Familial hypobetalipoproteinemia (FHBL) 1 is a rare genetic disorder with an autosomal codominant mode of inheritance and is caused by defects in the apolipoprotein (apo) B (APOB) gene that disable lipoprotein formation. ApoB proteins are required for the formation of very low-density lipoproteins (VLDLs), chylomicrons, and their metabolites. VLDLs transport cholesterol and triglycerides from the liver to the peripheral tissues, whereas chylomicrons transport absorbed lipids and fat-soluble vitamins from the intestine. Homozygous or compound heterozygotes of FHBL1 (HoFHBL1) are extremely rare, and defects in APOB impair VLDL and chylomicron secretion, which result in marked hypolipidemia with malabsorption of fat and fat-soluble vitamins, leading to various complications such as growth disorders, acanthocytosis, retinitis pigmentosa, and neuropathy. Heterozygotes of FHBL1 are relatively common and are generally asymptomatic, except for moderate hypolipidemia and possible hepatic steatosis. If left untreated, HoFHBL1 can cause severe complications and disabilities that are pathologically and phenotypically similar to abetalipoproteinemia (ABL) (an autosomal recessive disorder) caused by mutations in the microsomal triglyceride transfer protein (MTTP) gene. Although HoFHBL1 and ABL cannot be distinguished from the clinical manifestations and laboratory findings of the proband, moderate hypolipidemia in first-degree relatives may help diagnose HoFHBL1. There is currently no specific treatment for HoFHBL1. Palliative therapy including high-dose fat-soluble vitamin supplementation may prevent or delay complications. Registry research on HoFHBL1 is currently ongoing to better understand the disease burden and unmet needs of this life-threatening disease with few therapeutic options.

Aims: Nonalcoholic fatty liver disease (NAFLD) is known to be associated with atherosclerosis. This study focused on upstream changes in the process by which NAFLD leads to atherosclerosis. The study aimed to confirm the association between NAFLD and the cardio-ankle vascular index (CAVI), an indicator of subclinical atherosclerosis, and explore metabolites involved in both by assessing 94 plasma polar metabolites.

Methods: A total of 928 Japanese community-dwellers (306 men and 622 women) were included in this study. The association between NAFLD and CAVI was examined using a multivariable regression model adjusted for confounders. Metabolites commonly associated with NAFLD and CAVI were investigated using linear mixed-effects models in which batch numbers of metabolite measurements were used as a random-effects variable, and false discovery rate-adjusted p-values were calculated. To determine the extent to which these metabolites mediated the association between NAFLD and CAVI, mediation analysis was conducted.

Results: NAFLD was positively associated with CAVI (coefficients [95% Confidence intervals (CI)]=0.23 [0.09–0.37]; p=0.001). A total of 10 metabolites were involved in NAFLD and CAVI, namely, branched-chain amino acids (BCAAs; valine, leucine, and isoleucine), aromatic amino acids (AAAs; tyrosine and tryptophan), alanine, proline, glutamic acid, glycerophosphorylcholine, and 4-methyl-2-oxopentanoate. Mediation analysis showed that BCAAs mediated more than 20% of the total effect in the association between NAFLD and CAVI.

Conclusions: NAFLD was associated with a marker of atherosclerosis, and several metabolites related to insulin resistance, including BCAAs and AAAs, could be involved in the process by which NAFLD leads to atherosclerosis.

Aims: Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated low-density lipoprotein cholesterol (LDL-C) levels, which increases the risk of premature coronary artery disease. Early detection and treatment are vital, especially in children. To improve FH diagnosis in children, the Japan Atherosclerosis Society (JAS) released new guidelines in July 2022. This study assessed and compared the sensitivity and specificity of the clinical diagnostic criteria from the JAS pediatric FH guidelines of 2017 and 2022.

Methods: From September 2020 to March 2023, 69 children with elevated plasma LDL-C levels (≥ 140 mg/dL) were included in a pediatric FH screening project in Kagawa. The children were evaluated using genetic testing alongside the clinical diagnostic criteria from the JAS pediatric FH guidelines of 2017 and 2022.

Results: Using the JAS pediatric FH 2017 criteria, eight children were diagnosed as FH-positive and 61 children as FH-negative. The JAS pediatric FH 2022 criteria identified 15 children with definite FH, 31 with probable FH, and 23 with possible FH. Genetic testing detected FH pathogenic variants in 24 children. The sensitivity and specificity for the JAS pediatric FH 2017 criteria were 0.292 and 0.978, respectively. For the JAS pediatric FH 2022 criteria, the sensitivity was 0.542 for definite FH with a specificity of 0.956, and 0.917 for probable FH with a specificity of 0.467.

Conclusion: The clinical diagnostic criteria of the JAS pediatric FH 2022 guidelines demonstrated improved diagnostic efficiency compared with those of 2017, as evidenced by the increased sensitivity while preserving specificity.

Aim: Clinical risk scores for coronary artery disease (CAD) are used in clinical practice to select patients for diagnostic testing and therapy. Several studies have proposed that polygenic risk scores (PRSs) can improve the prediction of CAD, but the scores need to be validated in clinical populations with accurately characterized phenotypes. We assessed the predictive power of the three most promising PRSs for the prediction of coronary atherosclerosis and obstructive CAD.

Methods: This study was conducted on 943 symptomatic patients with suspected CAD for whom the phenotype was accurately characterized using anatomic and functional imaging. Previously published genome-wide polygenic scores were generated to compare a genetic model based on PRSs with a model based on clinical data. The test and PRS cohorts were predominantly Caucasian of northern European ancestry.

