Association of Strict Versus Lenient Cholesterol Lowering with Cardiac Outcomes, Diabetes Progression and Complications, and Mortality in Patients with Diabetes Treated with Statins: Is Less More?

Abstract

Introduction: Whereas some guidelines recommend statin use to achieve low-density lipoprotein cholesterol (LDL-C) goal < 70 mg/dL for primary prevention of atherosclerotic cardiovascular disease (ASCVD) in patients at higher risk, others recommend against a target LDL-C level. Achieving a target level < 70 mg/dL commonly requires the use of high intensity statins, which has been associated with higher risk of diabetes progression. The objective of this study is to assess the association of strict (≤ 70 mg/dL) versus lenient (> 70 to100 mg/dL) LDL-C lowering on major adverse cardiovascular events (MACE), diabetes progression, diabetes microvascular complications, and total mortality in patients with diabetes.

Methods: This was a retrospective propensity score (PS)-matched study from a national cohort of, predominantly male, veterans diagnosed with diabetes without prior cardiovascular disease (from fiscal years 2003-2015), who were initiated on a statin. We created PS to match strict (mean LDL-C during follow-up ≤ 70 mg/dL) versus lenient (mean LDL-C during follow up > 70-100 mg/dL) using 65 baseline characteristics including comorbidities, risk scores, medication classes usage, vital signs, and laboratory data. Outcomes included MACE, diabetes progression, microvascular diabetes complications, and total mortality.

Results: From 80,110 eligible patients, we PS-matched 21,294 pairs of statin initiators with strict or lenient LDL-C lowering. The mean (SD) age was 64 (9.5) years and mean (SD) duration of follow-up was 6 (3) years. MACE was similar in the PS-matched groups [6.1% in strict versus 5.8% in lenient; odds ratio (OR): 1.06; 95% confidence interval (95% CI) 0.98-1.15, P = 0.17]. Diabetes progression was higher among the strict vs lenient group (66.7% in strict versus 64.1% in lenient; OR 1.12; 95% CI 1.08-1.17, P < 0.001). There was no difference in microvascular diabetes complications (22.3% in strict versus 21.9% in lenient; OR 1.02; 95% CI 0.98-1.07, P = 0.31) and no difference in total mortality (14.6% in strict versus 15% in lenient; OR 0.97; 95% CI 0.92-1.02, P = 0.20).

Conclusion: Strict compared with lenient lowering of LDL-C with statins in men with diabetes without preexisting ASCVD did not decrease the risk of MACE but was associated with an increased diabetes progression. Clinicians should monitor their patients for diabetes progression upon escalating statins to achieve LDL-C levels ≤ 70 mg/dL.