Genetic determinants of statin intolerance

BACKGROUND: Statin-related skeletal muscle disorders range from benign myalgias – such as non-specific muscle aches or joint pains without elevated serum creatinine kinase (CK) concentration – to true myositis with >10-fold elevation of serum CK, to rhabdomyolysis and myoglobinuria. The genetic basis of statin-related muscle disorders is largely unknown. Because mutations in the COQ2 gene are associated with severe inherited myopathy, we hypothesized that common, mild genetic variation in COQ2 would be associated with inter-individual variation in statin intolerance. We studied 133 subjects who developed myopathy on statin monotherapy and 158 matched controls who tolerated statins without incident or complaint. RESULTS: COQ2 genotypes, based on two single nucleotide polymorphisms (SNP1 and SNP2) and a 2-SNP haplotype, all showed significant associations with statin intolerance. Specifically, the odds ratios (with 95% confidence intervals) for increased risk of statin intolerance among homozygotes for the rare alleles were 2.42 (0.99 to 5.89), 2.33 (1.13 to 4.81) and 2.58 (1.26 to 5.28) for SNP1 and SNP2 genotypes, and the 2-SNP haplotype, respectively. CONCLUSION: These preliminary pharmacogenetic results, if confirmed, are consistent with the idea that statin intolerance which is manifested primarily through muscle symptoms is associated with genomic variation in COQ2 and thus perhaps with the CoQ10 pathway

Quantitative and qualitative differences in subcutaneous adipose tissue stores across lipodystrophy types shown by magnetic resonance imaging

BACKGROUND: Lipodystrophies are characterized by redistributed subcutaneous fat stores. We previously quantified subcutaneous fat by magnetic resonance imaging (MRI) in the legs of two patients with familial partial lipodystrophy subtypes 2 and 3 (FPLD2 and FPLD3, respectively). We now extend the MRI analysis across the whole body of patients with different forms of lipodystrophy. METHODS: We studied five subcutaneous fat stores (supraclavicular, abdominal, gluteal, thigh and calf) and the abdominal visceral fat stores in 10, 2, 1, 1 and 2 female subjects with, respectively, FPLD2, FPLD3, HIV-related partial lipodystrophy (HIVPL), acquired partial lipodystrophy (APL), congenital generalized lipodystrophy (CGL) and in six normal control subjects. RESULTS: Compared with normal controls, FPLD2 subjects had significantly increased supraclavicular fat, with decreased abdominal, gluteal, thigh and calf subcutaneous fat. FPLD3 subjects had increased supraclavicular and abdominal subcutaneous fat, with less severe reductions in gluteal, thigh and calf fat compared to FPLD2 subjects. The repartitioning of fat in the HIVPL subject closely resembled that of FPLD3 subjects. APL and CGL subjects had reduced upper body, gluteal and thigh subcutaneous fat; the APL subject had increased, while CGL subjects had decreased subcutaneous calf fat. Visceral fat was markedly increased in FPLD2 and APL subjects. CONCLUSION: Semi-automated MRI-based adipose tissue quantification indicates differences between various lipodystrophy types in these studied clinical cases and is a potentially useful tool for extended quantitative phenomic analysis of genetic metabolic disorders. Further studies with a larger sample size are essential for confirming these preliminary findings

Treatment of dyslipidemia with lovastatin and ezetimibe in an adolescent with cholesterol ester storage disease

<p>Abstract</p> <p>Background</p> <p>Cholesterol ester storage disease (CESD) is an autosomal recessive illness that results from mutations in the <it>LIPA </it>gene encoding lysosomal acid lipase. CESD patients present in childhood with hepatomegaly and dyslipidemia characterized by elevated total and low-density lipoprotein cholesterol (LDL-C), with elevated triglycerides and depressed high-density lipoprotein cholesterol (HDL-C). Usual treatment includes a low fat diet and a statin drug.</p> <p>Results</p> <p>In an 18-year old with CESD, we documented compound heterozygosity for two <it>LIPA </it>mutations: a novel frameshift nonsense mutation and a deletion of exon 8. The patient had been treated with escalating doses of lovastatin for ~80 months, with ~15% decline in mean LDL-C. The addition of ezetimibe 10 mg to lovastatin 40 mg resulted in an additional ~16% decline in mean LDL-C.</p> <p>Conclusion</p> <p>These preliminary anecdotal findings in a CESD patient with novel <it>LIPA </it>mutations support the longer term safety of statins in an adolescent patient and provide new data about the potential efficacy and tolerability of ezetimibe in this patient group.</p

