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- Hukkanen, J., et al.
(författare)
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The effect of atorvastatin treatment on serum oxysterol concentrations and cytochrome P450 3A4 activity
- 2015
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Ingår i: British Journal of Clinical Pharmacology. - : Blackwell Publishing. - 0306-5251 .- 1365-2125. ; 80:3, s. 473-479
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Atorvastatin is known to both inhibit and induce the cytochrome P450 3A4 (CYP3A4) enzyme in vitro. Some clinical studies indicate that atorvastatin inhibits CYP3A4 but there are no well-controlled longer term studies that could evaluate the inducing effect of atorvastatin. We aimed to determine if atorvastatin induces or inhibits CYP3A4 activity as measured by the 4β-hydroxycholesterol to cholesterol ratio (4βHC : C).Methods: In this randomized, double-blind, placebo-controlled 6 month study we evaluated the effects of atorvastatin 20mg day1 (n=15) and placebo (n = 14) on oxysterol concentrations and determined if atorvastatin induces or inhibits CYP3A4 activity as assessed by the 4βHC : C index. The respective 25-hydroxycholesterol and 5α,6α- epoxycholesterol ratios were used as negative controls.Results: Treatment with atorvastatin decreased 4βHC and 5α,6α-epoxycholesterol concentrations by 40% and 23%, respectively. The mean 4βHC : C ratio decreased by 13% (0.214 ± 0.04 to 0.182 ± 0.04, P = 0.024, 95% confidence interval (CI) of the difference –0.0595, –0.00483) in the atorvastatin group while no significant change occurred in the placebo group. The difference in change of 4βHC : C between study arms was statistically significant (atorvastatin –0.032, placebo 0.0055, P = 0.020, 95% CI of the difference – 0.069, –0.0067). The ratios of 25-hydroxycholesterol and 5α,6α- epoxycholesterol to cholesterol did not change.Conclusions: The results establish atorvastatin as an inhibitor of CYP3A4 activity.Furthermore, 4βHC : C is a useful index of CYP3A4 activity, including theconditions with altered cholesterol concentrations.
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| 2. |
- Pinola, Pekka, et al.
(författare)
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Androgen Profile Through Life in Women With Polycystic Ovary Syndrome : A Nordic Multicenter Collaboration Study
- 2015
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 100:9, s. 3400-3407
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Tidskriftsartikel (refereegranskat)abstract
- Context: Women with polycystic ovary syndrome (PCOS) have increased androgen secretion throughout fertile life; however, the data on the effect of menopause on hyperandrogenemia in these women are scarce. Nevertheless, large comprehensive comparative studies on age-related androgen levels in women with PCOS are lacking. Objective: The objective of the study was to investigate the effect of age on serum androgen levels in women with PCOS and to determine cutoff values for androgens and SHBG associated with a PCOS diagnosis. Design: This was a case-control study. Setting: The study was conducted in five university sites in the Nordic countries. Patients: In all, 681 women with PCOS and 230 referent women were grouped according to age into seven age groups (18 to > 50 y). Interventions: There were no interventions. Main Outcome measures: T, SHBG, free androgen index (FAI), calculated free T (cFT), androstenedione (A4), and dehydroepiandrosterone sulfate were measured. Results: Androgen levels in women with PCOS decreased with age toward menopause. The difference between women with PCOS and the referent women narrowed and individual variation increased as they approached menopause. T levels, FAI, and cFT were significantly higher in women with PCOS aged 18-44 years (P <.001, adjusted for body mass index). The best predictive factors for having PCOS were cFT (>= 0.40 ng/dL, odds ratio [OR] 7.90), FAI (>= 2.0, OR 6.71), and A4 (>= 277.94 ng/dL, OR 6.16). Conclusions: Women with PCOS had elevated serum androgen levels also after menopause. The parameters that best predicted PCOS at all ages were cFT, A4, and FAI.
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