Design: Concomitant cross sectional comparison of randomly selected 50 year old men without serious acute or chronic disease. Methods and equipment were identical or highly standardised between the centres.

Setting: Linköping (Sweden) and Vilnius (Lithuania).

Subjects: 101 and 109 men aged 50 in Linköping and Vilnius respectively.

Main outcome measures: Anthropometric data, blood pressure, smoking, plasma lipid and lipoprotein concentrations, susceptibility of low density lipoprotein to oxidation, and plasma concentrations of fat soluble antioxidant vitamins.

Results: Systolic blood pressure was higher (141 v 133 mm Hg, P>0.01), smoking habits were similar, and plasma total cholesterol (5.10 v 5.49 mmol/l, P>0.01) and low density lipoprotein cholesterol (3.30 v 3.68 mmol/l, P>0.01) lower in men from Vilnius compared with those from Linköping. Triglyceride, high density lipoprotein cholesterol, and Lp(a) lipoprotein concentrations did not differ between the two groups. The resistance of low density lipoprotein to oxidation was lower in the men from Vilnius; lag phase was 67.6 v 79.5 minutes (P>0.001). Also lower in the men from Vilnius were mean plasma concentrations of lipid soluble antioxidant vitamins (ß carotene 377 v 510 nmol/l, P>0.01; lycopene 327 v 615 nmol/l, P>0.001; and lipid adjusted gamma tocopherol 0.25 v 0.46 µmol/mmol, P>0.001. Alpha Tocopherol concentration did not differ). Regression analysis showed that the lag phase was still significantly shorter by 10 minutes in men from Vilnius when the influence of other known factors was taken into account.

Conclusions: The high mortality from coronary heart disease in Lithuania is not caused by traditional risk factors alone. Mechanisms related to antioxidant state may be important.

Department of Health and Environment,
Faculty of Health Sciences,
S-58185 Linköping,
Sweden
Margareta Kristenson,
head of department

Clinical Research Centre,
Faculty of Health Sciences,
S-58185 Linköping
Bo Ziedén, medical student

Department of Physiology and Biochemistry,
Faculty of Medicine,
2021 Vilnius,
Lithuania
Zita Kucinskienë, professor
Algis Abaravicius, associate professor
Laima Razinkovienë, senior chemist

Department of Medical Biochemistry and Biophysics,
Faculty of Medicine, Karolinska Institute,
S-171 77 Stockholm,
Sweden
Liselotte Schäfer Elinder, research fellow

Department of Medicine and Care,
Faculty of Health Sciences,
S-58185 Linköping
Björn Bergdahl, associate professor
Anders G Olsson, professor

Department of Preventive Medicine,
Centre of Public Health Sciences,
S-58185 Linköping
Birgitta Elwing, nutritionist

Department of Gastroenterology and Dietetics,
Faculty of Medicine,
2021 Vilnius,
Lithuania
Henrikas Calkauskas, associate professor

Design: Prospective population study.

Setting: Eastern Finland.

Subjects: 1,605 randomly selected men aged 42, 48, 54, or 60 who did not have either symptomatic coronary heart disease or ischaemia on exercise testing at entry to the Kuopio ischaemic heart disease risk factor study in between 1984 and 1989.

Main outcome measures: Number of acute myocardial infarctions; fasting plasma vitamin C concentrations at baseline.

Results: 70 of the men had a fatal or non-fatal myocardial infarction between March 1984 and December 1992. 91 men had vitamin C deficiency (plasma ascorbate >11.4 µmol/l, or 2.0 mg/l), of whom 12 (13.2%) had a myocardial infarction; 1514 men were not deficient in vitamin C, of whom 58 (3.8%) had a myocardial infarction. In a Cox proportional hazards model adjusted for age, year of examination, and season of the year examined (August to October v rest of the year) men who had vitamin C deficiency had a relative risk of acute myocardial infarction of 3.5 (95% confidence interval 1.8 to 6.7, P = 0.0002) compared with those who were not deficient. In another model adjusted additionally for the strongest risk factors for myocardial infarction and for dietary intakes of tea, fibre, carotene, and saturated fats men with a plasma ascorbate concentration >11.4 µmol/l had a relative risk of 2.5 (1.3 to 5.2, P = 0.0095) compared with men with higher plasma vitamin C concentrations.

Conclusion: Vitamin C deficiency, as assessed by low plasma ascorbate concentration, is a risk factor for coronary heart disease.

