Journal of clinical lipidology最新文献

Objective: The importance of any enhanced atherogenicity of triglyceride (TG)-rich lipoproteins (TRLs) will depend on the relative abundance of these particles compared with LDL or total apolipoprotein (apo)B. Accordingly, we determined the contribution that TRLs make to total apoB as TG or apoB concentrations increase. We also describe compositional changes in TRLs as TG or apoB increase to assess whether VLDL-C is a valid proxy for VLDL-apoB.

Methods: We used sequential ultracentrifugation to separate lipoprotein fractions in plasma samples from 1940 dyslipidemic patients not on lipid-lowering medication, and measured apoB, cholesterol and TG in the plasma and in each subfraction. We analyzed this data in quartiles of TG or apoB.

Results: There was wide variance in all parameters in all quartiles of both TG and apoB. Although VLDL-apoB accounted for almost all the increase in total apoB across TG quartiles, LDL-apoB still accounted for 80 % of the total in TG quartile 4. In contrast, LDL-apoB accounted for 90 % of the increase in apoB across apoB quartiles. As TG increases, the increase in VLDL-C is explained more by increased VLDL-C/apoB when TG is moderately elevated, and more by increased VLDL-apoB when TG is very high.

Conclusions: In conclusion, VLDL-apoB only becomes a substantial component of total apoB with extreme hypertriglyceridemia and VLDL-C is not an appropriate proxy for VLDL-apoB.

Background: Autosomal recessive hypercholesterolemia (ARH) is an ultrarare dyslipidemia caused by variants in the LDLRAP1 gene. Clinically, this condition is indistinguishable from other homozygous familial hypercholesterolemia (HoFH).

Case: We present the cases of two siblings diagnosed with ARH caused by LDLRAP1 gene c.617-14C>A splicing homozygous variant. Over a five-year treatment period, the older sibling experienced an 81 % reduction in low-density lipoprotein cholesterol (LDL-C) levels with the maximal dose of pitavastatin plus ezetimibe, while the younger sibling achieved a 75 % reduction. After three sessions, the older brother no longer required LDL apheresis, and the sibling never had LDL apheresis.

Conclusion: Our findings demonstrate a rapid and significant response to lipid-lowering therapy (LLT) in patients with ARH caused by c.617-14C>A splicing VUS variant, a condition that mimics HoFH at diagnosis. Long-term follow-up studies in large pediatric cohorts of ARH patients treated with pitavastatin plus ezetimibe from childhood are necessary to better define the risk of cardiovascular disease (CVD) development.

Background: The present study was performed to determine the association between changes in the HDL-C concentration and incident CVD.

Methods: Time-dependent Cox regression models were used to evaluate the association between changes in the HDL-C concentration and the risk of incident CVD. Participants were followed up from 2015 to 2021.

Results: In total, 24,123 participants with a median follow-up of 4.26 years were analyzed, and the mean age of the cohort was 56.24 years, 57.8 % were female, 24.3 % were current smokers, and 12.8 % had a history of alcohol use. Low, normal, and high HDL-C was defined as <40, 40-80, and >80 mg/dL, respectively. The average time for the two HDL-C measurements was 2.8 years,compared with participants whose HDL-C was maintained at a normal level, the risk of CVD was higher in those whose HDL-C changed to a low level, remained unchanged at a low level(HR, 1.24; 95 % CI, 1.01-1.40,P < 0.001), similarly, the risk of CVD was higher in those whose HDL-C changed from very high level to normal level(HR, 0.81; 95 % CI, 0.67-0.99,P = 0.039). Also compared with participants whose HDL-C was maintained at a normal level, the risk of CVD was lower in those whose HDL-C increased from low to normal and high(HR, 0.80; 95 % CI, 0.66-0.98,P = 0.029).

Conclusions: Participants whose HDL-C changed to a low level and whose low HDL-C level was maintained had a higher risk of CVD, whereas participants whose HDL-C changed from low to high had a lower risk of CVD.

Background: Patients suffering from sitosterolemia with ABCG5/8 mutation typically present with early-onset or rapidly progressive atherosclerosis. Their kindreds with partial genetic deficiencies of ABCG5/8 are often considered healthy. However, discerning sitosterolemia from its familial kindreds and hyperlipidemia subjects has remained challenging.

Methods: Here we retrospectively recruited seven families including 8 individuals diagnosed with sitosterolemia subjects, and 14 kindreds carrying single gene mutations. Additionally, 17 individuals with hyperlipidemia and 130 healthy controls served as positive and negative controls, respectively. A total of 6 phytosterols combined with cholesterol absorption indices (including sitosterol, campesterol, stigmasterol, and cholestanol) and cholesterol synthesis markers (desmosterol and 7-dehydrocholesterol), was compared across the aforementioned four groups.

