History of bariatric surgery and COVID-19 outcomes in patients with type 2 diabetes: Results from the CORONADO study.

OBJECTIVE: This study assessed the impact of a history of metabolic and bariatric surgery (MBS) on the clinical outcomes in patients with type 2 diabetes (T2D) and severe obesity hospitalized for COVID-19. METHODS: In this post hoc analysis from the nationwide observational CORONADO (Coronavirus SARS-CoV2 and Diabetes Outcomes) study, patients with T2D and a history of MBS were matched with patients without MBS for age, sex, and BMI either at the time of MBS or on admission for COVID-19. The composite primary outcome (CPO) combined invasive mechanical ventilation and/or death within 7 and 28 days following admission. RESULTS: Out of 2,398 CORONADO participants, 20 had a history of MBS. When matching for BMI at the time of MBS and after adjustment for diabetes duration, the CPO occurred less frequently within 7 days (3 vs. 17 events, OR: 0.15 [0.01 to 0.94], p = 0.03) and 28 days (3 vs. 19 events, OR: 0.11 [0.01 to 0.71], p = 0.02) in patients with MBS (n = 16) vs. controls (n = 44). There was no difference in CPO rate between patients with MBS and controls when matching for BMI on admission. CONCLUSIONS: These data are reassuring regarding COVID-19 prognosis in patients with diabetes and a history of MBS compared with those without MBS.

Improvement in arterial stiffness (pOpmètre®) after bariatric surgery. Results from a prospective study.

BACKGROUND: Arterial stiffness (AS) is an independent predictor of cardiovascular risk, and could be used as a surrogate marker of improvement in cardiovascular risk following bariatric surgery. The aim of this study was to compare AS before and after surgery. METHODS: One hundred and thirty-four patients undergoing bariatric surgery between May 2016 and January 2019 were prospectively included. AS was measured on pulse wave velocity (PWV) with the pOpmètre® device pre- and postoperatively. The main endpoint was change in PWV between baseline and 3 months post-surgery. RESULTS: Overall, mean PWV was 6.87m/s preoperatively and 6.71m/s at 3 months (P=0.7148). Patients with pathologic PWV (>2 standard deviations from expected value for age) showed significant improvement at 3 months (31 patients; 10.1m/s preoperatively vs 7.5m/s at 3 months; P=0.007). These results did not correlate with improvement in other clinical or biological parameters following surgery (excess weight loss, mean blood pressure, fasting blood glucose, waist circumference, body composition). CONCLUSION: These results suggest that pathological arterial stiffness may resolve following bariatric surgery independently of the other factors influencing cardiovascular risk in obesity.

In vivo evidence for transintestinal cholesterol efflux in patients with complete common bile duct obstruction.

BACKGROUND: Beyond the hepatobiliary pathway, studies have demonstrated that direct transintestinal cholesterol efflux (TICE) of plasma-derived cholesterol may contribute to reverse cholesterol transport. The clinical evidence of TICE in human remains challenged because of the difficulty to discriminate the hepatobiliary and transintestinal routes in vivo. OBJECTIVE: To provide the first proof of concept that TICE exists in vivo in humans by demonstrating that plasma labeled cholesterol can be excreted in the feces of patients with complete bile duct obstruction. METHODS: Plasma, bile, and fecal cholesterol excretion was measured by mass spectrometry 24, 48, and 72 hours after intravenous injection of D7-cholesterol in two patients presenting cholangiocarcinomas with a total obstruction of their primary bile duct. RESULTS: No trace of bile acids was detected in the feces of the two patients. Despite this, a significant amount of plasma D7-cholesterol was quantified in the feces of the two patients 48 hours and 72 hours after the intravenous injection. CONCLUSION: Our data bring a direct proof that TICE is an active pathway in humans.

Circulating PCSK9 levels are not associated with the severity of hepatic steatosis and NASH in a high-risk population.