Research Institute of Public Health,
University of Kuopio,
PO Box 1627,
70211 Kuopio,
Finland
Kristiina Nyyssönen, clinical biochemist
Riitta Salonen, research scientist
Jukka T Salonen, academy professor

Department of Clinical Chemistry,
Kuopio University Hospital,
PO Box 1777,
70211 Kuopio
Markku T Parviainen, principal clinical biochemist

Department of Epidemiology and Health Promotion,
National Public Health Institute of Finland,
Mannerheimintie 166,
00300 Helsinki,
Finland
Jaakko Tuomilehto, research scientist

Correspondence to: Professor J T Salonen.

Design: Matched pairs study.

Setting: Coronary care unit in central Leicester.

Subjects: 238 pairs of patients admitted during 1987-93 matched for age (within 2 years), sex, date of admission (within 3 months), type of infarction (Q/non-Q), and site of infarction.

Main outcome measures: Incidence of angina, reinfarction, or death during follow up of 1-7 years.

Results: Patients of Indian subcontinent origin had a higher prevalence of diabetes (35% v 9% in patients of European origin, P>0.001), lower prevalence of smoking (39% v 63%, P>0.001), longer median delay from symptom onset to admission (5 hours v 3 hours, P>0.01), and lower use of thrombolysis (50% v 66%, P>0.001). During long term follow up (median 39 months), mortality was higher in patients of Indian subcontinent origin (unadjusted hazard ratio=2.1, 95% confidence interval 1.3 to 3.4, P=0.002). After adjustment for smoking, history of diabetes, and thrombolysis the estimated hazard ratio fell slightly to 2.0 (1.1 to 3.6, P=0.02). Patients of Indian subcontinent origin had almost twice the incidence of angina (54% v 29%; P>0.001) and almost three times the risk of reinfarction during follow up (34% v 12.5% at 3 years, P>0.001). The unadjusted hazard ratio for reinfarction in patients of Indian subcontinent origin was 2.8 (1.8 to 4.4, P>0.001). Adjustment for smoking, history of diabetes, and thrombolysis made little difference to the hazard ratio. Coronary angiography was performed with similar frequency in the two groups; triple vessel disease was the commonest finding in patients of Indian subcontinent origin and single vessel disease the commonest in Europeans (P>0.001).

Conclusions: Patients of Indian subcontinent origin are at substantially higher risk of mortality and of further coronary events than Europeans after first myocardial infarction. This is probably due to their higher prevalence of diffuse coronary atheroma. Their need for investigation with a view to coronary revascularisation is therefore greater. History of diabetes is an inadequate surrogate for ethnic origin as a prognostic indicator.

Department of Medicine and Therapeutics and Public Health,
University of Leicester,
Leicester
N Shaukat, British Heart Foundation research fellow
J Lear, senior house officer in medicine
A Lowy, lecturer in epidemiology
S Fletcher, research assistant
D P de Bono, professor of cardiology
K L Woods, professor of therapeutics

Correspondence to: Dr N Shaukat,
Department of Cardiology,
Kettering General Hospital NHS Trust,
Rothwell Road,
Kettering NN16 8UZ.

Design: An observational study analysing data from an ongoing cross sectional postal survey. Every three months a representative sample of 250 doctors recorded prescribing activity for four weeks. This provided 4,000 general practitioner weeks of recording per year.

Setting: A representative panel of general practitioners in England, Wales, and
Scotland.

Subjects: Patients who began a new course of an antidepressant or had their treatment stopped or changed by the general practitioner between 1 July 1990 and 30 June 1995.

Main outcome measures: Numbers of patients prescribed a new course of antidepressant; numbers discontinuing treatment; the ratio of antidepressant discontinuations to antidepressant inceptions; reasons for discontinuation; proportion of switches to another antidepressant.

Results: There were 13,619 inceptions and 3,934 discontinuations of selective serotonin reuptake inhibitors and tricyclic antidepressants during the study. The number of newly prescribed courses of antidepressants increased by 116%, mostly due to an increase in prescribing of serotonin reuptake inhibitors. The ratio of total discontinuations to inceptions was significantly lower for serotonin reuptake inhibitors (22%) than for tricyclic antidepressants (33%). Differences persisted when controlled for age and sex of patients and severity of depression. However, there was more switching away from selective serotonin reuptake inhibitors when they failed (72%) than from tricyclic antidepressants (58%).

Conclusions: Selective serotonin reuptake inhibitors are less likely than tricyclic antidepressants to be discontinued. A prospective study is needed in general practice to assess the implications of differences in discontinuation rates and switches on clinical and economic outcomes.

Division of General Practice and Primary Care,
St George's Hospital Medical School,
London SW17 0RE
Richard M Martin, prescribing research fellow
Sean R Hilton, professor
Sally M Kerry, statistician

CompuFile Ltd,
Send,
Woking,
Surrey GU23 7EF
Nicky M Richards, director

Correspondence to: Dr Martin.