Statin myopathy: over-rated and under-treated?

Association of metformin and statin uses with the prognosis of colon cancer: a meta-analysis

BACKGROUND

Metformin and statins are commonly used globally for the treatment of type 2 diabetes mellitus and dyslipidemia, respectively. Recently, multiple novel pathways have been discovered, which may contribute to the treatment of various types of cancer. Several meta-analysis studies have reported that the use of metformin or statins is associated with a lower risk of colon cancer compared to nonusers. In this study, our aim was to perform a meta-analysis and investigate the prognostic roles of these two medications in colon cancer.

METHODS

To identify relevant articles, literature searches were performed in the PubMed and Web of Science databases using a combination of keywords related to metformin, statins and colon cancer prognosis until August 2023. The study utilized STATA 12.0 software (Stata Corporation, College Station, Texas, USA) to compute all the hazard ratios (HRs) and 95% confidence intervals (CIs) regarding the association between metformin or statin uses and prognostic-related outcomes.

RESULTS

Our analysis revealed that the use of metformin was associated with a significantly lower overall mortality of colon cancer (HR = 0.63; 95% CI = 0.51-0.77; I2  = 94.9%; P  < 0.001), as well as lower cancer-specific mortality of colon cancer (HR = 0.68; 95% CI = 0.50-0.94; I2  = 91.9%; P  < 0.001). Similarly, the use of statins was also associated with a lower overall mortality of colon cancer (HR = 0.68; 95% CI = 0.60-0.78; I2  = 93.8%; P  < 0.001), as well as a lower cancer-specific mortality of colon cancer (HR = 0.74; 95% CI = 0.67-0.81; I2  = 82.2%; P  < 0.001).

CONCLUSION

Our meta-analysis study suggests that statins and metformin may have potential as adjuvant agents with significant benefits in the prognosis of colon cancer.

If something looks like an apple, is it necessarily an apple? - reflections on so-called "statin-induced polymyalgia rheumatica"

The existence of polymyalgia rheumatica (PMR) induced by statins has been hypothesised by some investigators. This review article highlights the fact that there is no evidence it is real. On the contrary, PMR and statin-associated muscle symptoms (SAMS) are two totally different conditions. Shoulder and hip ultrasound (US) examinations can make an important contribution in distinguishing a true case of PMR from a PMR-like illness induced by statins. The possibility that SAMS may worsen the clinical manifestations of a PMR patient should be taken into account in clinical practice, and drug discontinuation should be proposed when deterioration or relapse is not otherwise justifiable.

Mechanisms of statin-associated skeletal muscle-associated symptoms

Statins lower the serum low-density lipoprotein cholesterol and prevent cardiovascular events by inhibiting 3-hydroxy-3-methyl-glutaryl-CoA reductase. Although the safety of statins is documented, many patients ingesting statins may suffer from skeletal muscle-associated symptoms (SAMS). Importantly, SAMS are a common reason for stopping the treatment with statins. Statin-associated muscular symptoms include fatigue, weakness and pain, possibly accompanied by elevated serum creatine kinase activity. The most severe muscular adverse reaction is the potentially fatal rhabdomyolysis. The frequency of SAMS is variable but in up to 30% of the patients ingesting statins, depending on the population treated and the statin used. The mechanisms leading to SAMS are currently not completely clarified. Over the last 15 years, several research articles focused on statin-induced mitochondrial dysfunction as a reason for SAMS. Statins can impair the function of the mitochondrial respiratory chain, thereby reducing ATP and increasing ROS production. This can induce mitochondrial membrane permeability transition, release of cytochrome c into the cytosol and induce apoptosis. In parallel, statins inhibit activation of Akt, mainly due to reduced function of mTORC2, which may be related to mitochondrial dysfunction. Mitochondrial dysfunction by statins is also responsible for activation of AMPK, which is associated with impaired activation of mTORC1. Reduced activation of mTORC1 leads to increased skeletal muscle protein degradation, impaired protein synthesis and stimulation of apoptosis. In this paper, we discuss some of the different hypotheses how statins affect skeletal muscle in more detail, focusing particularly on those related to mitochondrial dysfunction and the impairment of the Akt/mTOR pathway.

Pro-protein subtilisin kexin-9 (PCSK9) inhibition in practice: lipid clinic experience in 2 contrasting UK centres

BACKGROUND

Prescribing criteria have been suggested for proprotein convertase subtilisin kexin-9 (PCSK-9) inhibitors but few studies exist of their real-world effectiveness.

METHODS

This study audited PCSK-9 inhibitor therapy in 105 consecutive patients from two hospital centres-a university hospital (UH; n = 70) and a district general hospital (DGH; n = 35). Baseline characteristics including cardiovascular disease risk factors, NICE qualification criteria, efficacy and side effects were assessed.

RESULTS

Baseline LDL-C levels were similar in both centres. NICE criteria were met for 2.05 items in the whole study (UH patients 1.7 and DGH patients 2.7). District general hospital patients were more likely to have familial hypercholesterolaemia (89 vs 69%; P = .02); intolerance to statins (94 vs 52%; P < .001) and polyvascular disease (42% vs 17%; P = .005). Prescriptions (evolocumab 73%; alirocumab 23%) were collected by 76% of patients (UH 64% vs DGH 100%). Therapy was discontinued by time of review in 15% of patients (UH 7% vs DGH 25%; P = .02). In adherent patients PCSK-9 inhibitor treatment reduced TC by 28% (2.24 ± 2.39 mmol/L; P < .001) and LDL-C by 49% (2.10 ± 1.33 mmol/L; P < .001). A LDL-C < 2.5 mmol/L was achieved in 30% of patients and <2.0 mmol/L in 20%. PCSK-9 therapy was effective and safe in patients with increased lipoprotein (a), diagnosed muscle diseases (including myopathies and muscular dystrophy) or poststatin rhabdomyolysis, nephrotic syndrome or HIV disease. Mixed results were obtained in patients with significant mixed hyperlipidaemia.

CONCLUSIONS

This study suggests that PCSK-9 inhibitors are effective but that prescriptions should not be changed to long-term delivery until patients have been reviewed and shown to be adherent.

Statins, Muscle Disease and Mitochondria

Cardiovascular disease (CVD) accounts for >17 million deaths globally every year, and this figure is predicted to rise to >23 million by 2030. Numerous studies have explored the relationship between cholesterol and CVD and there is now consensus that dyslipidaemia is a causal factor in the pathogenesis of atherosclerosis. Statins have become the cornerstone of the management of dyslipidaemia. Statins have proved to have a very good safety profile. The risk of adverse events is small compared to the benefits. Nevertheless, the potential risk of an adverse event occurring must be considered when prescribing and monitoring statin therapy to individual patients. Statin-associated muscle disease (SAMS) is by far the most studied and the most common reason for discontinuation of therapy. The reported incidence varies greatly, ranging between 5% and 29%. Milder disease is common and the more serious form, rhabdomyolysis is far rarer with an incidence of approximately 1 in 10,000. The pathophysiology of, and mechanisms leading to SAMS, are yet to be fully understood. Literature points towards statin-induced mitochondrial dysfunction as the most likely cause of SAMS. However, the exact processes leading to mitochondrial dysfunction are not yet fully understood. This paper details some of the different aetiological hypotheses put forward, focussing particularly on those related to mitochondrial dysfunction.