Place of pitavastatin in the statin armamentarium: promising evidence for a role in diabetes mellitus

Long-term outcomes of statin dose, class, and use intensity on primary prevention of cardiovascular mortality: a national T2DM cohort study

PURPOSE

To investigate how statins reduce cardiovascular mortality in patients with type 2 diabetes (T2DM) in a dose-, class-, and use intensity-dependent manner.

METHODS

We used an inverse probability of treatment-weighted Cox hazards model, with statin use status as a time-dependent variable, to estimate the effects of statin use on cardiovascular mortality.

RESULTS

Adjusted hazard ratio [aHR; 95% confidence interval (CI)] for cardiovascular mortality was 0.41 (0.39-0.42). Compared with nonusers, pitavastatin, pravastatin, simvastatin, rosuvastatin, atorvastatin, fluvastatin, and lovastatin users demonstrated significant reductions in cardiovascular mortality [aHRs (95% CIs) = 0.11 (0.06, 0.22), 0.35 (0.32, 0.39), 0.36 (0.34, 0.38), 0.39 (0.36, 0.41), 0.42 (0.40, 0.44), 0.46 (0.43, 0.49), and 0.52 (0.48, 0.56), respectively]. In Q1, Q2, Q3, and Q4 of cDDD-year, our multivariate analysis demonstrated significant reductions in cardiovascular mortality [aHRs (95% CIs) = 0.63 (0.6, 0.65), 0.44 (0.42, 0.46), 0.33 (0.31, 0.35), and 0.17 (0.16, 0.19), respectively; P for trend < 0.0001]. The optimal statin dose daily was 0.86 DDD, with the lowest aHR for cardiovascular mortality of 0.43.

CONCLUSIONS

Persistent statin use can reduce cardiovascular mortality in patients with T2DM; in particular, the higher is the cDDD-year of statin, the lower is the cardiovascular mortality. The optimal statin dose daily was 0.86 DDD. The priority of protective effects on mortality are pitavastatin, rosuvastatin, pravastatin, simvastatin, atorvastatin, fluvastatin, and lovastatin for the statin users compared with non-statin users.

Different effects of statins on induction of diabetes mellitus: an experimental study

Background

To determine the effect of different statins on the induction of diabetes mellitus.

Materials and methods

Four statins (atorvastatin, pravastatin, rosuvastatin, and pitavastatin) were used. Cytotoxicity, insulin secretion, glucose-stimulated insulin secretion, and G₀/G₁ phase cell cycle arrest were investigated in human pancreas islet β cells, and glucose uptake and signaling were studied in human skeletal muscle cells (HSkMCs).

Results

Human pancreas islet β cells treated with 100 nM atorvastatin, pravastatin, rosuvastatin, and pitavastatin had reduced cell viability (32.12%, 41.09%, 33.96%, and 29.19%, respectively) compared to controls. Such cytotoxic effect was significantly attenuated by decreasing the dose to 10 and 1 nM, ranged from 1.46% to 17.28%. Cells treated with 100 nM atorvastatin, pravastatin, rosuvastatin, and pitavastatin had a reduction in the rate of insulin secretion rate by 34.07%, 30.06%, 26.78%, and 19.22%, respectively. The inhibitory effect was slightly attenuated by decreasing the dose to 10 and 1 nM, ranging from 10.84% to 29.60%. Insulin secretion stimulated by a high concentration of glucose (28 mmol/L) was significantly higher than a physiologic concentration of glucose (5.6 mmol/L) in all treatment groups. The glucose uptake rates at a concentration of 100 nM were as follows: atorvastatin (58.76%) < pravastatin (60.21%) < rosuvastatin (72.54%) < pitavastatin (89.96%). We also found that atorvastatin and pravastatin decreased glucose transporter (GLUT)-2 expression and induced p-p38 MAPK levels in human pancreas islet β cells. Atorvastatin, pravastatin, and rosuvastatin inhibited GLUT-4, p-AKT, p-GSK-3β, and p-p38 MAPK levels in HSkMCs.

