The Cooper Institute
 

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH

 
 

Use of Statin Drugs and the Risk of Developing Diabetes: An Update from the Cooper Center Longitudinal Study

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Eat better

Thursday, Jul 02, 2015

 

If you watch television, you might have seen and heard a “non-attorney spokesperson” plead with persons who have been prescribed statin drugs to call the number provided due to the “dramatic increase in cases of type 2 diabetes caused by statin drugs.”

 

Statin drugs are commonly used to decrease blood levels of LDL-cholesterol and triglycerides, and have been shown to significantly decrease the risk of cardiovascular morbidity (illness) and mortality (death). In an earlier blog, Do Statin Drugs Increase the Risk of Diabetes?, we found that the benefits of reducing the risk of cardiovascular disease by taking a statin were much greater than the relatively small increased risk of developing diabetes as a result of statin use. Has anything changed since this earlier blog?

Recent data1 from the Cooper Center Longitudinal Study (CCLS) has shed further light on this important issue. A total of 6519 men and 2334 women who were generally healthy at baseline underwent Cooper Clinic comprehensive exams on two separate occasions. Both exams included a maximal treadmill exercise test to measure cardiorespiratory fitness (CRF). None of the patients were taking a statin drug at the time of their initial exam. Patients who were not placed on statin drugs between the two Cooper Clinic exams were designated as the ‘Never Statin’ group, while patients who were placed on statin drugs between the two exams were designated as the ‘Started Statin’ group.  There was an average of 3 years between the initial exam and the second exam. A total of 93 patients developed diabetes during this period. Less than 1% in the Never Statin group and 2.5% in the Started Statin group developed diabetes in between the first and second exams. Importantly, patients who had a normal fasting blood glucose level (<100 mg/dL) at the time of their initial exam did not have any increased risk of developing diabetes if they were placed on a statin drug. Furthermore, the risk of developing diabetes was markedly lower in patients with moderate to high CRF in the Started Statin group when compared to those patients with low CRF in the Started Statin group. Moderate to high levels of CRF were also protective against the development of diabetes in the Never Statin group. Therefore, while the use of a statin drug does modestly increase the risk of developing diabetes, this risk is substantially decreased in patients who have a normal fasting blood glucose level and moderate to high levels of CRF. Results of this study are summarized below in Table 1. The rates of diabetes per 1000 person-years* of follow-up are shown in both groups, stratified by cardiorespiratory fitness (CRF) level. For example, in the Never Statin group, only 1.3 persons with high CRF developed diabetes per 1000 person-years of follow-up.

Table 1. Rates of diabetes per 1000 person-years of follow-up stratified by statin use at visit 2 and cardiorespiratory fitness level at baseline.

Never Statin Rate Started Statin Rate
       
Low CRF  6.7 Low CRF 15.0
Moderate CRF  2.2 Moderate CRF   4.2
High CRF  1.3 High CRF   3.4
 

* Rates of disease are often expressed per 1000 person-years of follow-up. The number of person-years is calculated by taking the number of people studied and multiplying that number by the average number of years of follow-up. For example, if one person is followed for one year, then we have one person-year of follow-up. If 100 people are followed for 10 years, then we have 1000 person-years of follow-up, etc.

To learn more about how to maintain normal fasting blood glucose levels and achieve a moderate (or higher) CRF level, consider taking the Nutrition for Health and Fitness and/or the Personal Training Education courses. Both courses are available live in Dallas or online.

Reference

1Radford, N.B., DeFina, L.F., Barlow, C.E., et. al.  (2015). Effect of fitness on incident diabetes from statin use in primary prevention.  Atherosclerosis. 239:43-49.