Background: Measurement of plasma total homocysteine has become common as new methods have been introduced. A wide range of disorders are associated with increased concentrations of total homocysteine. The purpose of this review is to provide an international expert opinion on the practical aspects of total homocysteine determinations in clinical practice and in the research setting and on the relevance of total homocysteine measurements as diagnostic or screening tests in several target populations. Methods: Published data available on Medline were used as the basis for the recommendations. Drafts of the recommendations were critically discussed at meetings over a period of 3 years. Outcome: This review is divided into two sections: (a) determination of homocysteine (methods and their performance, sample collection and handling, biological determinants, reference intervals, within-person variability, and methionine loading test); and (b) risk assessment and disease diagnosis (homocystinuria, folate and cobalamin deficiencies, cardiovascular disease, renal failure, psychiatric disorders and cognitive impairment, pregnancy complications and birth defects, and screening of elderly and newborns). Each of these subsections concludes with a separate series of recommendations to assist the clinician and the research scientist in making informed decisions. The review concludes with a list of unresolved questions. © 2004 American Association for Clinical ChemistryIncreased plasma total homocysteine (tHcy) 7 is a sensitive marker of folate and cobalamin (vitamin B 12 ) deficiency (1, 2 ) and an independent risk factor for cardiovascular disease (CVD) (3,4 ). Plasma tHcy concentrations are also related to birth defects (5 ), pregnancy complications (6 ), psychiatric disorders (7 ), and cognitive impairment in the elderly (8 ). The measurement of tHcy in the clinical setting is thus potentially of great importance (9 ).The introduction of tHcy assays in the mid-1980s (10, 11 ) started a new era of research on Hcy. However, it was the advent of immunoassays in the latter half of the 1990s (12, 13 ) that changed tHcy determinations from research tools to widely used clinical chemistry tests. As a result, interest in this field has increased exponentially in both routine diagnostics and research.Although several reviews on tHcy determinations have been published (14 -18 ), few have provided recommendations for their use in clinical practice (19 -23 ). Our aim was to review the practical aspects of tHcy determinations in clinical practice as well as in the research setting and to survey the data on tHcy in diagnostics or as screening tests in several target populations.Ideally, guidelines should be established by a multidisciplinary team including all relevant stakeholders, and the recommendations should be according to evidence-based medicine (24 ). There are not sufficient data in the Hcy field, however, to use such an approach. In particular, -32 (2004) Review 3 data from controlled clinical trials are sparse. Neverth...

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Importance Colorectal cancer is a major health burden. Screening is recommended in many countries. Objective Estimate the effectiveness of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality in a population-based trial. Design Randomized controlled trial in individuals aged 50–64 years. Screening was performed in 1999–2000 (55–64 year age-group) and 2001 (50–54 year age-group). End of follow-up: Dec 31st 2011. Setting Population of Oslo city and Telemark County, Norway. Participants 100,210 individuals were identified in the screening areas. 1,415 individuals were excluded due to prior colorectal cancer, emigration, or death. Three individuals could not be traced in the population registry. Intervention Individuals randomized to the screening group were invited to screening. Within the screening group, individuals were randomized 1:1 to once-only flexible sigmoidoscopy or combination of once-only flexible sigmoidoscopy and fecal occult blood-testing (FOBT). Individuals with positive screening test (cancer, adenoma, polyp ≥10 mm, or positive FOBT) were offered colonoscopy. The control group received no intervention. Main outcome measures Colorectal cancer incidence and mortality. Results 98,792 individuals were included in the intention to screen analyses; 78,220 in the control group and 20,572 in the screening group (10,283 randomized to flexible sigmoidoscopy and 10,289 to flexible sigmoidoscopy and FOBT). Compliance with screening was 63%. After median 10.9 years, 71 individuals had died from colorectal cancer in the screening group, and 330 in the control group (31.4 vs. 43.1 deaths, absolute rate difference 11.7 (95% CI 3.0–20.4) per 100,000 person-years); hazard ratio [HR] 0.73 (95% confidence interval [CI] 0.56–0.94). Colorectal cancer was diagnosed in 253 individuals in the screening group, and 1,086 in the control group (112.6 vs. 141.0 cases, absolute rate difference: 28.4 (95% CI 12.1–44.7) per 100,000 person-years); HR 0.80 (95% CI 0.70–0.92). Colorectal cancer incidence was reduced in both the 50–54 year age-group (HR 0.68; 95% CI 0.49–0.94) and the 55–64 year age-group (HR 0.83; 95% CI 0.71–0.96). There was no difference between the flexible sigmoidoscopy only and the flexible sigmoidoscopy/FOBT screening groups. Conclusion and relevance In Norway, once-only flexible sigmoidoscopy screening or flexible sigmoidoscopy and FOBT reduced colorectal cancer incidence and mortality on a population level compared with no screening. Screening was effective both in the 50–54 and the 55–64 year age-group. Trial registration ClinicalTrials identifier NTC00119912, http://clinicaltrials.gov

About 75% of the subjects had metabolic signs of cobalamin deficiency, which was only partly explained by the vegetarian diet. If impaired cobalamin status is confirmed in other parts of India, it may have important health implications.

From 1992-93, we screened 18,043 subjects, aged 40-67 yr, and found 67 cases (0.4%) with total plasma homocysteine (tHcy) Ն 40 mol/liter. Compared to 329 controls, the cases had lower plasma folate and cobalamin levels, lower intake of vitamin supplements, consumed more coffee, and were more frequently smokers. Homozygosity for the C677T mutation in the methylenetetrahydrofolate reductase gene was observed in 73.1% of the cases and 10.2% of the controls. Only seven cases with cobalamin deficiency and one with homocystinuria received specific therapeutic instructions. 2 yr after the screening, 58 subjects were reinvestigated. 41 still had tHcy Ͼ 20 mol/liter, and in 37 of these, intervention with low dose folic acid (0.2 mg/d) was started. Notably, 34 of 37 (92%) had homozygosity for the C677T mutation. Plasma tHcy was reduced in all but two after 7 wk, and became normal within 7 mo in 21 of 37 subjects.