Increased risk of diabetes with statin treatment is associated with impaired insulin sensitivity and insulin secretion: a 6 year follow-up study of the METSIM cohort. Diabetologia

Abstract Aims/hypothesis The aim of this work was to investigate the mechanisms underlying the risk of type 2 diabetes associated with statin treatment in the population-based Metabolic Syndrome in Men (METSIM) cohort. Methods A total of 8,749 non-diabetic participants, aged 45-73 years, were followed up for 5.9 years. New diabetes was diagnosed in 625 men by means of an OGTT, HbA 1c ≥6.5% (48 mmol/mol) or glucose-lowering medication started during the follow-up. Insulin sensitivity and secretion were evaluated with OGTT-derived indices. Results Participants on statin treatment (N=2,142) had a 46% increased risk of type 2 diabetes (adjusted HR 1.46 [95% CI 1.22, 1.74]). The risk was dose dependent for simvastatin and atorvastatin. Statin treatment significantly increased 2 h glucose (2hPG) and glucose AUC of an OGTT at follow-up, with a nominally significant increase in fasting plasma glucose (FPG). Insulin sensitivity was decreased by 24% and insulin secretion by 12% in individuals on statin treatment (at FPG and 2hPG <5.0 mmol/l) compared with individuals without statin treatment ( p<0.01). Decreases in insulin sensitivity and insulin secretion were dose dependent for simvastatin and atorvastatin. Conclusions/interpretation Statin treatment increased the risk of type 2 diabetes by 46%, attributable to decreases in insulin sensitivity and insulin secretion

SIRT1 mRNA Expression May Be Associated With Energy Expenditure and Insulin Sensitivity

Objective: Sirtuin 1 (SIRT1) is implicated in the regulation of mitochondrial function, energy metabolism, and insulin sensitivity in rodents. No studies are available in humans to demonstrate that SIRT1 expression in insulin-sensitive tissues is associated with energy expenditure and insulin sensitivity. Research Design and Methods: Energy expenditure (EE), insulin sensitivity, and SIRT1 mRNA adipose tissue expression (n = 81) were measured by indirect calorimetry, hyperinsulinemic-euglycemic clamp, and quantitative RT-PCR in 247 nondiabetic offspring of type 2 diabetic patients. Results: High EE during the clamp (r = 0.375, P = 2.8 × 10$^{−9}$) and high $\Delta$EE (EE during the clamp − EE in the fasting state) (r = 0.602, P = 2.5 × 10$^{−24}$) were associated with high insulin sensitivity. Adipose tissue SIRT1 mRNA expression was significantly associated with EE (r = 0.289, P = 0.010) and with insulin sensitivity (r = 0.334, P = 0.002) during hyperinsulinemic-euglycemic clamp. Furthermore, SIRT1 mRNA expression correlated significantly with the expression of several genes regulating mitochondrial function and energy metabolism (e.g., peroxisome proliferator–activated receptor $\gamma$ coactivator-1$\beta$, estrogen-related receptor $\alpha$, nuclear respiratory factor-1, and mitochondrial transcription factor A), and with several genes of the respiratory chain (e.g., including NADH dehydrogenase [ubiquinone] 1$\alpha$ subcomplex 2, cytochrome c, cytochrome c oxidase subunit IV, and ATP synthase). Conclusions: Impaired stimulation of EE by insulin and low SIRT1 expression in insulin-sensitive tissues is likely to reflect impaired regulation of mitochondrial function associated with insulin resistance in humans

Increased risk of diabetes with statin treatment is associated with impaired insulin sensitivity and insulin secretion: a 6 year follow-up study of the METSIM cohort. Diabetologia

Abstract Aims/hypothesis The aim of this work was to investigate the mechanisms underlying the risk of type 2 diabetes associated with statin treatment in the population-based Metabolic Syndrome in Men (METSIM) cohort. Methods A total of 8,749 non-diabetic participants, aged 45-73 years, were followed up for 5.9 years. New diabetes was diagnosed in 625 men by means of an OGTT, HbA 1c ≥6.5% (48 mmol/mol) or glucose-lowering medication started during the follow-up. Insulin sensitivity and secretion were evaluated with OGTT-derived indices. Results Participants on statin treatment (N=2,142) had a 46% increased risk of type 2 diabetes (adjusted HR 1.46 [95% CI 1.22, 1.74]). The risk was dose dependent for simvastatin and atorvastatin. Statin treatment significantly increased 2 h glucose (2hPG) and glucose AUC of an OGTT at follow-up, with a nominally significant increase in fasting plasma glucose (FPG). Insulin sensitivity was decreased by 24% and insulin secretion by 12% in individuals on statin treatment (at FPG and 2hPG <5.0 mmol/l) compared with individuals without statin treatment ( p<0.01). Decreases in insulin sensitivity and insulin secretion were dose dependent for simvastatin and atorvastatin. Conclusions/interpretation Statin treatment increased the risk of type 2 diabetes by 46%, attributable to decreases in insulin sensitivity and insulin secretion

Simvastatin Impairs Insulin Secretion by Multiple Mechanisms in MIN6 Cells.

