421 PREVENTION OF CORONARY HEART-DISEASE a report in the communication given by me at the Conjoint B.M.A./C.M.A/I.M.A. Scientific Meeting in Dublin last June.’ In this report I was misquoted as stating that the coronary-heart-disease. mortality in the United States had dropped by 30% over the past 6-8 years. What I did say was that the coronary-heart-disease mortality in the general United States population had fallen by nearly 20%, although the fall amongst Metropolitan Life Insurance policy-holders was as great as 30%. These data are available from the Metropolitan Life Insurance,a’and their publication has received surprisingly little prominence in the medical and lay Press. This dramatic reduction in the incidence of coronary heartdisease reported from the United States strongly supports the plea of Dr Bradshaw and others for a more positive approach to primary prevention and emphasises the relevance of the report on primary prevention by the Royal College of Physicians and the British Cardiac Society. There must be compelling reasons to believe that the secular changes in mortality in the United States are due to changing habits of diet and cigarette smoking among middleaged males which are known to have taken place. They may also be attributed to better recognition and treatment of hypertension and possibly to less obesity and to more exercise, especially amongst the high-income group. Current treatment methods of established coronary heartdisease, such as coronary care, bypass surgery, and improved secondary prevention measures, may play a part in reducing mortality, but the contribution from these areas must be rela-
SJR,-Dr Bradshaw (Aug. 7, p. 313) cites
British Medical Journal of
a
tively small. In the context of our present very complete knowledge of the attributes and characteristics associated with coronary heartdisease, changes in diet, in smoking habits, and in the management of hypertension would provide a very plausible explanation for the highly significant changes in the United States. It is my belief that a partial reduction in the "weight" of risk factors to which a population is exposed may lead to a disproportionately greater reduction in the incidence of coronary heartdisease and stroke, at least in people under 65 years. The United States experience must strongly justify the advocacy of primary prevention by the adoption of safe and simple changes m life habits which may not only reduce morbidity and mortality amongst people in the active stages of life but which may also lead to a more rational and satisfying life-style.
ponded to the administration of dexamethasone to the mother before delivery. The first sibling was a boy, of birth-weight 2220 g, born at 42 weeks’ gestation after a spontaneous labour. Severe respiratory distress was apparent immediately, and a chest X-ray and subsequent necropsy confirmed that he died of hyaline-mem’
brane disease. The second sibling was a girl weighing 3100 g at birth, having been induced at 39 wk. Again, severe respiratory difficulty was apparent almost immediately, and she died despite intermittent positive-pressure ventilation. Hyaline-membrane disease was
demonstrated post
mortem.
The third sibling weighed 3090 g at birth, and again severe respiratory distress became apparent within an hour of delivery. A chest X-ray was compatible with R.D.S. Intermittent positive-pressure ventilation was required, but the baby did well and has developed normally. In view of the previous two neonatal deaths, the fourth pregnancy was monitored closely, and at 37 wk amniocentesis revealed a lecithin/sphingomyelin (L/s) ratio of 0.8. Following 4 mg of dexamethasone daily for 4 days, the L/s ratio a week later had risen to 3-66. At 41 wk the mother went into spontaneous labour, and a normal boy was delivered. He did not develop respiratory difficulties, and he was discharged home at 7 days and is progressing normally. It is unfortunate that the L/s ratios in the amniotic fluid were not routinely available until after the birth of the third infant. Nevertheless, X-ray and post-mortem evidence suggests that these babies had R.D.S. occurring at or near term. An L/s ratio of 0.8 is usually associated with a fetal maturity of approximately 30-32 wk,b’and one of 3.66 with pulmonary maturity. It is almost certain, therefore, that the fourth fetus would have been delivered with very immature lungs had dexamethasone not been given to the mother. One can only conclude, then, that these four siblings all had surfactant deficiency at or near term and that these babies all had a maturation delay in the development of pulmonary surfactant, the basis for which is unknown but is possibly, in this case, familial. General
Hospital, Northampton, NN1 5BD
M. PANTER-BRICK
RAPID MEASUREMENT OF PLASMA-GLUCOSE The Sisters of Charity, St. Vincent’s Hospital, Dublin 4, Republic of Ireland
SIR,-We RISTEARD MULCAHY
DEXAMETHASONE IN PREVENTION OF RESPIRATORY-DISTRESS SYNDROME
S’R,—In 1967 Roberton and his co-workers5 drew attention to the occurrence of the respiratory-distress syndrome (R.D.S.) in2.2-6.5% of all term babies. These infants had severe respiratory difficulties, hypoxasmia, and clinical and radiological characteristics of
R.D.S.
The disease
was
protracted
and
severe, but the survivors did well. BBwish to record the occurrence of this syndrome in four successive siblings, all of whom apparently had pulmonary immaturity at term, which in the last instance seems to have res-
1 Mulcahy, R. Br. med. J. 1976, ii, 157. Metrop. Life Insurance, 1975, 56, 3. 3 ibid 1976, 57, 10. 4 Joint Working Party Jl. R. Coll. Physns. 1976, 10, 213. 5 Robertson, N. R. C., Hallidre-Smith, W. A., Davis, J. 108
Royal Infirmary, Glasgow G4 0SF
6. 7. 8.
2 Stat Bull
A. Lancet,
1967,
ii
were
interested to read the letter from Dr Clark
and his colleagues (July 31, p. 264). In this hospital ovxr the past four years the facility for rapid estimation of plasma-glucose at our diabetic outpatient clinic has proved useful. The ’Beckman Glucose Analyzer’ (Beckman-RIIC Ltd, Glenrothes, Fife) is used, and good correlation with ’AutoAnalyzer’ methods is obtained.8 Since after centrifugation the plasma sample is pipetted directly into the Beckman analyser without further treatment, the method is very convenient, and a rate of up to 50 samples per hour can be achieved. In addition, although the capital cost of the Beckman analyser is relatively high (approximately 2250) the reagent cost is about 4p per test as against 12p per test with the Calbiochem pack used by Dr Clark and his colleagues, so that for prolonged use in a busy diabetic clinic the Beckman analyser is an attractive alternative. C. M. KESSON D. A. ROBERTSON
Caspi, E., et al. Br. J. Obstet. and Gynœc. 1976, 83, 189. Liggins, G. C., Howie, R. N. Pediatrics, Springfield. 1972, 50, 515. Morrison, B., Scotland, C. J., Fleck, A. Clin. chim. Acta, 1972, 39, 301.