Eight studies that examined the relation between snoring and vascular disease were identified. The prevalence of habitual snoring, measured by questionnaire or interview, varied from 3% to 29% of adults and was dependent on age, sex, obesity, and smoking habit. In men, habitual snoring was associated with hypertension and ischaemic heart disease, with adjusted relative risks in the range 1.3-2.0. For women, only one study provided adjusted estimates of relative risk, which were 2.8 for hypertension and 1.2 for angina. Adequately adjusted relative risks for cerebrovascular disease have not been reported, but unadjusted estimates varied from 1.6 to 10.3. These studies had several limitations, including the lack of a standard definition of snoring, the use of unvalidated questionnaires, and failure to account for confounding variables and the possibility of reporting bias. Only one study was prospective. Epidemiological criteria for a causal association between snoring and vascular disease have not been satisfied. The apparent excess risk is probably due to the consequences of sleep apnoea rather than snoring itself.

Meta-analysis was used to study patients' preference in 37 crossover trials that compared indomethacin with newer non-steroidal, antiinflammatory drugs (NSAIDs). 3 reports did not present numerical data. Patients who withdrew from the trial were included in the analysis. The difference between the proportion of patients who preferred the new drug and the proportion who preferred indomethacin (the therapeutic gain) was 14%. After exclusion of 2 unreliable studies the therapeutic gain was only 7%, and when 4 preliminary reports were also ignored, the gain was 5% (95% confidence interval 0 to 10%). In two additional analyses in which the 2 outlying results were excluded, the gain was also 5%. The findings do not support the trend to replace indomethacin with newer NSAIDs.

Very low concentrations of the vasoconstrictor peptide endothelin cause intense long-lasting renal vasoconstriction. In the isolated perfused rat kidney, the concentration of endothelin required to reduce blood-flow by 50% is 200 pmol/l, compared with 1000 pmol/l angiotensin II (previously the most potent known vasoconstrictor). Whereas angiotensin II has little effect on the glomerular filtration rate (GFR), a rise in endothelin from 100 to 800 pmol/l reduces GFR by 90%. Endothelin is probably present in the circulation at low concentrations in vivo; events associated clinically with acute renal failure would tend to increase this concentration. Endothelin may be a mediator in the pathogenesis of acute renal failure.

Free-radical-mediated lipid peroxidation has become closely associated with destructive biochemical processes and, more recently, with disease. Its potential survival value may be overlooked.

Urine samples were cultured for aerobic, fastidious, and anaerobic bacteria in 88 patients (66 F, 22 M) before and after standard urodynamic investigations. 37 of 42 women with detrusor instability, and 14 of 17 women with stress incontinence, had evidence of bacteriuria with aerobic or fastidious bacteria before investigation, as did 6 of 13 men with bladder outflow obstruction. 8 men (36%) acquired bacteriuria with aerobic bacteria after investigation, compared with 10 women (15%). Recalcitrant, irritative urinary symptoms in women may be caused by an underlying infection, the urodynamic changes being secondary. In men who have urodynamic studies, antibiotic prophylaxis should be considered.