Background and aims: Statin-associated muscle symptoms (SAMS) are a major cause of treatment discontinuation. Clinical Pharmacogenetics Implementation Consortium (CPIC) recommend dose adjustment for statin treatment according to known SLCO1B1 genotype to reduce SAMS. We hypothesized that the association between SLCO1B1 genotype and SAMS is misestimated because of publication bias.
Methods: We searched published systematic reviews on the association between SLCO1B1 genotype and SAMS. To assessed publication bias, we used funnel plot visual inspection, Egger's test, and the Bayes Factor (BFPublication-bias) from Robust Bayesian Meta-Analysis (RoBMA). We compared the odds ratios (ORUncorrected) from meta-analyses before and after correcting for publication bias using trim-and-fill (ORTrim&Fill) and RoBMA (ORRoBMA) methods.
Results: We included 8 cohort and 11 case-control studies, totaling 62 OR of three SLCO1B1 genotypes and six statin drugs. In the primary analysis, the funnel plot was suggestive of publication bias, confirmed by Egger's test (p=0.001) and RoBMA (BFPublication-bias = 18). Correcting the estimate for publication bias resulted in loss of the association, from a significant ORUncorrected (1.31 95%CI [1.13-1.53]) to corrected ORs suggesting no difference: ORTrim&Fill (1.07 95%CI [0.89-1.30]) and ORRoBMA (1.02 95%CI [1.00-1.33]). This suggested that publication bias overestimated the association by 18 % and 23 %, respectively. Similar results were found for genotype rs4149056, simvastatin and atorvastatin.
Conclusions: The effect of the SLCO1B1 genotype on the risk of developing SAMS is overestimated in the published literature, especially rs4149056. This could lead prescribers to incorrectly decreasing statin doses or even avoiding statin use, leading to a loss of the potential cardiovascular benefit of statins.
Pancreatic ß-cells are glucose sensors in charge of regulated insulin delivery to the organism, achieving glucose homeostasis and overall energy storage. The latter function promotes obesity when nutrient intake chronically exceeds daily expenditure. In case of ß-cell failure, such weight gain may pave the way for the development of Type-2 diabetes. However, the causal link between excessive body fat mass and potential degradation of ß-cells remains largely unknown and debated. Over the last decades, intensive research has been conducted on the role of lipids in the pathogenesis of ß-cells, also referred to as lipotoxicity. Among various lipid species, the usual suspects are essentially the non-esterified fatty acids (NEFA), in particular the saturated ones such as palmitate. This review describes the fundamentals and the latest advances of research on the role of fatty acids in ß-cells. This includes intracellular pathways and receptor-mediated signaling, both participating in regulated glucose-stimulated insulin secretion as well as being implicated in ß-cell dysfunction. The discussion extends to the contribution of high glucose exposure, or glucotoxicity, to ß-cell defects. Combining glucotoxicity and lipotoxicity results in the synergistic and more deleterious glucolipotoxicity effect. In recent years, alternative roles for intracellular lipids have been uncovered, pointing to a protective function in case of nutrient overload. This requires dynamic storage of NEFA as neutral lipid droplets within the ß-cell, along with active glycerolipid/NEFA cycle allowing subsequent recruitment of lipid species supporting glucose-stimulated insulin secretion. Overall, the latest studies have revealed the two faces of the same coin.