Serum phosphorus and subclinical coronary atherosclerosis in asymptomatic subjects without kidney dysfunction.

BACKGROUND AND AIMS: There is limited data on the association between serum phosphorus concentration (SPC) and subclinical coronary atherosclerosis in low-risk asymptomatic subjects without kidney dysfunction. MATERIALS AND METHODS: We retrospectively analyzed 1,636 Korean individuals (mean age 52.6 ± 7.6 years; males: 712 (43.5%)) without traditional cardiovascular risk factors (CVRFs) and kidney dysfunction who voluntarily underwent coronary computed tomography angiography (CCTA) as part of a general health examination. Traditional CVRFs were defined as follows: systolic/diastolic blood pressure ≥ 140/90 mmHg, fasting blood glucose ≥ 126 mg/dL, hemoglobin A1c ≥ 6.5%, total cholesterol ≥ 240 mg/dL, low-density lipoprotein cholesterol ≥ 160 mg/dL, high-density lipoprotein cholesterol < 40 mg/dL, body mass index ≥ 25.0 kg/m2, currently smoking, and medical history of hypertension, diabetes, and hyperlipidemia. Study participants were stratified into tertiles according to their SPC levels (≤ 3.2, 3.3 - 3.6, and ≥ 3.7 mg/dL). RESULTS: 297 (18.2%) study participants had subclinical coronary atherosclerosis, characterized by any coronary plaque on CCTA. In multivariable regression analysis, the risk of subclinical coronary atherosclerosis increased in the second (odds ratio (OR): 1.629; 95% confidence interval (CI): 1.149 - 2.308; p = 0.006) and third (OR: 1.645; 95% CI: 1.093 - 2.476; p = 0.017) SPC tertiles compared to the first SPC tertile. In addition, the risk of calcified plaque increased in the second (OR: 1.605; 95% CI: 1.124 - 2.292; p = 0.009) and third (OR 1.790; 95% CI 1.179 - 2.716; p = 0.006) SPC tertiles. CONCLUSION: In low-risk asymptomatic Korean individuals without kidney dysfunction, a higher SPC level was an independent predictor of subclinical coronary atherosclerosis.

Effects of beta-carotene supplements on cancer prevention: meta-analysis of randomized controlled trials.

This meta-analysis aimed to investigate the effects of beta-carotene supplements alone on cancer prevention as reported by randomized controlled trials (RCTs). We searched PubMed, EMBASE, and CENTRAL. Among the 848 articles searched, 6 randomized controlled trials, including 40,544 total participants, 20,290 in beta-carotene supplement groups, and 20,254 in placebo groups, were included in the final analysis. In a meta-analysis of 6 RCTs, beta-carotene supplements had no preventive effect on either cancer incidence [relative risk (RR) = 1.08, 95% confidence interval (CI) = 0.99-1.18] or cancer mortality (RR = 1.00, 95% CI = 0.87-1.15). Similar findings were observed in both primary prevention trials and secondary prevention trials. Subgroup analyses by various factors revealed no preventive effect of beta-carotene supplementation on cancer prevention and that it significantly increased the risk of urothelial cancer, especially bladder cancer (RR = 1.52, 95% CI = 1.03-2.24) and marginally increased the risk of cancer among current smokers (RR = 1.07, 95% CI = 0.99-1.17). The current meta-analysis of RCTs indicated that there is no clinical evidence to support the overall primary or secondary preventive effect of beta-carotene supplements on cancer. The potential effects, either beneficial or harmful, of beta-carotene supplementation on cancer should not be overemphasized.

Effects of selenium supplements on cancer prevention: meta-analysis of randomized controlled trials.

This meta-analysis aimed to investigate the preventive effect of selenium supplements alone on cancer as reported by randomized controlled trials (RCTs). We searched PubMed, EMBASE, and the Cochrane Library in July 2009. Of the 461 articles searched, 8 articles on 9 RCTs, which included 152,538 total participants, 32,110 in antioxidant supplement groups, and 120,428 in placebo groups, were included. In a random-effects meta-analysis of all 9 RCTs, selenium supplementation alone was found to have an overall preventive effect on cancer incidence [relative risk (RR) = 0.76; 95% confidence interval (CI) = 0.58-0.99]. Among subgroup meta-analyses, the preventive effect of selenium supplementation alone on cancer was apparently observed in populations with a low baseline serum selenium level (<125.6 ng/mL) (RR = 0.64; 95% CI = 0.53 to 0.78; I(2) = 45.5%; n = 7) and in high-risk populations for cancer (RR = 0.68; 95% CI = 0.58 to 0.80; I(2) = 41.5%; n = 8). The meta-analysis of randomized controlled trials indicates that there is possible evidence to support the use of selenium supplements alone for cancer prevention in the low baseline serum selenium level population and in the high-risk population for cancer.

Effects of vitamin treatment or supplements with purported antioxidant properties on skin cancer prevention: a meta-analysis of randomized controlled trials.

AIMS: To investigate the effect of vitamin treatment or supplements with purported antioxidant properties on the primary and secondary prevention of skin cancer using a meta-analysis of randomized controlled trials (RCTs). METHODS: We searched PubMed, Embase and the Cochrane Library in June 2009. Among 398 articles searched, 11 articles on 10 RCTs were included in the final analysis. RESULTS: In a fixed-effects meta-analysis of all 10 trials, vitamin treatment or supplements with purported antioxidant properties were found to have no preventive effect on skin cancer [relative risk (RR) = 0.98; 95% confidence interval (CI) = 0.94-1.03]. Similar findings were observed in a subgroup meta-analysis of 10 studies on both primary prevention trials (RR = 0.98; 95% CI = 0.93-1.03) and secondary prevention trials (RR = 0.97; 95% CI = 0.83-1.13). Further, subgroup meta-analyses revealed no preventive effect on cancer by type of antioxidant, type of cancer and the methodological quality of the studies. CONCLUSION: The current meta-analysis of RCTs indicated that there is no clinical evidence to support an overall primary and secondary preventive effect of vitamin treatment or supplements with purported antioxidant properties on skin cancer. The effect of vitamin supplements on skin cancer should not be overemphasized.

Coffee consumption and risk of prostate cancer: a meta-analysis of epidemiological studies.

OBJECTIVE: To evaluate the association between coffee consumption and the risk of prostate cancer. METHODS: We searched PubMed, EMBASE, and the bibliographies of relevant articles in August 2009. Two evaluators independently reviewed and selected articles based on predetermined selection criteria. RESULTS: Twelve epidemiological studies (eight case-control studies and four cohort studies) were included in the final analysis. In a meta-analysis of all included studies, when compared with the lowest level of coffee consumption, the overall relative risk (RR) of prostate cancer for the highest level of coffee consumption was 1.16 (95% confidence interval [CI] 1.01-1.33). In subgroup meta-analyses by study design, there was a significant positive (harmful) association between coffee consumption and prostate cancer risk in seven case-control studies using both crude and adjusted data (RR 1.20, 95% CI 1.02-1.40; and RR 1.21, 95% CI 1.03-1.43, respectively), whereas there was no significant association in four cohort studies using crude or adjusted data (RR 0.97, 95% CI 0.68-1.38; and RR 1.06, 95% CI 0.83-1.35, respectively). CONCLUSION: Given that a cohort study gives a higher level of evidence than a case-control study, there is no evidence to support a harmful effect of coffee consumption on prostate cancer risk. Further prospective cohort studies are required.