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H Priemé

Publications and source records attributed to H Priemé.

6 recordsLinked to original sources

Randomized controlled smoking cessation study: transient increase in plasma high density lipoprotein but no change in lipoprotein oxidation resistance.

Low plasma levels of high density lipoprotein (HDL) and high levels of low density lipoprotein (LDL) as well as smoking are known risk factors in coronary heart disease. It has been suggested that oxidative modification renders LDL atherogenic. We investigated the influence of smoking cessation on plasma lipid and lipoprotein levels and on the ability of lipoproteins to resist oxidation in vitro (lag time). A total of 182 healthy smokers who smoked more than 15 cigarettes per day were randomized to stop smoking (smoking cessation group, n = 100) or to continue smoking for 4 weeks (control group, n = 82). The smoking cessation group was followed up after 26 weeks. After 4 weeks, the HDL level had increased from mean +/- SD 1.36 +/- 0.34 to 1.48 +/- 0.40 mmol l-1 (p < 0.001) in 62 successful quitters, while levels were unchanged in the control group (72 subjects in per-protocol analysis). However, after 26 weeks there was no change in HDL (1.34 +/- 0.36 vs. 1.36 +/- 0.35 mmol l-1) in 29 subjects from the smoking cessation group who fulfilled the study. Plasma levels of very low density lipoprotein (VLDL), LDL, total cholesterol, triglycerides and oxidation resistance of VLDL + LDL did not show significant changes any time during the study for either group. Thus, plasma levels of lipids and lipoproteins as well as oxidation resistance of lipoproteins seem unaffected by smoking cessation for 26 weeks.

Adult↗

Effect of smoking cessation on oxidative DNA modification estimated by 8-oxo-7,8-dihydro-2'-deoxyguanosine excretion.

BACKGROUND: Reactive oxygen species from, e.g. tobacco smoke are suggested to be involved in carcinogenesis by oxidative modification of DNA. The urinary excretion rate of the oxidized nucleoside 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) has been validated as a biomarker of the rate of oxidative DNA modification with mechanistic relation to carcinogenesis. In cross-sectional studies, the urinary excretion rate of 8-oxodG has been shown to be elevated in smokers compared with non-smokers. PURPOSE: In this randomised, controlled smoking cessation study, we investigated whether cigarette smoking per se causes oxidative DNA modification. METHODS: Of the 182 healthy smokers included, 100 were randomized to quit smoking after baseline samples had been taken, and 82 were randomized to continue usual smoking. Before the start of the study and after 4 weeks, the subjects collected 24-h urine samples that were analysed for 8-oxodG content by high-pressure liquid chromatography with electrochemical detection. The subjects randomized to smoking cessation were followed up after 26 weeks. RESULTS: Four weeks of smoking cessation resulted in a 21% decrease in 8-oxodG excretion rate (from mean +/- SD, 30.5 +/- 13.9 to 24.1 +/- 10.5 nmol/24 h, P < 0.001) in 58 quitters included in per-protocol data analysis. Sixty-five continued smokers included in per-protocol analysis showed a 9% decrease in 8-oxodG excretion rate (from 31.6 +/- 13.2 to 28.7 +/- 12.6 nmol/24 h, P = 0.026). After 4 weeks, the 8-oxodG excretion rate was 16% (95% confidence interval 4 to 28%) higher in the continued smokers than in the quitters (P = 0.0085, ANCOVA), demonstrating the effect of smoking per se. A 23% (P < 0.005) decrease in 8-oxodG excretion rate was sustained for 26 weeks in 27 quitters who completed the study. CONCLUSION: Smoking cessation significantly reduces the urinary excretion rate of 8-oxodG, giving direct and controlled evidence that cigarette smoking causes an increased rate of oxidative DNA modification. This could represent a mechanism by which tobacco smoke is carcinogenic.

8-Hydroxy-2'-Deoxyguanosine↗

No effect of supplementation with vitamin E, ascorbic acid, or coenzyme Q10 on oxidative DNA damage estimated by 8-oxo-7,8-dihydro-2'-deoxyguanosine excretion in smokers.

