Polymorphisms of the farnesyl diphosphate synthase gene modulate bone changes in response to atorvastatin.

Although their primary therapeutic indications are different, aminobisphosphonates and statins target enzymes in the mevalonate pathway, which is critical for bone homeostasis. Previous studies have shown that some polymorphisms of the gene encoding farnesyl diphosphate synthase (FDPS), the main target of aminobisphosphonates, modulate the response to these drugs. In this study, we explored whether those single nucleotide polymorphisms (SNPs) also influence the changes in bone mineral density (BMD) following therapy with statins. Sixty-six patients with coronary heart disease were studied at baseline and after 1-year therapy with atorvastatin. BMD was measured by DXA. Three SNPs of the FDPS gene (rs2297480, rs11264359 and rs17367421) were analyzed by using Taqman assays. The results showed that there was no association between the SNPs and basal BMD. However, rs2297480 and rs11264359 alleles, which are in linkage disequilibrium, were associated with changes in hip BMD following atorvastatin therapy. Thus, patients with AA genotype at the rs2297480 locus had a 0.8 ± 0.8 % increase in BMD at the femoral neck, whereas in patients with AC/CC genotypes, BMD showed a 2.3 ± 0.8 % decrease (p = 0.02). Similar results were obtained regarding changes of BMD at the femoral trochanter and when alleles at the rs11264359 locus were analyzed. However, there was no association between BMD and rs17367421 alleles. In conclusion, these results suggest that polymorphisms of the FDPS gene may influence the bone response to various drugs targeting the mevalonate pathway, including not only aminobisphosphonates but also statins.

Levels of DKK1 in patients with acute myocardial infarction and response to atorvastatin.

The Wnt-LPR5 signalling pathway plays an important role in skeletal homeostasis, especially in regulating osteoblastic activity. Activation of this pathway is regulated by various inhibitors, including DKK1. The objective of this study was to evaluate DKK1 levels in patients with ischemic heart disease, the response to atorvastatin and the relationship with bone mass. Twenty-one patients with acute myocardial infarction and twenty-three controls with a mean age of 61 ± 9 years with acute coronary syndrome were included. Patients were allocated to low (10-20mg) and high doses (40-80 mg) of atorvastatin according to baseline levels of cholesterol and triglycerides and the index of vascular risk. Patients were studied at hospital admission (baseline) and at 12 months of follow up. DKK1 was determined in all patients at baseline and at 12 months of follow up. Densitometric studies were conducted in the lumbar spine (L2-L4) and the femoral neck and trochanter using an X-ray densitometer. Patients had higher levels of DKK1 than controls, (111 ± 41 nmol/l versus 84 ± 27 nmol/l, p=0.014). Osteoporotic patients had higher levels of DKK1 (137.5 ± 33 nmol/l versus 95.4 ± 36 nmol/l, p=0.021). Analysis of the response to atorvastatin showed reduced DKK1 levels. In conclusion, in patients with acute coronary syndrome, atorvastatin decreases DKK1 levels. This may be a previously unreported mechanism of action of atorvastatin on bone, stimulating the Wnt signalling pathway and increasing bone mass.

Effect of the TNFalpha-308 G/A polymorphism on the changes produced by atorvastatin in bone mineral density in patients with acute coronary syndrome.

AIMS: To evaluate the effect of atorvastatin on bone mass and markers of bone remodeling in patients with acute coronary syndrome depending on the tumor necrosis factor-alpha (TNFalpha)-308 G/A polymorphism. METHODS: Sixty-two patients with acute coronary syndrome (35 males and 27 females), average age 60 +/- 10 years, were included. Patients were given low (10-20 mg) and high doses (40-80 mg) atorvastatin according to their baseline levels of cholesterol and triglycerides and their index of vascular risk. Patients were studied during hospital admission (baseline) and at 12 months of follow-up. Cholesterol, triglycerides, total calcium, phosphorus, magnesium, osteocalcin and urinary deoxypyridinoline were determined in all patients at baseline and at 12 months of follow-up. Densitometric studies were conducted in the lumbar spine (L(2)-L(4)), femoral neck and trochanter using an X-ray densitometer. The TNFalpha-308 G/A polymorphism was determined by the polymerase chain reaction. RESULTS: Forty-five patients were homozygous for G/G (72.5%) and 17 were heterozygous for G/A (27.5%). The prevalence of osteoporosis (T score < or = 2.5 in the lumbar spine and/or hip) was 33% for the G/G genotype and 35% for the G/A genotype, with no statistically significant differences between groups. There was a statistically significant increase in bone mineral density (BMD) in the lumbar spine (1.107 +/- 0.32 vs. 1.129 +/- 0.23; p = 0.0001) in patients with the G/G genotype. No changes were observed in patients with the G/A genotype. CONCLUSION: In patients with acute coronary syndrome, atorvastatin increases lumbar spine BMD solely in patients with the G/G genotype of the TNFalpha-308 G/A polymorphism.