BACKGROUND AND AIMS: Some studies suggested that proprotein convertase subtilisin kexin type 9 (PCSK9) is linked to liver steatosis severity and non-alcoholic steatohepatitis (NASH). We aimed to assess whether circulating PCSK9 levels are associated with either liver fat content (LFC) or histological markers of NASH in high-risk patients. METHODS: We present results from three cross-sectional studies from two French Hospitals: Dijon and Numevox (departments of Endocrinology) and Angers (department of Hepatology). Only patients without lipid-lowering therapy were included. All 132 patients had type 2 diabetes in Dijon, compared to 55/224 in Numevox (25%) and 39/122 in Angers (32%). LFC was assessed on MRI (Dijon and Numevox), and NASH lesion on liver biopsy (Angers). Additionally, we included mRNA results from 138 overweight patients of a Belgian Hospital (Antwerp). RESULTS: While circulating levels of PCSK9 were positively correlated with total cholesterol, LDL-C, triglycerides and non-HDL-C in all 3 cohorts, no significant association was found between PCSK9 and transaminases. Furthermore, no association was found between plasma PCSK9 levels and LFC in both Numevox (ßadjusted = 0.71 ±â€¯1.33, p = 0.60) and Dijon (ßadjusted = -1.03 ±â€¯0.90, p = 0.25). There was no correlation between circulating PCSK9 and histological liver lesions: steatosis severity (ßadjusted = -3.95 ±â€¯2.75, p = 0.15), NASH activity score (ßadjusted = -0.31 ±â€¯0.17, p = 0.082), lobular (ß = -0.067 ±â€¯0.055, p = 0.22) or portal inflammation (ß = -0.088 ±â€¯0.079, p = 0.27), ballooning (ß = -0.025 ±â€¯0.065, p = 0.70) and fibrosis (ß = -0.17 ±â€¯0.11, p = 0.12). Finally, hepatic PCSK9 mRNA levels were not correlated with NASH histological severity. CONCLUSIONS: Circulating PCSK9 concentrations are not associated with the severity of liver steatosis or histological markers of NASH. These data are reassuring regarding the clinical use of PCSK9 inhibitors in cardiovascular diseases.

Homozygous Familial Hypercholesterolemia Patients With Identical Mutations Variably Express the LDLR (Low-Density Lipoprotein Receptor): Implications for the Efficacy of Evolocumab.

OBJECTIVE: Evolocumab, a PCSK9 (proprotein convertase subtilisin kexin type 9)-neutralizing antibody, lowers low-density lipoprotein cholesterol (LDL-C) in homozygous familial hypercholesterolemic (HoFH) patients with reduced LDLR (low-density lipoprotein receptor) function. However, their individual responses are highly variable, even among carriers of identical LDLR genetic defects. We aimed to elucidate why HoFH patients variably respond to PCSK9 inhibition. APPROACH AND RESULTS: Lymphocytes were isolated from 22 HoFH patients enrolled in the TAUSSIG trial (Trial Assessing Long Term Use of PCSK9 Inhibition in Subjects With Genetic LDL Disorders). Ten patients were true homozygotes (FH1/FH1) and 5 identical compound heterozygotes (FH1/FH2). Lymphocytes were plated with or without mevastatin, recombinant PCSK9 (rPCSK9), or a PCSK9-neutralizing antibody. Cell surface LDLR expression was analyzed by flow cytometry. All HoFH lymphocytes had reduced cell surface LDLR expression compared with non-FH lymphocytes, for each treatment modality. Lymphocytes from FH1/FH2 patients (LDLR defective/negative) displayed the lowest LDLR expression levels followed by lymphocytes from FH1/FH1 patients (defective/defective). Mevastatin increased, whereas rPCSK9 reduced LDLR expression. The PCSK9-neutralizing antibody restored LDLR expression. Lymphocytes displaying higher LDLR expression levels were those isolated from patients presenting with lowest levels of LDL-C and apolipoprotein B, before and after 24 weeks of evolocumab treatment. These negative correlations remained significant in FH1/FH1 patients and appeared more pronounced when patients with apolipoprotein E3/E3 genotypes were analyzed separately. Significant positive correlations were found between the levels of LDLR expression and the percentage reduction in LDL-C on evolocumab treatment. CONCLUSIONS: Residual LDLR expression in HoFH is a major determinant of LDL-C levels and seems to drive their individual response to evolocumab.