Genetic determinants of statin intolerance

Abstract Background Statin-related skeletal muscle disorders range from benign myalgias – such as non-specific muscle aches or joint pains without elevated serum creatinine kinase (CK) concentration – to true myositis with >10-fold elevation of serum CK, to rhabdomyolysis and myoglobinuria. The genetic basis of statin-related muscle disorders is largely unknown. Because mutations in the COQ2 gene are associated with severe inherited myopathy, we hypothesized that common, mild genetic variation in COQ2 would be associated with inter-individual variation in statin intolerance. We studied 133 subjects who developed myopathy on statin monotherapy and 158 matched controls who tolerated statins without incident or complaint. Results COQ2 genotypes, based on two single nucleotide polymorphisms (SNP1 and SNP2) and a 2-SNP haplotype, all showed significant associations with statin intolerance. Specifically, the odds ratios (with 95% confidence intervals) for increased risk of statin intolerance among homozygotes for the rare alleles were 2.42 (0.99 to 5.89), 2.33 (1.13 to 4.81) and 2.58 (1.26 to 5.28) for SNP1 and SNP2 genotypes, and the 2-SNP haplotype, respectively. Conclusion These preliminary pharmacogenetic results, if confirmed, are consistent with the idea that statin intolerance which is manifested primarily through muscle symptoms is associated with genomic variation in COQ2 and thus perhaps with the CoQ10 pathway.</p

Treatment of Dyslipidemia with Lovastatin and Ezetimibe in an Adolescent with Cholesterol Ester Storage Disease

Background: Cholesterol ester storage disease (CESD) is an autosomal recessive illness that results from mutations in the LIPA gene encoding lysosomal acid lipase. CESD patients present in childhood with hepatomegaly and dyslipidemia characterized by elevated total and low-density lipoprotein cholesterol (LDL-C), with elevated triglycerides and depressed high-density lipoprotein cholesterol (HDL-C). Usual treatment includes a low fat diet and a statin drug. Results: In an 18-year old with CESD, we documented compound heterozygosity for two LIPA mutations: a novel frameshift nonsense mutation and a deletion of exon 8. The patient had been treated with escalating doses of lovastatin for approximately 80 months, with approximately 15% decline in mean LDL-C. The addition of ezetimibe 10 mg to lovastatin 40 mg resulted in an additional approximately 16% decline in mean LDL-C. Conclusion: These preliminary anecdotal findings in a CESD patient with novel LIPA mutations support the longer term safety of statins in an adolescent patient and provide new data about the potential efficacy and tolerability of ezetimibe in this patient group

Semi-automated Segmentation and Quantification of Adipose Tissue in Calf and Thigh by MRI: A Preliminary Study in Patients with Monogenic Metabolic Syndrome

Background: With the growing prevalence of obesity and metabolic syndrome, reliable quantitative imaging methods for adipose tissue are required. Monogenic forms of the metabolic syndrome include Dunnigan-variety familial partial lipodystrophy subtypes 2 and 3 (FPLD2 and FPLD3), which are characterized by the loss of subcutaneous fat in the extremities. Through magnetic resonance imaging (MRI) of FPLD patients, we have developed a method of quantifying the core FPLD anthropometric phenotype, namely adipose tissue in the mid-calf and mid-thigh regions. Methods: Four female subjects, including an FPLD2 subject (LMNA R482Q), an FPLD3 subject (PPARG F388L), and two control subjects were selected for MRI and analysis. MRI scans of subjects were performed on a 1.5T GE MR Medical system, with 17 transaxial slices comprising a 51 mm section obtained in both the mid-calf and mid-thigh regions. Using ImageJ 1.34 n software, analysis of raw MR images involved the creation of a connectedness map of the subcutaneous adipose tissue contours within the lower limb segment from a user-defined seed point. Quantification of the adipose tissue was then obtained after thresholding the connected map and counting the voxels (volumetric pixels) present within the specified region. Results: MR images revealed significant differences in the amounts of subcutaneous adipose tissue in lower limb segments of FPLD3 and FPLD2 subjects: respectively, mid-calf, 15.5% and 0%, and mid-thigh, 25.0% and 13.3%. In comparison, old and young healthy controls had values, respectively, of mid-calf, 32.5% and 26.2%, and mid-thigh, 52.2% and 36.1%. The FPLD2 patient had significantly reduced subcutaneous adipose tissue compared to FPLD3 patient. Conclusion: Thus, semi-automated quantification of adipose tissue of the lower extremity can detect differences between individuals of various lipodystrophy genotypes and represents a potentially useful tool for extended quantitative phenotypic analysis of other genetic metabolic disorders