Reduced detection of Chlamydia trachomatis by the ligase chain reaction assay due to suboptimal storage of urine.

Detection of Chlamydia trachomatis by the ligase chain reaction assay was assessed in urine samples that had been stored at 4 degrees C and at ambient temperature for 6-10 days before testing. Six of 67 (9%) ligase chain reaction-positive urine samples stored at 4 degrees C and 5 of 29 (17%) stored at ambient temperature became negative, a difference that is not statistically significant. Most of the urine samples that were negative after storage contained a small number of chlamydial elementary bodies, and almost three-quarters of them were from women. Optimal pretest storage conditions for urine samples should be maintained if the maximum benefit is to be obtained from this highly sensitive assay.

Qualitative and quantitative aspects of the ligase chain reaction assay for Chlamydia trachomatis in genital tract samples and urines.

The performance of the ligase chain reaction (LCR) assay for Chlamydia trachomatis was evaluated in a genitourinary medicine (GUM) clinic population. Its sensitivity was 100%, 91% and 95%, respectively, for cervical, vaginal and urine samples from 417 women, when compared with direct fluorescent antibody (DFA) staining of cervical samples, and 100% and 91%, respectively, for urethral and urine samples from 317 men, when compared with DFA staining of urethral smears. An enzyme immunoassay (EIA) was only 65% sensitive for cervical samples. Urethral swabs from a number of treated men remained LCR-positive when antigen was no longer detectable by DFA staining. An association between quantitative data from the LCR assay (i.e. the optical density of samples, measured in relation to internal controls and calibrators) and the antigen load of the samples, measured by DFA staining, indicated a lack of significant inhibition in the LCR assay in this study. This was probably due to freezing of the samples before testing. Diluting 20 LCR-positive urines with a range of antigen loads resulted in loss of positivity in 3, and a reduction in the signal in 13. The implications of the antigen load on the performance of detection assays for chlamydia-positive patients are discussed.

Prevalence of Chlamydia trachomatis in young men in north west London.

BACKGROUND: Chlamydia trachomatis is the most common, treatable, bacterial sexually transmitted infection in England and Wales. Among men, chlamydial infection is an important cause of non-gonococcal urethritis, epididymitis, and proctitis. The case for wider screening among women has been accepted by an expert advisory group. In the absence of estimates of the prevalence of infection in men, its potential impact at the population level is difficult to assess. OBJECTIVE: To estimate the prevalence of Chlamydia trachomatis in young men in clinic and community based samples in north west London. METHOD: Cross sectional survey in healthcare centres and general practices in north west London. 1002 males aged 18-35 years, living in north west London, were recruited by staff in occupational health departments, general practices, student health services, and a "well man" clinic and by postal recruitment in four GP practices. The men were tested for C trachomatis using the ligase chain reaction assay on urine samples. The main outcome measure was prevalence of C trachomatis infection in men aged 18-35 years. RESULTS: The overall response rate was 51%. Prevalence of confirmed infection was 1.9% (95% CI: 1.14% to 2.96%) in all men. Best estimated minimum prevalence of infection was 1% (95% CI: 0.58% to 1.50%). Estimated prevalence was highest among men aged over 30 years. CONCLUSIONS: The estimated prevalence among men is commensurate with that described for female populations in London. The results suggest that recruitment of men to screening programmes would be difficult. However, a higher proportion of chlamydial infection may be detected in men than in women by existing approaches to control through genitourinary medicine clinic based case finding and contact tracing. Screening of young women and the contact tracing of the male partners of positive females may be an efficient approach to improving chlamydia control.

