Statin use in prediabetic patients: rationale and results to date

LDL-C plays a causal role on T2DM: a Mendelian randomization analysis

Diabetic dyslipidemia is a common condition in patients with Type 2 diabetes mellitus (T2DM). However, with the increasing application of statins which mainly decrease low-density lipoprotein cholesterol (LDL-C) levels, clinical trials and meta-analysis showed a clearly increase of the incidence of new-onset DMs, partly due to genetic factors. To determine whether a causal relationship exists between LDL-C and T2DM, we conducted a two-sample Mendelian Randomization (MR) analysis using genetic variations as instrumental variables (IVs). Initially, 29 SNPs significantly related to LDL-C (P≤ 5.0×10^-8) were selected as based on results from the study of Henry et al, which processed loci data influencing lipids identified by the Global Lipids Genetics Consortium (GLGC) from 188,577 individuals of European ancestry. While 6 SNPs related to T2DM (P value < 5×10^-2) were deleted, with the remaining 23 SNPs without LD eventually being deemed as IVs. The combined effect of all these 23 SNPs on T2DM, as generated with use of the penalized robust inverse-variance weighted (IVW) method (Beta value 0.24, 95%CI 0.087~0.393, P-value=0.002) demonstrated that elevated LDL-C levels significantly increased the risk of T2DM. The relationship between LDL-C and Type 1 diabetes mellitus (T1DM) with this analysis producing negative pooled results (Beta value -0.202, 95%CI -2.888~2.484, P-value=0.883).

Statin users have an elevated risk of dysglycemia and new-onset-diabetes

OBJECTIVE

Statins are one of the most widely prescribed medications in the United States; however, there is a concern that they are associated with new-onset-diabetes (NOD) development. We sought to understand the risk of dysglycemia and NOD for a cohort of individuals that reflect real-world physician prescribing patterns.

METHODS

A retrospective cohort study was conducted among individuals with indications for statin use (n = 7064). To examine elevated glycosylated hemoglobin (>6.0%), logistic regression with inverse probability weighting was used to create balance between incident statin users and nonusers. To evaluate the risk of NOD development, Cox PH models with time varying statin use compared NOD diagnoses among statin users and nonusers.

RESULTS

A higher prevalence of elevated HbA1c (PD = 0.065; 95% CI: 0.002, 0.129, P = 0.045) occurred among nondiabetic incident users of statins. Additionally, statin users had a higher risk of developing NOD (AHR = 2.20; 95% CI: 1.35, 3.58, P = 0.002). Those taking statins for 2 years or longer (AHR = 3.33; 95% CI: 1.84, 6.01, P < 0.001) were at the greatest risk of developing NOD; no differences were observed by statin class or intensity of dose.

CONCLUSION

As lifestyle programs like the Diabetes Prevention Program are promoted in primary care settings, we hope physicians will integrate and insurers support healthy lifestyle strategies as part of the optimal management of individuals at risk for both NOD and cardiovascular disease. The relationships between statin use and glycemic control should be evaluated in large cohort studies, medical record databases, and mechanistic investigations to inform clinical judgment and treatment.

Effect of statins on fasting glucose in non-diabetic individuals: nationwide population-based health examination in Korea

BACKGROUND

Increasing evidence suggest that statin therapy has a diabetogenic effect. Individual types of statin may have a different effect on glucose metabolism. Using the repeated nationwide population-based health screening data in Korea, we investigated the longitudinal changes in fasting glucose level of non-diabetic individuals by use of statins.

METHODS

From the National Health Screening Cohort, we included 379,865 non-diabetic individuals who had ≥ 2 health screening examinations with fasting blood glucose level measured in 2002-2013. Using the prescription records of statins in the database, we calculated the proportion of days covered (PDC) and average number of defined daily doses per day (anDDD) by statins. We constructed multivariate linear mixed models to evaluate the effects of statins on the changes in fasting glucose (Δglu).

RESULTS

High PDC by statins had a significant positive effect on Δglu (coefficient for PDC 0.093 mmol/L, standard error 0.007, p < 0.001). anDDD by statins was also positively associated with Δglu (coefficient for anDDD 0.119 mmol/L, standard error 0.009, p < 0.001). Unlike statins, the PDC by fibrate and ezetimibe were not significantly associated with Δglu. There was no significant interaction effect on Δglu between time interval and statin. Considering individual types of statins, use of atorvastatin, rosuvastatin, pitavastatin, and simvastatin were significantly associated with increase of Δglu. Pravastatin, lovastatin, and fluvastatin were also positively associated with Δglu, but were not statistically significant.

CONCLUSIONS

More adherent and intensive use of statins was significantly associated with an increase in fasting glucose of non-diabetic individuals. In subgroup analysis of individual statins, use of atorvastatin, rosuvastatin, pitavastatin and simvastatin had significant association with increase in fasting glucose. Pravastatin, lovastatin, and fluvastatin had non-significant trend toward an increased fasting glucose. Our findings suggest the medication class effect of statins inducing hyperglycemia.

