Association of Statins with Diabetes Mellitus and Diabetic Complications: Role of Confounders During Follow-Up

Abstract

Studies have associated statin use with increased risk of diabetes and diabetic complications. These studies often ensure comparability of statin users and non-users at baseline; however, most studies neglect to consider confounders that occur during follow-up. Failure to consider these confounders, such as new medications or procedures, may result in identification of a spurious association between statins and outcomes. The objective of this study was to examine the association of statins with diabetes mellitus and diabetic complications; and to examine potential confounders during the follow-up period that might affect this relationship. We conducted a retrospective cohort study using Tricare data (from October 1, 2003 to March 31, 2012). We propensity score-matched statin users and non-users on 115 baseline characteristics before starting statins; these characteristics would be potentially associated with the use of statins or the outcomes of interest. Outcomes included the risk of diabetes mellitus and diabetic complications. Out of 60,455 patients (10,910 statin users and 49,545 non-users), we propensity score-matched 6728 statin users to 6728 non-users. Statin users had higher ORs for diabetes (OR 1.34, 95% CI 1.24 to 1.44) and diabetes with complications (OR 1.28, 95% CI 1.16 to 1.42). Adjustment for potential confounders that occurred during the follow-up period did not explain or diminish the association between statins and adverse outcomes. Statin users in comparison to similar non-users were more commonly diagnosed with diabetes and diabetic complications, even after adjustment for potential confounders that occurred during the follow-up period.

Treatment patterns and low-density lipoprotein cholesterol (LDL-C) goal attainment among patients receiving high- or moderate-intensity statins

“…Although switches and up-titration of statin dose may represent attempts to improve patients’ ability to achieve the LDL-C goal, few patients exhibited those treatment modifications. The low occurrence of these treatment modifications may be indicative of clinicians’ desire to avoid prescribing high-intensity statins if possible, concerns about increased risk of diabetes [ 24 , 25 ] and about statin tolerability at higher doses/intensity, or patients’ unwillingness to modify their therapy regimen [ 26 ].…”

Association of Statin Use With Risk of Back Disorder Diagnoses

“…5 Inclusion criteria were being older than 30 years and having at least 1 medical encounter during the baseline period (2 years before the index date) and the follow-up period (starting 90 days after the index date through March 1, 2012, except for nonusers who were subsequently prescribed statins and for whom follow-up was censored at the date they filled their statin prescription). 5 …”

“…5 Prevalent statin users were excluded. This study was approved by the institutional review boards of Brooke Army Medical Center and the VA North Texas Health System.…”

Association of Statin Use with Increased Risk of Musculoskeletal Conditions: A Retrospective Cohort Study

“…Statin users were also taking more prescription medications than nonusers. [11] Among those on a statin, prescriptions for simvastatin (72%) constituted the majority of statins prescribed, followed by atorvastatin (22%), pravastatin (3%), rosuvastatin (2%), and lovastatin or fluvastatin (<1%).…”