Conclusion

Statins similar but different degree of effects on pancreas islet β cells damage and induce insulin resistance in HSkMC.

Pathogenesis and management of the diabetogenic effect of statins: a role for adiponectin and coenzyme Q10?

There is growing evidence to suggest that statin therapy is associated with an increased risk of incident diabetes. The risk for statin-related diabetes depends upon many factors including age, pre-existing diabetic risk, type and potency of statin. Several mechanisms have been suggested for the diabetogenic effects of statins involving processes that alter islet ß-cell function, resulting in impaired glucose metabolism. Recent evidence suggests that the association of statin therapy with the development of diabetes may be partly mediated by a statin-induced decrease in circulating adiponectin and coenzyme Q10. The available evidence suggests the benefit of statins in reducing cardiovascular events outweigh the risk of developing diabetes. Moreover, statin therapy does not impair glycemic control in diabetic patients. Expert recommendations for the use of statins in people at risk of developing diabetes have recently been published. However, further research is required to elucidate both the association between statin use and incident diabetes as well as underlying mechanisms.

Statin use and risk of diabetes mellitus

The 3-hydroxy-methylglutaryl coenzyme A reductase inhibitors, statins, are widely used in the primary and secondary prevention of cardiovascular diseases to lower serum cholesterol levels. As type 2 diabetes mellitus is accompanied by dyslipidemia, statins have a major role in preventing the long term complications in diabetes and are recommended for diabetics with normal low density lipoprotein levels as well. In 2012, United States Food and Drug Administration released changes to statin safety label to include that statins have been found to increase glycosylated haemoglobin and fasting serum glucose levels. Many studies done on patients with cardiovascular risk factors have shown that statins have diabetogenic potential and the effect varies as per the dosage and type used. The various mechanisms for this effect have been proposed and one of them is downregulation of glucose transporters by the statins. The recommendations by the investigators are that though statins can have diabetogenic risk, they have more long term benefits which can outweigh the risk. In elderly patients and those with metabolic syndrome, as the risk of diabetes increase, the statins should be used cautiously. Other than a subset of population with risk for diabetes; statins still have long term survival benefits in most of the patients.

Effect of pitavastatin on vascular reactivity in hypercholesterolemic rabbits

Background

Pitavastatin is the newest statin available in Brazil and likely the one with fewer side effects. Thus, pitavastatin was evaluated in hypercholesterolemic rabbits in relation to its action on vascular reactivity.

Objective

To assess the lowest dose of pitavastatin necessary to reduce plasma lipids, cholesterol and tissue lipid peroxidation, as well as endothelial function in hypercholesterolemic rabbits.

Methods

Thirty rabbits divided into six groups (n = 5): G1 - standard chow diet; G2 - hypercholesterolemic diet for 30 days; G3 - hypercholesterolemic diet and after the 16^th day, diet supplemented with pitavastatin (0.1 mg); G4 - hypercholesterolemic diet supplemented with pitavastatin (0.25 mg); G5 - hypercholesterolemic diet supplemented with pitavastatin (0.5 mg); G6 - hypercholesterolemic diet supplemented with pitavastatin (1.0 mg). After 30 days, total cholesterol, HDL, triglycerides, glucose, creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT) were measured and LDL was calculated. In-depth anesthesia was performed with sodium thiopental and aortic segments were removed to study endothelial function, cholesterol and tissue lipid peroxidation. The significance level for statistical tests was 5%.

Results

Total cholesterol and LDL were significantly elevated in relation to G1. HDL was significantly reduced in G4, G5 and G6 when compared to G2. Triglycerides, CK, AST, ALT, cholesterol and tissue lipid peroxidation showed no statistical difference between G2 and G3-G6. Significantly endothelial dysfunction reversion was observed in G5 and G6 when compared to G2.

Conclusion

Pitavastatin starting at a 0.5 mg dose was effective in reverting endothelial dysfunction in hypercholesterolemic rabbits.