Cardiovascular disease in women with polycystic ovary syndrome at long-term follow-up: a retrospective cohort study.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is associated with higher prevalence of cardiovascular risk factors but the relative prevalence of cardiovascular disease in women with PCOS has not previously been reported. We have compared cardiovascular mortality and morbidity in middle-aged women previously diagnosed with PCOS and age-matched control women. DESIGN: A retrospective cohort study of women diagnosed with PCOS in the United Kingdom before 1979. PATIENTS: Seventy cohort members died before 31 March 1999. Morbidity data were collected from 319 women with PCOS and 1060 age-matched control women. Sixty-one women with PCOS and 63 control women attended a clinical examination. MEASUREMENTS: Data were collected from death certificates, general practitioners' records and questionnaires with measurement of cardiovascular risk factors in a subsample of questionnaire respondents. RESULTS: All-cause and cardiovascular mortality in the cohort were similar to women in the general population (standardized mortality ratios (95% CI): 93 (72-117) and 78 (45-124), respectively). Women with PCOS had higher levels of several cardiovascular risk factors: diabetes (P = 0.002) hypertension (P = 0.04), hypercholesterolaemia (P < 0.001), hypertriglyceridaemia (P = 0.02) and increased waist:hip ratio (P = 0.004). After adjustment for BMI, odds ratios (OR) were 2.2 (0.9-5. 2) for diabetes, 1.4 (0.9-2.0) for hypertension and 3.2 (1.7-6.0) for hypercholesterolaemia. A history of coronary heart disease (CHD) was not significantly more common in women with PCOS (crude OR (95%CI) 1.5 (0.7-2.9)) but the crude OR for cerebrovascular disease was 2.8 (1.1-7.1). CONCLUSION: At long-term follow-up, a history of nonfatal cerebrovascular disease and cardiovascular risk factors including diabetes are more prevalent among women with polycystic ovary syndrome. Morbidity and mortality from of coronary heart disease among women with polycystic ovary syndrome is not as high as previously predicted. This finding challenges our understanding of the aetiology of coronary heart disease in women.

Quantification of Chlamydia trachomatis in cervical and urine specimens from women attending a genitourinary medicine clinic: implications for screening strategies.

Population screening and intervention programmes can reduce the prevalence and incidence of infection with Chlamydia trachomatis, especially if sensitive molecular diagnostic tests are used. However, diagnostic tests that perform well on genitourinary medicine (GUM) clinic populations may be less useful for screening, particularly if the majority of infected subjects are asymptomatic and their samples contain fewer organisms. We have compared the extent of low organism load in cervical and urine samples from symptomatic and asymptomatic chlamydia-positive women, by using a direct fluorescent antibody staining method and counting the chlamydial elementary bodies (EBs). We have investigated the ability of an enzyme immunoassay (EIA; MicroTrak) and a DNA amplification (ligase chain reaction; LCR) assay to detect low numbers of organisms in cervical samples and the ability of the LCR assay to detect low numbers of organisms in urine. A low organism load (< 10 EBs) was seen by direct fluorescent antibody (DFA) staining in about 30% of cervical samples and in about 75% of urines from chlamydia-positive women; the proportions in symptomatic women were not significantly different from those in asymptomatic women. The EIA identified only 16% of cervical samples that contained < 10 EBs by DFA staining; the LCR identified 100% of cervical samples and 93% of urine samples that contained < 10 EBs by DFA staining. The findings suggest that the ability of chlamydial diagnostic tests to identify positive women should be similar among patients attending a GUM clinic and those taking part in a population screening programme, and that sensitive molecular assays such as the LCR should identify subjects with a low organism load in both groups.

Mortality of women with polycystic ovary syndrome at long-term follow-up.

Metabolic disturbances associated with insulin resistance are present in most women with polycystic ovary syndrome. This has led to suggestions that women with polycystic ovary syndrome may be at increased risk of cardiovascular disease in later life. We undertook a long-term follow-up study to test whether cardiovascular mortality is increased in these women. A total of 786 women diagnosed with polycystic ovary syndrome in the United Kingdom between 1930 and 1979 were traced from hospital records and followed for an average of 30 years. Standardized mortality ratios (SMRs) were calculated to compare the death rates of these women with national rates. The SMR for all causes was 0.90 (95% CI, 0.69-1.17), based on 59 deaths. There were 15 deaths from circulatory disease, yielding an SMR of 0.83 (95% CI, 0.46-1.37). Of these 15 deaths, 13 were from ischemic heart disease (SMR 1.40; 95% CI, 0.75-2.40) and two were from other circulatory disease (SMR 0.23; 95% CI, 0.03-0.85). There were six deaths from diabetes mellitus as underlying or contributory cause, compared with 1.7 expected (odds ratio 3.6; 95% CI, 1.5-8.4). Breast cancer was the commonest cause of death (SMR 1.48 based on 13 deaths; 95% CI, 0.79-2.54). We conclude that women with polycystic ovary syndrome do not have markedly higher than average mortality from circulatory disease, even though the condition is strongly associated with diabetes, lipid abnormalities, and other cardiovascular risk factors. The characteristic endocrine profile of women with polycystic ovary syndrome may protect against circulatory disease in this condition.