Results: As expected, the sitosterolemia subjects with double mutations demonstrated significantly elevated levels of sitosterol and other cholesterol absorption indices. Meanwhile, sitosterolemia kindreds with single gene mutation showed a similar pattern of activated cholesterol-absorption ability to the hyperlipidemia group, but not as high as the double mutation group. Notably, the cholesterol-synthesis enzyme 7-dehydrocholesterol reductase displayed an increase in the hyperlipidemia group but a decrease in the sitosterolemia kindred group, suggesting a potential discriminative role of 7-dehydrocholesterol in distinguishing between these two groups. The combination of phytosterols was more valuable than clinical lipid index for sitosterolemia diagnosis.

Conclusion: Our study revealed mild disruptions of cholesterol absorption capacities in sitosterolemia kindreds with single mutations. Furthermore, the combination of 6 phytosterols proved effective in distinguishing between sitosterolemia, its single mutation carriers, and hyperlipidemia patients.

Background: Familial Hypercholesterolaemia (FH) is a monogenic disorder that causes high levels of low-density lipoprotein (LDL) cholesterol. Cascade testing, where relatives of known individuals with FH ('index') are genetically tested, is effective and cost-effective, but implementation in the UK varies.

Objective: This study aims to provide evidence on current UK FH cascade yields and to identify common obstacles cascade services face and individual- and service-level predictors of success.

Methods: Electronic health records from 875 index families and 5,958 linked relatives in the UK's Welsh and Wessex FH services (2019) were used to explore causes for non-testing and to estimate testing rates, detection yields, and how relative characteristics and contact methods relate to the probability of relatives being tested (using logistic regression).

Results: In Wales (Wessex), families included 7.35 (7.01) members on average, with 2.41 (1.66) relatives tested and 1.35 (0.96) diagnosed with FH per index. Cascade testing is limited by individualised circumstances (too young, not at-risk, etc.) and FH services' reach, with approximately one in four relatives out-of-area. In Wales, first-degree relatives (odds ratio (OR):1.55 [95 % confidence interval (CI):1.28,1.88]) and directly contacted relatives (OR:2.11 [CI:1.66,2.69]) were more likely to be tested. In Wales and Wessex, women were more likely to be tested than men (ORs:1.53 [CI:1.28,1.85] and 1.74 [CI:1.32,2.27]).

Conclusion: In Wales and Wessex less than a third of relatives of an index are tested for FH. Improvements are likely possible by integrating geographically dispersed families into cascade testing, services directly contacting relatives where possible, and finding new ways to encourage participation, particularly amongst men.

Background: Olpasiran and pelacarsen are gene-silencing therapies that lower lipoprotein(a). Cardiovascular outcome trials are ongoing. Mendelian randomisation studies estimated clinical benefits from lipoprotein(a) lowering.

Objective: Our study estimated prices at which olpasiran and pelacarsen, in addition to standard-of-care, would be deemed cost-effective in reducing risk of recurrent coronary heart disease (CHD) events in the Australian healthcare system.

Methods: We developed a decision tree and lifetime Markov model. For olpasiran, participants had CHD and lipoprotein(a) 260 nmol/L at baseline and three-monthly injections, profiled on OCEAN(a) Outcomes trial (NCT05581303). Baseline risks of CHD, costs and utilities were obtained from published sources. Clinical trial data were used to derive reductions in lipoprotein(a) from treatment. Mendelian randomisation study data were used to estimate downstream clinical benefits. Annual discounting was 5 %. For pelacarsen, participants had CHD and lipoprotein(a) 226 nmol/L at baseline and one- monthly injections, profiled on Lp(a) HORIZON (NCT04023552) trial.

Results: Olpasiran in addition to standard-of-care saved 0.87 discounted quality-adjusted life years (QALYs) per person. Olpasiran in addition to standard-of-care would be cost- effective at annual prices of AU$1867 (AU$467 per dose) at threshold AU$28,000 per QALY. Pelacarsen would be cost-effective at annual prices of AU$984 (AU$82 per dose). For ICER threshold AU$50,000 per QALY, olpasiran and pelacarsen would be cost-effective at annual prices AU$4207 and AU$2464 respectively.

Conclusion: This early health technology assessment model used inclusion criteria from clinical trials. Olpasiran and pelacarsen would be cost-effective if annual treatment prices were AU$1867 and AU$984 respectively, from the Australian healthcare perspective.