Effectiveness and safety of statin initiation for primary prevention of cardiovascular events and mortality in adults with type 1 diabetes mellitus and dyslipidaemia

Abstract

<p>Background and Aims: Specific evidence from randomised trials supporting the effectiveness and safety of statins in adults with type 1 diabetes mellitus (T1DM) is lacking. We aimed to emulate a pragmatic randomised trial to determine the effects of statin initiation among individuals with T1DM and dyslipidaemia for primary prevention of cardiovascular events and mortality.</p><p>Methods: UK primary care data from the IQVIA Medical Research Data database were used with the sequential trial approach to compare statin initiation versus non-initiation among adults 25-84 years with T1DM and dyslipidaemia (low-density lipoprotein cholesterol ≥2.6 mmol/L or non-high-density lipoprotein cholesterol ≥3.4 mmol/L). We estimated 10-year risk differences (RD) and numbers needed to treat (NNT) or harm (NNH) for the observational analogues of intention-to-treat (ITT) and per-protocol (PP) effects. Primary outcomes were all-cause mortality and major cardiovascular disease. Secondary outcomes were myopathy and liver dysfunction.</p><p>Results: We included 4,176 statin initiator and 16,704 non-initiator person trials with median follow-up of 6 years. Compared with non-initiation, statins reduced all-cause mortality (RD_ITT −1.66%, 95%CI −2.79% to −0.45%; NNT 61; RD_PP −3.48%, 95%CI −4.68% to −2.07%; NNT 29) and major cardiovascular disease (RD_ITT −1.63%, 95%CI −2.57% to −0.53%; NNT 62; RD_PP −2.69%, 95%CI −4.00% to −1.22%; NNT 38). In some analyses, there was a small increased risk of liver dysfunction but not myopathy. In subgroup analyses, women, individuals ≥40 years and individuals with larger predicted cardiovascular risk (≥20% 10-year QRISK3 score) had larger RDs for all-cause mortality and major cardiovascular events.</p><p>Conclusions: Among adults with T1DM and dyslipidaemia, statin initiation reduced all-cause mortality and major cardiovascular disease with a potentially small increased risk of liver dysfunction. The results of this study are valuable to inform patient-centred decisions about the benefits and risks of statin initiation in men and women with T1DM.</p>