Sensitivity of the ligase chain reaction assay for detecting Chlamydia trachomatis in vaginal swabs from women who are infected at other sites.

OBJECTIVE: To assess the sensitivity of the ligase chain reaction (LCR) assay for Chlamydia trachomatis in vaginal swabs from women who were positive in cervical samples and/or urines. SUBJECTS: 413 women attending the genitourinary medicine clinic, St. Mary's Hospital, Paddington. METHODS: The LCR assay was used to test vaginal swabs from 46 women who were C trachomatis positive at one or both of the other sites by direct fluorescent antibody (DFA) staining, by an enzyme immunoassay (EIA), or by the LCR assay. RESULTS: The LCR assay of vaginal swabs had the following sensitivity values using confirmed positive results: 93% (41/44) compared with DFA staining of cervical deposits, 93% (41/44) compared with the LCR assay of cervical samples, 93% (28/30) compared with an EIA for cervical samples, 91% (39/43) compared with DFA staining of urine deposits, and 93% (39/42) compared with the LCR assay of urine. Four women had vaginal swab samples negative by the LCR assay; one was positive only in the urine and two had cervical samples containing a small number of chlamydial elementary bodies. CONCLUSION: Testing vaginal swabs by the LCR assay is a sensitive method of detecting chlamydial infection; the results suggest that this procedure could be used as an alternative to examining urines in a screening programme for chlamydial infection in the community.

Association of early-onset coronary heart disease in South Asian men with glucose intolerance and hyperinsulinemia.

BACKGROUND: Rates of coronary heart disease are higher in South Asians (Indians, Pakistanis, and Bangladeshis) settled overseas than in other ethnic groups. We tested the hypothesis that this excess risk results from metabolic disturbances associated with insulin resistance. METHODS AND RESULTS: There were 1,421 South Asian men and 1,515 European men aged 40-69 years in London examined in the Southall Study. Prevalence of ischemic ECG abnormalities was higher in South Asians than in Europeans (17% versus 12%, p < 0.001), with an excess of major Q waves (Minnesota codes 1-1 or 1-2) in younger South Asian men (p = 0.01 for the age-ethnicity interaction). Major Q waves were strongly associated with glucose intolerance and hyperinsulinemia in younger South Asians; these factors accounted statistically for 73% of major Q waves in those aged 40-54 years. Age-standardized prevalence of a positive history of coronary heart disease was similar in South Asians and Europeans (8.5% versus 8.2%, NS), and positive history without Q waves was not associated with glucose intolerance or hyperinsulinemia in South Asians. Smoking rates and average plasma cholesterol were lower in South Asians than in Europeans; in a logistic model controlling for smoking and cholesterol, the odds ratio for major Q waves in South Asians compared with Europeans was 2.4 (95% CI, 1.5-3.8). Adjusting for glucose intolerance and hyperinsulinemia reduced this ratio to 1.5 (95% CI, 0.9-2.5). CONCLUSIONS: These results are consistent with the hypothesis that insulin resistance underlies the high coronary risk in South Asian people and strengthen the evidence for a fundamental role of this metabolic pattern in the etiology of coronary heart disease.

Relationship of glucose intolerance and hyperinsulinaemia to body fat pattern in south Asians and Europeans.

Type 2 (non-insulin-dependent) diabetes mellitus and insulin resistance are associated with centrally-distributed obesity. These disturbances are especially prevalent in people of South Asian (Indian, Pakistani and Bangladeshi) descent. We examined the relationship of glucose intolerance to body fat pattern in a population survey of 2936 men and 537 women of South Asian and European origin living in London, UK. In both groups glucose intolerance (defined as diabetes or impaired glucose tolerance) was more strongly associated with waist-hip girth ratio than with skinfolds or body mass index. The associations between body mass index and glucose intolerance were fully accounted for by waist-hip ratio. In European men with normal glucose tolerance fasting insulin levels were more strongly correlated with body mass index than with waist-hip ratio. Physical activity scores were lower in South Asians than in Europeans but no statistically significant associations between glucose intolerance and low physical activity were detectable. Leisure-time physical activity scores were inversely correlated with 2 h insulin levels in both groups. In contrast with other studies these results suggest that a specific effect of intra-abdominal fat deposition underlies the association between glucose intolerance and obesity. The association between hyperinsulinaemia and obesity is less specific for centrally-distributed fat. When measured appropriately waist-hip ratio is the most valid anthropometric index for identifying individuals whose obesity predisposes them to glucose intolerance.