline excretion and IJ amplitude showed much weaker rhythmicity, statistically significant only with the cosinor technique. The remaining variables showed no rhythmicity with either technique. It was concluded that constant conditions (including sleep deprivation) markedly disturb or even obliterate the circadian rhythms of cardiovascular variables and urinary noradrenaline excretion. It was also concluded that most of the amplitude of cardiovascular circadian rhythms measured under habitual sleep/wake conditions must be due to the alternation between sleeping and waking. The present data do not, however, rule out the existence of selfsustained circadian rhythmicity in cardiovascular variables; a design including continuous wakefulness may well have concealed endogenous low-amplitude rhythms.