Effect of Physical Activity on Plasma PCSK9 in Subjects With High Risk for Type 2 Diabetes

The effect of resistance training on PCSK9 levels in patients undergoing cardiac rehabilitation after coronary artery bypass grafting: a randomized study

BACKGROUND

Resistance training is commonly recommended as part of secondary prevention for post-coronary artery bypass graft (CABG) patients in conjunction with aerobic exercise. Despite its potential benefits, there is currently a lack of studies investigating the impact of resistance training on proprotein convertase subtilisin kexin 9 (PCSK9).

AIM

To evaluate the effect of intensive resistance training on proprotein convertase subtilisin kexin 9 (PCSK9) levels among post-CABG patients undergoing cardiac rehabilitation (CR).

METHODS

In this prospective, open-label, randomized trial, 87 post-coronary artery bypass graft (CABG) patients were randomly assigned into two groups: moderate to high intensity resistance training and aerobic training (n = 44) or aerobic training alone (n = 43) for a total of 12 sessions. Changes in PCSK9 levels was determined as a primary endpoint, while secondary endpoints included changes in the six-minute walk test (6-MWT) results, aerobic capacity, WHO-5 well-being index, fasting blood glucose, and lipid profile. Both groups underwent intention-to-treat analysis.

RESULTS

Following completion of cardiac rehabilitation program, the intervention group demonstrated a significant decrease in mean PCSK9 levels when compared to the control group (β = -55 ng/ml, 95% CI -6.7 to -103.3, p = 0.026), as well as significant improvements in the 6-MWT result (β = 28.2 m, 95% CI 2.4-53.9, p = 0.033), aerobic capacity (β = 0.9 Mets, 95% CI 0.1-1.7, p = 0.021), and WHO-5 well-being index (β = 8.1, 95% CI 2.0-14.4, p = 0.011) in patients who received resistance and aerobic training. No statistically significant changes were observed in fasting blood glucose, cholesterol, LDL-C, HDL-C, and triglyceride levels.

CONCLUSION

Resistance training in CR significantly reduced PCSK-9 levels and increases patient's functional capacity and quality of life. (NCT02674659 04/02/2016).

CLINICAL, INSTRUMENTAL AND BIOCHEMICAL ASSOCIATIONS OF THE DEGREE OF PHYSICAL RECOVERY IN PATIENTS SUFFERED FROM ACUTE CORONARY SYNDROME AT THE COMPLETION OF IN-HOSPITAL REHABILITATION PERIOD

OBJECTIVE

The aim: To determine the clinical, instrumental and biochemical factors associated with the degree of physical recovery in patients suffered from acute coronary syndrome (ACS) at the completion of in-hospital rehabilitation period.

PATIENTS AND METHODS

Materials and methods: We enrolled 88 patients (all were males); 77 patients had ACS/STEMI and 11 with ACS/unstable angina. The mean age was (median, interquartile range) was 58 (49-64) years. We analyzed clinical, laboratory (including the circulating proprotein convertase subtilisin/kexin type 9 (PSK9) level in blood serum), transthoracic echocardiography and (urgent or delayed) coronary angiography data. Symptom-limited exercise tolerance (ET) test was performed predominantly at the second week of in-hospital stay. According to ET-test results, patients were subdivided into the groups with low (G1; 43 [48,9 %]) and high ET (G2; n=45 [51,1 %]).

RESULTS

Results: G1 (vs. G2) was characterized by older age, lower estimated glomerular filtration rate (eGFR) and higher left atrial (LA) dimension. The cases of any left anterior descending artery (LAD) lesion were more frequent in G1 (25 % vs. 2 % in G2, respectively; p=0,004). We revealed a decrease in PSK9 level after ET-test (pre-ET vs. post-ET: 824,0 (371,0-1073,0) vs. 676,0 (441,9-995,9) ng/ml, respectively; p=0,004 [N=35]).

CONCLUSION

Conclusions: At the completion of in-hospital rehabilitation period, the insufficient physical recovery in patients suffered from ACS associated with older age, lower eGFR, higher LA dimension, and more frequent any LDA lesion cases. Physical exercises favored the decrease in PCSK9 levels in blood serum.

Physical activity to reduce PCSK9 levels

The amount of physical activity (PA) people practice everyday has been reducing in the last decades. Sedentary subjects tend to have an impaired lipid plasma profile with a higher risk of atherosclerosis and related cardio- and cerebrovascular events. Regular PA helps in both primary and secondary cardiovascular prevention because of its beneficial effect on the whole metabolism. Several studies reported lower levels of plasma lipids in trained subjects, but the precise mechanisms by which PA modulates lipoproteins remain only partially described. Thereupon, proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serin protease whose main function is to reduce the amount of low-density lipoprotein cholesterol (LDL-C) receptors, with the direct consequence of reducing LDL-C uptake by the liver and increasing its circulating pool. Accordingly, recently developed PCSK9 inhibitors improved cardiovascular prevention and are increasingly used to reach LDL-C goals in patients at high CV risk. Whether PA can modulate the levels of PCSK9 remains partially explored. Recent studies suggest PA as a negative modulator of such a deleterious CV mediator. Yet the level of evidence is limited. The aim of this review is to summarize the recent reports concerning the regulatory role of PA on PCSK9 plasma levels, highlighting the beneficial role of regular exercise on the prevention of atherosclerosis and overall CV health.

