Background: Cardiovascular complications (CVD) represent one of the leading causes of morbidity and mortality in patients with type 2 diabetes. Pharmacogenetics is emerging as a potential strategy to optimize cardiovascular prevention in this population. A common variant in the PPARA gene (rs6008845), associated with increased expression of the fenofibrate target gene (PPAR-α) in certain tissues (e.g. retina and whole blood), has recently been linked to an improved response to fenofibrate in terms of major cardiovascular events. However, the mechanisms underlying this genetic modulation remain poorly understood. Objectives: The aim of this study was to identify the pathophysiological mechanisms underlying this genetic modulation of fenofibrate cardiovascular effectiveness. Methods: Between May 2022 and August 2024, patients with type 2 diabetes were recruited at the Padua University Hospital. Inclusion criteria were treatment with statins, LDL-c levels < 100 mg/dL, triglyceride levels < 200 mg/dL, stable antidiabetic treatment with HbA1c < 8% and preserved renal function (glomerular filtration rate > 60 ml/min/1,7m2). Patients were randomized to receive either fenofibrate or placebo for a period of 12 weeks. The rs6008845 genetic variant was analysed, along with a genetic score (eQtGs) consisting of 4 polymorphisms associated with increased PPARA expression in the retina. The genetic effect on the fenofibrate response (gene x fenofibrate interaction) was assessed in relation to endothelial function (reactive hyperemia index, RHI), arterial stiffness (carotid-femoral pulse-wave-velocity, PWV-cf), lipid, inflammatory, hepatic and renal profiles. Results: A total of 180 patients (92 randomized to placebo and 88 to fenofibrate) completed the study. The mean age was 66 years, with 23% of patients being female, 26% with a history of cardiovascular events and excellent control of cardiovascular risk factors (mean values: HbA1c 6,6% (SD ± 0,6), LDL-c 62 (SD ± 19) mg/dL, triglycerides 102 (SD ± 44) mg/dL and systolic/diastolic blood pressure 135/77 mmHg). In addition, 55% were treated with GLP1-RA and 28% with SGLT2 inhibitors. Fenofibrate did not significantly modify RHI or PWV-cf, nor was any genetic modulation observed of these parameters. However, fenofibrate significantly reduced triglyceride levels (-21 mg/dL) and ApoCIII (-2 mg/dL), and increased ApoAII (+9 mg/dL), LDL cholesterol (+5 mg/dL) and the LDL/ApoB ratio (+0,08). The eQtGs genetic score significantly modulated the LDL cholesterol and ApoB response (interaction p < 0,05). This modulation was in the expected direction and consistent with the anticipated cardiovascular benefits. A higher eQtGs score was associated with a reduction in ApoB and LDL cholesterol levels, which was not observed in subjects with a lower score. Similar trends were observed for rs6008845. A significant and positive interaction was also observed with the increase in liver transaminases. Conclusions: The study confirms the role of PPARA genetic regulation in the individual response to fenofibrate, supporting a precision medicine approach. However, these effects do not appear sufficient to fully explain the cardiovascular benefits observed in previous trials, suggesting the involvement of additional mechanisms that need to be explored.
Presupposti dello studio: Le complicanze cardiovascolari (CVD) rappresentano una delle principali cause di morbilità e mortalità nei pazienti con diabete tipo 2. La farmacogenetica sta emergendo come possibile strategia per ottimizzare la prevenzione cardiovascolare in questa popolazione. Una variante comune nel gene PPARA (rs6008845), associata a maggiore espressione del gene target del fenofibrato (PPAR-α) in alcuni tessuti (es. retina e sangue intero), è stata recentemente collegata a una miglior risposta del fenofibrato sugli eventi cardiovascolari maggiori. Tuttavia, i meccanismi alla base di questa modulazione genetica restano poco noti. Scopo dello studio: Lo scopo di questo studio è stato quello di identificare i meccanismi fisiopatologici alla base di tale modulazione genetica. Materiale e metodi: Presso l’Azienda Ospedaliera di Padova tra maggio 2022 e agosto 2024, sono stati reclutati pazienti con diabete tipo 2 in terapia con statina e livelli di LDL-c < 100 mg/dL, livelli di trigliceridi < 200 mg/dL, stabile terapia antidiabetica con HbA1c < 8% e filtrato renale conservato (filtrato glomerulare > 60 ml/min/1.7m2). I pazienti sono stati randomizzati a fenofibrato o placebo per un periodo di 12 settimane. Si è analizzata la variante genetica rs6008845, e si è valutato uno score genetico (eQtGs) formato da 4 polimorfismi associati a maggiore espressione di PPARA nella retina. Si è valutato l’effetto genetico nella risposta al fenofibrato (interazione gene x fenofibrato) su: funzionalità endoteliale (reactive-hyperemia index, RHI), rigidità arteriosa (pulse-wave-velocity carotido-femorale, PWV-cf), profilo lipidico, infiammatorio, epatico e renale. Risultati: In totale 180 pazienti (92 randomizzati a placebo e 88 a fenofibrato) hanno completato lo studio. L’età media era di 66 anni, con il 23% dei pazienti di sesso