Urine-sample-derived human induced pluripotent stem cells as a model to study PCSK9-mediated autosomal dominant hypercholesterolemia.

Proprotein convertase subtilisin kexin type 9 (PCSK9) is a critical modulator of cholesterol homeostasis. Whereas PCSK9 gain-of-function (GOF) mutations are associated with autosomal dominant hypercholesterolemia (ADH) and premature atherosclerosis, PCSK9 loss-of-function (LOF) mutations have a cardio-protective effect and in some cases can lead to familial hypobetalipoproteinemia (FHBL). However, limitations of the currently available cellular models preclude deciphering the consequences of PCSK9 mutation further. We aimed to validate urine-sample-derived human induced pluripotent stem cells (UhiPSCs) as an appropriate tool to model PCSK9-mediated ADH and FHBL. To achieve our goal, urine-sample-derived somatic cells were reprogrammed into hiPSCs by using episomal vectors. UhiPSC were efficiently differentiated into hepatocyte-like cells (HLCs). Compared to control cells, cells originally derived from an individual with ADH (HLC-S127R) secreted less PCSK9 in the media (-38.5%; P=0.038) and had a 71% decrease (P<0.001) of low-density lipoprotein (LDL) uptake, whereas cells originally derived from an individual with FHBL (HLC-R104C/V114A) displayed a strong decrease in PCSK9 secretion (-89.7%; P<0.001) and had a 106% increase (P=0.0104) of LDL uptake. Pravastatin treatment significantly enhanced LDL receptor (LDLR) and PCSK9 mRNA gene expression, as well as PCSK9 secretion and LDL uptake in both control and S127R HLCs. Pravastatin treatment of multiple clones led to an average increase of LDL uptake of 2.19 ± 0.77-fold in HLC-S127R compared to 1.38 ± 0.49 fold in control HLCs (P<0.01), in line with the good response to statin treatment of individuals carrying the S127R mutation (mean LDL cholesterol reduction=60.4%, n=5). In conclusion, urine samples provide an attractive and convenient source of somatic cells for reprogramming and hepatocyte differentiation, but also a powerful tool to further decipher PCSK9 mutations and function.

Characterization of Autosomal Dominant Hypercholesterolemia Caused by PCSK9 Gain of Function Mutations and Its Specific Treatment With Alirocumab, a PCSK9 Monoclonal Antibody.

BACKGROUND: Patients with PCSK9 gene gain of function (GOF) mutations have a rare form of autosomal dominant hypercholesterolemia. However, data examining their clinical characteristics and geographic distribution are lacking. Furthermore, no randomized treatment study in this population has been reported. METHODS AND RESULTS: We compiled clinical characteristics of PCSK9 GOF mutation carriers in a multinational retrospective, cross-sectional, observational study. We then performed a randomized placebo-phase, double-blind study of alirocumab 150 mg administered subcutaneously every 2 weeks to 13 patients representing 4 different PCSK9 GOF mutations with low-density lipoprotein cholesterol (LDL-C) ≥70 mg/dL on their current lipid-lowering therapies at baseline. Observational study: among 164 patients, 16 different PCSK9 GOF mutations distributed throughout the gene were associated with varying severity of untreated LDL-C levels. Coronary artery disease was common (33%; average age of onset, 49.4 years), and untreated LDL-C concentrations were higher compared with matched carriers of mutations in the LDLR (n=2126) or apolipoprotein B (n=470) genes. Intervention study: in PCSK9 GOF mutation patients randomly assigned to receive alirocumab, mean percent reduction in LDL-C at 2 weeks was 62.5% (P<0.0001) from baseline, 53.7% compared with placebo-treated PCSK9 GOF mutation patients (P=0.0009; primary end point). After all subjects received 8 weeks of alirocumab treatment, LDL-C was reduced by 73% from baseline (P<0.0001). CONCLUSIONS: PCSK9 GOF mutation carriers have elevated LDL-C levels and are at high risk of premature cardiovascular disease. Alirocumab, a PCSK9 antibody, markedly lowers LDL-C levels and seems to be well tolerated in these patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01604824.