Glucose turnover in type I diabetic subjects during exercise. Effect of selective and nonselective beta-blockade and insulin withdrawal.

OBJECTIVE: To assess the effect of selective beta 1-blockade (atenolol and betaxolol) and nonselective beta-blockade (propranolol) on glucose turnover in subjects with insulin-dependent (type I) diabetes mellitus during moderate exercise. RESEARCH DESIGN AND METHODS: Five subjects with type I diabetes were infused with insulin and then exercised for 1 h, after pretreatment with each of the three drugs or saline and, on a separate day, after withdrawal of insulin. Glucose turnover was measured using tritiated glucose. RESULTS: Plasma glucose, initially 9.2 +/- 0.5 mmol/L (mean +/- SE) when insulin infused and 14.0 +/- 0.8 when insulin was withdrawn, fell on exercise by 3.4 +/- 1.1 mmol/L (P < 0.05) saline, 4.0 +/- 0.8 mmol/L (P < 0.01) with betaxolol, 3.8 +/- 0.7 mmol/L (P < 0.01) with atenolol, 5.0 +/- 0.6 mmol/L (P < 0.005) with propranolol, and 1.7 +/- 1.0 mmol/L (NS) when insulin was withdrawn. Propranolol, but not the other beta-blockers, caused a significantly greater fall in glucose on exercise than during the control study. Glucose appearance rate (Ra) was similar basally and rose to an almost identical level in all five groups during exercise. Glucose disappearance rate (Rd) rose similarly during exercise, except after propranolol when the rise was significantly greater than with saline (P < 0.01). Failure of glucose to change significantly during exercise when insulin had been withdrawn was associated with the smallest rise in Rd and the highest nonesterified fatty acid concentrations. Propranolol and betaxolol, but not atenolol, reduced nonesterified fatty acids. CONCLUSIONS: We conclude that the greater fall in glucose on exercise after beta-blocking drugs is probably largely a direct effect of beta 2-blockade on muscle, increasing the exercise-induced rise in Rd glucose. This offers support to the use of beta 1-specific drugs, where beta-blockade is necessary in type I diabetes.

The effect of inaccuracies in death certification and coding practices in the European Economic Community (EEC) on international cancer mortality statistics.

An investigation into the effect of national death certification and coding practices on published mortality statistics in eight EEC countries is reported. Doctors in each country were asked to complete specimen death certificates for a bank of written case histories. Certificates from each country were coded by their own offices and then by a WHO reference centre. Within and between countries, discrepancies occurred both in the doctors' diagnoses and in the codes assigned to certificates. At an international level these differences had serious implications for the comparability of mortality data for cancers of the cervix and uterus, and for mesotheliomas.

Lung function of farmers in England and Wales.

A study was performed to compare respiratory symptoms and lung function measurements in a sample of male farmers and farmworkers in different regions of England and Wales with the results obtained in a similar number of control men working in industries in the same areas. A total of 428 farmers and farmworkers drawn from 146 farms were studied. The prevalence of symptoms of chronic bronchitis assessed by the Medical Research Council questionnaire did not differ between farmers and controls. Farmers were older, taller, and heavier than controls; were less likely to smoke; and had significantly higher forced vital capacity (FVC). When each of these factors was taken into account, together with social class and geographical region, in a multiple linear regression analysis farmers were found to have significantly lower forced expiratory volume in one second (FEV1) and forced mid expiratory flow rate (FEF25-75). Among the farmers, those doing dairy farming and silage work were the only groups on their own to have significantly reduced lung function. The results of this survey suggest the need for further exploration of the mechanism of an effect of farming occupations on lung function.

Death certification of farmer's lung and chronic airway diseases in different countries of the EEC.

An EEC Working Party has investigated death certification of respiratory disease in eight EEC countries by sending ten standard case histories to a sample of certifying doctors in each country. Results of interest to clinicians with reference to certification of farmer's lung, and of obstructive airway diseases, are presented. For a case of farmer's lung, a majority of certifying doctors in all countries certified an interstitial lung disease, but the proportion certifying farmer's lung ranged from 70% to 0% (overall 26%). Rural doctors certified farmer's lung more frequently than others only in some countries. For four cases of different types of airways disease (chronic obstructive bronchitis, emphysema or asthma) there were wide differences between countries of certification of these conditions or of unspecified chronic airways obstruction. Some countries certify more emphysema, and others, particularly younger doctors in English speaking countries, more unspecified chronic airways obstruction. There are also large differences in the certification of asthma. The differences are presumed to be attributable to differences of medical education. Epidemiological studies and patient care might be helped by more uniformity of diagnostic criteria within the EEC.

Single-dose etoposide in combination with vincristine and doxorubicin in the treatment of small-cell lung cancer (SCLC).

From July 1980, 104 consecutive patients with previously untreated small-cell lung cancer (SCLC) received vincristine 1.4 mg/m2, doxorubicin (Adriamycin) 40 mg/m2, and Etoposide (VePesid) 300 mg/m2 intravenously (as a single infusion) every 3 weeks. The overall response rate (complete response plus partial response) was 58%. In 47 patients with limited disease the response rate was 66% with 21/47 (45%) complete responders. Treatment was delivered on an outpatient basis. Toxicity was mild, and in 455 rapid infusions of etoposide, there have been no adverse reactions.

Propranolol and giving up smoking.

A placebo-controlled double-blind clinical trial was conducted to determine whether propranolol helps cigarette smokers to stop smoking; 73 subjects entered the trial but at the end of eight weeks only six had stopped smoking, three in the propranolol and three in the placebo group. There was no evidence of any helpful effect of propranolol in subjects trying to stop smoking.

Relation between pulmonary gas exchange and closing volume before and after substantial weight loss in obese subjects.

Relations between expiratory reserve volume (ERV), closing volume (CV) as a percentage of vital capacity (CV/VC%), and pulmonary gas exchange have been investigated in the sitting and supine postures in eight severely obese subjects before and after substantial weight loss. CV/VC% exceeded predicted values but did not change with posture or weight loss; the increase could have been owing to the smoking habits of the subjects. Arterial oxygen pressure (PaO(2)) was significantly less in the supine than in the sitting posture and improved after weight loss in six subjects. The reduction in PaO(2) was correlated with the extent to which dependent airways were closed within the range of tidal breathing, shown by increasing negativity of ERV-CV as a percentage of VC. A good correlation was also found between PaO(2) and ERV, an easier measurement for routine use. Improvement of pulmonary gas exchange occurred only in those patients who lost weight to within 30% in excess of ideal.