The protective effect of fruit and vegetables against cancer has been related to their high antioxidant content. However, results from intervention trials have not been conclusive on the protective effect of antioxidant supplementation. In a randomized placebo-controlled trial we investigated the effect of dietary supplementation with antioxidants on a biomarker of oxidative DNA damage with mechanistic relation to carcinogenesis. One hundred forty-two smoking men aged 35-65 y were randomly assigned to one of the following seven treatments for 2 mo: 100 mg D-alpha-tocopheryl acetate plus 250 mg slow-release ascorbic acid twice a day (n = 20), 100 mg D-alpha-tocopheryl acetate twice a day (n = 20), 250 mg ascorbic acid twice a day (n = 21), 250 mg slow-release ascorbic acid twice a day (n = 21), 30 mg coenzyme Q10 in oil three times a day (n = 20), 30 mg coenzyme Q10 as granulate three times a day (n = 20), or placebo twice a day (n = 20). The trial outcome was the urinary excretion rate of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG)-a repair product of oxidative DNA damage. Two months of supplementation did not result in significant changes in the urinary excretion rate of 8-oxodG in any group. The lack of effect of antioxidant supplementation on the excretion rate of 8-oxodG, despite substantial increases in plasma antioxidant concentrations, agrees with the results from recent large intervention studies with cancer as an endpoint. The cancer-protective effect of fruit and vegetables seems to rely not on the effect of single antioxidants but rather on other anticarcinogenic compounds or on a concerted action of several micronutrients present in these foods.

8-Hydroxy-2'-Deoxyguanosine↗

Genotype and phenotype of glutathione S-transferase mu in testicular cancer patients.

The incidence rate of testicular cancer has been steadily increasing during the last 50 years, and only cryptorchidism, i.e. undescended testes, has been identified as an important risk factor. An interplay between changing environmental factors and genetic susceptibility e.g. in foreign compound metabolizing enzymes, may have important influences on the risk. The aim of this study was to investigate if glutathione S-transferase mu (GST mu) deficiency, which in previous studies has been associated with malignant melanoma and cancers of the lung and bladder, is a risk factor of testicular cancer. Three hundred and seventy-eight men participated (80 seminomas, 104 non-seminomas and 194 controls) in a population-based case-control study. The phenotype of GST mu was determined in 366 men by ELISA, the genotype was determined in 324 men by polymerase chain reaction. The concordance between geno- and phenotype was 94.4%. The odds ratio of having the GST mu negative phenotype and testicular cancer was 1.08, (0.72-1.64; 95% confidence interval (CI)), and the odds ratio of having the GSTM1 null genotype and testicular cancer was 1.10; CI95% (0.71-1.70). This study provides no evidence of an association between phenotypically determined GST mu deficiency or GSTM1 null genotype and testicular cancer. The narrow confidence intervals rule out GST mu as a major single risk factor for testicular cancer.

Adult↗

Smoking cessation does not change urinary albumin excretion in normal subjects.

The aim of the study was to examine the effect of smoking cessation on urinary albumin excretion (UAE) in normal subjects. The study consisted of two parts. The first was a randomized 4-week study, in which 182 heavy smokers were asked to quit smoking immediately (n = 69, available for analysis) or to continue smoking for another 4 weeks (n = 70, available for analysis). After 4 weeks, the latter group was also asked to stop smoking. The second part was a non-randomized follow-up study comparing UAE in 33 unsuccessful and 57 successful quitters followed for 26 weeks. Measurements of UAE (ELISA) were taken from 24-h urine samples before smoking cessation, after 4 weeks, and after 26 weeks. After 4 weeks, no statistically significant change in UAE was found within each group or between quitters and smokers. The 95% confidence intervals of the change in log UAE were -7.4 to 9.9% of the initial value in the smoker group and -4.9 to 11.3% in the quitter group. In the second part of the study, after 26 weeks, a 16% increase (95% confidence interval 5.5 to 26.5%) in mean log UAE was found in the group that had stopped smoking (p < 0.003), but no statistically significant difference in UAE between continued smokers and quitters was found after adjusting for the baseline level (ANCOVA). In conclusion, smoking cessation seems to have no effect on UAE within the physiological range in normal subjects over an observation period of 4 weeks, and no sign of a decrease in UAE was seen after 26 weeks of smoking cessation.

Adult↗