Molecular and cellular biology of PCSK9: impact on glucose homeostasis

Proprotein convertase substilisin/kexin 9 (PCSK9) inhibitors (PCSK9i) revolutionised the lipid-lowering therapy. However, a risk of type 2 diabetes mellitus (T2DM) is evoked under PCSK9i therapy. In this review, we summarise the current knowledge on the link of PCSK9 with T2DM. A significant correlation was found between PCSK9 and insulin, homeostasis model assessment (HOMA) of insulin resistance and glycated haemoglobin. PCSK9 is also involved in inflammation. PCSK9 loss-of-function variants increased T2DM risk by altering insulin secretion. Local pancreatic low PCSK9 regulates β-cell LDLR expression which in turn promotes intracellular cholesterol accumulation and hampers insulin secretion. Nevertheless, the association of PCSK9 loss-of-function variants and T2DM is inconsistent. InsLeu and R46L polymorphisms were associated with T2DM, low HOMA for β-cell function and impaired fasting glucose, while the C679X polymorphism was associated with low fasting glucose in Black South African people. Hence, we assume that the impact of these variants on glucose homeostasis may vary depending on the genetic background of the studied populations and the type of effect caused by those genetic variants on the PCSK9 protein. Accordingly, these factors should be considered when choosing a genetic variant of PCSK9 to assess the impact of long-term use of PCSK9i on glucose homeostasis.

Ramadan Intermittent Fasting Is Associated with Changes in Circulating Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in Metabolically Healthy Obese Subjects

Background and Objectives: Dietary modification is the principal approach to the management of hyperlipidemia in adults. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of plasma cholesterol and a target for novel lipid-lowering pharmacotherapies. This study aimed to explore how circulating levels of PCSK9 changed during Ramadan intermittent fasting in metabolically healthy obese subjects. Materials and Methods: This cross-sectional study used convenience sampling to recruit 55 overweight and obese participants (22 females and 33 males) who observed Ramadan fasting. Body weight and composition, glucoregulatory factors, serum PCSK9 concentration, dietary intake, and physical activity were assessed 1 week before and at the end of Ramadan fasting. Results: The median (interquartile range) age was 35 (22) years, and body mass index was 30.2 (5.4). We found significant (p < 0.05) increases in serum levels of PCSK9, serum insulin, insulin resistance, and leptin at the end of Ramadan compared with pre-fasting levels. Significant (p < 0.05) reductions in body weight, waist circumference, systolic and diastolic blood pressure, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and adiponectin were also observed at the end of Ramadan. Conclusions: Observing Ramadan fasting was associated with increased PCSK9 levels in metabolically healthy obese subjects. The complex relationships between PCSK9 and insulin resistance and dysregulation of adipokine secretion in relation to dietary and lifestyle modifications during Ramadan warrant further research.

PCSK9 Levels and Metabolic Profiles in Elderly Subjects with Different Glucose Tolerance under Statin Therapy

Proprotein convertase subtilisin/kexin type 9 (PCSK9) degrades low-density lipoprotein cholesterol (LDL-C) receptors, and thus regulates the LDL-C levels in the circulation. Type 2 diabetics often have elevated LDL-C levels. However, the functions of PCSK9 in patients with alterations of glu-cose metabolism and statin therapy are still unclear. Method: we investigated a large cohort of 608 subjects, born in 1945 in Oulu, Finland (Oulu Cohort 1945). We studied the effects of PSCK9 lev-els with different glucose tolerances (normal glucose tolerance (NGT), prediabetes (PreDM) or type 2 diabetes (T2D)) with and without statin medication, and analyzed clinical data, NMR metabolomics and PCSK9 plasma levels. Results: PCSK9 plasma levels did not significantly differ between the three groups. Statin therapy significantly increased the PCSK9 levels in NGT, PreDM and T2D groups compared with subjects with no statins. In the NGT group, negative associations between PCSK9 and LDL-C, intermediate-density lipoprotein cholesterol (IDL-C), very low-density lipoprotein cholesterol (VLDL-C), total cholesterol and LDL and IDL triglycerides were observed under statin medication. In contrast, in the PreDM and T2D groups, these associa-tions were lost. Conclusions: our data suggest that in subjects with abnormal glucose metabolism and statin therapy, the significant PCSK9-mediated effects on the lipid metabolites are lost com-pared to NGT subjects, but statins reduced the LDL-C and VLDL-C levels.