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Abstract Background The short-term cholesterol-lowering efficacy of plant stanol esters has been open to debate, and the data from different clinical studies with hypercholesterolemic subjects are variable, partly due to lack of systematic studies. Therefore, we investigated the time in days needed to obtain the full cholesterol-lowering effect of stanol esters in hypercholesterolemic subjects. Methods Eleven mildly to moderately hypercholesterolemic subjects consumed stanol ester margarine (2.0 g/day of stanols) as a part of their habitual diet for 14 days and the changes in serum lipid values were measured three times at 4, 8 and 15 days after the initiation of test margarine consumption (0 day). The returning of serum lipid concentrations to baseline was measured two times after 2 or 3 days and after 7 days of the end of the test margarine consumption. Results Serum LDL cholesterol concentrations were reduced from 0 day (4.51 ± 0.66 mmol/l) by 3.5% (P = ns), 9.9% (p < 0.05) and 10.2% (P < 0.05) at 4, 8 and 15 days, respectively. Serum campesterol/total cholesterol ratio, an indirect marker of intestinal cholesterol absorption, was significantly reduced on day 4 already. After ending the stanol ester use serum cholesterol concentrations began to return rapidly and after 7 days serum LDL cholesterol was 5.3% less than the initial value (P = ns). Conclusion The specific effect of plant stanol esters on serum LDL cholesterol can fully be obtained within 1–2 weeks of the use of plant stanol ester-enriched margarine.

Polymorphisms of the ABCG5 and ABCG8 genes interfere with cholesterol absorption and synthesis. We determined whether common polymorphisms of these genes regulate the responses of serum cholesterol and vascular function during long-term inhibition of cholesterol absorption. Mildly to moderately hypercholesterolaemic subjects (n 282) completed a 1-year study consuming plant stanol or sterol ester (2 g stanol or sterol) or control spread. Serum cholesterol and non-cholesterol sterols, markers of cholesterol absorption and synthesis, and variables of vascular function and structure were analysed in relation to common polymorphisms of ABCG5 and ABCG8. At baseline, subjects with the 54K allele of ABCG8 had higher brachial endothelial-dependent flow-mediated dilatation than those without it (5·79 (se 0·31) v. 4·46 (se 0·44) %; P = 0·049), and subjects with the 632V allele of ABCG8 had larger brachial artery diameter than those without it. Polymorphisms of ABCG5 and ABCG8 were neither associated with serum cholesterol reduction nor changes in cholesterol metabolism or in vascular function. However, in subjects with the 400K allele of ABCG8, intima media thickness (IMT) was increased in all groups more than in those without it (P < 0·05). In conclusion, serum cholesterol lowering with absorption inhibition was not associated with polymorphic sites of ABCG5 and ABCG8. However, regulation of baseline cholesterol metabolism and vascular function and structure, and IMT progression during 1 year seemed to share some of the common polymorphic sites of these genes, suggesting a gene-regulated interaction between cholesterol metabolism and vascular function and structure. [ABSTRACT FROM PUBLISHER]

Background and methods Serum cholestanol and plant sterol ratios to cholesterol, surrogate markers of cholesterol absorption, are assumed to be high in type 1 diabetes (T1D), and the ratios of cholesterol precursor sterols (markers of synthesis) are assumed to be low reflecting downregulated cholesterol synthesis. To this end, we measured serum sterols with gas-liquid-chromatography in 56 men with T1D and in 18 controls to evaluate cholesterol metabolism. Subjects were categorised into tertiles by the cholestanol to cholesterol ratio of controls indicating low to high absorption of cholesterol. Results The ratios of the synthesis markers were negatively related to the absorption markers in controls, but less consistently in T1D. The absorption markers were positively related to each other, but interrelation of the synthesis markers was less consistent in T1D. In the low absorbers the absorption markers were higher in T1D than in controls (e.g. sitosterol ratio 173 ± 9 in T1D vs 135 ± 11 102 × mmol/mol of cholesterol in controls, p < 0.05). In the high absorbers, the absorption markers were similar in T1D and controls, but the synthesis markers were higher in T1D than in controls (e.g. lathosterol ratio 154 ± 10 in T1D vs 120 ± 5 102 × mmol/mol of cholesterol in controls, p < 0.05). Conclusions Absorption and synthesis of cholesterol are less closely related to each other in T1D than in controls, but the markers of cholesterol absorption are interrelated also in T1D. Absorption of cholesterol is higher in T1D than in controls within the range of low absorption, but similar in those with relatively high cholesterol absorption. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]