femminile, il 26% con pregresso evento cardiovascolare e con ottimo controllo dei fattori di rischio cardiovascolari (valori medi di: HbA1c 6,6% (DS ± 0,6), LDL-c 62 (DS ± 19) mg/dL, trigliceridi 102 (DS ± 44) mg/dL, PAS/PAD 135/77 mmHg) e trattati con GLP1-RA (55%) e/o SGLT2i (28%). Il fenofibrato non ha modificato significativamente RHI o PWV-cf, né si è osservata una modulazione genetica su tali parametri. Ha invece ridotto significativamente i valori dei trigliceridi (-21 mg/dL) e ApoCIII (-2 mg/dL) e aumentato i valori di ApoAII (+9 mg/dL), colesterolo LDL (+5 mg/dL) e del rapporto LDL/ApoB (+0,08). Il genetic score eQtGs ha modulato in modo significativo la risposta del colesterolo LDL e ApoB (p di interazione < 0.05). Tale modulazione andava nella direzione attesa e coerente con i benefici cardiovascolari attesi. Uno score più elevato di eQtGs si associava a riduzione di ApoB e di colesterolo LDL che non si osservava nei soggetti con score più basso. Trend simili si osservavano per rs6008845. Un’interazione significativa e positiva è stata osservata anche con l’incremento delle transaminasi (AST e ALT). Conclusioni: Lo studio ha confermato il ruolo della regolazione genetica di PPARA nella risposta individuale al fenofibrato, supportando un approccio di medicina di precisione. Tuttavia, tali effetti non appaiono sufficienti a spiegare i benefici cardiovascolari osservati in precedenti trial, suggerendo il coinvolgimento di meccanismi aggiuntivi da esplorare.
Medicina di precisione nel diabete di tipo 2: studio farmacogenetico randomizzato controllato sugli effetti del fenofibrato
COSMA, RICCARDO
2024/2025
Abstract
Background: Cardiovascular complications (CVD) represent one of the leading causes of morbidity and mortality in patients with type 2 diabetes. Pharmacogenetics is emerging as a potential strategy to optimize cardiovascular prevention in this population. A common variant in the PPARA gene (rs6008845), associated with increased expression of the fenofibrate target gene (PPAR-α) in certain tissues (e.g. retina and whole blood), has recently been linked to an improved response to fenofibrate in terms of major cardiovascular events. However, the mechanisms underlying this genetic modulation remain poorly understood. Objectives: The aim of this study was to identify the pathophysiological mechanisms underlying this genetic modulation of fenofibrate cardiovascular effectiveness. Methods: Between May 2022 and August 2024, patients with type 2 diabetes were recruited at the Padua University Hospital. Inclusion criteria were treatment with statins, LDL-c levels < 100 mg/dL, triglyceride levels < 200 mg/dL, stable antidiabetic treatment with HbA1c < 8% and preserved renal function (glomerular filtration rate > 60 ml/min/1,7m2). Patients were randomized to receive either fenofibrate or placebo for a period of 12 weeks. The rs6008845 genetic variant was analysed, along with a genetic score (eQtGs) consisting of 4 polymorphisms associated with increased PPARA expression in the retina. The genetic effect on the fenofibrate response (gene x fenofibrate interaction) was assessed in relation to endothelial function (reactive hyperemia index, RHI), arterial stiffness (carotid-femoral pulse-wave-velocity, PWV-cf), lipid, inflammatory, hepatic and renal profiles. Results: A total of 180 patients (92 randomized to placebo and 88 to fenofibrate) completed the study. The mean age was 66 years, with 23% of patients being female, 26% with a history of cardiovascular events and excellent control of cardiovascular risk factors (mean values: HbA1c 6,6% (SD ± 0,6), LDL-c 62 (SD ± 19) mg/dL, triglycerides 102 (SD ± 44) mg/dL and systolic/diastolic blood pressure 135/77 mmHg). In addition, 55% were treated with GLP1-RA and 28% with SGLT2 inhibitors. Fenofibrate did not significantly modify RHI or PWV-cf, nor was any genetic modulation observed of these parameters. However, fenofibrate significantly reduced triglyceride levels (-21 mg/dL) and ApoCIII (-2 mg/dL), and increased ApoAII (+9 mg/dL), LDL cholesterol (+5 mg/dL) and the LDL/ApoB ratio (+0,08). The eQtGs genetic score significantly modulated the LDL cholesterol and ApoB response (interaction p < 0,05). This modulation was in the expected direction and consistent with the anticipated cardiovascular benefits. A higher eQtGs score was associated with a reduction in ApoB and LDL cholesterol levels, which was not observed in subjects with a lower score. Similar trends were observed for rs6008845. A significant and positive interaction was also observed with the increase in liver transaminases. Conclusions: The study confirms the role of PPARA genetic regulation in the individual response to fenofibrate, supporting a precision medicine approach. However, these effects do not appear sufficient to fully explain the cardiovascular benefits observed in previous trials, suggesting the involvement of additional mechanisms that need to be explored.| File | Dimensione | Formato | |
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Tesi di Laurea Cosma Riccardo.pdf
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https://hdl.handle.net/20.500.12608/86456