Written by Timothy Huzar — Fact checked by Anna Guildford, Ph.D.
In a new study, researchers found a link between statin use and an increased likelihood of type 2 diabetes disease progression.
The research, which appears in the journal JAMA Internal Medicine, gives clinicians more information to ensure that statins are appropriate when prescribed.
The Food & Drug Administration (FDA) says statins are medications that help lower cholesterol levels in a person’s blood.
If individuals have too much cholesterol in their blood, they have a greater risk of cardiovascular disease, heart attack, or stroke.
People can lower their cholesterol by staying physically active and eating foods low in saturated and trans fats, including fruit and vegetables. However, the FDA points out that for some individuals, genetic factors mean that they may still have too much cholesterol, even if they follow a healthy lifestyle.
According to a review in the journal Medicina Clínica, statins, like all drugs, can have some side effects. However, the side effect rate is so low that the benefits of taking them for someone with cholesterol levels that are too high outweigh the drawbacks.
Nonetheless, researchers want to understand these side effects better to ensure that when a doctor prescribes statins, it is the best option for the patient, and they fully comprehend any potential risks.
Researchers have discovered one potential side effect of taking statins is decreased insulin sensitivity, which means that a person is more at risk of type 2 diabetes.
Type 2 diabetes is a condition that causes the level of sugar, or glucose, in the blood to become too high. This occurs because an individual either cannot produce enough insulin or is less sensitive to insulin. Insulin helps cells absorb glucose in a person’s blood.
By not producing enough insulin or having reduced sensitivity to it, a person’s blood sugar levels increase, making them more at risk of cardiovascular disease.
Speaking to Medical News Today, Prof. Ishak Mansi, M.D., of the Department of Medicine and the Department of Population and Data Sciences, University of Texas Southwestern, Dallas, TX, and the corresponding author of the present study, said that understanding the clinical implications of insulin resistance due to statins was important.
“Prior research has shown statins to be associated with increased insulin resistance. But doctors do not routinely measure ‘insulin resistance’ for their patients. Rather, it is done [in] research and academic circles only, but not in everyday life.”
“Increased insulin resistance may result in less controlled diabetes, [the] escalation of anti-diabetes medications,
. The global diabetes prevalence in 2019 is estimated to be 463 million people, rising to 578 million by 2030.”
“With [an] increasing number of patients diagnosed with diabetes, it is important to examine if the effect of statins on insulin resistance […] translates into any meaningful clinical outcome that may influence patient management,” said Prof Mansi.
To do this, Prof. Mansi and his colleagues developed a large, retrospective study looking at patient health records from the Department of Veterans Affairs between 2003 and 2015.
The selected individuals had to have a type 2 diabetes diagnosis during the study period, be 30 years of age or older, and regularly use the Veterans Affairs health system.
The researchers matched 83,022 people taking statins with an active comparison group of patients. The latter group was either taking a type of heartburn medication, known as an H2 blocker, a proton-pump inhibitor, but not taking statins.
The researchers found that 55.9% of the patients taking statins had diabetes progression during the study period, compared with 48% in the active comparison group.
The statin users were more likely to begin insulin treatment, have related high blood sugar levels and complications, and have more prescriptions for medications that lower blood sugar levels relative to the active comparator patients.
Prof. Mansi said to MNT that while the association between statin use and diabetes progression was important, it was only one of several elements requiring consideration when prescribing statins.
“[There are] three important precautions in reading our study: no patient should stop taking their statins based on our study, association does not prove causation, and no single study should dictate treatment policy but [rather] all the pieces of evidence together.”
“Current guidelines from several scientific societies recommend statins prescription to patients with diabetes aged 40 to 75 with [low-density lipoprotein] cholesterol ≥70 milligrams per deciliter to prevent cardiovascular diseases from occurring. Statins have been shown to lower the risk of cardiovascular diseases.”
“However, our study is very important because it translated findings reported [in] academic studies of increased insulin resistance associated with statin use in research papers into [the] everyday language of patient care — that is, patients on statins may need to escalate their anti-diabetes therapy.”
“Hence, it may alert clinicians that they may need to pay close attention and expect to adjust anti-diabetes medications when they initiate statins. Adjusting anti-diabetes medications is a common practice in managing diabetes.”
Prof. Mansi also stressed that statins could still be a crucial medical intervention.
“Of course, we have to differentiate between using statins for [the] primary prevention of cardiovascular diseases — that is, in patients who never had any cardiovascular disease previously — and those using statins for secondary prevention — those who have pre-existing cardiovascular disease. In the latter group, statins are one of the most important lines of treatment, and their benefits are tremendous.”
Speaking to MNT, Dr. Marina Basina, a clinical professor and diabetes expert at Stanford University, CA, agreed that finding a balance was necessary regarding the risks and benefits of prescribing statins.
“This was a very large study, although retrospective, showing an association but not the causative mechanism of diabetes progression with the use of statins.”
“The information is important in helping clinicians [address the] risk-benefit ratio of the use of the medication with their patients. This risk should be carefully weighed against the significant benefits from multiple randomized and observational trials showing significant beneficial effects of statins in [the] reduction of cardiovascular events and mortality in individuals with diabetes and nondiabetes high risk patients,” said Dr. Basina.
For Dr. Basina, a healthcare professional needs to approach each patient differently depending on their specific situation.
“[A] personalized approach to each patient is important. Clinicians should assess [the] cardiovascular risk factors of each patient, address [the] small risk of diabetes progression and [the] possible need of the escalation of diabetes therapies.”
“But at the same time, it is important to explain to the patient that the benefits of statins in [the] reduction of cardiovascular events and mortality outweigh the risk of diabetes progression.”
“Emphasizing [a] healthy lifestyle with smoking cessation, regular exercise, and healthy diet, is an essential part of the therapy and will help in [the] reduction of the risk of diabetes progression,” added Dr. Basina.
For Prof. Mansi, more research is necessary on the benefits and risks of statins for individuals with diabetes.
“We know well about the benefits [of statins], but the harms are much less investigated — despite [the fact] that statins have been in use for [more than] 30 years! Observational data and registries can be an excellent method to examine this topic.”
“Specifically, what [are] the population characteristics that may benefit less from [the] use of statins for primary prevention or get more harm? This type of [study] should be prioritized since diabetes is very common in the [United States] and the world. Hence, answering these questions impact[s] hundreds of millions of patients and cannot be postponed,” said Prof. Mansi.
Prof. Mansi added that funding would also be necessary to understand better some of the side effects of common drugs, such as statins.
“There should be dedicated funding for such research about unintended adverse effects of commonly used medications — not only statins. There is no dedicated funding mechanism for a study like our[s]. I can see many researchers deterred from performing necessary research due to [the] difficulty in obtaining funding,” added Prof. Mansi.
For Dr. Basina, high-quality studies are necessary to help clinicians offer a personalized treatment plan for people with diabetes.
“Further research is needed to tailor [a] patient’s individual needs in balancing cardiovascular benefits with the risk of diabetes. Large scale, randomized controlled trials are needed to answer these questions.”
“In the meantime, it is important to use [a] personalized approach to [an] individual patient’s risk factors, discuss [the] risk-benefit ratio of statin therapy, and [statin therapy’s] significant benefit in the improvement of cardiovascular outcomes, especially in high risk individuals with diabetes,” said Dr. Basina.