Hypolipidemic Drugs and Diabetes Mellitus-Mechanisms and Data From Genetic Trials

Clinical trials and meta-analyses have shown that statins can dose dependently increase the incidence of new-onset diabetes mellitus (DM) especially in patients with underlying abnormalities of carbohydrate homeostasis. Mendelian randomization studies support these findings since genetic variants in the gene encoding the target of statins, the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase, are associated with increased incidence of new-onset DM, suggesting that the so-called diabetogenic effect of statins is an "on-target effect" possibly related to their main mechanism of action, that is the increased low-density lipoprotein (LDL) receptor expression. Additionally, Mendelian randomization studies have shown that genetic variants as proxies of other drugs that increase LDL receptor expression (ezetimibe and proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors) also increase the risk of new-onset DM. This concept is supported by the fact of decreased DM prevalence in patients with familial hypercholesterolemia who have decreased LDL receptor expression. In contrast, hypolipidemic drugs, such as the cholesteryl ester transfer protein inhibitors, that decrease LDL cholesterol without directly interfering with the LDL receptor expression do not seem to detrimentally affect carbohydrate homeostasis. However, the clinical trials of ezetimibe and PCSK9 inhibitors have not shown an increased DM risk, possibly suggesting that other potential non-well-defined "off-target effects" of hypolipidemic drugs may affect carbohydrate homeostasis. Thus, the long-term effect of hypolipidemic drugs on DM risk depends not only on their final mechanism of hypolipidemic action but also on other "on-target" and "off-target" effects of these drugs.

Efficacy and safety of alirocumab in people with prediabetes vs those with normoglycaemia at baseline: a pooled analysis of 10 phase III ODYSSEY clinical trials

AIM

To assess the lipid-lowering efficacy and safety of alirocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, in people with hypercholesterolaemia and prediabetes at baseline vs people with normoglycaemia at baseline in a pooled analysis of 10 ODYSSEY phase III trials.

METHODS

People classified as having prediabetes had baseline HbA1c ≥39 mmol/mol (5.7%) and <48 mmol/mol (6.5%), or two baseline fasting plasma glucose values ≥5.6 mmol/l (100 mg/dl) but no more than one fasting plasma glucose value ≥7.0 mmol/l (126 mg/dl), or had specific terms reported in their medical history; people diagnosed with diabetes at baseline were excluded, and the remainder were classified as having normoglycaemia. Participants received alirocumab or control (placebo/ezetimibe) for 24-104 weeks, with maximally tolerated statin in most cases. The primary efficacy endpoint was LDL cholesterol reductions from baseline to week 24 in the intention-to-treat population using the mixed-effect model with a repeated measures approach.

RESULTS

Reductions in LDL cholesterol from baseline to week 24 with alirocumab were 44.0-61.8% (prediabetes group) and 45.8-59.5% (normoglycaemia group). In both subgroups, LDL cholesterol reductions were generally similar in those with and without baseline triglycerides ≥1.7 mmol/l (150 mg/dl). Alirocumab was not associated with changes in HbA1c or fasting plasma glucose over time in either subgroup (up to 24 months' follow-up). Adverse event rates were generally similar in those with and without prediabetes.

CONCLUSIONS

Over a mean follow-up of 24-104 weeks, alirocumab treatment resulted in significant LDL cholesterol reductions from baseline that were similar in participants with prediabetes and those with normoglycaemia at baseline, with no effect on glycaemia and a safety profile similar to that of the control.

Pharmacotherapy with Thymoquinone Improved Pancreatic β-Cell Integrity and Functional Activity, Enhanced Islets Revascularization, and Alleviated Metabolic and Hepato-Renal Disturbances in Streptozotocin-Induced Diabetes in Rats

Aims: This study is aimed at evaluating the antidiabetic effects of thymoquinone (TQ) on streptozotocin (STZ)-induced diabetes in rats, and exploring the possible underlying mechanisms. Methods: Diabetes was induced in adult male Wistar rats by intraperitoneal injection of freshly prepared STZ (65 mg/kg). After disease induction, 42 rats were equally assigned to: controls, STZ-diabetic group, and STZ-diabetic group treated with oral TQ (35 mg/kg/day) for 5 weeks. Fasting blood glucose levels were determined weekly, and the animals were euthanized at day 38 post-STZ injection. Blood samples were assessed for glucose-insulin homeostasis parameters (plasma glucose, glycated hemoglobin, serum insulin, homeostatic model assessment of insulin resistance, and insulin sensitivity index) and lipid profile. Resected pancreases were subjected to histological examination and immunohistochemical or enzyme-linked immunosorbent assay assessment to determine the pancreatic expression of insulin sensitizing β-cells, anti-apoptotic protein “survivin,” apoptosis-inducer “caspase-3,” prototypic angiogenic factors (vascular endothelial growth factor [VEGF] and endothelial cluster of differentiation 31 [CD31]), pro- and anti-inflammatory cytokines (interleukin-1beta [IL-1β] and interleukin-10 [IL-10], respectively), thiobarbituric acid reactive substances (TBARS), total glutathione (GSH), and superoxide dismutase (SOD). The hepato-renal statuses were assessed biochemically and histologically. Results: Therapy with TQ markedly improved the integrity of pancreatic islets, glucose-insulin homeostasis-related parameters, lipid profile parameters, and hepato-renal functional and histomorphological statuses that collectively were severely deteriorated in untreated diabetic group. Mechanistically, TQ therapy efficiently increased insulin producing β-cells, upregulated survivin, VEGF, CD31, IL-10, GSH and SOD, and downregulated caspase-3, IL-1β, and TBARSs in the pancreatic tissues of STZ-diabetic rats. Conclusions: These findings prove the anti-diabetic potential of TQ and its efficacy in regenerating pancreatic β-cells and ameliorating pancreatic inflammation and oxidative stress, and highlight its novelty in repressing apoptosis of β-cells and enhancing islet revascularization in STZ-diabetic rats. Further studies are required to support these findings and realize their possible clinical significance.