Statins are widely used in the treatment of hypercholesterolemia and are efficient in the prevention of cardiovascular disease. Molecular mechanisms explaining statin-induced impairment in insulin secretion remain largely unknown. In the current study, we show that simvastatin decreased glucose-stimulated insulin secretion in mouse pancreatic MIN6 β-cells by 59% and 79% (p<0.01) at glucose concentration of 5.5 mmol/l and 16.7 mmol/l, respectively, compared to control, whereas pravastatin did not impair insulin secretion. Simvastatin induced decrease in insulin secretion occurred through multiple targets. In addition to its established effects on ATP-sensitive potassium channels (p = 0.004) and voltage-gated calcium channels (p = 0.004), simvastatin suppressed insulin secretion stimulated by muscarinic M3 or GPR40 receptor agonists (Tak875 by 33%, p = 0.002; GW9508 by 77%, p = 0.01) at glucose level of 5.5 mmol/l, and inhibited calcium release from the endoplasmic reticulum. Impaired insulin secretion caused by simvastatin treatment were efficiently restored by GPR119 or GLP-1 receptor stimulation and by direct activation of cAMP-dependent signaling pathways with forskolin. The effects of simvastatin treatment on insulin secretion were not affected by the presence of hyperglycemia. Our observation of the opposite effects of simvastatin and pravastatin on glucose-stimulated insulin secretion is in agreement with previous reports showing that simvastatin, but not pravastatin, was associated with increased risk of incident diabetes

Effect of simvastatin (Simva) and other compounds on the intracellular calcium levels in MIN6 β-cells.

<p>The effect of simvastatin (0.5–12.5 μM) in the presence of 16.7 mM glucose (<b>A</b>); effect of simvastatin (14.4 μM) and nifedipine (Nif, 5 μM) in the presence of 5.5 mM glucose (<b>B</b>); effect of simvastatin (14.4 μM) in the presence of 16.7 mM glucose (<b>C</b>); effect of tolbutamide (Tol, 100 μM) alone or in combination with simvastatin (14.4 μM) (<b>D</b>); effect of KCl (40 mM) alone or in combination with simvastatin (7.2 μM) (<b>E</b>); effect of acetylcholine (Ach, 10 μM) alone or in combination with simvastatin (7.2 μM) (<b>F</b>); effect of a combination of tolbutamide and acetylcholine with or without simvastatin (14.4 μM) (<b>G</b>); effect of simvastatin (14.3 μM) alone or in combination with either GLP-1 (100 nM) or GPR119 agonist AS-1269574 (40 μM) in the presence of 16.7 mM glucose (<b>H</b>). Dashed lines represent the duration of the treatments.</p

Effect of simvastatin on the glucagon-like peptide 1 (GLP-1) receptor and GPR119 pathways in MIN6 β-cells and GPR119 cell line.

<p>The effect GLP-1 amide (100 nM) and a GLP-1 agonist exendin-4 (20 nM) alone or in combination with simvastatin (Simva) on insulin secretion at 5.5 mM (<b>A</b>) and 16.7 mM glucose concentrations (<b>B</b>); the effect of the GPR119 agonist AS-1269574 (40 μM) alone or in combination with simvastatin on insulin secretion at 5.5 mM (<b>C</b>) and 16.7 mM glucose concentrations (<b>D</b>); the effect of simvastatin and pravastatin (26.3 μM) on cAMP concentration in GPR119 receptor overexpressing CHO-K1 cell lines using cAMP HTRF^™ functional assay (<b>E</b>); the effect of the cAMP activator forskolin (Forsk, 10 μM) alone or in combination with simvastatin on insulin secretion at 5.5 mM glucose concentration (<b>F</b>); the effect of simvastatin on insulin secretion stimulated by a cAMP analog that activates both protein kinase A (PKA) and Epac2 (8-Bromo-cAMP, 1 mM), and a cAMP analog specific for activation of Epacs (8-pCPT-2′-O-Me-cAMP, 50μM) (<b>G</b>); the effect of GLP-1 amide (100 nM) and AS-1269574 (40 μM) alone or in combination with PKA specific inhibitor H89 (10 μM) or Epac specific inhibitor ESI-05 (20 μM) on insulin secretion at 5.5 mM glucose concentration (<b>H</b>); the effect of GLP-1 amide (100 nM) and AS-1269574 (40 μM) in combination with nifedipine (Nif, 5 μM) or diazoxide (Diaz, 250 μM) on insulin secretion at 5.5 mM glucose concentration (<b>I</b>); the effect of a combination of GLP-1 amide (100 nM) and AS-1269574 (40 μM) alone or with simvastatin, nifedipine or diazoxide on insulin secretion at 5.5 mM glucose concentration (<b>J</b>); the effect of forskolin at 3 different concentrations (2.5, 5, and 10 μM) on insulin secretion in calcium-free KRBH buffer at 5.5 and 16.7 mM glucose concentration (<b>K</b>). Insulin secretion was normalized with protein concentration, data are mean ± SEM relative to control (100%). Simvastatin was used in concentration of 14.3 μM. p values were calculated with the Mann-Whitney test, *p<0.05, **p<0.01 compared to control or other reference as indicated, p^##<0.01 and p^###<0.001 compared to simvastatin treatment. Each group had 8 (A, B), 6 (C, D, I, K), or 4 (F, G, H, J) replicates. See also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142902#pone.0142902.s005" target="_blank">S1 Fig</a>.</p