Results: All three PRSs predicted coronary atherosclerosis and obstructive CAD statistically significantly. The predictive accuracy of the models combining clinical data and different PRSs varied between 0.778 and 0.805 in terms of the area under the receiver operating characteristic (AUROC), being close to the model including only clinical variables (AUROC 0.769). The difference between the clinical model and combined clinical + PRS model was not significant for PRS1 (p=0.627) and PRS3 (p=0.061). Only PRS2 slightly improved the predictive power of the model (p=0.04). The likelihood ratios showed the very weak diagnostic power of all PRSs.

Conclusion: The addition of PRSs to conventional risk factors did not clinically significantly improve the predictive accuracy for either coronary atherosclerosis or obstructive CAD, showing that current PRSs are not justified for routine clinical use in CAD.

Aims: Weight changes from a young age are known to be associated with poor life outcomes in the general population. However, little is known about the association between weight change from a young age and life expectancy in patients with chronic kidney disease (CKD).

Methods: Data of 2,806 nondialysis CKD patients who participated in the Fukuoka Kidney Disease Registry (FKR) Study, a multicenter observational study, were analyzed. The primary outcome was all-cause death, whereas the secondary outcome was cardiovascular mortality. The covariate of interest was weight change, defined as the difference between body weight at study enrollment and at 20 years old. Cox proportional-hazards models were used to estimate the risks of mortality for participants with weight changes of ≥ 5 or ＜5 kg compared with those with stable weights.

Results: During the 5-year observation period, 243 participants died from all causes and 62 from cardiovascular disease. The risk of all-cause mortality in the weight-loss group was significantly higher than that in the stable-weight group (multivariable-adjusted hazard ratio, 2.11; 95% confidence interval [CI], 1.52–2.93). Conversely, the risk of cardiovascular mortality in the weight-loss group was significantly higher than that in the stable-weight group (multivariable-adjusted hazard ratio, 2.48; 95% CI, 1.32–4.64). However, no significant association was observed between weight gain and the risks of all-cause and cardiovascular mortalities.

Conclusion: Weight loss from 20 years of age was found to be associated with higher risks of all-cause and cardiovascular mortalities in patients with CKD.

Aims: Identifying patients with vulnerable plaque who have poor prognosis among those with coronary artery disease (CAD) is crucial to deciding future therapeutic interventions. We previously reported that male CAD patients with low anti-apolipoprotein B-100 autoantibody (anti-apoB-100 Ab) levels were at an increased risk of developing unstable plaque lesions. This study focused on the autoantibodies against lipoprotein lipase (LPL), a key enzyme in triglyceride metabolism, which is another risk factor for atherosclerosis, and investigated their association with plaque characteristics.

Methods: We measured serum anti-LPL Ab levels using a homemade enzyme-linked immunosorbent assay in 80 male CAD patients. Coronary plaque properties were evaluated using iMAP^®-intravascular ultrasound.

Results: Serum anti-LPL Ab levels were not correlated with plaque burden but were significantly negatively and positively correlated with fibrotic and necrotic plaques, respectively. High-risk patients with low anti-apoB-100 Ab levels were divided into groups according to their anti-LPL Ab levels. The group with high anti-LPL Ab levels exhibited more necrotic plaques and fewer fibrotic plaques as well as higher remnant-like lipoprotein particle levels than the group with low anti-LPL Ab levels.

Conclusions: Serum anti-LPL Ab levels can serve as a marker of plaque instability in CAD patients and can help identify higher-risk cases when combined with anti-apoB-100 Ab levels.

Aim: Less is known about the impact of supper time on cardiovascular disease (CVD) risk among hypertensives and nonhypertensives. We aimed to explore this issue in a cohort study.

Methods: We analyzed the data of 72,658 participants (15,386 hypertensives and 57,272 nonhypertensives) aged 40–79 years without a history of CVD at baseline (1988–1990) under the Japan Collaborative Cohort study. Supper time was assessed based on self-reported questionnaires categorized as before 17:00, between 17:00 and 20:00, after 20:00, irregular supper time, and reference supper time (17:00–20:00). Hazard ratios (HRs) and 95% confidence intervals (95% CI) of CVD mortality were calculated according to supper time after adjustment for potential confounders, stratified by hypertensive status and age group (＜65 and ≥ 65 years).

Results: During a median of 19.4 years of follow-up, 4,850 CVD deaths were recorded. Compared with the reference time, the risk of CVD mortality was higher for irregular supper time for the total population, either hypertensives or nonhypertensives, more specifically hypertensives aged ≥ 65 years; the multivariable HR (95% CI) of CVD mortality in the total population was 1.28 (1.11–1.50, P＜0.01). The supper time of ＞20:00 tended to be associated with the higher risk only for hypertensives; the multivariable HR was 1.39 (0.98–1.96, P=0.06).

Conclusion: Irregular supper time was associated with an increased risk of CVD mortality. Supper timing could be a surrogate marker for CVD risk.

Familial chylomicronemia syndrome (FCS) and multifactorial chylomicronemia (MCM), characterized by highly variable triglyceride levels with acute episodes of severe hypertriglyceridemia (HTG), are caused by rare variants in genes associated with the catabolism of circulating lipoprotein triglycerides, mainly including LPL, APOC2, APOA5, GPIHBP1, and LMF1. Among them, the LMF1 gene only accounts for 1%. This study described a Chinese patient with severe HTG carrying compound heterozygous variants of a rare nonsense variant p.W168X in exon 3 and a missense variant p.R416Q in exon 9 in the LMF1 gene. These heterozygous variants account for his family’s decreased lipase activity and mass, which caused the FCS phenotype.