Effect of simvastatin on the GPR40 signaling pathway in MIN6 β-cells and on the erythrocyte membrane fatty acid (EMFA) levels in humans.

<p>The effect of simvastatin (Simva, 14.3 μM) on insulin secretion stimulated by GPR40 agonists TAK875 (40 μM) and GW9508 (40 μM) at 5.5 mM (<b>A</b>) and 16.7 mM glucose concentrations (<b>B</b>); the effect of pravastatin (26.3 μM) alone or in combination with TAK875 on insulin secretion at 5.5 mM (<b>C</b>) and 16.7 mM glucose concentrations (<b>D</b>); the effect of oleic acid (OA) at 10 μM, 30 μM, 0.5 mM and 1 mM concentrations and linoleic acid (LA) 0.5 mM concentration alone or in combination with simvastatin on insulin secretion at 5.5 mM glucose concentration (<b>E</b>); the effect of simvastatin treatment on the levels of EMFAs in 1,332 non-diabetic men from the METSIM study (<b>F</b>); SFA—total saturated fatty acids, PUFA—total polyunsaturated fatty acids. Insulin secretion were normalized with protein concentration, data are mean ± SEM relative to control (100%). p values were calculated with the Mann-Whitney test (A-E) or with t-test (F), *p<0.05, **p<0.01 compared to control, p^#<0.05, p^##<0.01 compared to simvastatin treatment. Each group has 6 (4–6 in E) replicates.</p

Effect of simvastatin on intracellular calcium and the glycolysis pathway in MIN6 β-cells.

<p>The effect of the 2-aminoethoxydiphenylborate (2-APB, 100 μM), a functional and membrane permeable IP3 receptor antagonist, on insulin secretion, and the effect of 2-APB on insulin secretion stimulated by GPR40 activator GW9580 (40 μM) in MIN6 β-cells (<b>A</b>); the effect of simvastatin on insulin secretion stimulated by the ryanodine receptor activator caffeine (10 mM) and the effect of ryanodine receptor inhibitor ryanodine (5 μM) on insulin secretion at 5.5 mM glucose concentration (<b>B</b>); the effect of simvastatin on glucose uptake at 5.5 mM (<b>C</b>) and 16.7 mM glucose concentrations (<b>D</b>), GLUT2 protein expression and corresponding western blots at 16.7 mM glucose concentrations (<b>E</b>), pyruvate levels at 5.5 mM glucose concentration (<b>F</b>), and the ADP/ATP ratio at 5.5 mM (<b>G</b>) and 16.7 mM glucose concentrations (<b>H</b>) in MIN6 β-cells. Insulin secretion values were normalized with protein concentration. GLUT2 protein expression values were normalized with actin protein levels. Data are mean ± SEM relative to control (Ctrl) (100%). p values were calculated with the Mann-Whitney test, *p<0.05, **p<0.01 compared to control. Each group has 6 (A-D, F-H) or 8 (E) replicates.</p

Effect of simvastatin on insulin secretion mediated by ATP dependent potassium channels, L-type voltage-gated calcium channels, acetylcholine, and phorbol myristate acetate in MIN6 β-cells.

<p>The effect of simvastatin (Simva, 14.3 μM) on insulin secretion stimulated by tolbutamide (Tol, 100 μM) and potassium chloride (KCl, 40 mM) at 5.5 mM (<b>A</b>) and 16.7 mM glucose concentrations (<b>B</b>); the effect of simvastatin and nifedipine (Nif, 5 μM) on insulin secretion at 5.5 mM (<b>C</b>) and 16.7 mM (<b>D</b>) glucose concentrations; the effect of simvastatin on insulin secretion stimulated by acetylcholine (Ach, 10 μM) at 5.5 mM glucose concentration (<b>E</b>); and the effect of simvastatin on insulin secretion stimulated by phorbol myristate acetate (PMA, 0.5 μM) at 5.5 mM glucose concentration (<b>F</b>); and the effect of simvastatin (14.3 μM) on the PKC activity in MIN6 β-cells at 5.5 and 16.7 mM glucose concentration (<b>G</b>). Insulin secretion was normalized with protein concentration, data are mean ± SEM relative to control (100%). p values were calculated with the Mann-Whitney test, *p<0.05, **p<0.01 compared to control. The number of replicates was 6 for A and E, 8 for B, C, and D, 4 for F, and 2–4 for G.</p